Some of the principles of technical drawing simply illustrated – Part 2

In the first part I finished with this drawing of a relatively simple brick structure, which represents many of the fundamentals of technical drawing and is conveyed in a style which is generally agreed to be appropriate to the purpose. The purpose of technical drawing is principally to provide clear and accurate information for making, but in many disciplines the technical drawings also serve other purposes. For example if the subject is a theatre set, or one for a film or a television show, the designer’s ground-plans become essential information used by almost all the other production departments. The set of drawings become a final ‘blueprint’ for the physical/spatial practicalities of the production including for example stage-management and costing. But as I also pointed out, the designer will often find that measured drawing is an essential tool for ‘working out’ the design even in a rough way during the early stages.

complete orthographic information

The object above doesn’t bear much resemblance to a theatre set .. for one thing it’s a solid object rather than a space, so it’s viewed from the outside rather than the inside. However, the principles for drawing a spatial design are much the same. Here is a somewhat ‘stripped down’ drawing of a setting .. part of a derelict house. I’ve omitted text and written measurements partly to focus better on arrangement.

Showing the arrangement of views of a set design on the drawing sheet

The most important and influential feature of a technical drawing is its layout .. the arrangement of views of the object and other parts of the drawing. The views of the object itself are the most important and everything in the arrangement should emphasize this importance, for example the other ‘parts’ such as rows of measurements are kept at a respectful distance and the views themselves are not generally disturbed with text or too many other lines unless there’s no alternative. The arrangement of the views on the sheet is also a prime device in understanding them .. they are aligned with each other so that one can directly relate an elevation, a wall seen upright, with its counterpart on the ground-plan next to it. In this sense it really is like ‘reading in three dimensions’!

Unlike a solid object, a room seen from within can be flattened out like a cardboard box, as above. In this example, at least the three main walls can be laid out in direct relationship to the ground-plan. The other two inner walls also need elevations to describe them but these need to go somewhere else. Ideally these should be positioned where they line-up with and directly relate to something else. This usually means that some measurement lines can then be shared, which helps to reduce the clutter!  When I say ‘line-up’ I really mean ‘have the same spatial orientation as’ and the same relationship to the floor plane. For example with wall ‘D’ I had the choice of either lining it up with wall ‘C’ or wall ‘A’ .. but the relationship with wall ‘A’ is a little more direct and .. very importantly .. it gives more space to include the cross-section view ‘G’ with it.

Just briefly at this point .. because I will be dealing with this in more detail again .. you will have gathered that the overall layout of the sheet is not something that happens all by itself but something that needs to be carefully designed! But often the most effective layout is only apparent after all the elements required have been drawn up! There are various ways of ‘rehearsing’ what to do, and this is a separate subject for later.

I called ‘G’ a cross-section because this is a more familiar and descriptive term but in technical drawing these are commonly just called sections. They show the structure, or part of it, sliced through at a chosen point. This often provides valuable information which is not immediately clear from reading the ground-plan and elevation. In the case of ‘G’ it is just a simple wall of even thickness, which could be guessed from the ground-plan, but at least the section confirms it .. sections are often just there to confirm.

detail of technical drawing showing a section view

Sections become more crucial when the wall has more to it .. i.e. a window structure, door frames, decorative profiles etc .. all of which benefit from being described in cross-section. Everything ‘cut through’ is commonly represented in bold line and filled with diagonal hatching. Close, repeated diagonals make a lot of sense because these areas are then distinguished from most else that’s likely to be in the drawing. But there’s a very human, historical aspect to this custom of hatching .. the lines relate to the marks made in wood when it’s sawn through.

In Part 1 I explained the value of pinpointing both the direction and the position of view for the different elevations by means of arrows surrounding the ground-plan. For the section shown above this is clearer .. the dashed line shows the exact position of the ‘cut’ and the arrow shows the direction from which we’re looking at the cut face. It’s also accepted that what’s drawn in the section is not only the cut surface itself but also what we see beyond it, hence in ‘G’ the lines underneath the hatched area represent the side of the doorway we would see and, above, the broken top of the wall. One could describe the use of letters to identify the views and the link to the arrow symbol a method of ‘labelling’, but in technical drawing this aspect is commonly known as coding.

detail showing ground-plan

The ground-plan is rarely as simple as the one above, especially those that are meant to serve as the ‘master’ ground-plan for a set. These may need to show how other overhead elements, such as flying bars or lighting rigs, relate to what’s on the floor or show the position of floor openings etc. .. but this simple one will serve for the moment to illustrate a number of additional principles in technical drawing.

The ground-plan is also a form of cross-section. It’s not usually stated on the drawing, because this is another of those ‘agreed assumptions’ introduced in Part 1, but the ground-plan is actually a ‘view’ cutting through the whole at about the eye-height of a person in the space. The reason for ‘eye-height’ is that it gives us more significant information concerning doorways, window openings etc .. a viewpoint of ‘most information’ in other words. This is not strictly adhered to because, as I will show, information is often included relating to structures above this viewpoint and it doesn’t mean that everything in the space needs to be faithfully ‘lopped off’ at the same height. If it can be called a rule .. it’s a loose one. But the eye-height view means that generally window openings are cut through at an informative point. If there were proper window frames in this example we would also see these constructions chopped through, which would tell us the position of the window frame within the wall, the thickness of the struts and even the position of the ‘glass’ if the drawing is that detailed. In this example all we see when we look down are the wall edges making the bottom of the window opening and we see these as unbroken lines.

detail showing groundplan relating to elevation

We don’t see those unbroken lines when it’s a door opening because there’s most often nothing there below except floor. But with doorways it’s also customary to indicate that the wall continues solid above the doorway and that’s the reason for the dashed lines included here. This is one example of including so-called hidden lines, which are always either dashed or sometimes dotted, and include properly ‘hidden’ i.e. important structural lines which would not otherwise be actually seen because they’re masked by something and also, as in this case, structural lines which are above or behind the point of view taken by the drawing.

Technical drawing is much like driving a car .. anyone can learn how do it properly because it involves more knowledge than actual skill, though it really does help if you have the right ‘mindset’ for it .. and that at the very least, you’re able to concentrate!

Car driving shouldn’t allow for too much ‘freedom of expression’ .. there are things that have to be done and things that shouldn’t be done. Nevertheless, often the driving style of an individual expresses their personality! Is it the same with technical drawing? How much room for choice is there? More importantly how much opportunity is there to be overtly individual, personal, creative, stylish, decorative .. even anarchic .. while still informing clearly and accurately? This is one of the aspects I’m most interested in and I hope to explore this, amongst other things, in later articles.

 

 

Some of the principles of technical drawing simply illustrated – Part 1

Have a look at this drawing. This is ‘technically speaking’ a technical drawing .. but a naked one! It describes an exact three-dimensional form in just three views, just using lines to represent the visible edges.

Orthographic projection without scale

Technical drawing relies on a number of agreed assumptions: .. that all views are of the same object and only that object, but from different viewpoints and that all views are the same scale; that all visible edges are shown by a line and that we assume those edges progress away from us to form faces which are normally flat and at right-angles unless otherwise indicated elsewhere on the drawing; that there is no perspective used in the drawing. In other words our lines of ‘sight’ do not converge with distance but are parallel and perpendicular (at right-angles to) the face of the object shown; that wherever possible these views are ‘lined up’ with each other so that we can easily relate one to another, moving three-dimensionally in space, as it were, around the object and that most often the ground-plan view is placed at the bottom because it is the ‘basis’ from which all else is elevated.

If you had not read  the above and had never seen a technical drawing before you wouldn’t be able to read much with certainty from these shapes. But when one takes on these agreed assumptions .. known as conventions in technical drawing .. one can start to read it, deducing various things, albeit not with complete certainty yet.

For example, if the bottom view is the ground-plan view then the shape above it is most likely to be the front face because it’s the same length and it explains that the line we see dividing the bottom form is because the block extends upwards at that point. Because the shape to the right of the front view is lined up on the same ‘level’ we can assume we’ve turned on a horizontal axis so it’s a side view and it looks the right width if we compare this to what we see on the ground-plan. We can be certain that we are looking at the left-hand side because this is the only view that fits with the other information we’ve got. We’ve had to do a small amount of mental/spatial visualization to get this! As I’ve said, this drawing has been stripped of all the additions which are supposed to make it easier to read than a visual puzzle .. but nevertheless a certain amount of mental visualization is always needed.

simple orthographic layout

Of course it all becomes easier to interpret if this is added .. a simple 3D line drawing using perspective! Now we can see clearly that we were right about the ground-plan view and the front, although we still have to use our power of visualization a little for the side. Despite being undeniably helpful, perspectival views haven’t been common in technical drawings up to now. This is probably because they take too long to do and are somewhat outside the skills or motivation range of most draughtsmen. It may also come from the purist notion that technical drawings shouldn’t need them, or that it even goes against the rulebook of using a language devoted to strict parallel projection. But nowadays it’s so easy to create perspective views in programmes such as SketchUp and either print or trace them, with or without shading, onto the drawing if there is an available space to put them.

The first version shown above satisfies many of the fundamental strictures of a proper technical drawing .. but of course not all. The most important missing are scale and measurement. Here below is the same drawing .. now almost fully ‘clothed’. Now it is clear what size we are dealing with .. the scale used for the drawing is given in the block of information commonly termed the title block and in any case the measurements are also displayed. We could get all the measurements if we scaled up the drawing 10 times (the scale given is 1:10) but the inclusion of most (often not completely all) of the measurements is a recognised courtesy, so that the reader of the drawing doesn’t have to use the scale ruler for everything. It’s also possible that a drawing can distort during copying, whereas written measurements remain exact. Also, if the scale is there but no measurements given against any lines, how can you be certain that the drawing has been copied at 100%?

basic orthographic drawing with measurement info

These measurements are written in millimetres here, the most common practice for theatre in the UK and increasingly now .. thank goodness! .. in film and television. Notice how the longer, overall measurements are kept a little separate to make them easier to find and notice how heights and lengths are not needlessly repeated. Notice how these ‘clothes’ sit .. comfortably, with some breathing space. The structure itself is still very clear, because the measurement lines are thinner and spaced a little away from the edge of it. Because of this the beginning and end of each measurement line needs to be emphasized, hence the slight crosses. Notice also that the measurements are written to be read in just two directions, from bottom-top and left-right .. rather than circling like ants!

We now also have important written information .. the views are labelled to remove any remaining doubt and the title block has, as the name suggests, a title! The sheet is identified as ‘1 of 3′ and the version dated. All this, and sometimes more, is necessary to keep track of what might become a large batch of drawings within a single project.

But what is represented here is a very simple form which assumes no significant surface detail. I intended this playground ‘street furniture’ unit to be made of brick and chose the dimensions to conform to standard brick measurements, but I wanted a specific pattern. When the designer intends an appearance which directly affects the construction of it, this information must also be on the drawing. I also had to draw all visible sides first in scale just to work out how standard bricks could be laid in the pattern I wanted. This illustrates yet another fundamental .. that measured drawing is not just a final rendition after all design decisions have been made, but an important tool for working things out even in the early stages.

complete orthographic information

The drawing is now starting to look more typical of the densely packed set drawings you may have seen if you’ve had a chance to look at any from theatre, film or television. The perspective view has had to go, to make room for the two remaining elevations as they’re now called, and to avoid any possible confusion arising from ‘back’ or ‘front’, ‘left’ and ‘right’, these are given letters which correspond with clear indications of viewpoint arranged around the ground-plan. This is a more sensible method, because these pointers not only indicate the direction of view but also where the point or rather the plane of view is. The identification and linking of parts of the drawing by means of letters and symbols is known as coding.

Notice also how the measurement lines are now arranged .. overall measurement on the outside with more detailed divisions closer to the object. The line bordering the sheet may seem just a presentation nicety .. but it actually has a more serious purpose. When the drawing is copied it indicates that the whole drawing has been copied, i.e. with nothing missing at the edges.

So, in conclusion to this first part, the ‘principles’ I referred to in the title are firstly those general and often unspoken assumptions I listed at the beginning, plus the following which I’ve tried to illustrate in this article, namely:

.. that technical drawings need four qualities above all else: accuracy (both drawn and written measurements should be correct, precise and in the right place); clarity (both meaning and appearance should be clear and readable); consistency (the ‘language’ used should be used in the same way throughout); economy (the drawing should be uncluttered by needless repetition)

.. that the layout, the arrangement of views on the sheet, is fundamental to the understanding or ‘reading’ of what they mean

.. that technical drawing primarily involves common sense in the way three-dimensional structures are represented in line but that common sense alone is not enough to either create or to read them. The special language of conventions has been developed to assist and it is expected to be used. This reduces the amount of mental visualization we need to employ when trying to understand three-dimensional space from a two-dimensional drawing, but it will always involve some!

.. that there should be no room for misinterpretation, no ‘reading between the lines’. The reader of the drawing should not have to make guesses outside of the agreed ‘assumptions’ or conventions referred to.

.. that the object views themselves should be treated a lot like VIPs or ‘untouchables’ .. clearly defined, with everything else at a respectful distance

.. that technical drawing is not just the ‘final account’ where all the sums are checked but an important tool in developing the design

.. that at the very least the primary measurements should always be written even if the scale is clear and that this is not only a courtesy but also allows the reader to check the accuracy of the copy

.. that the drawing should include all important information that directly concerns the structural making of the object or anything in ‘relief’ but doesn’t usually include details of painted design or colour. It is also generally agreed that the designer’s responsibility is to convey what is seen but not necessarily how it will be made

So far though I’ve illustrated using a simple, solid object which doesn’t bear much resemblance to a theatre or film set .. we’ve dealt with a simple block from ‘without’ rather than a box from within. When something like this is the object of the drawing there are some major differences .. the layout usually has to be different, the ground-plan contains much more information, and there is often the need for sections in addition to elevations, a device we haven’t considered yet. These and other things will be featured in Part 2.

 

5 favorited in July – Institute of Making, Grace Emily Manning, Salao Coboi, Edwina Camm, Casting About

It’s about time that I started a Links page .. because there are so many useful websites or examples of inspirational work I’d like to share .. so I’ve set it up above and hope to add to it whenever I can. Here are the first few entries .. just the first ones that came to mind.

Salao Coboi

Salao Coboi sculpted figures

http://salaocoboishop.tictail.com/

Although the figures produced by ‘Salao Coboi’ reference the familiar from comics and toys, there’s also much about them that’s really quite unique. Salao Coboi means ‘cowboy salon’ and the name was adopted by a Portuguese artist’s collective in 2009, though the figures exhibited from 2011 onwards are largely the work of the group’s co-founder Apolinario Pereira. Although they may look as if they should be small, many were more than a foot high and produced as hand-painted resin casts in limited editions.

 

Institute of Making

Institute of Making

http://www.instituteofmaking.org.uk/

The Institute of Making describes itself as a ‘cross-disciplinary research club for those interested in the made world’, opened in March 2013 and housed in the Engineering faculty of University College London. Full membership of the ‘club’ is only open to UCL students and staff .. but the website, the excellent Materials Library and a variety of talks and workshops are open to the public. This is not all about the search for flexible concrete or transparent aluminium .. recent public masterclasses have included spoon-carving, felt-making, animatronics and ‘low-cost 3D scanning’.

 

Grace Emily Manning

Screenshot from the intro of 'Pupa' by Grace Emily Manning

http://graceemilymanning.co.uk/

I first saw Grace’s work at her BA Performance Design and Practice degree show presentation at Central Saint Martins this year. Her 7.49min stop-motion animation Pupa is what I’d call ‘the genuine article’ .. charming, unpretentious, and really well-made for what it sets out to be, in her words ‘motivated by non-precious childlike creation’ and founded on exploring tactile and material experiences. It’s certainly one of the most glutinous, squashy and fibrous pieces of animation I’ve seen!

 

Edwina Camm

Edwina Camm 'The Tale of Thomas Dudley'

http://www.edwinacammillustration.com/

A couple of years ago, when I was doing my usual sessions on ‘white card’ model-making for film/tv production design students at Wimbledon College of Art, I searched around for some more interesting examples combining model and drawing .. and found exactly what I had been looking for in Edwina’s work! Edwina originally studied film/tv design at Kingston but then went on to do an MA Illustration Authorial Practice at Falmouth. The image above is from her own on-going project ‘The Tale of Thomas Dudley’ for which she combines narrative, 2D illustration and 3D models.

 

Casting About

Richard Arm, Casting About homepage detail

http://www.castingabout.co.uk/Home.html

This useful, well-organized and friendly looking ‘how to’ website .. a ‘dedicated electronic resource for mould-making & casting methods and materials’ .. is the work of Richard Arm, Senior Technician/Lecturer in the School of Art and Design at Nottingham Trent University. It is perfect for anyone looking for a clear introduction or an overview of the creative possibilities.

Does foamed PVC have a grain?

Although this question will not be of much value to most people, it is certainly of interest to those few .. like myself .. who work with this material. The answer is .. yes, it does .. and this has a significant bearing on how one can get the best out of it! I have to confess that even though I’ve been using it for years, I’ve never properly realised this until now. There’s hardly any visible indication and although I had noticed at times that cutting in one direction seemed slightly harder than another I didn’t attribute a cause. I’d always assumed that sheet plastics just don’t have a ‘grain’, or rather a directional difference, because of the way they’re made and this would be especially so with foamed materials. In all these years I’ve never noticed any reference to a ‘grain’ in any of the product information available .. until now.

I should point out that I’m going on the basis of the tests I’ve made with the brand I use, which is Palight and Palfoam foamed Pvc manufactured by Palram. But I’m assuming that the manufacturing process for foamed Pvc will differ very little between the various brands even though there is often a difference in hardness. After looking more closely at the manufacturer’s documents available for download, I found this tucked away in some notes entitled ‘Installation':

‘Palight is manufactured as an extruded foam PVC product with a directional grain running the entire length of the sheet. This manufacturing process gives Palight greater flexural strength in the direction of the extrusion. The grain of the Palight should always be installed perpendicular to the fastening point.’

In other words if a thin strip is cut along the direction of the grain this will have more rigidity than the same strip cut at a right-angle to it or ‘against’ the grain .. just like wood! To test this, amongst other things, I first had to find a way of recognising the grain direction, because as I’ve said .. it’s hardly noticeable when looking at the surface or the cut edges! If you hold a piece of Palight up to the light (better still a light that’s glancing the surface) and look at it closely, then rotate the piece 90° and look again, you may just about discern a faint direction of surface texture in one of these views. Another test involves making an indented line with a metal point, such as an embossing tool, a nail or a compass. Along the grain progress will be fairly smooth and hardly make any sound, whereas against the grain there will be a higher, scratchy sound and the surface will resist a bit more. A third test just involves cutting a strip, and is perhaps more noticeable in the thicker versions of Palight. I tested with squares of 1mm, 2mm and 5mm Palight, cutting strips just 5mm wide, first along one edge of the square and then the other. I made sure to keep my exertion with the knife roughly the same, and I found that I consistently needed a couple more strokes to cut against the grain. These strips were also noticeably more bendable than those cut along the grain.

So, I’ve already implied the possible advantages of utilising the grain direction and I’m guessing that the following will apply to all thicknesses .. having tested 1mm, 2mm and 5mm with the same results.  Thin structures will be stronger if the grain follows their length, and they will also be easier to cut! If strips are intended to be bent, this will be easier if they’re cut at a right-angle to or ‘against’ the grain. Finally, and as I’ve illustrated in my page ‘Palight’ brand foamed Pvc under constructing in the Materials section, Palight can be scraped with sandpaper to simulate a wood-grain surface and this will be easier following the actual grain of the plastic. Pvc can also be embossed, ideally using a smooth-pointed embossing tool, and a slightly different quality of line is produced either with or against the grain. You’ll have to try it out, to see which you prefer.

How to refurbish a cutting mat

A cutting mat should only be used to cut on and not as a general work-surface for all sorts of other things such as gluing and painting. I try to say this to everyone I’m teaching .. and I try to remind myself of it whenever I’m working. Even the slightest spots of paint can contribute to diminishing the purpose of the cutting mat, because it’s not just table surfaces that cutting mats are supposed to protect .. it’s also us! The surface of the cutting mat is designed to grip, so that when for example one’s pressing down firmly on something while cutting it, it’s less likely to slip around. If that happens it not only makes it difficult to cut cleanly .. it also makes it dangerous!

But the practical fact is that it’s often a real bother to take the cutting mat away every time one’s finished cutting something. Few of us have the luxury of large workspaces where separate ‘stations’ can be reserved for separate tasks. Usually everything gets done in the same tight table space, the one where the light is best .. and the cutting mat gradually becomes a playing-field for just about everything involved. If we accept that the cutting mat needs to stay put, a better way of cleaning needs to be found.

I’ve tried various ways of cleaning cutting mats in the past .. scrubbing with detergent, scraping with paint scrapers or razor blades .. but none have been that effective. There is certainly no way of removing superglue from the rubber with a knife-blade without damaging the surface. But recently I tried a different approach, and it worked surprisingly well!

cutting mat with superglue

Above is a portion of a cutting mat with a dribbling of superglue .. very common! Unless it is wiped immediately from the surface superglue will set to a rock-hard mass. But superglue is brittle .. one reason why it never lasts if it has to fill even the slightest gap .. and although near impossible to carve into, the surface can be easily broken down by abrasion. It only takes a couple of minutes .. below is the same portion of cutting mat sanded, using first a coarse (60 grit) sandpaper to break down the raised parts and then a finer (120 grit) one to finish the surface.

cutting mat sanded

This will only work properly if the sandpaper is mounted on blocks, such as the ones I make shown below, which will give the abrasive surface maximum strength and also ensure that sanding remains flat and even. If careful, even most of the printed grid can be preserved and the slightly roughened surface actually enhances the cutting mat’s grip.

sanding blocks 60 and 120 grit

Another thing that can very easily happen to a cutting mat is that it can warp .. but only with heat! I can remember, when we used to get a consistent run of hot days, if a cutting mat had been left on a studio window-sill it would end up permanently warped .. no amount of bending or leaving flattened down under heavy books would alter this. Unfortunately this is the end of the story! I’ve tried laying cutting mats in hot water, or laying newspaper on top and ironing them .. they can’t be flattened again. I’m assuming this is because cutting mats are composed of bonded layers, with a tougher interior layer. Heat causes the top layer to expand but the interior layer is less affected, and the top layer does not contract properly again on cooling. On the other hand cutting mats can take a lot of physical bending without any permanent harm i.e. if bending them makes transportation easier I’ve always found that they’ll lie completely flat after about half an hour.

But here’s an alternative idea for making the working situation easier! When I first started out I remember that I invested in the largest cutting mat I could find .. A1 size .. thinking that I would then be prepared for any eventuality. On the diagonal the maximum cutting length is a little over a metre. But I rarely had the free space to use this without a time-consuming clearup! Over the years I’ve acquired at least one of every size of cutting mat, starting with A5, and by default now I use the smallest one I can get away with for the job I’m doing. If I’m suddenly faced with having to cut a much longer line I’ve found it more practical just to place two A3 cutting mats on end, giving a maximum reach of up to 940mm on the diagonal with a little margin. I also keep one very small, A5, cutting mat purely for fine or intricate cutting. Even after a lot of use the surface looks hardly touched, because it’s not subjected to much pressure, so I can rely on it to remain the best support for delicate work.

Modelling with Milliput

Here is the page on Milliput I’ve just completed for the Modelling part of the Materials section. It’s a summary of all you’ll need to know about this modelling material, together with a few suggestions re. similar products. I only discovered recently that Milliput can be pushed .. if heated carefully with a heat gun .. to cure rock-hard within minutes.

My page entries are usually meant to be added to and often start with general outline information, price guidance, suppliers and useful links followed by my worklog where I can put further info and photos when I have them.

Definition

Milliput is a 2-part, very hard-setting epoxy modelling putty, available in two fineness grades and a few different colours. It is most suitable for small, delicate work. ‘Standard’ Milliput is a light yellow/grey colour when mixed while the extra-fine grade is white. When equal amounts of both parts are thoroughly blended together (until the colour is uniform) the putty begins to harden, not requiring additional heat to cure. It remains easy to model for around 40-60mins, after which it gets gradually more ‘rubbery’ (but see below for making use of these changes while modelling).

Milliput standard grade

Advantages of using it

It sets much harder and stronger than most other modelling materials .. stronger than fully baked Sculpey for example .. and this final hardness is not dependent on bulk i.e. very small forms will cure just as hard as larger ones. This makes Milliput (more especially the fine white version) more ideal for delicate forms.

1:25 figures modelled in Milliput. First stage of modelling

The 1:25 figures above were modelled with a blend of ‘Terracotta’ and fine white Milliput. They represent the first modelling stage after completion of the wire armatures described in the post Modelling small-scale figures – Part 1: ‘twisted wire’ armature from March 2013.

Milliput sticks very well to a variety of materials, again unlike Sculpey, and is often used for repairs or as a gap-filling cement. It is commonly used in the restoration of antiques and art objects because of it’s high adherence and its strength when cured.

Once it has hardened it can be easily sanded and tooled (i.e. sawn, drilled), even carved with a scalpel. Scraping with the scalpel can work particularly well for fine smoothing once fully cured.

There is no noticeable shrinkage, and that coupled with its strength means that it’s very unlikely to crack.

Unlike most 2-part epoxy materials it can be used with water! This can be used to help smooth the surface while modelling, or water can even be mixed in to make a softer paste i.e. to use as a gap-filling cement or to join Milliput parts while working. But Vaseline on the fingers can also be effective for fine smoothing, as is methylated spirits.

When used as directed and left to cure on its own it will harden more quickly than air-drying modelling materials, reaching an apparent full hardness in 3-4 hours (though full curing will continue for a few more). However, this can also be accelerated by using heat and, with care, Milliput can be rendered rock-hard in a matter of minutes (see .. below). Even if the advantage of heating is not taken up, benefit should be made of the fact that it will start to become firmer after about 40mins .. so for example basic modelling could be done first and then later, when this becomes a firmer support and the surface less sticky, detail modelling can be easier.

What it can’t do

It is very sticky when first mixed, noted above as an advantage, but this also means that it can clog the fingers annoyingly while modelling .. when I’m working with it I need to have a moistened flannel on hand to keep them clean.

Even in its freshly mixed state, Milliput has more ‘push-back’ than modelling wax or Super Sculpey .. i.e. it is slightly rubbery. This increases as it cures and starts to get firmer, so for example after a full hour impressions can still be made with modelling tools but they will diminish a little as the material springs back.

Because of the cost relative to other modelling materials Milliput is not a viable option for large work (see cost comparison of different modelling materials in Modelling and shaping, part of the Making realistic models series in the Methods section).

What it costs and where to get it

Milliput is sold in most good art or hobby shops such as Tiranti, 4D  Price (2014) c.£2.28-£5.06 (Tiranti) per 113g packet dependant on type (ranging from standard to fine grade and colours e.g. terracotta, black). See ‘Quick view materials info’ for ‘modelling’ in the ‘Materials’ section for current suppliers and prices.

Working life

According to the manufacturer it has a shelf life of c. 2yrs if stored cool, dry, sealed in polythene bags provided.. but see notes below.

Further info sources

http://www.milliput.com

http://www.mbfgfiles.co.uk/docs/milliput_tech.pdforklog

Worklog

July 2013

At the time of writing I have not found any other epoxy putty to compare with it. You may come across similar looking 2-part epoxy putties in DIY shops but these are not marketed as ‘modelling’ material and tend to be even more expensive. An exception may be Magic Sculp which looks promising but I’ve yet to try it .. see below July 2014.

Apparently the setting of Milliput can be speeded to just a few minutes by applying heat (Tiranti website) .. but see June 2014 below. Best method of mixing; portion equal amounts and press these together, then roll this into a long ‘string’, gather up and twist together then roll long string again .. repeat etc. After 3-4 hrs hardening, it needs at least the same amount of time to fully cure. Heat resistant up to 130C. Can be coloured by blending in powder pigment (or even oil paint, or spirit-based colourants) while mixing. Different Milliput versions are intermixable but also resin or hardener parts between them (as long as one knows which is which) are interchangeable. The ‘hardener’ is usually the darker of the two and will develop a resinous crust over time. If used as a press-casting material, ‘talc or a light oil’ can be used as a releasing agent according to the Milliput website. Another tip from this website is that, if you have to interrupt work during modelling, it will keep in its uncured state for up to 36hrs if put in the freezer.

How to model with Milliput Use should be made of the fact that Milliput will change in consistency as it cures i.e. for the first 30mins rough build-up when at it’s softest, after which fine detail especially imprinting and smoothing are easier once its getting firm. Carving can be done after c. 2-3 hrs when almost set, then sanding/filing after 3-4hrs.

Accelerating hardening 7/2013 ‘Tips’ found (not yet verified) include: baking in oven (max 50C) for 30mins. Since cured Milliput is heat-resistant up to 130C successive adding/baking is possible (but see later addition June 2014 below).

How long will Milliput remain usable? I recently made a test of some Milliput I’ve had for at least 10 years. In fact, I was going to throw it away because it had become rock-hard and the darker ‘hardener’ part (as I assume it to be) had developed a tough, resinous skin. I was surprised though that after managing to chop off two equal pieces and starting to squeeze them between the fingers they became softer and eventually soft enough to start mixing together. For this first test I left the tough skin on, believing that it might still blend, but it remained as small hard granules.

mixing Milliput

Above, my usual method of mixing Milliput is first to combine the two parts roughly and then start rolling the mass into a long thin string, which I then divide, twist the strands together and then repeat a few times until the colour is even. The hard fragments of skin remained so I tried chopping and pressing the mixture on a tile in case that got rid of them.

mixing Milliput_2

It didn’t help much, so I stopped blending (it had taking altogether about 20 minutes) and left the piece to harden, below. The consistency was not good (compared to fresh Milliput), ok perhaps for rough work but rather fibrous and prone to fissuring when stretched.

10 year old Milliput

I did another test but this time peeling off the crust from the darker Milliput stick, just using what remained. This mixed very smoothly, a little harder than new Milliput but still a good, smooth consistency, below. I needed 10 minutes to mix it thoroughly.

crust removed before mixing

I’ve never properly timed the setting of Milliput up to now and I’m glad I did that with these tests because I’ve generally been telling people that they have about an hour to model with it. In fact it’s much longer .. if one can make use of the changes to model differently (and later carve) as it toughens. I made a further control test using new Milliput in addition to the two above.

10 year old Milliput with ‘skin’ included After 1 hour firmer but still could be kneeded and modelled; less sticky, and ideal in this state for impressing with tools; little rubbery ‘springback’ as yet i.e. marks made with tools stay as made. After 2 hours no longer easily kneeded or modelled, but still very flexible; still easily cutable with a knife; still good for impressing though slight ‘springback’ i.e. marks made with tools fill in a little; easier to smooth the surface without distorting the form.

10 year old Milliput with ‘skin’ discarded After 1 hour same as above. After 2 hours same as above, though a little firmer and impressions spring back more

Both tests After 3 hours still cutable with a knife; still bendable, but no longer mouldable; can be squeezed but springs back like rubber and impressions do not hold; very good for carving. After 4.5 hours like tire rubber; ideal state for carving

New Milliput thorough blending took 10 minutes. After 1 hour still very soft, a little firmer, a little less sticky. After 2 hours still mouldable and very flexible; cutable with a knife; still takes impressions well with minimal springback, but fissures occur when trying to ‘smear’. After 3 hours no longer mouldable; still flexible and cutable but impressions do not hold.

7/2013 the nationwide £shop chain ’99p Stores’ now stock a form of mixable epoxy putty from the ‘Do It Right’ brand. This is packaged in small, pre-portioned pellets which one just has to blend together. Each pellet is c. 4g and there are 8 to a pack so this doesn’t work out any cheaper than standard Milliput.. just could be easier to get hold of on the ‘high street’. It has different properties though, as one can guess from the smell which is more like regular epoxy glue than Milliput. For a start it’s much softer and stickier when first mixed (so much so that using one’s fingers becomes rather difficult) and there’s a graininess that doesn’t really disappear. The only other possible advantage (depending on what you use it for) is that it sets up much quicker than Milliput; in my test it was a bit too firm to model with after 15 minutes and had reached almost complete hardness after 2 hours. When fully cured it was also very strong. It may be ideal as a gap-filling glue or repair medium, but not so good for modelling.

'Do It Right' putty

The mixed test piece above was gently flattened and pulled out in the same way as the Milliput tests but the graininess and fissuring are apparent here.

Heating Milliput

June 22 2014

The Milliput website (address in the main text above) mentions that the curing of Milliput can be accelerated with heat but goes no further in explaining how much heat or how much quicker this can be. I recently did my own test .. mixing up a little standard (yellow-grey) Milliput and quickly modelling a basic head, torso and arms on a very small (1:25) figure armature of twisted garden wire (see Modelling and shaping in the Making realistic models series in the Methods section). I used brand new Milliput, which was particularly soft. For a heat source I used a Wagner brand ‘Heat Tool 400′ which is a hand-sized heat gun, not so available in the UK anymore but a similar type can be found in Hobbycraft. This type has only one heat setting and will deliver a temperature of up to 400 degrees C, but this represents the local temperature reached if it is focused on a spot for a length of time, and it is normal to keep the heat gun and/or the victim moving, when baking Super Sculpey for example, because otherwise it will quickly burn!

I held the heat gun at a careful distance of c.20cm from the figure parts and moved it back and forth while also rotating the figure slowly. I estimated that it had been about 15-20mins since the Milliput had been mixed. I noticed after about 10secs that the Milliput surface was starting to ‘bubble’ very slightly and appeared to expand a little, but when I took the heat gun away the bubbles disappeared. From that point I was very careful, heating very slowly and I noticed that gradually I could move the heat gun closer without the surface blistering. I gave it around 5mins heat gun treatment all over, then left it to cool down. On cooling the figure was rock-hard, just as if left to cure normally and carving with the scalpel showed no weaknesses in the surface.

The hardened Milliput showed no signs of the earlier blistering. Gentle, more gradual heating may have solved this; or starting with a lower temperature then building up. It may also be prevented if the material is allowed to cure a little more first i.e. 30mins after mixing rather than 20, or older Milliput may even react better .. I’m guessing now, it’s something I intend to test so if you want to try this method it would be worth doing the same first.

July 2 2014

http://www.magicsculp.co.uk

From what I’ve recently read Magic Sculp may be well worth trying! It sounds identical to Milliput in all respects .. working/hardening time, water-solubility, toughness when cured, effect of heat etc. .. but with better price options. For example, when ordering from the UK website, a 200g packet will cost £8.40 inc. VAT and standard 3-4 day delivery is also free. This is more expensive than the best shop price (Tiranti) for the standard grade but cheaper than the other white or coloured types. Magic Sculp is available in natural/grey, white, flesh colour or black .. all the same grade. The natural/grey is perhaps a comfort for those who may be slightly sickened by the ‘yellow/grey’ weirdness of standard Milliput. But the advantages over Milliput may increase if one needs larger amounts. For example 1.6kg will cost £34.99 including VAT and delivery, giving a price of £2.47 per weight of a Milliput pack, for a product which is, according to others .. finer, softer and in colours!

Magic Sculp like Milliput, is a UK product. I rang the manufacturer and I was told that the reason why there’s a ‘Magic Sculp’ here and a ‘Magic Sculpt’ in the US .. with a ‘t’ added, if you didn’t spot it! .. is that the US firm copied the UK product and the agreement was reached that ‘Magic Sculpt’ would only be sold in the US. I was also told that Magic Sculp is softer to work with than Milliput because it contains less clay filler. As I’ve said, I haven’t worked with it yet, though I certainly intend to .. so you’ll have to judge for yourself how it compares. If there’s anything you think I should know, I’d be happy to hear it!