Which Foam ?

[skip_dye]

I'm going to increase my skill set by learning to turn my own nosecones. All the various build threads and resources I find all show using a pink foam. I just returned from the hardware store and all they carried was a blue foam (made by Dow and they were 4 x 8 sheets) and white foam (unnamed manufacture, 2 x 4 sheets). Can I use either of those? I do plan to fiberglass over the foam.

Thanks,

Alan

NAR/TRA Level 2

 

[gpoehlein]

Take a close look at the foam. If it looks solid and all one piece, it should be fine. I'm betting the blue foam looks like that and will work. The white foam could be beaded polystyrene. If so, a close look will show what looks like little balls of foam squashed together. Turning this stuff will just peal away the balls and leave you with a lumpy mess. Beaded foam has its uses, but turning for nose cones is definitely not one of them. Blue foam and pink foam are (usually) pretty much interchangeable.

 

[DAllen]

One annoying thing I found with some rigid foam insulation is a plastic layer they sometimes apply. I have found it best to peel this plastic off before doing anything. The last bit of foam I bought for this type of application I made a point of buying foam without this plastic layer. I have not used it yet for making any nose cones but probably will soon.

-Dave

 

[Micromeister]

I'm going to increase my skill set by learning to turn my own nosecones. All the various build threads and resources I find all show using a pink foam. I just returned from the hardware store and all they carried was a blue foam (made by Dow and they were 4 x 8 sheets) and white foam (unnamed manufacture, 2 x 4 sheets). Can I use either of those? I do plan to fiberglass over the foam.

Thanks,

Alan

NAR/TRA Level 2

Alan:
either Pink and Blue panels available from the big box home repair stores will work. As Greg was saying you just want to be sure your getting open cell foam, that means it doesn't clumble into little round balls when it's rubbed or broken, rather a fine almost sandy particles. plain Old white closecell styrofoam can be used but your gonna end up with a much rougher core than with the open cell materials.
I've even used floral foam from Micheals in a pinch but it's really crumbly, I'd stick with either Pink or blue Styrofoam building insulation panels instead. I usually buy 1", 2" or 3" thick material for turning.
Be sure to ware at least a particle mask while turning the stuff, you don't want to be breathing in the dust

Even better, though way more expensive are the Hi-density urethane foams. Any of them form 15 to 22 lb/cu ft are great for turning cones.
Hope this helps a little and Good luck with your turnings.

 

[skip_dye]

Thanks guys.

..and I can fiberglass right on top of the open cell foam?


Alan

 

[DAllen]

Absolutely...Just to be absolutely sure since there are lots of different foams (and I am not a chemist by any stretch of the imagination) you might want to mix up a bit of the epoxy/resin you are using for the fiberglass and coat a junk piece of the foam. That will ensure that the glassing process won't do anything funky to the foam.

Another thing to consider is whether or not you really need to use fiberglass. Depending on your application a skim coating of epoxy might be all you need. Just a thought.

-Dave

 

[Micromeister]

IF: and I say if you are mixing a large batch of epoxy that's going to generate a lot of heat it will deform a bit of any of the Styrofoams we've been talking about. I had a BT-80 cone get a little dimpled due to my way over application of two much coating epoxy. I leaned it's much better to apply a thin coat (with or without glass) then go back with a second layer if I really think it's necessary, which by the way it really shouldn't be