Has anyone used the Home Depot Great Stuff foam in a rocket? I have the 2 part foam, but want something lighter. Mine is 4lb stuff. Since the Great stuff is air dry, will it dry in an enclosed space? Thanks.
The rap on it has been that it's expansion and hardening are not predictable, I've heard stories, admittedly anecdotal evidence, about airframes being damaged well after the foam was thought to be cured. The stuff that you mix yourself is easily observed giving one more confidence in the process.Bummer.
One can per rocket unless I line them up and prepare all of the rockets for foam. It works for me every time. I’ve put G-80’s in rockets that normally launch motors like F26… the G force alone tells me the foam works. Obviously, i do not know how much force is at the tip of the rail/rod but all I have to do is repack and put another motor in.A common issue with spray foams is their inability to cure completely when applied in a too-thick layer, as they rely on moisture in the air to cure. Another is that some foams will expand or contract significantly with temperature, causing a bump or hollow in a nose cone. Had it happen to one of my rockets and to a friend's. It may be related to the irregular sizes of the voids in the cured foam, I don't know.
And of course, most of the canned spray foams must be used up shortly after their first use. Two-part foams are good for some months as long as they're tightly sealed.
It's not a matter of strength. Yes, can in a foam and two-part foam are strong enough to prevent most damage to a thin-walled cone.One can per rocket unless I line them up and prepare all of the rockets for foam. It works for me every time. I’ve put G-80’s in rockets that normally launch motors like F26… the G force alone tells me the foam works. Obviously, i do not know how much force is at the tip of the rail/rod but all I have to do is repack and put another motor in.
I pour my 2 part foam in "lifts" about 2-3" cured depth per pour, by doing it in stages I dont normally get swelling/distortion issues. My 2 part foam of choice is Sika Post Fix also a fence post setting foam.It's not a matter of strength. Yes, can in a foam and two-part foam are strong enough to prevent most damage to a thin-walled cone.
In my Big Daddy nose cone the foam in a can ended up expanding a bit more on one part of the nose, leaving a perceptible bump. And on my mentor's 7.5" Phoenix the space between TTW fin tabs was filled with foam in a can. Apparently there was one or more oversize bubbles during expansion. Whatever the cause, if he left the rocket in the sun too long or just outside on a hot day, a bulge formed in the body tube between two fins.
Once there is a bulge or depression, about the only thing that can be done is to live with it. Which I did for the Big Daddy until the last landing, when it ended up only partly assembled.
There are other similar accounts I've read about on the forum. It's common enough that I'd prefer to go with two part foam, either the stuff I'm using now, or a commercial variety; the commercial stuff that comes in two cans/bottles is roughly 4-8 times as expensive as the Fast 2K.
I wonder if building it up in layers with some cure time in between would work for you project.Has anyone used the Home Depot Great Stuff foam in a rocket? I have the 2 part foam, but want something lighter. Mine is 4lb stuff. Since the Great stuff is air dry, will it dry in an enclosed space? Thanks.
So why use foam for a cardboard and wood, mid-power rocket or even for a L1 type rocket? Personally I try and avoid the use of foam but it does have certain uses.Dry and ready for a G-80! Just a bit of sandpaper!
Thats what I did for my 8" PNC-80BB upscale nosecone that was two pieces, glued them together and used a piece of 6" sonotube as a structural element and recovery anchor point, then filled the void space with Sika Post Fix 2 part expanding foam.On mine, I 3D printed a hollow shell and wanted to make it landing proof. New term I just thought up. Only added a couple of ounces and , at least I think it is stffer.
Just a choice.So why use foam for a cardboard and wood, mid-power rocket or even for a L1 type rocket? Personally I try and avoid the use of foam but it does have certain uses.
I respect that.Just a choice.
Hahahaa sticky conversation for sure
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