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Correct Sealant for Windows, Marker Lights, Rain Gutter, ?

Baja_Man
Explorer
Explorer
I use Dicor Lap Sealant self-leveling to touch up fixtures on roof (vents, TV antenna, front and rear seams, etc).

Now I want to caulk around some areas that appear to have a clear (but dirty) sealant. It does not appear to be a lap sealant. It is a factory sealant as original owner never sealed anything (although trailer was covered).

These areas include, windows, side/front/rear marker lamps, rain gutter, water, TV,, 120V plug and several other items on sides of trailer.

I know NOT to use silicone anywhere on an RV.

What is preferred sealant for these areas?
How to clean/prep these areas prior to application?

Are there just two sealants used on trailers.....roof (lap, self leveling) and one for everything else?

Is lap self leveling used on the last 4"-5" of front and rear seams (between front fiberglass section and rear wall) that are essentially vertical? I have a crowned roof. I was worried the self leveling sealant would drip down if applied on these areas. Currently it appears to be lap sealant (white, not clear).

Thanks!
2023 GMC, 3500HD, Crew Cab, 6.6L Gas/6 Speed Auto, 4X4, Standard Bed; SRW
2011 Outback 250RS - Anniversary Edition
Equal-i-zer 10K
15 REPLIES 15

theoldwizard1
Explorer
Explorer
Tyler0215 wrote:
I use butyl tape.

I SECOND this !

IMHO, there is NO PERFECT SEALANT/CAULK ! They all will eventually leak, some sooner than others. Add in the fact that on any RV the "joint" is going to move.

Butyl tape is perfect for a joint that can be disassembled. It is easy to remove and leaves little or no residue.

frisco_dave
Explorer
Explorer
Another vote for Proflex RV
2011 KZ Coyote 232SS
2011 Expedition 3.73

Vintage465
Nomad
Nomad
I'm not sure this is the best stuff, but it's what ORV uses. It has a "a bit of self leveling" attribute to it, but not in a runny way. So when you apply it to clearnace lights or hatches it will just lay down a little to make a smooth application. When you need to remove it, it comes up nicely with a heat gun and a putty knife with rounded edges. Geocel 2300 Clear Tripolymer Construction & Pro Roofing
V-465
2013 GMC 2500HD Duramax Denali. 2015 CreekSide 20fq w/450 watts solar and 465 amp/hour of batteries. Retired and living the dream!

JIMNLIN
Explorer
Explorer
Its not just rv folks that found out by actual experience pure silicone didn't bond well when used as a sealant. That depends on the class silicone used.

GE has three different class of silicone sealants for exterior use.(doors and windows)

a all purpose class 25...

a advanced all purpose class 35 with 5X stronger adhesion...

a supreme silicone class 50 with 7X stronger adhesion...

Probably why some silicone users had no adhesion issues and others did. I'm sure other silicone brands are about the same as GE.

Lots of info on the net from rv forums/boating repair shops/construction trades/etc about wrong class of silicone lack of adhesion issues.
"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers

'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 two slides

Tyler0215
Explorer
Explorer
I use butyl tape.

2112
Explorer II
Explorer II
I use Proflex RV
2011 Ford F-150 EcoBoost SuperCab Max Tow, 2084# Payload, 11,300# Tow,
Timbrens
2013 KZ Durango 2857

Pbutler97
Explorer
Explorer
JIMNLIN wrote:
I've learned this non sense from the pros that do the job for a living on rv another website. (rv brand website) Those pros recommended using sealants made for rvs.

Actually silicone residue is a major problem depending on type of silicone and how its blended.
Silicone comes in acetoxy or a neutral cure form.

Acetoxy can leave a acetic acid residue which can cause bonding issues when used on certain materials. Its a fast curing product and smells like vinegar.

The neutral cure silicone leave no residue and has no odor and bonds well with different materials ...but does take longer to cure.




Bingo.


TurnThePage
Explorer
Explorer
Pbutler97 wrote:


That silicone residue BS is just that....BS. RV forum nonsense.

Dude, have at it then. I'm VERY confident that you'll learn from an experience that you can't easily back track on.

In 2005 I had that exact conversation with a warranty worker at a Fleetwood manufacturing facility, while my RV was being repaired. He said they used silicone too, but not because it was the right product. In fact, I don't even think they paid much attention to horizontal vs vertical surface applications.

After our conversation, he admitted that maybe they should rethink their methods.
2015 Ram 1500
2022 Grand Design Imagine XLS 22RBE

JIMNLIN
Explorer
Explorer
I've learned this non sense from the pros that do the job for a living on rv another website. (rv brand website) Those pros recommended using sealants made for rvs.

Actually silicone residue is a major problem depending on type of silicone and how its blended.
Silicone comes in acetoxy or a neutral cure form.

Acetoxy can leave a acetic acid residue which can cause bonding issues when used on certain materials. Its a fast curing product and smells like vinegar.

The neutral cure silicone leave no residue and has no odor and bonds well with different materials ...but does take longer to cure.

Other RV related sealants can have there own non silicone/siliconized blends so long term performance may vary.

So yeah that tube of 100 percent silicone from Lowes that smells like vinegar isn't the best idea for a rv sealing or resealing job.
"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers

'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 two slides

Gdetrailer
Explorer III
Explorer III
Pbutler97 wrote:

That silicone residue BS is just that....BS. RV forum nonsense.


I have a 700+ square square foot garage with a leaking metal roof that you are more than welcome to come over and show me just how easy it is to remove silicone without residue so I can apply something that lasts a lot longer than silicone without leaking.

Silicone caulking on anything that you hold near and dear to your heart in the hopes that it will never leak is a pipe dream.

There is at a min of 400 linear feet of silicone garbage you can "erase" with your name reserved on it if you want a real challenge. To win the challenge, you must complete the removal in less than 8 hrs, use no chemicals and it must be 100% silicone free.. The panels are 2ft wide so there is lots and lots of seams for you to clean..

The only thing I found that works is to completely bridge the silicone with a 6" wide self sticking rubber roofing membrane.

My only other choice would to be rip up the entire roof and start over with fresh steel at the cost of $10K at now days pricing.

Once silicone decides to become unstuck in random places, you can not ever get it to reseal, new silicone does not stick to old silicone, no other caulk, paint or even tar will stick to it.

And by the way, you believed a RV "factory rep"? Yeah, you are gullible. Every RV on this earth is built using cheap Butyl rubber caulking for things like doors, windows and trim.. All told at a cost of at the most $10 for the entire RV.

Pbutler97
Explorer
Explorer
Baja Man wrote:
Pbutler97 wrote:
Baja Man wrote:


I know NOT to use silicone anywhere on an RV.



Why not? Thats what Keystone RV that built your Outback uses for anything other than trim that touches roof membrane such as the top of the gutter rails /awning rails, or the front and rear term bar/angle. Keystone uses Tremco Trempro 645 everywhere else.


TREMPRO 645


Because silicone leaves behind a residue that is difficult to remove and nothing else will stick when touching up where silicone is/was.

How do you know that Keystone uses Tremco?
What do they use at rain gutter and other areas as you described?


Because I've owned two Keystone trailers and I asked a factory rep at Hershey when I had them. The last one was a 2013 so they may have changed since.

That silicone residue BS is just that....BS. RV forum nonsense.

Baja_Man
Explorer
Explorer
I checked Lexel website but did not any reference to UV qualities. It appears to be more for home use.
2023 GMC, 3500HD, Crew Cab, 6.6L Gas/6 Speed Auto, 4X4, Standard Bed; SRW
2011 Outback 250RS - Anniversary Edition
Equal-i-zer 10K

Baja_Man
Explorer
Explorer
Pbutler97 wrote:
Baja Man wrote:


I know NOT to use silicone anywhere on an RV.



Why not? Thats what Keystone RV that built your Outback uses for anything other than trim that touches roof membrane such as the top of the gutter rails /awning rails, or the front and rear term bar/angle. Keystone uses Tremco Trempro 645 everywhere else.


TREMPRO 645


Because silicone leaves behind a residue that is difficult to remove and nothing else will stick when touching up where silicone is/was.

How do you know that Keystone uses Tremco?
What do they use at rain gutter and other areas as you described?
2023 GMC, 3500HD, Crew Cab, 6.6L Gas/6 Speed Auto, 4X4, Standard Bed; SRW
2011 Outback 250RS - Anniversary Edition
Equal-i-zer 10K

Pbutler97
Explorer
Explorer
Baja Man wrote:


I know NOT to use silicone anywhere on an RV.



Why not? Thats what Keystone RV that built your Outback uses for anything other than trim that touches roof membrane such as the top of the gutter rails /awning rails, or the front and rear term bar/angle. Keystone uses Tremco Trempro 645 everywhere else.


TREMPRO 645