Foam Sheets from Home Depot for Nosecones?

I have been looking for a way to turn large nosecones out or foam (6 - 12") Typically with my smaller models I have purchased blocks of foam
from Michaels or AC Moore, and sanded them into shape using a drill press, and then coated them with epoxy. I can come up with a homemade lathe for the size, but am having a hard time finding some kind of blank stock. I would need too many small blocks to make one large enough, and it would be cost prohibitive. Has anyone tried anything similer using the Home Depot Sheets? I have tried some foam in the past that does not sand well. If you've tried it, how does it sand, into dust that falls straight to the floor, or dust that flies everywhere?
Thanks, Charles
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Charles- If I'm not mistaken, the only "foam" that should give you problems is the stuff with those annoying pellets. The stuff I've personally seen in Home Depot is actually an insulation grade, which should sand quite easily, using finer grit paper, of course. Good Luck with your project, Bob352
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Delurking a moment --
Have you considered expansion foam? www.mrfiberglass.com sells a two-part expansion foam that is truly awesome -- you mix the two ingredients together and in 60 seconds it starts foaming up to 15 times its size, and hardens in an hour. You could make a nosecone mold and pour as many as you wanted. You can even color it.
Here's a link --
http://www.mrfiberglass.com/urethane_foam.html
Bob
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Charles,
I've built quite a few large nosecones from the blue and pink insulation foam from Home Depot. Largest is 16" in diameter. I've even used the white foam and expandable foam. The biggest problem I had with the expandable foam was it continues to expand over time in high heat and I ended up with a split cone. I cut the rings into disks and stack them. It's important not to get glue where you will be cutting or it will chug out a big chunk of foam when the cutter hits the glue.
I built a lath but I don't spin the cone and cut it like you would on a typical lath. My lath doesn't have a motor for spinning the cone. I use a router with an end cutting bit and a guide to shape the contour. I hold the router against the guide and turn the cone by hand. I use wall spackle to fill any voids and hand sand smooth. After covering with fiberglass (2 layers of 6oz) I sand with a belt sander and then a final sanding with a palm sander.
Bob Heninger Glendale, AZ

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Hello Charles:
As Bob352 noted, the so-called "beadboard" made of tiny white styrofoam pellets is of little use in nose-cone making. The stuff that works well is "extruded" styrofoam, usually comes in blue or pink, from 1/2 to 2" thick. Sometimes a construction site will have scraps of the stuff laying around; ask if you can have it.
Cut circles of foam, larger in diameter than the cone, and stack 'em. Do not cut rectangles longer than the cone and stack 'em. When attempting to turn the latter, the cone will end up sad and lumpy.
The foam I've used has a clear plastic peel-off coating. Peel it off. Apply a very thin layer of epoxy to both sides to be glued. Stack, weight, and wait.
A few pointers: The stuff makes dust that flies everywhere. I use a coarse rasp for initial shaping and sandpaper for the final shape. Both shop doors are left open so the breeze blows dust out the door.
I like Bob Heninger's idea of using a router to shape the cone. It would avoid the problem of spinning a big lump of foam at high speed. The stuff always vibrates a bit when spinning. And sometimes it comes off the lathe. Been there, done that.
For a perfect shoulder, turn the shoulder down to a tight fit inside a piece of coupler tubing, then glue the coupler tubing in place for the shoulder.
Best -- Terry
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snipped-for-privacy@hotmail.com writes:

A fileting knife does a nice job rough hacking out the foam. A nail and string make a workable compass for cutting circles.

I also had good luck with yellow glue and with spray foam.
--
Bob Kaplow NAR # 18L >>> To reply, there's no internet on Mars (yet)! <<<
Kaplow Klips & Baffle: http://nira-rocketry.org/Document/MayJun00.pdf
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Terry's right make a coupler and put a band of the body tube at the top to make the lip, holds up much better then foam.
Bob Heninger Glendale, AZ

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I used foam blocks from Lowes to make the nose cone for a project I did last year. It worked out very well, and came in at 2" thick. I used a wire cutting jig similar to what they show on Rock Team Vatsaas' website and a hot wire to shape the foam. Then I hit it with some sand paper, glassed it and sent it on it's way! The foam I used was the white insulation foam with the thin plastic on it. I definitely recommend peeling it off before you shape it. I used a small dab of epoxy to make sure the foam pieces would hold together when I cut.
Hope that works for ya!
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Charles wrote:

http://www.vatsaas.org/rtv/construction/styrofoamfixture.aspx http://www.vatsaas.org/rtv/construction/hotwirecutter.aspx
Mark E. Hamilton NAR #48641-SR ARSA #418
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