How long should caulking hold up before redoing it?

[imq707s]

I've had our 2011 Crossroads Zinger for close to three year now. When I first got it I went through everything and cleaned out the old caulking on all of the joints, and redid it. Then last summer I noticed that some of that caulking had started to crack and look pretty bad so I redid a bunch of it again.

And now this summer/fall I've started to notice that once again, I can see several spots were the caulking around things has started to pull away and/or crack...and needs to be redone.

I've always used the high quality (and expensive) RV caulk, and it just doesn't seem to last very long.

Is that pretty normal, or am I doing it wrong??

[_1nobby]

myredracer wrote:



Beware of some internet advice like from this dude who used silicone on his camper. He even made a short how-to vid here. Wow. Just wow... :S

Wow is right.

He even sounds quite pleased with himself.

[Ralph_Cramden]

myredracer wrote:
Wondering if it's perfectly okay to put new Proflex over old stuff without having to remove any of the old caulk? I removed some along the top of the fender skirt a couple of seasons ago using white gas and plastic scraper. Even tried a little heat from a blow dryer. OMG, not easy... Would rather just add more even if it doesn't look as nice.

You can go over Proflex with Proflex. The trick is cleaning the old Proflex to get a good bond. The best thing I have found to prep Proflex is "Klean Strip Prep All". Find it at auto body supply places. Just use it sparingly around decals. It will clean the old Proflex and soften the surface, taking some off to some extent. When I remove Proflex I cut out as much as possible with an exacto knife. You can cut in from two directions carefully, then peel it off in a strip. Harbor freight sells a set of red plastic scrapers for a few bucks the work great that I use to scrape it off after cutting. You can sharpen them up with a slow running belt sander with 220 grit paper. Then use the Prep All to remove the remaining residue.

And you also can go over silicone with silicone. It depends on the brand. By saying that I am referring to certain commercial grades and generally not the silicone you buy at the Big Box or Ace, its done all the time on concrete parking garages and other structures. It usually requires a specific primer.

Keystone uses/used Tremco Trempro 645 Silicone for any joints that did not touch roof membrane. Not sure if they still do or not, but a friend and I successfully went over our 2013 and 2012 Keystone Passports with it after prepping with a combination of prep all and denatured alcohol. The issue with the 645 is its hard to find unless your an OEM, but its made for the transportation and RV Industries.

[westend]

If anyone is trying to remove silicone or an unknown sealant, 3M and other Mfg's make a caulk remover that works well. For removal, I typically apply the remover, cover the caulk with Saran wrap and wait overnight. In the morning, the caulk comes off in long ribbons and I use a rag with mineral spirits to remove any remaining sealant film. I had to do this to my roof as there were many different sealants applied, including roofing tar. The caulk remover worked exceptionally well.

[myredracer]

Wondering if it's perfectly okay to put new Proflex over old stuff without having to remove any of the old caulk? I removed some along the top of the fender skirt a couple of seasons ago using white gas and plastic scraper. Even tried a little heat from a blow dryer. OMG, not easy... Would rather just add more even if it doesn't look as nice.

I want to use a blower to pressurize the exterior to find any leaks but am running out of time for this season. A local RV shop will rent out his Seal Tech blower.

Hannibal wrote:
Would be really nice if Dicor would offer their lap sealants in smaller squeeze tubes for touch ups.

So true!!! I just hate that.

imq707s wrote:
I thought silicon caulk on a camper/trailer was a big no no?

Some people refer to any caulk as "silicone". Ordinary 100% silicone caulk on the exterior is a no-no. For one thing, unlike RV exterior caulks, can't put fresh silicone over cured silicone as it won't adhere.

I just used some DAP Alex Plus caulk around a door on our house as in the photo. It's acrylic latex with silicone and says it's good for 40 years, is highly flexible, is easy to apply and tool, easy to clean up with water and has excellent adhesion. Why can't they come up with something similar for RVs?? The painter used it on our house exterior when it was built 10+ years ago. Still in excellent shape.



Beware of some internet advice like from this dude who used silicone on his camper. He even made a short how-to vid here. Wow. Just wow... :S Why didn't he at least use clear? Um, never mind. :B

[GrandpaKip]

CaLBaR wrote:

GrandpaKip wrote:

imq707s wrote:
I thought silicon caulk on a camper/trailer was a big no no?

Most campers (all?) have the trim caulked with silicone to start with. I am slowly getting to all the exterior trim and replacing the silicone on ours.

This is exactly what I noticed when looking at new trailers. I was really surprised. Guess I should not have been. I will start to replace the silicone with something else too. Just not sure what yet. I was using 3M 4200 marine caulk and it worked great. I think it only comes in white and the new trailer is not white so might look funny. Need to check if it comes in clear.

Comes white or black. Most of the trim is black so that should work.

Having been around boats most of my life and usually being the one who has to remove old caulk, I would not use 3M 4200 on my camper. There are better alternatives out there that have been mentioned in this thread.

[westend]

I'm looking for a better lap joint/non sag type of sealant.

I've used the Geocel polymer sealants with good success. They offer a few varieties for the transportation industry, including Proflex RV. If you wish to never caulk the roof again, plan on covering every seam with Eternabond tape. The stuff is really a great product!

[Ralph_Cramden]

CaLBaR wrote:

GrandpaKip wrote:

imq707s wrote:
I thought silicon caulk on a camper/trailer was a big no no?

Most campers (all?) have the trim caulked with silicone to start with. I am slowly getting to all the exterior trim and replacing the silicone on ours.

This is exactly what I noticed when looking at new trailers. I was really surprised. Guess I should not have been. I will start to replace the silicone with something else too. Just not sure what yet. I was using 3M 4200 marine caulk and it worked great. I think it only comes in white and the new trailer is not white so might look funny. Need to check if it comes in clear.

Comes white or black. Most of the trim is black so that should work.

Silicone being a no no is a common RV board misconception. Keystone RV uses silicone for every joint that is not against roof membrane but its not the silicone you run out and buy at the big box. They were using Tremco Trempro, at least as late as 2013, a neutral cure high quality silicone caulk that is really tenacious when it comes to adhesion.

Most Forest River brands almost all use Geocell Proflex.

Where people get into trouble is attempting to touch up non silicone caulk with silicone or vice versa. Sometimes when touching up silicone with silicone. They key to touching up silicone is to use the exact same product, clean it properly, and use a primer.

[Ralph_Cramden]

imq707s wrote:
I've had our 2011 Crossroads Zinger for close to three year now. When I first got it I went through everything and cleaned out the old caulking on all of the joints, and redid it. Then last summer I noticed that some of that caulking had started to crack and look pretty bad so I redid a bunch of it again.

And now this summer/fall I've started to notice that once again, I can see several spots were the caulking around things has started to pull away and/or crack...and needs to be redone.

I've always used the high quality (and expensive) RV caulk, and it just doesn't seem to last very long.

Is that pretty normal, or am I doing it wrong??

If you're specifically talking about self leveling lap sealant here is a story for you that brought back memories from a 2011 Aerolite we had which was built in 2010. Back around that time (2009/2010) Dicor had sent a bad batch of lap sealant to multiple manufacturers, and since your 2011 could of been built as early as late fall of 09, perhaps your rig received a dose of it. On our 2011 Aerolite all the roof lap sealant dried out and started cracking at about 1 year past the build date. I traded it in not long after and the dealer knew about it. I assume he took care of it before re selling, and was reimbursed by Dutchmen/Dicor.

I have not had one prior, or of the two since, where the lap sealant cracked like it did on that 2011.

[imq707s]

I have used that 3M marine caulk on other projects, the only problem is that when it cracks (it will) and needs to be scraped off and replaced.....good luck. That stuff is extremely strong and bonds like glue. Just something to think about.

[CaLBaR]

GrandpaKip wrote:

imq707s wrote:
I thought silicon caulk on a camper/trailer was a big no no?

Most campers (all?) have the trim caulked with silicone to start with. I am slowly getting to all the exterior trim and replacing the silicone on ours.

This is exactly what I noticed when looking at new trailers. I was really surprised. Guess I should not have been. I will start to replace the silicone with something else too. Just not sure what yet. I was using 3M 4200 marine caulk and it worked great. I think it only comes in white and the new trailer is not white so might look funny. Need to check if it comes in clear.

Comes white or black. Most of the trim is black so that should work.

[LarryJM]

proxim2020 wrote:
On the roof I've switched over to Eternabond tape wherever I could. Do it right the first time and don't worry about it again.

Yep I did the same for my entire roof back in early 2008 and haven't had to touch it since except for the caulking along the front edge of the Eternabond on the front cap to keep it from lifting due to constant wind when traveling. Same went for all the seams and screw heads on the slide out and along the bottom faring of the sides of the trailer.

Larry

[_1nobby]

I used the Dicor self leveling on the flat surfaces of the roof.

But I used Tremco 830 on all other seams....windows, lights doors, basement hatches etc.

This is what all the professional contractors use on windows etc up here in Canada.

There is a lot of expansion / contraction with the 4 seasons and this stuff is the best.

[GrandpaKip]

imq707s wrote:
I thought silicon caulk on a camper/trailer was a big no no?

Most campers (all?) have the trim caulked with silicone to start with. I am slowly getting to all the exterior trim and replacing the silicone on ours.

[JIMNLIN]

I use nothing but Dicor on my 32' roof on a '97 trailer. I do a roof check in the spring before the trailer hits the road. Most of the sealant up there is still OEM. The first Dicor I used was when the trailer was 5 years old and the skylite cracked. I had too replace it while we were camped 480 miles from home.

Most folks use too much (thick) roof sealant which may crack in a couple of years. We see lots of OEM jobs that looks like that.
However sealant cracks may not mean it can leak.
1st line of defence against water intrusion is is the grey butyl tape. If that job was done right it won't leak.
2nd line of defence is a good sealant properly applied over the screws and around the edges like the brands mentioned.

There is no sealant or tape that is maintenance free.