jamie.y
New Member
can anyone recommend me a good epoxy expanding foam system?
its for a low volume application so no worries about exotherm
cheers
its for a low volume application so no worries about exotherm
cheers
epoxy foam
- Thread starter jamie.y
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oldsaltoz
Well-Known Member
I doubt the is one available, but will be monitoring this thread just in case.
William_H
Well-Known Member
Foam
I imagine Jamie is confused with the name. Most expanding foam is polyurethane. It can be bought as a pressure pack but most commonly as a 2 part mix together and wait for it to foam.
The 2 pack takes some time to reach its max volume so can be really tricky to use. You tend to put too much into a tight space and it expands beyond expectations spreading the formers with some force. So it is best to do it n several layers for deep shapes. good luck olewill
I imagine Jamie is confused with the name. Most expanding foam is polyurethane. It can be bought as a pressure pack but most commonly as a 2 part mix together and wait for it to foam.
The 2 pack takes some time to reach its max volume so can be really tricky to use. You tend to put too much into a tight space and it expands beyond expectations spreading the formers with some force. So it is best to do it n several layers for deep shapes. good luck olewill
Simes
Well-Known Member
Hi Jamie,
What is your intended application? I have never heard of an "Expanding Epoxy Foam" (does not mean that there is not one somewhere). I have however used a good number of the Expanding PU (Poly-Urethane) foams to good effect onboard. from insulating fixing and sealing (mast boot/chock supports have been very successful).
I have been looking for a "Closed Cell" PU foam. Lots of uses for that, esp' if it comes in cans!
Simes
What is your intended application? I have never heard of an "Expanding Epoxy Foam" (does not mean that there is not one somewhere). I have however used a good number of the Expanding PU (Poly-Urethane) foams to good effect onboard. from insulating fixing and sealing (mast boot/chock supports have been very successful).
I have been looking for a "Closed Cell" PU foam. Lots of uses for that, esp' if it comes in cans!
Simes
snowleopard
Well-Known Member
There are two types commonly available:
REP (rigid expanded polyurethane) that comes as two liquids which you mix and pour in. It's easy to use and does a good job as long as you keep it away from water. It is supposedly closed-cell but the cell walls are weak and immersion even in shallow water can break them down whereupon it can absorb 20+ times its own weight of water as many owners of older foam-filled hulls have found to their cost.
Builder's expanding foam is a little more tricky to use as it doesn't flow as it comes out of the can. It expands by 100-200% as it sets and if injected into a confined space it builds up huge pressures and can distort the container. Its performance in contact with water is excellent. It adheres better to damp surfaces than dry and doesn't absorb water. I tested it by immersing a piece in water for a year and it absorbed no water at all. If filling a large void you need to do it in stages and let each application set before adding more.
REP (rigid expanded polyurethane) that comes as two liquids which you mix and pour in. It's easy to use and does a good job as long as you keep it away from water. It is supposedly closed-cell but the cell walls are weak and immersion even in shallow water can break them down whereupon it can absorb 20+ times its own weight of water as many owners of older foam-filled hulls have found to their cost.
Builder's expanding foam is a little more tricky to use as it doesn't flow as it comes out of the can. It expands by 100-200% as it sets and if injected into a confined space it builds up huge pressures and can distort the container. Its performance in contact with water is excellent. It adheres better to damp surfaces than dry and doesn't absorb water. I tested it by immersing a piece in water for a year and it absorbed no water at all. If filling a large void you need to do it in stages and let each application set before adding more.
SvenH
Well-Known Member
Jamie MAY be confused but the rest is ignorant:
http://www.mcmc-uk.com/products-epoxy-foams.html
p.s. Being ignorant is easy, I do it all the time
http://www.mcmc-uk.com/products-epoxy-foams.html
p.s. Being ignorant is easy, I do it all the time
Last edited:
DownWest
Well-Known Member
That's interesting, SvenH, thanks.
BTW, the 2 part foams mentioned are ico-cyanate (I think) and the fumes are toxic. As for pressure, I watched the foredeck of a runabout blow off after a little too much mix was used.
jamie.y
New Member
Thanks for that i found this just before you posted myself and had a chat with the guys there. Im making a set of foils and the method they use in the video seems fantastic.
if you have a good set of molds you can use the foam and there suggested method to get a full monocock laminate with a strong foam core!!
No the cheapest product on the market but deffonatly something im considering!! Especially as i hate PU foa...horrible stuff!
SvenH
Well-Known Member
Can't you use (non foaming) Polyurethane resin with low density filler? Probably cheaper and quicker.
Mike.s
New Member
I have used some this expanding foam..
once you get the hang of it it is mint! be carful with volumes tho!! if you use to much and your molds arent up to the extra pressure then they might deform
i heard you needed ali tooling but i just made some normal fairly strong tooling out of chop and it was fine! just made sure i put a couple of extra layers on!!
once you get the hang of it it is mint! be carful with volumes tho!! if you use to much and your molds arent up to the extra pressure then they might deform
i heard you needed ali tooling but i just made some normal fairly strong tooling out of chop and it was fine! just made sure i put a couple of extra layers on!!
jamie.y
New Member
First foil made seems to have worked a treat!! feels pretty stiff and strong but the real test is when its in the water!
but as expanding foams go one of the best products ive used! very predictable expansion time and volume. very relaxing- especialy when compared with expanding PU foam ive used!!
It wasnt cheap but if it performs in the way it says then it should be worth it!!
but as expanding foams go one of the best products ive used! very predictable expansion time and volume. very relaxing- especialy when compared with expanding PU foam ive used!!
It wasnt cheap but if it performs in the way it says then it should be worth it!!
Falcoron
Well-Known Member
Pro set expanding epoxy foam is what you want for boats, it’s a slowly expanding closed cell hard set foam not a PU foam which is way to fast at expanding and can cause blow outs
This stuff is superb for repairing rotten balsa inner skin
This stuff is superb for repairing rotten balsa inner skin