Using foam in a can to fill gaps

We used it quite a bit to keep mice out. Works well. No issues that we can think of except when needing to replace a line that runs through the spray foam. It takes a little longer.

Just know that a little goes a long way. It really does expand!

I too use spray in foam around the small opening all around my trailer. My POPUP trailer does not have the under belly material so I can lay under my trailer at night with the interior lights ON and can really see where most of the small holes are at located...

Great stuff for that...

In my other 5th wheel trailer I am forever running RG and Video cables in and out of the built-in Air Conditioner ducts in the ceiling. This is my major route to get from the back to the front of the trailer as both ends opens up into a ceiling mounted cabinet. Everytime I punch a hole thru the foam duct there I use the spray foam to build up the around the new hole I have made to seal it off so the air conditioner can build build up some air pressure when being used...

Roy Ken

I have used it in several rigs to plug gaps and voids. It pays to go easy as it does expand considerably. They have a new low expansion product out now. I prefer the original as I can cut back over burden.

There are a couple of kinds; the non-expanding type that just fills the gaps and the expanding foam that goes everywhere. To just fill the gaps I would think the non-expanding foam would be more controllable.

Buy the non expandable type.

Thanks for the quick replies. I'll be spraying s-l-o-w-l-y.

If you care about the appearance, landscape foam is a dark gray and it works like the ugly yellow stuff.

If you haven't worked with it before, be aware that it's rather messy stuff. It'll stick very well to your clothing, your skin, your cute little Scottie with the red bandana around her neck....

It's also not a good bet that you'll be able to store away a half-used can and get it to work afterwards. The stuff in the can is OK, but the trigger mechanism and tube are hard to clean sufficiently for another use. If you have a bunch of things to be foamed, get them all prep'd and then go around and spray them all.

The standard high expansion kind can sometimes expand beyond what you want, especially if confined in a tight place, and cause some things to buckle or warp. This is probably not a big problem with water lines, but can (for instance) be very troublesome when sealing around double-hung windows or doors in a house.

Particularly in an area exposed to light, it's not a bad plan to put some paint on top of the foam once it's fully cured as UV light breaks it down over time.

DrewE wrote:
If you haven't worked with it before, be aware that it's rather messy stuff. It'll stick very well to your clothing, your skin, your cute little Scottie with the red bandana around her neck....

It's also not a good bet that you'll be able to store away a half-used can and get it to work afterwards. The stuff in the can is OK, but the trigger mechanism and tube are hard to clean sufficiently for another use. If you have a bunch of things to be foamed, get them all prep'd and then go around and spray them all.

The standard high expansion kind can sometimes expand beyond what you want, especially if confined in a tight place, and cause some things to buckle or warp. This is probably not a big problem with water lines, but can (for instance) be very troublesome when sealing around double-hung windows or doors in a house.

Particularly in an area exposed to light, it's not a bad plan to put some paint on top of the foam once it's fully cured as UV light breaks it down over time.

Paint or use spray rubber in a can to seal and protect the foam from breakdown.