Ideal minimum temperature for 2lb foam?

[Boomyal]

I'm finally a week away from foaming my new floor. Our weather has turned uncharacteristically cool for September days. Normallly we would be in the high 70's to low 80's. All month we've been in the '60's<br /><br />I'm concerned that I might not get adequate expansion at these temperatures. If the temperature is somewhat critical, I'll hold off and hope that we, at least, get a few normal September days.<br /><br />This morning I was running some 8" 8 oz FG tape along both sides of my stringers when it started to pour. I reached up and pulled the boat cover over the boat and had to crawl out the outdrive hole in the transom. Fortunately I'm using the US Composite medium catalyst and with the cool temperatures I was able to wait out the downpour without the resin setting off. Grrrr!

 

[18rabbit]

Re: Ideal minimum temperature for 2lb foam?

Know what you mean. Just about ready for priming after weeks of sanding and epoxy filling, and sanding, and sanding ... Expecting rain Sunday.

 

[Boomyal]

Re: Ideal minimum temperature for 2lb foam?

Originally posted by 18rabbit:<br /> Know what you mean. Just about ready for priming after weeks of sanding and epoxy filling, and sanding, and sanding ... Expecting rain Sunday.

Rotten weather everywhere, I guess? I've been fortunate, in my project. There has been a minimum of sanding and grinding epoxy. But I have sure mixed up a zillion batches of resin.<br /><br />You posting any pictures, 18R?

 

[Winger Ed.]

Re: Ideal minimum temperature for 2lb foam?

I've had the best luck when it was about a hundred degrees, but you got to be fast too.<br /><br /><br />Blow a heater up under your cover or something, but I wouldn't use it under about 80.<br /><br />The cooler it is-<br />The foam will work, but the bubbles will be smaller, hence the pour will be stronger structurally, but also heavier and you won't get as much 'mileage' for however much foam you bought. <br /><br />For what you're doing, the better of a fill you get is more critical than how strong the foam is.<br />Even 2 lb. foam blown when its hot! is strong enough to have ten times more structural integrity than you'll ever need if there are no voids in it.<br /><br /><br />And if you come up short on foam,,,,, Then we get to the subject of other fillers such as milk jugs & soda bottles.<br /><br />This was well discussed here a few months ago and should still be in the back pages.

 

[JasonJ]

Re: Ideal minimum temperature for 2lb foam?

I did mine when the temps were in the 60s, and it seemed to work fine. It definately generates its own heat, I could feel the heat when I put my hand on the outside of the hull. I have the feeling that when poured into a small enclosed space like a stringer void the heat it generates is sufficient to get a good expansion and cure. If mixed and poured out in the open, I bet it wouldn't expand as much as the heat would leach off more quickly. Just a guess...

 

[Uncle Dave]

Re: Ideal minimum temperature for 2lb foam?

Temperature definately affect the expansion of foam.<br />I painted the cans of foam with black paint. Then sat them in the sun a few hours prior to mix. Loosen the lid prior to setting in sun. The added heat gives the foam a better kick. Also the smaller the batch the less heat generated and it may not work as well. Try to mix at least a pint of each with each pour. Also use plastic or paper containers. They will not "sink" away the heat as much as metal. I would not reccomend heating the material on a gas or electric stove.<br />If you preheat and then the added heat of the mix be careful as the foam mix will become hot enough to cause a burn on the skin.<br />Fitz

 

[Boomyal]

Re: Ideal minimum temperature for 2lb foam?

Originally posted by Mr. Fitz:<br /> Temperature definately affect the expansion of foam.<br />I painted the cans of foam with black paint. Then sat them in the sun a few hours prior to mix. Loosen the lid prior to setting in sun. The added heat gives the foam a better kick. Also the smaller the batch the less heat generated and it may not work as well. Try to mix at least a pint of each with each pour. Also use plastic or paper containers. They will not "sink" away the heat as much as metal. I would not reccomend heating the material on a gas or electric stove.<br />If you preheat and then the added heat of the mix be careful as the foam mix will become hot enough to cause a burn on the skin.<br />Fitz

Thanks for tip, Mr Fritz, re sun heating the cans of foam. The only problem is that our cool temperatures are accompanyed by cloooooooooooooouds, ie no sun. But as soon as I finish this post I am going to go bring the cans into the house where they will at least stay above 70 degrees. A previous post stated as you, to mix a quart, total, at a time. <br /><br />I am ready to foam but I am awaiting arrival, by UPS, of my 'secret' drainage material. I need to position and affix the 'material' before I can screw/glue down the floor and pour the foam. Maybe when it arrives, this coming week, the temperature will have improved.