Introduction:
This is for anyone who has looked at the foam trays you can buy and thought, "that''s just not quite what I need", or "that doesn''t look that tough, surely I can make that" or my personal favourite, "Gee they''re expensive, its got to be cheaper to make it myself". Let me just start this off by saying that a) they are a lot harder to make than you think and b) they are probably more expensive than you think.

One thing to keep in mind through this is that it has been over ten years since I last did any wood working so if I can make this, then anyone can. It also means that there are probably a lot smarter ways to do things than I came up with, but at the end of the day, what I did worked (to one degree or another).

Having said this, gee it is a lot of fun and I get a real sense of satisfaction! I''ll try and walk you through the necessities and the ideologies of making your own foam trays, but if I miss anything or you have questions, feel free to email me and I''ll either add what I missed or will just reply directly to you. At the end of the day I hope this either answers some of your questions about whether its possible to do it yourself or whether its worth it to do it yourself.

Concept:
Basically we are going to make a mould and fill it with expanding foam. This will in theory allow you to make a mould to snugly fit any miniature or vehicle you own. Sounds simple enough doesn''t it? ...hehe.... That''s what I thought!

You may be looking at the tools and saying that they more or less make sense but wondering why the hammer is under the recommended materials not the required. Well the truth is the hammer was for fractional fitting. You know the old saying of ''if at first you don''t succeed, use a bigger hammer?'' Well I prescribe to this logic religiously. Alternatively you could just be more careful than I.

Step 1. Designing your tray:
This is the key. With a good mould you can make a thousand trays. A bad mould and you''ve probably spent a lot of time and money for no useable result. As far as the dimensions go you can make whatever size you want. I used the dimensions for a carry case at Bunning''s as the basis for my measurements, which then dictated the width and height of each tray. This is very fiddly but very important to get the measurements correct here. 1cm out and you''ve got a problem. Here is the basic plan of what I used for a large troop tray.

IMPORTANT: Don''t get too fancy and try and make your walls less than about 1cm thick. Otherwise they will be too thin and will tear as you remove your foam from the mould.

This means that each wall was 1cm wide with the holes for the troops being 5cm by 6cm. I can strongly recommend making the holes for the troops larger rather than trying to get 100 troop slots to a tray. The reasons for this are simple, higher margin for error plus much faster build time.

Ok so you have a plan, what do you do with it now? Basically you have to make a mould or if you are thinking of photography, a negative of this plan.

Step 2. Making the Mould:
This is where all the problems arise but if you do it well, the rewards will come in having a good base to pump out many trays down the track. Get yourself some wood. I used MIFF (medium density fibreboard) after consulting some Special Effects (FX) guys, but there isn''t really any hard and fast rule here. The main trick is that the finished surface needs to be very smooth and ideally have non-stick properties, just like a non-stick fry pan. A tip her, if you are using MIFF, make sure you have a circular saw, it will take you hours to saw through it with a conventional saw and it will not give you a smooth finish on the edges which you would have to file down so add a couple more hours.

Once you have the MIFF it is relatively simple to cut the walls and base to make an open box. The lid is the tricky bit as you need to have a block 5cm x 6cm in the location of every cavity where your troops will sit. I put the blocks on the lid to make it easier to remove the finished tray from the mould. Technically there is nothing stopping you from attaching them to the base, but I don''t envy your task of removing the foam without tearing it.

Attaching the blocks is very tough. I have made 3 moulds and I have gotten better at making them, but it is still hard. Ideally you would design the blocks (cavity sizes) to match that of a piece of wood you already own. The more sawing and cutting you have to do will mean the less uniform everything turns out. I am yet to master this. Ultimately it will still work, but its nice if things are all lined up and square.

The first mould I made did not have any plastic on all of the faces, just straight MIFF with a release spray applied just before adding chemicals. This basically worked except for the fact that it took me about one and a half hours of strain to remove the foam from the mould. I then went back to the FX guys and asked for a solution. This is where the builders plastic comes into it. Wrap all the surfaces that will be in contact with the foam with the plastic. I just went to Bunning''s and asked for builders plastic and they sent me straight to the right section.

Failed First Mould attempt

I used an electric staple gun at this point to attach the plastic nice and tight to each piece, but you can also get a manual staple gun from the same section in the Hardware store for about $10. Alternatively a Hammer and small tacks or nails would also do the job. A couple of tips here are to wrap the blocks, walls, lid and base before you attach them all.

Successful Second attempt Mould

This is where it comes in handy to have less, larger miniature cavities. In my large troop tray which you will see below, I had 15 cavities and that was still a pain to wrap each one in plastic. Imagine wrapping 30 or more blocks!

IMPORTANT: Make sure you wrap the blocks as tightly as possible. Any sections where liquid can get into will cause problems when you want to remove the Foam. Use your Staple gun generously here to get a nice smooth finish on all blocks.

ALSO IMPORTANT: You will need to drill a large hole (almost a cm in diameter) in the lid so that the foam has somewhere to escape to once all the cavities fill inside the box.

Step 3. Adding the chemicals
This is quite tricky and I would recommend further research rather than just taking my word for it here. In fact I don''t just recommend I am telling you go and research it! The reasons are simple, chemicals are dangerous! These chemicals produce heat and gases as a by-product of the reaction so be careful! At the very least if you pick up nothing else from this, make sure you have adult supervision, a well vented area and make sure you read the safety instructions on the chemical bottles. I hate reading boring instructions as much as the next guy, but this is important stuff. Goggles are a must here!

You have a very short time to get this done so don''t stuff it. I took a couple of attempts to get it right so don''t feel bad if it doesn''t work the first time. The key to the chemicals is that you need to mix them really well, a wooden spoon just doesn''t cut it (so I found out anyway).  I got a cheap paint mixer attachment for the power drill and this worked a treat. Another tip for beginners was that if you want the foam to be a bit more spongy you just need to add a couple of mls of water. I mean that, a couple of mls. I added about 10mls of water to 300mls of foam chemicals and I would not add any more!

There are lots of varieties of foam to choose from. The one you are after is called "Flexible Polyurethane Foam". There are also a number of different types of this so get the one that has a density of about 50kg/m cubed. I got mine from www.dalchem.com.au and it is called HR50, but there are a number of alternatives.

The chemicals are a 2 part mix. You simply add X amount of part A, then add 2X of part B. As soon as you do this you need to stir it very quickly as you only have about 30 seconds before it is going to start setting and sticking. I stirred it on a pretty high speed for about 10 seconds then poured it straight into the mould.

Give it about 10 hours to make sure its set.

IMPORTANT: Once you have poured in your chemicals, use your 4 clamps to seal the box shut tight! Otherwise the expanding foam will just push off the lid and the whole thing will be stuffed.

NOTE: You can also colour your foam at this point by adding dyes to it.

Step 5. Remove the Foam
This sounds like the easiest part but it is still tricky. No matter how carefully you have been with the plastic in the mould, there will still be locations that will stick. Just take your time and remove it bit by bit. It took me about 10 minutes to remove my foam from the mould with plastic but be careful. Don''t tear it all out otherwise you''ll find that you''ve left half your walls in.

There will be excess foam on your mould as you can see on the edges above. Just take a Stanely/utility knife and trim these off and your done.

Finished:
So as you can see below, it comes up alright. It feels about as dense as a foam bed but with a plastic feel to it. Total labour time for this from go to stop is about 4.5hrs although with this mould made, I can make a lot more of these moulds very easily and with only about 30 minutes labour time.

Here is a picture of me squishing it just to give an idea of how flexible it is.

And the finished product

If this all looks a bit hard, and I don''t blame you if it does, below are some websites in no particular order that sell the completed products.

Cheers & Good Luck,

Ant

http://www.battlefoam.com/

http://www.games-workshop.com/gws/home.jsp

http://www.saboldesigns.net/home.html

http://www.charonproductions.com/catalog/index.php?manufacturers_id=10

http://www.mini-soft.com.au/