"How to stop terrain boards from warping?" Topic

For years I've occasionally tried to make 2 by 2 terrain tiles or 3 by 4 (one time) with varying types of styrofoam in different thicknesses atop mdf board. They almost always warped after I glued them down which then basically ruined the whole project. Any ideas as to how to stop the warping? I was thinking to get sheets of 1/8 or a bit thicker acrylic cut which I was hoping might not warp in place of the mdf.

Have you tried painting the bottom of the mdf base to counteract the pull of the glue holding the styrofoam down? That's a solution that has been suggested here on TMP.

Jim

Duke Seifried made his later 2'x 2' terrain boards out of a base of "gator foam," a more expensive & tougher version of foam core. He said these wouldn't warp, were strong yet lighter weight than using an mdf board or plywood base.

Maybe trying a different glue would work as well.

Ok

The solution is you make a torsion box in the lower third of the the piece. You cut 2 MDF boards 2 1/16 by 2 1/16. You make a frame work inside of board. You then cut the box down with a tablesaw to 1 15/16. Glue on side rails of MDF and fit the blue foam in the top.

The box will keep it flat and light weight.

Link to some 2 foot by 4 foot WW1 Board using T-boxes.
imgur.com/a/DFaUbrn

Try using contact cement to attach the foam to the MDF board. When MDF absorbs water from PVA Glue, it will lead to warping.

Contact cement is dangerous stuff, so follow directions carefully. It is strong enough, as well as permanent. It is solvent based, not water based. It will not lead to warping. Cheers!

All good ideas, never heard of Gator Foam!

Ten years ago I built a set of 6'x2' terrain boards using high quality 2" thick blue insulation foam, and then as months turned into years, had the "warp" experience. A decade later those original boards remain usable, but far from perfect. My solution was similar to Wackamole9's, but a little simpler. I built open-topped "boxes", ripping 1"x3" boards (which are in reality 3/4"x2-3/4") down to 2" height -- to go flush with my 2" thick blue insulation foam -- used wood-glue and screws to fasten them along the edges of the MDF baseboard, then trimmed the foam pieces to fit and glued it inside the "box".

It's labor intense but it works like a charm. If you build a wood frame for your foam board to fit into, said foam board will never suffer 1mm of warp. I actually started making the wood frames for some river boards, but then realized how successful they were at preventing any warping. Despite the added time and effort, I've built wood frames for every terrain board I've made since then. In fact I just built one new 2'x6' board and a pair of 2'x2' small square boards this past Summer. If you have minimal wood-working knowledge you will have little or no problem. If you don't have a table-saw or jigsaw at home you should be able to get all the frame pieces cut down to the sizes you'll need at the local lumberyard where you buy the wood. The wood frame does add a lot of weight to the finished board -- especially the 6' long kind -- but even those are not too heavy for one person to move when needed.

Here's a LINK to a post on my blog about building one of those boards this past Summer:

link

link

Many options here but not cheap! Anyone know which types were used by Mr. Seifried.

Mad Guru, this looks much easier actually, as I just got a new table saw last year with a nice table top extension. I could then use the cheap pink foam and shape it easily and add elevations, etc. I think with three four by 3 pieces the dreaded "cracks and gaps appearing" will not be an issue. Also, a two foot wide piece might be okay as well. Four tiles would make a 4 by 8 table which although not as big as our biggest terrain mat at 6 by 12 is still quite nice.

I recently built a portable table of 3 panels, each panel is 2x4. This gives me a4x6 table. Sealed and paint the MDF , used 1x1 wood strips to frame the underside of the panels with an additional piece running across the center. I used a piece of 7/16 boar. If I was to make another, it would be 3/8 plywood. Thick MDF is just a little heavy. Plywood has a resistance to warping because of the vary grain directions of a sheet.

I use 2ft x 2ft blue styrofoam panels as the basis of my terrain boards with 1ft x 1ft panels for 'special' terrain features.The edges are protected by masking tape and the actual surface is based upon basket liner and static grass. This means no warping and the edges are relatively 'soft' and flexible which allows them to be closely pushed together by the wooden frame attached around my 10ft x 6ft table.

The boards are fine for domestic use but they probably would not survive constant travel.

The Gator board that Duke used was closer to 1" thick.

I use 1/8-inch artist MDF panels, but I coat each side with a water sealer and let dry for a day or two before adding terrain with glue. I use B-I-N by Zinsser as my sealant, in both brush and spray applications. The boards are mostly 12 by 16". I've had no warping at all, over several years now.

Smaller panels in 6 by 8", also treated the same way, can be added for greater variety, especially for towns and such.

These are for 6mm terrain, where depth/height is minimal. I might have braced with plywood, as above, if I'd been adding deeper, carved terrain, or other features.

Using extruded polystyrene for the base is probably the best, and it's not too expensive.

Otherwise, the warping is largely due to humidity. Paint all sides of any base, with the possible exception of extruded polystyrene.

I have had good luck using elmers glue and gluing a sheet of paper to the back of the board. When it dries the paper and glue shrink and pull the board back into shape. Sometimes I've had to do it more than once to get the board fully all the way back. But its a noticeable difference each time.

It works on MDF and foamcore pretty well.
Not so much on plywood.

And its a lot cheaper than paint or tacking another board on.

That is a new (to me) and good idea Tin Dictator.

Here's a YouTube link on how to do it.
Its in German but there are subtitles and its pretty self explanatory anyway.

YouTube link

Wow -- Tin Dictator, that video tutorial is a potential windfall, thanks very much for posting it! I'm not sure if it will work on my terrain boards, since they feature 2" thick blue insulation foam on top of their MDF base-boards, but I am going to give it a try on the board with the worst warping. When I get around to it I'll come back and post the results -- good, bad or indifferent. THANKS again for posting that video!