Being self crowned "King of Chincey" , I have experimented with a lot of different new materials that pretty much replace the use of Balsa and save money (don't take me wrong, Balsa still has a lot of uses trumped).

What I have found is pretty serious in building and can bite you in the b*tt as it did me..so here goes

I "discovered" this cool new material called foamcore that everyone seemed to be building with ...bought typically at Hobby Lobby craft stores (not the RC Hobby (dash) Lobby)).

By itself (unpeeled) it has two slick thick paper faces that are sort of heavy for our "normal" use (its pretty stiff and strong unpeeled, and can be used that way fine and is not as strong but lighter than lightply).

What is not known is if you buy this stuff and peel it (many tricks to do this and other threads describe how), it ends up looking and working sort of like Depron, only a little softer.

Here's the problem. I thought WOW, I'll build several planes of this stuff and laminate the edges of the tail surfaces with a 1/16" brich dowel (soaked) or a 1/8" balsa strip to give it some integrity and stiffness. Well that worked...BUT (doncha just love it)...on every one of them...(5 in all) about a week later the surfaces began to look like tulip petals....YUK...I mean YIKES!!

Here we have several models built and ready for finish (I prefer acrylic ) and the tail surfaces are all warped horribly....not even iron on covering could get the warps out....nor could a heat iron or heat gun.

At first I thought it may have been the disimilarity of the shrink of hardwood or balsa to the foam core... but then I tried the same on Depron and CellFoam available at RCFOAM.

No problem...never a warp...no matter what the humidity or time left unpainted/unsealed.

So...

Never use FoamCore for anything you would add stiffening to (ie laminating edges, stiffening carbon fiber strips, balsa reinforcement strips)

It's a good material to use "as is" with its facing as this actually controls the shrink of the foam material...but don't try to use it after spending a lot of time stripping it of those faces. I posted some pics of this "phenomenon" on other forums on a couple of build projects that got seriously delayed trying to solve this mystery.

My advice...don't waste time with foamcore...just buy depron or *cellfoam (*which is just as cheap as foamcore) and same all the grief of stripping it and discovering this anomaly later.

I found cellfoam here to sample

http://rcfoam.com/cart.php?target=ca...ategory_id=107