# Bad day at Pinsch Mountain



## 4meandthem (Nov 11, 2011)

I have been cutting foam board and filling in my track.I have been using adhesive foam tape to hold everything down. It has been working great for weeks but I went out this morning and everything is cupping. I even have some board that are still in the plastic wrapper and they are cupping. I have a heck of a lot of time already invested in this.

Anybody else experience the cupping and did it relax back down at all. I bought some different glues and have plenty of weights to try and fight it but I would feel alot better if I knew it wouldn't keep happening or getting worse. I would bet it is weather related and I could heat the garage to a pretty warm to maybe counter it befor gluing the foams to the track.

Any suggestions?


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## tjd241 (Jan 25, 2004)

Pics of what's going on would help us see exactly the issue your facing.


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## AfxToo (Aug 29, 2003)

It's related to the different rate of expansion between the paper and the foam with moisture. As the paper absorbs moisture it swells or shrinks, the foam doesn't, so you get warping. I've seen this quite a bit because I use foam board to help choose colors for painting a room, painting up foam boards with sample colors and then seeing how they look in the room - because foam board is cheap and lightweight. When one side of the foam board is painted it almost always warps in a few days. Painting both sides of the board at the same time with a non-latex primer paint to seal it from moisture may help but I can't say for sure. Give it a try on the boards that are not yet warped.

If you're using this strictly for turn borders then you could switch over to cork, high density foam, rubber strips, or cut your own from wood or masonite. There is a heavy duty and warp resistant alternative to foam board called Gator Board but it is pricy. If you are using this for filling the vast infield areas of your track to make it look inlaid then unfortunately you are not going to find an easy solution to the warping that has already occurred. Once it warps it seems to stay warped despite your best efforts to un-warp it.

What I've used for filling in vast areas to the level of the track (one quarter inch) is 1/4" rigid foam insulation (residing board). One issue is that it comes in a fan-folded 50 foot length which is probably a heck of a lot more than you will ever need. It is also soft enough to be damaged by steel guide pins. When I use it I peel off the plastic skin so the glue or paint adheres to the foam directly. I typically coat it with other landscaping material like paint and flocking, plaster, Sculptamold, latex caulk, or fabric so I have not seen any damage to the foam from cars.


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