Sealant for Horizontal Openings

Slackers

I am replacing the outside shower box (result of a rookie mistake) and am interested in what you recommend to use around the exterior box.  I'll also then have to inspect around the windows, a/c vent, and outside storage access panel.  If any need more sealant, any other recommendations for those are also welcome.

Bayliss

@Slackers, when sealing something outside the trailer, whether it is an area of aluminum or fiberglass, always use a urethane or polyurethane based caulk/sealant.  Do not use silicone.  Silicone will degrade or pull away over time, plus it does not adhere well to fiberglass.

I previously made a note that Creed at nüCamp recommended using Geocel MHRV 2300.  Geocell ProFlex RV Sealant, which may be the same thing, is also a good choice, as is Sikaflex Polyurethane Adhesive.  

Slackers

I understand about not using Silicone.  I am curious if anyone had any brand or specific products to use.

Bayliss

@Slackers, I edited my comment above to provide some specific products, but similar products should work just as well.

Slackers

@Bayliss thanks for the quick responses!  I have come across some of the ones listed above, so I'll look more into those.  

qhumberd

We had to remove the outdoor shower on our 400 when we noted water leaking just before winterizing. After removal found that a simple plumbers tape and hand tightening stopped the leak, but we then had to replace the sealant. We noted that polyurethane was recommended for the Azdel panel so after looking at several recommendations we selected the 3M Marine 4200 product. I sourced a small tube and found it easy to apply and smooth. It looks good and holds well. It can be removed as well if needed. The extra I sealed up and placed in the freezer. It is pretty expensive it seems. Good luck.

https://www.3m.com/3M/en_US/company-us/all-3m-products/~/3M-Marine-Adhesive-Sealant-Fast-Cure-4200FC/?N=5002385+8709375+8709962+8710954+3291170224&preselect=5581375+8710676+8710815&rt=rud

Radcat

My son has been living/running a small business out of an RV for about 7 years and he swears by FLEX SHOT® Thick Rubber Adhesive Sealant. I saw a job he did on the outside of his unit a couple of days ago and was pretty impressed with the results. Nice finish and seemed to bond well. 

Slackers

@qhumberd thanks for the recommendation.  I purchased a tube of the 3M 4200 for the job but Amazon delivered it without the nozzle.   So thought I'd ask here to be sure I get the right product after I return the tube. As for the shower unit, before I replace the box I'll make another attempt to tighten hot and cold sides.  Thanks!

Slackers

@Radcat thanks for the recommendation.

qhumberd

Slackers said:

@qhumberd thanks for the recommendation.  I purchased a tube of the 3M 4200 for the job but Amazon delivered it without the nozzle.   So thought I'd ask here to be sure I get the right product after I return the tube. As for the shower unit, before I replace the box I'll make another attempt to tighten hot and cold sides.  Thanks!

Our Shower box is a Fontana and was leaking at the mixing connection but we decided to disconnect the three connections hot cold and connection to spray hose and wrap all with plumbers tape and then hand tighten. All then felt more secure. I feel the road vibration made them loosen but with the tape I am hoping that will not happen again.

Slackers

Ours only leaks on the cold water side.  I'm pretty sure it's cracked because last summer we also replaced the shower head.  It had numerous pin-hole leaks.  We have the replacement Fontana box.  Based on what you said, we'll first try the plumber's tape fix before pulling the box.  And we'll probably have to reseal around the box because I noticed some hairline cracking of the sealant there and other locations on the trailer.

TomCanada

After too much analysis paralysis, I ended up going with plain old butyl tape on to reinstall my exterior power receptacle (removed to facilitate an onboard EMS install).  Sounds like this is already more than the factory provides (which was limited to small dollops of some clear sealant but definitely not thoroughly applied).  After tightening the screws and the butyl tape oozing out (pic below) I scraped the excess off with a plastic edge guard I typically use for caulking, and the end result I'm pretty happy with. Some people recommend the polyurethane over top but others say this is plenty - and I figure it's already way better than the factory seal so I'm inclined to leave it as is..

4ncar

Butyl tap is the bomb!  In my previous life, we used it for our work; I had 12 rolls of it when I sold the business...I have applied it every where, and given to friends as gifts!!😂