Types of Foam and Glue

[teflyer]

Hello all,
I was wondering what was the difference between different types of foam? More specifically, what is depron, elmer's foamboard, and dollar tree foam made of?

The reason I am wondering is because sometimes a glue melts the foam and sometimes not and I was wondering what compound is in foams so that glues such as CA glue sometimes melts a hole in the foam and sometimes does not, I think with EPP.

 

[earthsciteach]

CA is nasty stuff to foam. But, there is foam safe CA which costs too much. I find foam safe CA to be quite brittle, especially if kicker is used. Kicker accelerates the reaction so that the bond is pretty much instant. Its nice for field repairs and areas that don't take much stress, but don't count on it for much beyond that, in my experience.

I think its the acetone and other "tones" that melt the foam. There are plenty of other foam safe glues on the market. My favorite is white Gorilla Glue. Good stuff!

 

[lobstermash]

I used to use epoxy for everything, but thanks to the show I've used pretty much nothing but hot glue.

The only issue I've had with it was on a recent trip to Adelaide, where the temp was around 38 degrees C (the magic 100 degree F) in the shade. My funbat (put together exclusively with hot glue) flew fine through the first battery, but on landing on the second battery fell apart in a few place. The glue went chewy.

Now that I'm back home, where it's rarely anywhere near that hot, I'm back on the hot glue. It's fantastic for scratch building, as it sets very quickly and can be removed with less fuss than most other glues too.

 

[teflyer]

Thanks guys! earthsciteach, I use white gorilla glue too! Would Shoe goo work with elmer's foamboard or dollar tree foam?

Lobstermash: Thanks! In the summer, down in south U.S., it gets pretty hot (90-106 degrees F) so I do not usually use hot glue much. Wish I could though... seems so much easier....

 

[jetpackninja]

Not sure on the shoe goo on the dollar tree foam. But Shoe Goo or any of the Amazing Goop products work great on EPP

 

[earthsciteach]

Is GOOP the stuff that they covered the leading edge of the flying wing in one of the FT episodes?

 

[teflyer]

Yes. I know it work on EPP, but not sure about others. I either had put it on EPS or Dow Blue Core Foam and the glue dissolved the foam.

 

[Tritium]

Almost any glue (or paint) works on foamboard al long as the paper coating is intact. Now the core of foamboard is a different matter entirely. It is very similar to depron in glue resistance.

Thurmond

 

[teflyer]

I always strip off the paper since I use elmer's foamboard and stripping of the paper takes off half the weight. What glues can depron stand?

 

[Pilot Scott]

White depron, black depron, grey depron and our depron aero build best with foam safe ca, low & hot temp hot glue, goo or shoe goo, foam tac and epoxy.

I always strip off the paper since I use elmer's foamboard and stripping of the paper takes off half the weight. What glues can depron stand?

 

[teflyer]

Thanks, Pilot Scott!

 

[lobstermash]

My motto is 'if you can't hot glue it, use epoxy'. Epoxy is safe on pretty much all foams (except those with a really low melting temp).

 

[jetpackninja]

Is GOOP the stuff that they covered the leading edge of the flying wing in one of the FT episodes?

yes- It comes in several different flavors- household, plumbers, etc. Pretty much the same as Shoo Goo.
I'm a hot glue fan myself. The only time it is a real concern here is on the hottest days of summer.