Spray foam and temperature?

[Bon Voyage]

If it is flammable it will have warnings on the canisters. I know the foam I got is a flame resistant foam so it burns much slower, as in hours to burn. I don’t know about the fumes but again the canister would say so.

 

[Ozbozz57]

PNWSteve, I have done exactly what you're asking about, and it worked fine. I had bought my 600 board foot kit (Foam It Green) and then it got cold. I waited all winter, and in March, with lows below freezing and highs in the mid 40s, I realized I'd have to wait until June or July to proceed with the spray foam. Not acceptable, since it was holding up everything else. I decided to try something. First, I put the foam cans in a small bathroom with a heater, and kept them at 75F for a solid week. Then I took all the fiberfill insulation I had removed from the bus' ceiling and walls, and laid it ON TOP of the roof, along with any other insulation-like stuff I had around. Then I covered that with old blankets and moving pads, etc, and covered it all with visqueen to keep it dry. I put three electric heaters totalling about 4500 watts inside with a fan to blow the hot air around. I ran three cords out from my shop from three different circuits to the heaters so the breakers wouldn't blow. Left the heaters and fan run all night, and went out in the morning (frost on the ground) and the IR thermometer read the interior surface of the roof skin at 108F. I opened the door to let it cool off while I carried my foam canisters out to the bus and set up the spray hose and stuff. When the roof skin got down to 80F I started spraying. It went really well, the foam expanded properly, bonded well, and cured nicely. My ribs were 2 inches thick. I filled the spaces in two - one inch-thick coats. Trimmed it down flush with the ribs, added 1 inch thick furring strips to the ribs, made up from 2 layers of half inch plywood glued together and screwed to the bottom of the ribs as a thermal break, then 1 inch mylar foil faced flexible foam board (white styro board from Lowe's) between the furring strips, and 1x6 T&G pine for a finished ceiling. The bus went from being ridiculously wet inside just from condensation to bone dry. This may be a little long-winded for a response, but it CAN be done. Good luck!

 

[Phoebus]

May be out of the question, but perhaps you could take a long weekend trip somewhere warm enough with the bus to have it sprayfoamed instead of perhaps needing to wait a few months. Once again, not sure if that is an option as I see you are in the NorthWest, so that may require driving further than one would probably like

 

[Rock-N-Ruth]

Hey Everyone,

I had really hoped to get to the point where I was ready to spray foam insulation before it turned cold. Too late...

We are seeing high 20s to low 30s at night and around 50 during the day.

Has anyone here had any experience with trying to heat the inside of the bus to allow spraying the foam at correct temperatures?

I considered using my propane heater but I am afraid that it will add too much moisture.

I have a 3500 watt portable electric heater but cannot find an extension cord (NEMA 15-30).

I am considering buying a 120v portable heater and see how that works.

Thoughts or suggestions?

Thanks

Consider that though you may get the air temp up , the metal skin is going to be a big heat sink. You will be unlikely to get the right surface temperature for proper curing. Better be patient and wait till you have a mid winter thaw or a few warm spring days. Temperature is very important in proper curing.

 

[Phoebus]

Ross, that’s mighty ambitious. Very impressive and resourceful, well done!

 

[kidharris]

Hey Everyone,

I had really hoped to get to the point where I was ready to spray foam insulation before it turned cold. Too late...

We are seeing high 20s to low 30s at night and around 50 during the day.

Has anyone here had any experience with trying to heat the inside of the bus to allow spraying the foam at correct temperatures?

I considered using my propane heater but I am afraid that it will add too much moisture.

I have a 3500 watt portable electric heater but cannot find an extension cord (NEMA 15-30).

I am considering buying a 120v portable heater and see how that works.

Thoughts or suggestions?

Thanks

I would check with the foam manufacturer MSDS and see what gases the foam produces when it out gases and when it burns. Don't want explosive gases around fire or deadly, toxic gases if the foam catches fire. Cyanide based gases were a concern with early versions of some foams when catching on fire many years ago.



My 2 cents... Rig up or tent/drape a clear plastic cover, aka green house, and see if it warms it up enough. Sand or dirt can be put on top of the plastic at ground level to seal and add wind resistance. Blankets or similar could be put on the top of the roof before covering with the plastic for insulation. If the bus can be parked next to a reflective wall/building/whatever, more solar can be focused on the bus. Without some help, a 1500 watt heater is not going to keep with the rate of heat loss through the bus skin. Condensation caused by burning anything inside the bus without being vented through a flue would be a problem as well as noxious, toxic fumes would be a health hazard.

 

[kidharris]

May be out of the question, but perhaps you could take a long weekend trip somewhere warm enough with the bus to have it sprayfoamed instead of perhaps needing to wait a few months. Once again, not sure if that is an option as I see you are in the NorthWest, so that may require driving further than one would probably like

Good idea. Or take to a pro who has a warm shop to do it in.

 

[TheHubbardBus]

One of the few jobs we plan on farming out to pros will be the foam. As others have said, you only get one shot at it, without the benefit of any experience, and now you're adding in the additional complication of low temps. When we researched the cost diff - it wasn't enough to justify the labor & risk from our perspective. That was without the additional equipment you may be considering to warm the bus. I'm assuming the pros doing it would involve some guarantee of the job done right. That right there would be worth the $$ for me.

 

[TheHubbardBus]

Consider that though you may get the air temp up , the metal skin is going to be a big heat sink. You will be unlikely to get the right surface temperature for proper curing. Better be patient and wait till you have a mid winter thaw or a few warm spring days. Temperature is very important in proper curing.

Great point.

 

[brokedown-SKO]

Steve, obviously the right idea is to drive south until the temperatures match the label on the product.

I'm actually grumping about hos its in the 60s/low 70s and I want to paint.

 

[kidharris]

I am inclined to take the manufacturers advice. I doubt they would tell me that they recommend running the heater while spraying if the fumes are flammable. In fact they told clearly "the fumes are NOT flammable."

I had my first bus spray foamed. I moved into it full time about two months later. I lived in that bus for 7+ years. I did not have any issues with offgassing.

That said.... I am reconsidering having it done professionally. Unfortunately the outfit that does it here wants almost $1900 to do the walls and ceiling. None on the floor. I'm using sheet foam on the floor.

"NOT flammable" does not mean "NOT noxious" or "NOT toxic". Sorry, I once worked in a factory where they paid bonuses to the first person to spot a piece of foam in a fire because of the toxic gases produced by the foam off gassing because of the heat. Many products can be said to not burn because they do not burst into flames. Some are said to be self extinguishing because the gasses produced will put the fire out. They will also put you out. Just watch these non burning products disappear in front of your eyes as they turn into gasses while not burning.


Not absolutely sure about this, but I don't think "not flammable" means "not combustible" either. I'm thinking it means more like won't easily burst into flames as in the difference between gasoline or propane and diesel.