Wednesday, December 8, 2021


Foam gap filler is a quick fix for cracks and holes in the RV

The first time I used foam gap filler we were covering a few holes in our old RV. The foam expanded a lot, amazingly, all over the holes and all over my hands. Pretty soon my hands were covered and firmly stuck together. Think: super glue on steroids! I couldn’t get it off so I couldn’t drive. I had to walk to the hardware store to buy whatever would cut it. After the store staff quit laughing, they kindly sponged it off. So, lesson learned: Wear gloves.

The foam gap filler made by Great Stuff is a great tool for filling small and large holes and is particularly useful for the RVer. Unfortunately, we use it a lot to fill the cracks and holes mice in the desert always seem to find. It expands and quickly dries. It dries so quickly that it is difficult to clean the nozzle and tube enough to allow reuse. An old fashioned pipe cleaner works great! The nozzle comes apart for cleaning and a pipe cleaner can even whisk out the foam filler from the tip of the can. Foam filler dispensing tubeClean foam filler dispensing tube with pipe cleanerCleaning foam filler dispensing nozzel with pipe cleaner

Cleaning foam filler can nozzel with pipe cleaner

Tape the tube to the can and it’s all ready for the next use!

Foam filler dispensing tube

Keep a can of this in your RV. It’ll come in handy more often than you think. Find it here for a great price.



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Michael Theis
9 days ago

I have used this on my house but would have some concerns on my travel trailer. After a while, it becomes very brittle. Vibration and the flex of the frame could cause some of this filler to disintegrate and leave gaps in the ‘seal’.

15 days ago

I find that the nozzle and tube cleanup nicely with a little acetone. It also removes residue from unintended places if it hasn’t cured yet.

Dan A
15 days ago

I bought the rodent repellent foam. I had a packrat under my dash that I managed to chase out before it did any damage when we were camped in Joshua Tree RV park. Ace is the place! I filled the hole that I had missed earlier.

15 days ago

They also make a pest control foam that will keep critters out.

15 days ago

The water based (latex) foam is good unless you are trying to keep critters out. It is soft and minimal expanding. Mice have no problem chewing through it. That type is used for insulating around doors and windows since it will not expand and push the frames out of square.
When I sealed the penetrations under my trailer, I first cut a piece of 1/4 inch hardware cloth, metal screening, used the foam and then pressed the screen into it. Then covered with another layer of foam. You an also use steel wool first an then the foam.
Wear disposable gloves to keep your hands clean.
Finger nail polish remover or acetone will remove the foam while it is still pliable.

John Goodell
15 days ago

The only solvent I know that will cut “Good Stuff” is the special solvent that is made by the same company and should be sold on a shelf near the Good Stuff. It only works on fresh wet Good Stuff foam, and after the Stuff dries, you are S.O.L., as far as I know. I will be looking for the water soluble stuff next time I need some. Spray paint covers Good Stuff very well and if the water soluble stuff is white then I will be buying some.

Scott R. Ellis
15 days ago

There are water-based insulating foams that work just as well, are a much-less-ugly white color, clean off with (duh) water, and are in dispensers designed to be cleaned and re-used. Should be on the shelf right next to this stuff.

15 days ago

This foam may be fine for cracks or gaps under a trailer or RV. Don’t use it where you will see it. We tried to seal a front window with this. It yellowed and looked terrible. It was very hard to clean off if it got on the trailer and left yellow smudges. And yes it was sticky! We don’t use this anymore.