The commercial modular boards can be very expensive. The DIY designs I've seen are for large boards that need to be stored behind the couch and are not easily portable.
This design is modular and portable. The board breaks down into 2ft x 2ft (about 600mm x 600mm) sections and easily clips together when you want to play. You just need a table or floor space to put the board on.
There are a few things I could of done better, but at least you can learn from my mistakes :)
Step 1: Materials and Tools
EVA Floor mats - Bought a pack of 6 from Kmart ($AUD 28) The ones I got were 620mm square.
Styrene Plastic Sheet - 1mm thick styrene plastic sheet also known as plasticard. This usually comes in large sheets from plastic suppliers. They can usually cut it to size for you. I actually used 2mm thick but was not necessary. It also cost more. Mine was black but white would of been better. ($AUD 70 for 2mm thick, 1mm thick would be about half price)
Spray-on Contact Adhesive - I used 3M 80 Neoprene Contact Adhesive ($AUD 32 for a can) which is a bit expensive. You could use any contact adhesive that is solvent based. It should slightly disolve the surface of the styrene and stick well to the EVA foam. I was able to test the adhesive with some scrap styrene and some EVA holes that hadn't detached from a tile.
Spray Paint - Auto Primer Spray Cans (Grey and Tan)
Methylated Spirit- (Denatured alcohol) for cleaning plastic before gluing.
Metal ruler - 600mm or 1 meter metal ruler (or 1 yard metal ruler)
Very sharp knife - box cutter or utility knife
Clamps - ratchet or locking clamps, though G clamps can be used.
Straight Edges - aluminium angle, square tube, or straight lengths of wood.
Engineers Scriber or Fine Permanent Marker - for marking out the styrene for cutting. Scriber for black plastic (or a white wax pencil). Fine marker for white plastic.
Sandpaper - medium grit say 300 to 600
Tape - masking tape, packing tape or wide plastic tape
Newspaper or a drop cloth - lots of it, to stop glue landing on things it shouldn't.
Face mask - to stop you breathing in glue and paint.
Step 2: Measuring Up
My correct measurements were 587mm square. But yours may be different.
The idea is that the styrene tops are going to cover the whole tile except the knobs on two adjacent sides. That way the exposed knobs of one tile will mesh with the covered ones of another tile and the plastic tops will touch without a gap. (see picture)
Once you are sure of your measurements you can order your styrene plastic and have it cut by the plastic supplier. You can then skip the cutting part and go to Step 4: Prepare for gluing.
My supplier only supplied 1200mm x 2400mm sheets but would cut it to any size for a small fee.
If you can't get it cut or want to do it yourself then goto the next step.
In my case, I measured incorrectly and ordered the plastic cut too large (lucky). So I had to cut it to the correct size, hence the next step. I also ordered it in black. I thought that black would be better for painting since you always give your Warhammer models a black base coat. White would of been better for marking out as you can use a fine permanent marker. Also when painting black plastic you need to use more paint as the black shows through.
Step 3: Cutting the Plastic Tops
Cutting styrene is very easy. You just need to score it and then bend it over a table edge until it snaps. The break is usually very clean and square. I find that for the thicker sheets and longer cuts, bending it a little at a time all along the length gives better results.
When you are scoring it, you don't need to press really hard. If you have a steel ruler clamped along the line you want to cut, then you can score the plastic lightly several times. Each time the groove will get deeper. When scoring make sure the blade is in contact with the ruler so your line is perfectly straight
You'll find the styrene plastic has one side with a plastic film. The film is to protect the smooth shiny finish. Usually when dealing with any plastic sheet you mark the side without the film and then cut with that side up (the film protects the other side). When cutting the styrene by scoring, I find that the plastic film is either left hanging there or it starts to pull the rest off. To stop this I scored from the film side, that way you cut the film and score the styrene in one hit.
Measure out your styrene using the measurements from the previous step. If you got white styrene then you can mark it out using a fine permanent marker. If you got black styrene then you will have to use the Engineers scriber or white wax pencil. I cut the film off the corners so I could mark directly on the plastic with the scriber. If the film is stuck firmly to the plastic then you can mark directly onto the film.
Once marked, clamp your ruler to the plastic and table and score the plastic. Remember to use several light but firm scores. You don't have to cut through the plastic. I use a knife with snap off blades as the blades get dull fairly quickly when scoring the styrene. I also like to flex the blade slightly towards the ruler so it stays in contact and gives a straight line.
Once you have scored the styrene unclamp it and move it over the edge of the table. Make sure the score line is right on the edge of the table or slightly past it. Start by holding the styerene that is on the table by pressing down on it with one hand. Then start to bend the styrene on the other side of the score with your other hand. Don't bend it all the way down, just bend it a small amount and work your way down the length of the cut. Repeat (2 to 3) bending the plastic a little more each time until it breaks off.
The edge should be straight and square. You can either lightly sand the edge or scrape it with the blade of the knife, but it shouldn't be needed.
Step 4: Prepare for Gluing
To remove any grease or oils wipe the surface with a lint free cloth and some methylated spirits. Don't use lots of the methylated spirts pour just enough on the cloth to wipe down the surface.
The EVA foam tiles I bought have a pattern embossed (non slip?) on one side and are smooth on the other. I glued the tops to the smooth side as I thought there would be more contact surface for the tops to stick to.
The foam tiles should have some masking tape placed over the knobs along two adjacent edges on the smooth side. This will stop the knobs from being covered in glue. I didn't have any masking tape at the time so I used some 1 inch packing tape.
Step 5: Applying Glue
Place newspaper or a drop sheet on the ground to stop the glue covering the ground when spraying. I also used a box to raise the styrene tops and foam tiles above the newspaper. If you spray with the tops and tiles on the newspaper the excess glue will start to stick them and the newspaper together. This will make it messy to lift it from the newspaper, even more so if there is a breeze or wind and the newspaper flips onto the top or tile.
Make sure that you spray an even coat of glue on the tops and tiles. The spray glue I used sprayed out in a stringy figure 8 and so didn't go all over the place. Some spray glues produce a fine mist that goes every where.
I sprayed one top and one tile at a time and let the glue dry until it was tacky. Once you have sprayed the glue on the foam tile you can peel off the masking tape on the two sides. You should have a nice clean line between the glue and the line of knobs on those sides.
Mistake - I used too much glue and only got 4 tops and 4 tiles done. I should of been able to do 6 of each.
Step 6: Gluing Tops to Bases
Once the glue has become slightly tacky you can place the foam tile on the bench (glue side up) and push it against the straight edges. Make sure that the knobs with glue on them are against the straight edges, the ones without glue are opposite the straight edges.
Take the top and with the glue side facing down, start to lower it onto the foam tile. Make sure the edges of the top are pressing against the straight edges as you lower the top. As soon as the top contacts the tile the glue should stick firmly. You might want to press all over the top to make sure that contact has been made all over. You'll notice that the top doesn't cover the knobs without glue.
Once all the tops/tiles are done leave them on a flat surface to dry out overnight or longer. I would recommend a spare room with an open window or outside in the garage/shed. The glue I used gave off fumes for several days, possibly due to using too much glue.
Step 7: Matching Tiles
This could of been due to my gluing technique or the foam tiles and tops not being identical. I'm open to any sugestions that can improve this. A couple of things come to mind but I haven't tried them.
1. Glue the first top and tile with the straight edge method, then connect the next tile with glue already on it. Make sure that the next tile has it's knobs with glue meshing with the first tiles knobs without glue. Then place the top on it so it lines up with the first top. Do this for all the other tops and tiles. The knobs without glue shouldn't stick to the plastic tops.
2. Make the tops slightly oversized (by 1-2mm). Then once the glue has dried, sand the plastic edges to match up. (too much work?)
In my case I started swapping the tiles around until I got minimum of gaps and the tops seemed to line up. I then numbered the tiles on the back so I could put them together in the same order.
Step 8: Painting
Remove the protective film from the tops. Start spraying some patches of grey with the auto primer(rock). Then fill in the rest with the tan(sand). I used the auto primer since it would leave a slightly rough matt finish, rather than the shiny plastic or auto paint. I think that the primer will give a better surface if you want to paint the board with modelling (acrylic) paint, though I haven't tried this.
Just add some landscape such as hills, rocks, and trees and you're ready for a game. I found a plastic carry bag that was just the right size at a disposals store. It's zippered at the top and has carry handles. It can store the board, parts and scenery and carry them around.
As you can see there are only 4 tiles, I haven't had the time to finish the last 2. There is no limit to the size of your board. If you are going to play on a table you must have a big enough table for your board as the tiles need support to stay together.
The photos of the finished product have been taken about 4 months after I finished the board. Since then the tiles have bent upwards and the gaps seem to be bigger. I'm not sure what has caused this. Glue shrinkage or auto paint affecting the styrene? It might also be that it's due to storing the tiles vertically instead of horizontally, but the unglued tops and tiles haven't bent. Again, suggestions are welcome.
Something to try - The store bought boards have details like broken ground with buried skulls showing. You could cut out parts of the top/s and even cut away some of the foam tile and then stick a smaller piece of styrene under the hole (use plastic or super glue). Once the top is glued to the tile you can glue plastic skulls and bones in the holes.
To make the holes you can use a drill or hole saw to make a large hole and then cut out jagged pieces by scoring (up to the hole) and flexing the plastic until it breaks along the score lines.