I have previously used Geocel ProFlex caulk for the outside of my fifth wheel. I found it was very difficult to remove the old caulk when it came time to re-apply. I also found that the caulk itself is not the easiest to work with as it is oil based and is quite messy to apply, particularly when you are just trying to apply a small bead. It just dries too quickly!Since my trailer sets outside it seems like in about 2 years after applying new ProFlex it starts to get very hard and the flexing of the trailer, as it travels down the road, causes very small cracks in the caulk bead.Has anyone tried a common latex caulk to fill in these small cracks? If so, what are results?

I have found the same as you with the proflex. I had an especially bad place on the front of the trailer that split every time the temperature changed. Us 3M 4000UV and so far 6 months later still in great shape. There is another guy on here who caulked 8 years ago with this and still in great shape. I have another tube to do the rest of the trailer this summer. Rob

I found Phenolseal to work well...comes white or translucent. Works easily as it is water based but actually does a better job then silicone once cured. I also used it on construction jobs for years. Lowes...HD...and good hardware stores have it for about 4.50 a tube. Also a GOOD caulking gun should be used not a 2.99 one

Any products containing latex or silicone will not last for RV exterior applications. I have only used Eurethane based caulk and Pro Flex is one product I have had good success with. Another option is Dicor lap sealant.

therink wrote:Any products containing latex or silicone will not last for RV exterior applications. I have only used Eurethane based caulk and Pro Flex is one product I have had good success with. Another option is Dicor lap sealant.I won't dispute your opinion because it is conventional wisdom, but why am I having cracking issue with my application? Putting a thicker bead on will look awful, and I've generally found unneeded with good caulk. As I mentioned, getting it off is a bear.Proflwx is just too brittle. There has got to be some type of caulk that will flex. Looks like the 2 posters above have had pretty good results.More opinions on us of Proflex appreciated.

Cracking is probably being caused by excessive flexing at the joint. It could be anything from loose mating parts to weak frame, to thermal expansion of disimilar materials. I think it is time you do some serious inspection to root out the cause

Exterior caulk question | Good Sam Community

CaLBaR
Explorer
Jan 31, 2016
I have found the same as you with the proflex. I had an especially bad place on the front of the trailer that split every time the temperature changed. Us 3M 4000UV and so far 6 months later still in great shape. There is another guy on here who caulked 8 years ago with this and still in great shape. I have another tube to do the rest of the trailer this summer.

Rob
spadoctor
Explorer
Jan 31, 2016
I found Phenolseal to work well...comes white or translucent. Works easily as it is water based but actually does a better job then silicone once cured. I also used it on construction jobs for years. Lowes...HD...and good hardware stores have it for about 4.50 a tube. Also a GOOD caulking gun should be used not a 2.99 one
therink
Explorer
Jan 31, 2016
Any products containing latex or silicone will not last for RV exterior applications. I have only used Eurethane based caulk and Pro Flex is one product I have had good success with. Another option is Dicor lap sealant.
dryfly
Explorer
Jan 31, 2016
therink wrote:
Any products containing latex or silicone will not last for RV exterior applications. I have only used Eurethane based caulk and Pro Flex is one product I have had good success with. Another option is Dicor lap sealant.

I won't dispute your opinion because it is conventional wisdom, but why am I having cracking issue with my application? Putting a thicker bead on will look awful, and I've generally found unneeded with good caulk. As I mentioned, getting it off is a bear.

Proflwx is just too brittle. There has got to be some type of caulk that will flex. Looks like the 2 posters above have had pretty good results.

More opinions on us of Proflex appreciated.
donn0128
Explorer II
Jan 31, 2016
Cracking is probably being caused by excessive flexing at the joint. It could be anything from loose mating parts to weak frame, to thermal expansion of disimilar materials. I think it is time you do some serious inspection to root out the cause
RJsfishin
Explorer
Jan 31, 2016
Dicor WILL NOT harden or crack,......in 15 years I know for sure. Much of that time was in full summer sun also.
Almot
Explorer III
Jan 31, 2016
Dicor will eventually become harder after some years, though not as hard as a regular caulk. The problem is that Dicor flows too easily, difficult to work on vertical surfaces.

Exterior Urethane caulk from Home Depot should work too. I used it 2 years ago, no cracking, though I don't move around much.

Another thing worth trying is Lexel. Sticks to anything. I sued it on some spots last year because needed a clear color.
DrewE
Explorer II
Jan 31, 2016
Almot wrote:
Dicor will eventually become harder after some years, though not as hard as a regular caulk. The problem is that Dicor flows too easily, difficult to work on vertical surfaces.

Be aware that there are two different types of Dicor available. The Dicor Self-Leveling Lap Joint Compounds is intended for horizontal application on roofs and will run down a vertical surface. There is also Dicor Non-Sag compound, intended for vertical applications. I haven't used it myself, but I assume it doesn't run too much to be hard to work with.
Almot
Explorer III
Jan 31, 2016
Yeah, I've heard about non-sag Dicor. Haven't heard anybody using it though.
dryfly
Explorer
Jan 31, 2016
I've only used the Dicor self leveling sealant, not familiar with other types they make.

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