AFV Modeller - Issue 13 - 4 - Scale Welding

AFV/13 Nov/Dec 03

21/10/03

11:40 am

Page 36

Scale Welding the application of accurate weld effects on 1/35th scale armoured vehicles By Lee Lloyd

Introduction

Basic Welding Techniques

Other weld types often referred to are lap welds, corner welds, edge welds etc but

This article is a culmination of

Virtually all types of welded joint are

basically these are just variations of the

ongoing work that has been

classified into two major types:

two weld types above. Note that in our work here we are not concerned with the

carried out on a modelling project

physical process of welding but only the

as well as numerous discussions

•Fillet Weld:

on the same subject at my model

triangular in cross section between two

visual product that remains once the

club. In this article I shall

sections that are not in the same plane.

welding process has been completed.

A Fillet weld is roughly

describe one technique that has been developed to replicate scale

In all cases of replicating weld seams

welding based upon real-life

some thought must be made prior to

methods and welding processes.

actual application and to what kind of

I shall describe the tools and

effect we are trying to achieve. This must

materials used for this work and

take into account the materials to be

then illustrate in practice both

welded, the circumstances under which

some simple and complex

work would have taken place and the skill

examples of scale welding. The

level of the welder. Whilst the latter three

article will be finished with a brief

points may seem a bit excessive to be

description of other methods,

•Butt Weld: A Butt weld is a weld between

concerned with, if you are trying to make

both scratch building and

two sections in the same plane.

your scale welds as accurate as possible

aftermarket products that can

they should be considered. With respect to

also be used to replicate these

materials and armoured vehicles we are

effects.

usually looking at either the welding of armour plates or on-vehicle accessories. The welding of armor plates is usually done under factory conditions with skilled

36

AFV/13 Nov/Dec 03

21/10/03

11:40 am

Page 37

personnel. This should mean that welded

The Tools to Be Used

Stage 1

joints are very uniform and neat; i.e. the welding of armour on German tanks

So how can we replicate such effects? We

especially in the early years of World War

need a set of tools. In our case our welding

2. This can be contrasted with the skill

torch will be a set of hand made brass

level of Russian welders of the same

formers, our weld beads will be milliput

period whose main tasks were not

and our section to be joined will be the

necessarily to do things perfectly but

plastic, brass sections etc of our kits. The shaded portion of the tube above

instead to complete them fast. If you look at welds on Russian vehicles of this period

In order to make a tool that can simulate

needs to be removed. This can be carried

we can see on average that the weld

the look of a weld bead we have to identify

out with a standard flat face needle file but

quality on AFV’s was of a very mixed

exactly what such beads look like. If we

care needs to be taken especially when

quality. As the project work to be carried

look at the diagram below we can see how

dealing with the very thin diameter tube

out here is on such a Russian vehicle of

a weld is formed. It should have the look of

sections. The end result should look as

this time period we will attempt to show

a number of evenly spaced ridges that

below:

weld effects of both good and poor quality.

have a half moon shape and that run a distance with constant width.

Some examples of weld joints that can be easily replicated and are relevant to all types of vehicles of all time frames can be Stage 2

illustrated below:

•Fillet Welds Round off the edges of the semicircular mitre

multiple

edge of the tube by removing the shaded blue portions above, this should result in the tool shape below:

convex

convex

convex

Stage 3

concave

Depending upon the thickness of the tube being modified you should chamfer the tool edge to ensure that the weld edge is

•Butt Welds

as sharp as possible. This is illustrated The tools to be used to create such effect

below:

should therefore be capable of creating a half moon shape when applied to our welding material. To create such tools we need to use a number of brass tubular square

sections, in our case K&S brass tube was

chamfer this edge

used in a number of small diameters. It is best to make a number of such tools from as many varied diameters of tubing that can be obtained in order to make welds of different widths. single vee with backing bar

To create the tool we need to perform the following steps:

37

AFV/13 Nov/Dec 03

21/10/03

11:40 am

Page 38

For the weld seam itself I always use

is at all times to keep your fingers, milliput

superfine white milliput. I have tried other

and work surfaces wet! In this image the

materials, most recently Revell Plasto

weld is currently about half the final

putty, but in most cases I have found the

diameter that we require.

1

cohesive consistency of such materials in small quantities to be very poor. When

Pic 2 shows the templates that we will use

using Milliput you can roll this material to

for our weld examples, basically they are

very thin diameters provided you keep the

squares of styrene covered with a grey

material wet. I mix my Milliput and roll it on

primer in order to make a good

a wooden table top in a pool of water and

photographic colour contrast. To lay the

with a bit of care and attention can roll out

weld we wet with a paintbrush the corner

>1mm diameter lengths of putty. I have

groove that we are to use and then lay the

found once you have created a desired

milliput roll into that same space.

2

putty diameter you have a relatively short working time as in such small quantities

Now that we have the weld roll in place we

the Milliput tends to dry out quite quickly.

must cover the area in water. This will serve to blend the edges of the milliput to

Once you have your Milliput welds lengths

the sectional surfaces as well as providing

it is a simple matter to ‘drape’ them

a medium that will prevent the weld tool

around/on the unit to be welded. Make

from sticking to the milliput. Let the milliput

sure when you do this you keep you

harden for a few minutes so that a surface

applicator (fingers?) wet as in such small

skin forms before applying another small

quantities the Milliput has a fantastic ability

amount of water.

to stick to anything other than what you

3

want it too! For the sections to be welded

In Pic 4 we can see the weld tool in a pin-

a certain amount of preparation is also

vice before application to the milliput

necessary. When making a fillet weld there

surface. To create a convex weld we use

should really be no modifications made to

the OPEN end of the groove in the tool,

the sections as the putty can be applied

facing the weld, and then sharply jab the

directly at the desired location. If a butt

tool repeatedly, but not deeply, into the

weld is to be made it is best to score the

surface of the milliput. What we are trying

surface as per the weld example pictures

to achieve is a ridged effect that is semi-

so that the weld can be built up properly

circular in shape but that does not

and does not stand too proud of the

penetrate completely the milliput. Always

sectional surfaces when finished. A good

draw the tool down the weld, i.e. as in the

tool for creating such scribed lines is a

direction of the arrow as shown as this will

panel scriber. This tool has a reverse cut

create the correct overlapping nature of

blade that creates cut lines that leaves no

the weld. It is VERY important to keep the

burs in a plastic surface. By creating a

end of the tool wet when welding

groove into which the putty can be set you

otherwise the milliput WILL lift from the

are guaranteed to keep the putty in place

surface.

4

while making your weld seam. In Pic 5 we can see the finished weld

Basic Welding Simulation

before a final blending of the edges with water and a paintbrush into the sectional

Now that we know how to make our weld

surfaces again (application of the weld tool

seams let us put the practice into theory.

will always tend to move the milliput

In this section we shall make some simple

around regardless of how careful you are).

welds.

In this image you can see how certain areas are tidy, others are rough and

Example 1: 90° fillet weld (convex)

downright messy, but overall we have an accurate 3-dimensional fillet weld. The look

38

This is the simplest type of weld to make.

of the finished weld is purely up to how you

In pic 1 we can see the rolling out of

want you work to look again depending on

milliput to very fine diameters – the secret

the time frame and type of vehicle/weld.

5

AFV/13 Nov/Dec 03

21/10/03

11:40 am

Page 39

6

7

8

9

10

11

pic 11 (Note there is still some edge clean

Example 2: 90° fillet weld (concave)

Example 3: 90° butt weld

In our next example we shall perform the

In the last of the simple weld examples we

same process as described above but this

will cover a butt weld. In this case the

time we shall replicate a concave weld.

template to be used is two sections of

The same process for creating a roll of

styrene with a small gap left between

milliput and priming the sectional surfaces

them, backed by another styrene strip.

In this section we will look at some

with water is as previously.

Here we are trying to replicate the gap

examples of more complex welding

between sectional surfaces that would

effects. We shall only cover two examples

Instead of blending the edges of the

naturally exist or that has been replicated

here but the range of effects to be

milliput into the adjoining areas, we force

on a kit using a panel line scriber. This

achieved is only dependant upon what the

the milliput into the corner surfaces as

template can be seen in pic 8.

effect is that you are trying to replicate.

here by the use of the end of a paintbrush.

In pic 9 we can see the milliput roll has

Example 1: 90° multiple fillet weld

Once we have the milliput in the shape we

been pressed into our gap between our

desire we must once again wet the surface

weld sections. Don’t worry if part of the

A multiple fillet weld is a join that has

and leave to allow a skin to form.

milliput is squeezed out over the edges as

overlapping weld seams that are designed

To create the weld seam in this case we

this is an effect that we want. Again make

to give a greater strength between the join

must use the CURVED back edge of the

sure the surface has been layered with

of sectional surfaces. The effect that we

weld tool. This is used in exactly the same

water and the surface left to harden.

are trying to replicate here can be seen in

up to be carried out here).

Complex Welding Simulation

smoothly as possible. This we have done

manner as in the previous weld but in this

our examples as described in the section

case we will leave our ridges in a concave

To create our weld we use our tool as

on Basic Welding Techniques. In our case

shape. This is illustrated in pic 7 before the

before using the OPEN end of the tool. This

though we will cheat slightly as we do not

final blend of the edges into the

time we press down through the milliput so

need to create an entire series of

surrounding sections has been carried out.

that all excess material is squeezed out to

overlapping welds.

The image does not show too clearly the

the sides. What this should leave is a weld

concave nature of the final shape of the

that is at the level of the sections that is

In Pic 12 we have taken our fillet sections

weld but rest assured this is the exact

being welded and can be seen in pic 10.

and have added a small strip of triangular

shape you get. This can be compared to

Scrape away the excess material and

styrene directly into the grooved area. This

similar welds on vehicles and once painted

again with some water and a paintbrush,

is done to save us time and effort in having

and washed/weathered will blend in very

gently blend in the edges of the weld to

to build the depth up using milliput. Note

well with the surrounding detail.

the sectional sides. This should leave a

that in this example we are creating a big

weld that has an appearance to that as in

volume weld. In most multiple weld 39

AFV/13 Nov/Dec 03

20/10/03

4:40 pm

Page 40

scenarios you will probably only need

consistency from the others; essentially we

decided to mix in some of the coarse

overlapping rolls of milliput with no depth

will try to create a splatter kind of weld

grained CAST’a’COAT into a roll of milliput

filler to create the desired effect.

effect.

before application to the weld area. This

As before the same procedures apply with

In the same manner as before we have a

respect to layering of water on the

butt weld template to which we have

Once this was mixed in, and by this I mean

surfaces to be worked. In Pic 13 we can

already applied a single weld bead

the CAST’a’COAT was rolled into the

see the first layer of weld has been applied

(convex), using the methods as described

surface, rolled back into a ball, rolled out

along with the surface effects being

previously, see Pic 15. In this example you

again and into more CAST’a’COAT until I

finished. Blending of the weld to the

can see a small run of milliput to the left of

had a nice consistency of material

sections is not done at this stage.

this seam. This is a small roll of milliput I

throughout the volume of the milliput and

added as a base filler as I had made the

not just stuck to the surface.

can be seen in Pic 17.

In Pic 14 we can see the application of a

butt weld sections a bit too far apart! The weld was then applied to the sectional

second weld seam. All that needs to be done now is to blend the edges together

In Pic 16 we have added the second weld

surfaces but this time was detailed with a

using water and paintbrush again. Try not

seam. These have layered nicely together

toothpick as I did not want to create a

to blend in too much the division between

but as before no final blending is done until

ridged effect here. The toothpick was

the welds where they touch so that you

the final weld is added as we do not want

gently pressed into the weld surface and a

keep a fine line of demarcation. This photo

to apply too much water which could have

certain amount of material was picked out

again does not show the volumetric shape

the effect of dissolving too much milliput

to the sides in order to simulate a very

that is obtained by this method due to the

and thus ruining the fine detail on the weld

messy process indeed. The end result prior

angle at which the template has been held

ridges.

to water blending can be seen Pic 18. The final result looks very rough but even at

up to the camera but the general nature of

40

the finished product can be visualised by

The next stage is to create a weld seam

this stage the splatter weld has a very

again considering the shape of the depth

that has a much rougher surface

rough feel to it surface that with correct

area in Pic 13.

consistency. In order to make this I have

painting/washing etc will dramatically bring

used a product called CAST’a’COAT. This is

out the detail.

Example 2: multiple butt welds

a product that consists of sets of granular

In this example we shall go one step

materials in two grades. The idea behind

A good example of the effect I was trying

further and attempt to create a more

this product it to replicate the rough

to achieve here can be seen above We

complex example of welding. In this case

surface effects on a variety of materials

can see very clearly the triple weld with

we will create a triple butt weld where one

and surfaces.

different consistency

weld section has a very different

In order to create a ‘splatter’ type weld I

12

13

14

15

16

17

AFV/13 Nov/Dec 03

20/10/03

4:41 pm

Page 41

described above. However in my never ending search for accuracy in my work and in the interests of realism I have not found these methods generate the effects that I desire.

Aftermarket Goods Two products that exist as aftermarket products are from ABER and Archer Transfers. From ABER you get a very fine fret that has a number of weld seams that can be used for various effects. I have seen these and do not really care for them as the patterning on them is too regular and repeated and the runs tend to be of too constant a width.

Other Methods for Scale Welding

the material never resolves to the correct

With respect to the Archer Transfers (at the

surface plasticity as is required to work

time of writing I am not sure if these

This article has covered one method for

with. You either find that the weld is still too

products are still actually available) these

accurately replicating weld seams on scale

rigid to surface detail or in fact becomes

are designed to work by creating a slightly

military vehicles. Of course this is not the

too soft and will hold no detail. I have tried

raised surface once applied so that when

only means to do this and other methods

this method using the weld tools I have

painting & weathering they can be made to

exist in common practice that includes

created but could not correctly replicate

stand out. Again I have seen but never

both aftermarket products and other

the ridged effect of a weld.

used this product but as above I have found the runs to be too regular in shape.

scratch-building processes. 2) Pyrogravure. The use of what is really a

Also their very nature as transfers does not

Other scratch-built methods

low-temperature soldering iron is another

give them enough of a raised 3D shape

1) Perhaps the most common alternative

method for creating weld seams. In this

that is often required when replicating such

method for replicating weld seams is to

case the pyrogravure is actually applied to

effects.

use the stretched-sprue/styrene approach.

the surface of the kit (which may also be

In this method a circular section of styrene

previously applied stretched sprue) and is

A product which we have discussed at the

or plastic is heated or bent to fit the shape

used to ‘melt’ tiny areas to get the desired

Tyneside IPMS model club that would be of

of where a weld seam is to be made. An

effect.

use would be weld seams that are similar to ATAK/Cavalier zimmerit sheets. Very thin

application of liquid styrene glue is applied to the parts to be welded with an amount

I have never tried this method but have

sheets of resin could be created with a

of his glue being applied directly all over

seen some very nice but also very bad

wide variety of weld effects to replicate

the surface of the weld bead. Once this

results from using this tool. What you have

much of what we have covered here. It

glue has significantly melted/softened the

to remember is that in modifying the actual

would be nice to see a manufacturer

weld this part can be detailed by using

surface of the kit you are changing the

introduce such a product.

knife blades, toothpicks etc.

surface volumes into shapes that are not meant to exist – i.e. the melted material is

Conclusions

While this method does work I have found

not removed but is pushed to one side.

Hopefully I have shown here an effective,

that it is very difficult indeed to get an

This can result in raised areas that do not

highly accurate and cheap method for

accurate pattern to form on the weld as

replicate real volumes being modelled.

replicating all types of scale weld process

Also as the tip of a pyrogravure tends to be

seen on military vehicles. The method is

round (I am sure a tip the shape of a tool

simple and relies only on common tools

described here could be fabricated) when

that are available to all modellers and in

welding you will not achieve a ridged effect

fact is quite a quick process to replicate

in your work.

one you have carried it out a few times.

18

In summary as I have said I have seen some very good results produced when using both of the methods I have

41