After reviewing the reader responses to, “Rubber in a Can For Truck Campers”, the primary concerns are (1) trapping moisture and thus causing rot, (2) whether Rubber in a Can is the right material for the job, and (3) the need for long-term experience with the product and application with truck campers.
All of these concerns are 100-percent valid. We are particularly concerned about trapped moisture causing additional problems.
Taking a step back, our 13-year old project used camper already had significant rot in the rear skirt. We needed to do something to repair and protect this area before a complete rear skirt rebuild would be necessary.
After careful consideration, removing the rotted wood and using Rubber in a Can seemed like the best solution to the problem. Line-X and similar professional bed liners were evaluated, but are significantly more expensive, not to mention much thicker and heavier than Rubber in a Can.
While I share the concern about trapped moisture, the Rubber in a Can isn’t a project without context. We have already properly caulked and sealed the roof and sidewalls stem to stern and regularly inspect and repair those seals. Nobody should apply Rubber in a Can to their camper underbody if they don’t regularly maintain their roof and side seals.
What our extensive work with sealants has taught us is that traditional RV sealant materials and techniques are inadequate. They take far too much time, and are too imperfect to be 100-percent relied upon. From this realization, it only makes sense to explore the diverse products and technologies of coatings. Consider Rubber in a Can our first foray into this universe.
Getting back to the reader concerns, we will be carefully monitoring our rear skirt for signs of water collection. We may even put weep holes in the material after significant rains to see if any water emerges. If we find a way to allow this area to breathe without compromising the rubber seal, we’ll try that.
We will report what happens. This is what pushing forward, conducting experiments, and having a project camper is all about.
This week’s Question of the Week was, “Does it make sense to coat the underside of our truck campers – especially the rear skirt and overhang areas – with Rubber in a Can sealant?”
“Rubber spray for overhang/skirt areas looks like a very viable solution, especially if there is no need to access the basement from below. Line-X would also work for this purpose.
The long term test will be if water finds ways of getting behind the coating and doing destructive deeds. Thanks for testing Rubber in a Can for truck campers and sharing your experience.” – Klaus Jager, 2014 Ford F350, 2007 Lance 1130
“First you have to understand what Rubber in a Can does. It protects from water ingestion in both directions. What a fence keeps out, it also keeps in.
The answer to your question is yes and no. Yes, if what you are trying to protect has the ability to breathe if it does ingest water. If not, then all you have done is to guarantee rot, not prevent it.
That does not mean this is all or nothing. You can still add Rubber in a Can protection if you have some weep holes or some way of allowing air to circulate and dry out if and when it does get wet or damp. Or if you can completely encapsulate the area 100-percent if it’s dry to begin with.
I did much the same with my truck camper and Rubber in a Can. But what I did not do was completely seal the bottom (which was plywood). I was cautious in my application to insure I did not seal so well as to prevent its ability to dry and that makes it a great idea!” – Don Pryor, 2017 Ford F350, 2008 Arctic Fox 1150
“I’ve used Rubber in a Can for the exterior of a skylight, and it worked. I’ve used it to seal a rain gutter, and it worked. I also used it to seal drywall hairline cracks prior to mudding and painting. The stuff works.
Though I don’t own a truck camper at this time, I have used Rubber in a Can on the underside of my travel trailer’s frame beneath the propane tanks. It’s been in place for months and appears to be holding up well.
Silicone has its place, but not on truck campers, trailers, or motorhomes. It is one of the worst sealants that exists for the job intended. There are many other products on the market that one would think RV manufacturers would rather use in regards to current sealant technology. They do not. It’s left to the owners to deal with it.
This was a good article. I think you’ll find that the sealant will work for years to come with minimal maintenance.” – Tony Valdivia, 1996 Ford F250 XLT, 2016 Cougar 29RK
“The last truck camper I had was a 1980 Edson 11-foot. I sprayed the bottom of that camper and the rear wings with a rust check rubberized under coating. I get it at Walmart for $3.45 a can. That was ten years ago.