Underbelly spray foam

[Toy4Rick]

Hello all,

I need to re-seal several areas now that I had to pull the coroplast

Lot's of posts regarding closed cell spray foam, pond foam... and with boring-smith website down, for how long don't know...

What other options are there?

I have used "Great Stuff" on home projects and it works great when filling gaps but does a terrible job when trying to spray it on a surface like the underbelly. Just doesn't stick and you certainly can't build it up very well
Not to mention, the can needs to be upside down to work so working on the underbelly means fitting some type of tube to spray up

Is there a product that is actually sprayed on like expanding insulation rather than a gap filler?

Thanks, Rick

 

[Kevin2282]

This is what I used to seal gaps under my fifth wheel. It worked great and has a nice black color. It has held up great since it was applied.

https://www.lowes.com/pd/smartpond-Black-Pond-Foam-Sealer/1000846484

I used about 18” of vinyl tubing and a 6” piece of 1/4” copper tubing as a control tip so I could hold the can upside down. The vinyl tubing was press fit over the plastic tube that came with the can. The copper tubing tip allowed for very good control on where the spray foam went.

 

[Riverbug]

After sealing, reopening, sealing, reopening, sealing...several times last year while I worked on several projects under our new trailer, I started to use good 'ol black silicone caulk from the local big box stores. It can be applied in thick beads, spread thin, filled gaps, etc., but it also sticks well as intended but has the added benefit of being pretty easily removed and it is relatively cheap compared to other options. You might just give it a try and see what you think. It will look the same as the "rubberized" caulk that came from the factory. It won't look like the spray foam stuff, but that's fine it fills in the areas just as well. If a gap is a little to big to fill, you can put some tape over the gap as a backer and caulk over the area.

 

[traveldawg]

This is what I used to seal gaps under my fifth wheel. It worked great and has a nice black color. It has held up great since it was applied.

https://www.lowes.com/pd/smartpond-Black-Pond-Foam-Sealer/1000846484

I used about 18” of vinyl tubing and a 6” piece of 1/4” copper tubing as a control tip so I could hold the can upside down. The vinyl tubing was press fit over the plastic tube that came with the can. The copper tubing tip allowed for very good control on where the spray foam went.

I used the same thing. Just a different brand from Amazon.

 

[kb0zke]

"...I started to use good 'ol black silicone caulk..."

When we bought our trailer in 2023 it had a bad grey tank valve. The dealer cut the coroplast, fixed the problem, and taped the cut. The tape didn't make it the 200 miles back to The Ranch. I tried several tapes, none of which worked. I complained, and the dealer said I should just bring the trailer in (200 miles one-way) and they would retape it. I talked to Grand Design and they verified that the dealer should have dropped the coroplast to do the repair. I complained to Holiday World corporate, and they had the dealer order new coroplast. Before they started the work of replacing the coroplast, they explained that I would actually have MORE cuts in the coroplast because of how it is installed. They offered to put on the black caulk and said that would take care of the problem. I agreed, and it did. Why they didn't do that in the first place I don't know.

 

[Toy4Rick]

I reached out to Great Stuff and they confirmed all of their products are closed cell, the only outlier being the Door & Window" is slightly less closed cell

All should be painted or UV treated if used outside and don't use oil based paint, use latex

Picking some up today to finish the wiring job I set out to do last week

Thanks all

 

[PVISION]

"...I started to use good 'ol black silicone caulk..."

When we bought our trailer in 2023 it had a bad grey tank valve. The dealer cut the coroplast, fixed the problem, and taped the cut. The tape didn't make it the 200 miles back to The Ranch. I tried several tapes, none of which worked. I complained, and the dealer said I should just bring the trailer in (200 miles one-way) and they would retape it. I talked to Grand Design and they verified that the dealer should have dropped the coroplast to do the repair. I complained to Holiday World corporate, and they had the dealer order new coroplast. Before they started the work of replacing the coroplast, they explained that I would actually have MORE cuts in the coroplast because of how it is installed. They offered to put on the black caulk and said that would take care of the problem. I agreed, and it did. Why they didn't do that in the first place I don't know.

Hi there,
Do you know what kind of Black Caulk was used? I have to repair the check valve for the under sink gray tank, I'm sure I will need lots of caulk.

 

[kb0zke]

Sorry, no.