Pour Foam

[Countach74]

Like to know if Pour Foam is just rebadged Spray Foam Insulation? From what I have read they are both 2 lb. cubic foot and both are mixed 1:1

[macleodm3]

I used some spray foam in my gear leg fairings and used pour foam on my strake fairings.  The spary foam stayed softer and did not sand as well as the pour foam.

[Countach74]

Thanks Andrew, that is good to know! 

[Countach74]

Found this info. They ate diiferent

https://www.aeromarineproducts.com/product/2-lb-flotation-and-insulation-boat-foam/

[Kent Ashton]

Definitely stay away from the home store "expanding foam" in a spray can.  I have used the "minimally expanding" foam in a spray can.  They are all urethanes but I think you get a more even foam with the Aeromarine product above or X-30 from Spruce.  https://www.aircraftspruce.com/catalog/cmpages/x30foam.php  I imagine those are about the same.  I'd buy whatever is cheapest.   The more thoroughly you mix the pour foam, it will harden with smaller bubbles but it's a race because it begins to foam-up pretty fast.

Actually, if I can use scraps of blue styrofoam or urethane to fill an area, it works better for me.  Mix up a little pour foam to stick them together.  A pour foam surface requires a lot of filler before glassing and it tends to keep curing a long time after use.   I have noticed depressions where it seemed to shrink under the glass.

I have read that a spray of water will speed up the cure but I haven't tried that.  Might be useful if you are using pour foam to make cowl shapes.

[Countach74]

Excellent advise as always,Kent!!!

[Royal]

Spray foam cures with moisture. The pour foam is more like an epoxy.