Blue Foam Shrinkage

[Tommyblooz]

Has anyone noticed a shrinkage problem with Blue Foam. Someone mentioned to me that there is a significant amout of lateral shrinkage in the material as time goes by. The Blue Foam that I am referring to is the DOW Blue Foam. I was at Ken Pattersons lecture at CSC and I remember him mentioning shrinkage but I have never heard anyone else speak of it.

[ak-milw]

I have used blue foam for a couple of bluffs I made and haven't noticed any movement, they have been up for about 2 years. I use pink for the main base.

[mecrr]

blue foam is the complete sub base of my layout and have had no shrinkage in 10 years.
David

[jbvb]

Tommy, if you can, let us know the manufacturer/brand of the foam that shrank. I took enough chemistry and worked in chemical manufacturing QA long enough to be pretty sure there are ways to make foam cheaper that will have that side effect.

[NEMMRRC]

Ken Patterson noted during his photography clinic at CSC that his foam modules have shrunk. I cannot recall if he used pink or blue foam though.

Jaime

[gnatshop]

No Comment!

[willywally]

Wish I could comment, this stuff is rarer than hen's teeth around these parts.

[2manyhobbeez]

I can vouch for the fact that I have observed shrinkage with the pink foam, which I think is the same substance, different brand. I had a shelf layout partially built and kinda gave up on it for several years. I came back to it the other day prepared to rip it out and redo and on close observation found that the rail had buckled in several places. Now mind you this was an all-foam shelf, 2 layers of 1.5 inch laminated together, no plywood. I did minimal rail gapping because I thought the foam was dimensionally stable, plus there are no temp variations in that room and we don't have humidity issues here. But the foam shrank and that was that. I measured it and found that the original 8 foot length had diminished by 3/16 inch.

My new shelf is going to be one layer of foam on 3/4 inch plywood but I am going to cut the foam every 2 feet so it can't mess with me again.

George

[rebel]

I use the white foam and no shrinkage in 4 years or so.

[dottney]

I've been using blue and pink foam for years and have never noticed shrinkage. Heck I've made RC airplanes from the stuff and if there was shrinkage there would be more disastrous results than cracking model scenery (real cracked scenery & model ).
Dave