Supporting Blue Foam Boards

[Furt]

I'm ready to take the plunge into building a set of modular terrain boards and was hoping for some advice.

I have seen some of the master builders here using both blue foam without a base for support/protection and with a base for support/protection.

I would really like to hear peoples opinions on this, whether they think one (with or without) is better than the other and what support/protecting materials they use.

I personally was hoping to get away with mounting 20-25mm blue foam on 3-6mm mdf boards. Does anyone believe they will warp or be too fragile?

Thanks in advance

[bluewillow]

"6mm only way to be sure" 

It depends upon your sheet depth and if you are going to transport it or move it around, our club stuff is on 6mm though.

cheers
matt

[Malamute]

I haven't mounted mine, which may be a mistake in the future. They are stored in boxes for transport etc, so I felt they would be ok and I don't expect to be taking them too far afield.

The other option is too run some heavy duty masking tape around the edges which should afford some degree of protection from bumps and knocks if you odn't want to go the whole hog and mount them.

[Dewbakuk]

I personally was hoping to get away with mounting 20-25mm blue foam on 3-6mm mdf boards. Does anyone believe they will warp or be too fragile?

Depends what you'll be doing with them. If they're going to be travelling a lot or you'll be storing them on their sides then mount them on 6mm. If they're just going to be used at home and stored flat then 3mm will be fine.

20-25mm sheets will need to be mounted, they're too thin to be trusted by themselves. I'd mount everything below 40mm. 40mm and above is rigid/sturdy enough that you don't 'need' wood under it, although I'd still put 3mm under it if using it as a travelling board, vinyl floor tiles if at home. The vinyl doesn't give it any rigidity as it's not needed but it protects the base from 'dings' on the table edge and shelves etc.

[Svennn]

Mine are 50mm and have no support. They do not leave the house though.

This is thicker and stronger material than the white polystyrene flocked tiles from the likes of TSS which are not supported either and I have some of those that are around 25 years old and still fine.

[Hammers]

Mount them. Blue foam is sturdy but not enough for moving around. The weak spots are the corners and edges and that will show when you put segments next to each other. I for the same reason recommend that you protect the edges with veneer or tape.

[Furt]

Thanks for everyone's replies.

Malamute's beautiful 50mm boards prompted this topic - but personally I think I'd be wasting 50mm foam because I only require roads and a little contours to be cut into it. Hence why I want to use the thinner stuff, which I did assume was too thin to support its self. Although I consider myself very careful, I can also see the need to protect the edges somehow.

I don't see a need to travel with them anytime soon, but I was planning to store them on their side, so maybe 6mm is the smart way to go.

I'm taking it no one believes that thin blue foam will warp over time attached to thin mdf.

[Hammers]

Thanks for everyone's replies.

Malamute's beautiful 50mm boards prompted this topic - but personally I think I'd be wasting 50mm foam because I only require roads and a little contours to be cut into it. Hence why I want to use the thinner stuff, which I did assume was too thin to support its self. Although I consider myself very careful, I can also see the need to protect the edges somehow.

I don't see a need to travel with them anytime soon, but I was planning to store them on their side, so maybe 6mm is the smart way to go.

I'm taking it no one believes that thin blue foam will warp over time attached to thin mdf.

It doesn't warp since it doesn't absorb water. Extreme heat probably will.

Ipicked up a trick from Vikotnik which may be of help to you to. Gently go over the surface of the foam with a blowtorch. You need to be careful and do it in a ventilated area. It textures but also hardens the surface beautifully.

[Silent Invader]

How wide will your boards be?  Mine are 1.2m x 0.5m and tho I consider myself a careful chap and only play at home I still manage to ding them every now and then.  I wrapped mine with black gaffer tape, which really helps.

Mine don't have baseboards as they are 50mm thick.  I have often referenced a website called Quindia Studios which has a tutorial using the thinner foam and he mounts his as shown in the following link:

http://www.quindia.com/studioart32.htm

[Verderer]

In my experience almost anything on which you stick water soluable stuff, like white glue or filler, tends to warp. Blue foam is no exception. This is because the water evaporates from the glue or whatever, and the stuff shrinks, causing it to draw together.

To be sure, you can avoid this by using materials that are more resistant to warping, like thick enough or stiff enough materials, or covering the stuff on both sides, so it negates the warp. But warpage is always lurking there, in my experience. I have used 30 mm thick blue foam, and it warps like mad, if the piece is large enough. On smaller pieces the danger is not so great.

[Silent Invader]

In my experience almost anything on which you stick water soluable stuff, like white glue or filler, tends to warp. Blue foam is no exception. This is because the water evaporates from the glue or whatever, and the stuff shrinks, causing it to draw together.

To be sure, you can avoid this by using materials that are more resistant to warping, like thick enough or stiff enough materials, or covering the stuff on both sides, so it negates the warp. But warpage is always lurking there, in my experience. I have used 30 mm thick blue foam, and it warps like mad, if the piece is large enough. On smaller pieces the danger is not so great.

That's a good point.  I experienced this when PVA gluing terrain paper to 50mm boards - it was essential to weigh them down.

[SBRPearce]

Another step you can take to harden the boards against warping is to prime all sides (and edges) of your MDF with some sort of thinner-based paint like aerosol spray paint, or a primer-paint of some sort. This isolates the MDF from water infiltration, which causes it to swell and degrade, and it prevents the glue with which you attach the foam from causing that face to swell, which cups the boards in the opposite direction.


I wish I'd known this when I built certain pieces, since my basement is just a little bit damp and the atmospheric moisture has caused the fiberboard bases to die in sad and interesting ways, all too quickly.

[phreedh]

I never had any problems with unmounted boards of thick (50 mm) foam. Coated with several layers of pva and gravel, the only thing you risked was that they'd snap in half if you carried them around without supporting the weight.

Edge dentage might be an issue over time, but it's easily repaired so it all depends on how fancy you're doing them. One option is to cover the edges in silicone. Don't forget to paint the boards (and edges) before applying the silicone.

[Cheeky Monkey]

Whenever I use the thinner foams I always mount them on mdf or plywood. Painting the base material first is necessary to keep moisture out and causing the wood to warp. When gluing the foam to my base I like to use Liquid Nails for Foam - don't use the regular stuff as it will eat away your foam. It provides a very solid adhesion to your subsurface and will help avoid any warping from PVA glues when adding landscaping - although I have never had any warping of my foam - usually I prime my foam with latex paint appropriate to my ground area before adding textures etc (light browns for dirt, tans for desert, lt greys for rocky terrain) and that seems to do the trick.

[Furt]

There is a wealth of information here guys - thank you all.

Another thought - if one of the boards had say a ravine down the center of it that uses the baseboard as the bottom of the ravine and so had a strip of blue foam cut out the entire width of the board, would this make the board too fragile and allow it to bend/break at the ravine?

Hope that made sense.