Time to Re-caulk on Roof...Best Method?

[ArkRVHog]

Originally Posted by ChrisParise

There is a misunderstanding here.

The Dicor self leveling lap sealant will actually add less depth to the existing Dicor and fill in holes or gaps in the process. It self levels.
No smearing with a putty knife is needed nor is putting Lexel on top of new Dicor needed.

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Sorry...not following what you're saying. Applying the new Dicor to existing Dicor has to add "some" thickness unless it somehow melds down into the existing old Dicor product...which I doubt it does. I do understand that it might not add that much additional thickness due to the self-leveling but it will be some more. And a thicker amount of Dicor to scrape off if the original begins to peel up from my roof. Plus my latest product I'll use is brushed on now...no need to spread it with a tool.

[Larry-NC]

Originally Posted by Treybecky

Maybe you can read my old post: I have detailed post titled "Eternabond Tape Roof Install with photos"

12/21/21

Never need to look at the roof again, or the sides...

well, Once a year maybe, but no more fixing or worrying.

https://www.forestriverforums.com/fo...os-244498.html

...not pretty, but stops the cracking.

Heat gun can get the tape off Ive heard, hope to never find out.

Heat gun helps, but Eternabond says that if their product starts looking bad, just put another layer atop the original.

The Cherokee 38P had two skylights on the big slideout that were simply flat 1/16" polycarbonate ("Lexan") sheets, with Eternabond around the edges. When the polycarbonate aged (we leave them out all the time) from UV, they became brittle. A pinecone went right through one. I used a heat gun to remove the old Eternabond so I could get the old sheets off, and applied new Eternabond around the replacement (1/8") sheets.

Cherokee also used Eternabond to seal the place where the slideout flange (extreme outer edge) sealed to the slideout sides and top. They had screwed the flange in with round-head Robertson screws; should have used oven-head. After over a decade, the Eternabond had flowed around the screws and a few heads were poking through the vinyl. In this case, I simply cleaned the Eternabond in place and put a second layer over the first.

Just this summer I put Eternabond around all the roof openings and across the EPDM-metal transitions at front and rear roof ends.

[ChrisParise]

Originally Posted by ArkRVHog

Sorry...not following what you're saying. Applying the new Dicor to existing Dicor has to add "some" thickness unless it somehow melds down into the existing old Dicor product...which I doubt it does. I do understand that it might not add that much additional thickness due to the self-leveling but it will be some more. And a thicker amount of Dicor to scrape off if the original begins to peel up from my roof. Plus my latest product I'll use is brushed on now...no need to spread it with a tool.

You don't need to scrape off existing Dicor, another misconception.

Unless your roof is seriously damaged and you must remove it to reattach your roof decking, if you remove original factory applied self leveling lap sealant you are going to expose factory installed screws and flashing nooks and crannies which the Dicor fills to keep your unit waterproof.

Self leveling Dicor lap sealant will fill voids, gaps, and cracks and will not add any more depth, probably less, than any other non self leveling product. Unless a competing self leveling lap sealant is applied to existing lap sealant, the depth will always be greater with a non self leveling product no matter how carefully you apply it.

What is the product you are brushing on? Sounds messy and what kind of cleanup is involved? Does it have the same elastomeric properties of Dicor self leveling lap sealant? Are the factories using it?




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[Jake733]

I had some weather wear issues on our FR Surveyor about 2 yrs ago when it was 3 yrs old.The anchor points where our fixed ladder is fixed to the rear wall were showing signs of detachment and the sealant under the round flanges where they screw into the wall were parting and cracking. An obvious point of entry for water. I'd seen a posting on youtube by an experienced RVer. who extols the virtues of using Sikaflex, saying that it's a far superior product to Dicor, lasts infinitely longer. and is a much better price I repaired the points where the ladder anchors to the wall with white Sikaflex under the flanges then re-screwing them down. To date I have to say that that repair work holds up as new; no cracking or separation. Looks just as the day I did the job. Those anchor points can flex quite a bit with the strain of weight on the ladder, but as yet nothing's moved at all, and I've been up and down onto the roof quite a bit. I see that Sikaflex also make a self-leveling version. I'm going to give that a try when the Dicor on the roof starts to crack. Has anyone used that?

[Palinduff]

Originally Posted by ArkRVHog

So what would you use to clean the Dicor before laying down the Eternabond tape?

I asked a tech what he used to clean the dicor and he used Windex because it evaporated pretty good.

I inspect my roof twice or more yearly and usually find some thinning dicor.

I’ll clean that up and reseal that, or recover all the dicor at that spot.

I also wash my roof with rubber roof cleaner every year.

After working in the RV industry for four years, I’ve seen the damage done and the huge loss in value of water intrusion.

[mlmay12]

Originally Posted by 1100mike

I used denatured alcohol to clean everything before taping with Eternabond. It's been a couple years and still looks like I just did it..

X2 but Eternabond does make a spray cleaner for this. Eternabond Tape is great stuff, mine has been on for 3+ years and looks like the day I laid it down.

[JPageMD]

Dicor advises clean with Dicor roof cleaner, then wipe with denatured alcohol. When dry just apply Dicor lap sealant right over any suspect cracks etc. If the existing Dicor is coming up remove it. Just did it a week ago, feel pretty good about it. It didn't add any future work in scraping, I only added atop the existing dicor as needed.

[benchmarks]

Stop wasting your time reading these posts. Just tear it off and re-roof OR use the Eternabond. bahabaha! Stay away from the sealants, there just a regular maintenance issue.

[BriaBeck]

Originally Posted by Ken-m

If you start putting lexel on your roof you will be sorry.

Why?


If you're posting this idiom because you simply don't know anything about Lexel and you're afraid to try it yourself, then you're not doing anybody any favors... just spreading unwarranted fear.


If you have a valid reason, why did you not post it?

[ChrisParise]

Originally Posted by BriaBeck

Why?


If you're posting this idiom because you simply don't know anything about Lexel and you're afraid to try it yourself, then you're not doing anybody any favors... just spreading unwarranted fear.


If you have a valid reason, why did you not post it?

Trying to find out about Lexel. It seems it's more of a exterior door and window caulk. Is that correct?

I think this is the manufacturers website please correct me if I'm wrong.

They don't explicitly say it's for campers and rubber roofs are not listed as where to use.



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[BriaBeck]

Yes, that's the website. Sashco is the manufacturer. I think it is more properly defined as a sealant, rather than a caulk. But that's just semantics.


I've used Lexel for several years now. It sticks to almost anything. I've even put it places where there was silicone previously, and it sticks, even though Sashco says it isn't recommended. It stays flexible. It doesn't crack. It doesnt' seem to degrade over time, at least not very much, quite unlike Dicor products. You apply it just like a caulk, and I think if you applied it on a horizontal surface, it does have some limited self leveling properties, although not like the Dicor self leveling sealant.

Get yourself a tube of it, and do some experiments with it. I think it is a game changer.

[BriaBeck]

Lexel Tech Data sheet.

[BriaBeck]

I came across this video on YT today... the gentleman is an RV repairman. He talks about using Lexel and Sikaflex on RV's including on the roof.



https://youtu.be/iAxAqalfcZ8

[ArkRVHog]

As the OP, I thought I'd start out by buying a couple of tubes (to use with a caulk gun) of Lexel for my vertical seams on the RV...using especially over areas where my full body paint has cracked to try to seal and stop it from cracking any more.

After cleaning the intended area with 409 and letting it dry, I then masked the area on both sides with the blue "painter's tape" to keep my caulk from getting smeared on the unit. I applied a reasonable bead and then attempted to use both a caulk trim device and my finger to smooth it like I have many times with silicone caulk. The Lexel seemed to get very "tacky" very quickly and was hard to create a nice smooth vertical joint and a real challenge in cleaning off any excess.

I phoned Sashco/Lexel technical support who admitted it was hard to work with and said that using soapy water on your finger helps to keep the product from adhering to it and the smoothing process. They also shared that any tape you mask with needs to be pulled up immediately after the application/smoothing process or you'll end up messing up your caulk bead. My experience says that will still be a challenge.

IMPORTANT UPDATE: Also on this recent customer service call, the very knowledgeable rep shared that applying over DICOR was NOT a compatible substance to the LEXEL and that it might crack it and make it turn yellowish! (The first Sashco rep I spoke with said the Dicor application would be fine.)

So based on some poster's thoughts, I'm going back to cleaning my existing Dicor and then will apply a minimal amount over it to fill/hid the tiny cracks that it has developed and hope that holds me for a few more years and no leaks. And maybe I'll try to use the Eternabond tape as a test around some small roof vents and compare how that works out.

But now I'm wondering what's the best product for those VERTICAL seams on my fiberglass walls that is EASY to work with for a nice looking caulk job!

Thanks for all of the insightful dialog on this maintenance issue!

[BriaBeck]

I've had good luck with smoothing a bead of Lexel by first applying the bead, then spraying the bead with Windex or Sprayway glass cleaner, and then smoothing the bead with a finger.

[BriaBeck]

I asked Sashco directly through their website about Lexel being compatible with TPO or EPDM... here is the response I just received:

Hi Brian,
Both Lexel and Through the Roof are not compatible with TPO. TPO is made with EDPM rubber and resin. The solvents in Lexel and Through the Roof will warp and over time deteriorate the TPO.

Let me know if you have any additional questions.

Thank you!

Megan Avila
Customer Service Rep
800-767-5656 | Office
www.sashco.com

So, don't use Lexel on TPO or EPDM rubber roof.

[ChrisParise]

Originally Posted by ArkRVHog

As the OP, I thought I'd start out by buying a couple of tubes (to use with a caulk gun) of Lexel for my vertical seams on the RV...using especially over areas where my full body paint has cracked to try to seal and stop it from cracking any more.

After cleaning the intended area with 409 and letting it dry, I then masked the area on both sides with the blue "painter's tape" to keep my caulk from getting smeared on the unit. I applied a reasonable bead and then attempted to use both a caulk trim device and my finger to smooth it like I have many times with silicone caulk. The Lexel seemed to get very "tacky" very quickly and was hard to create a nice smooth vertical joint and a real challenge in cleaning off any excess.

I phoned Sashco/Lexel technical support who admitted it was hard to work with and said that using soapy water on your finger helps to keep the product from adhering to it and the smoothing process. They also shared that any tape you mask with needs to be pulled up immediately after the application/smoothing process or you'll end up messing up your caulk bead. My experience says that will still be a challenge.

IMPORTANT UPDATE: Also on this recent customer service call, the very knowledgeable rep shared that applying over DICOR was NOT a compatible substance to the LEXEL and that it might crack it and make it turn yellowish! (The first Sashco rep I spoke with said the Dicor application would be fine.)

So based on some poster's thoughts, I'm going back to cleaning my existing Dicor and then will apply a minimal amount over it to fill/hid the tiny cracks that it has developed and hope that holds me for a few more years and no leaks. And maybe I'll try to use the Eternabond tape as a test around some small roof vents and compare how that works out.

But now I'm wondering what's the best product for those VERTICAL seams on my fiberglass walls that is EASY to work with for a nice looking caulk job!

Thanks for all of the insightful dialog on this maintenance issue!

Thanks for your experimentation and results.

I've been using Proflex RV exclusively on vertical seams for 15 years. My dealer uses it in the shop too.

Use a finger wet with a heavy concentration of Dawn dish soap and water to smooth the bead. I cut the tip of the caulk tube very small and push the caulk in vs pulling it in.. And I only apply a 6 - 10" bead at a time releasing the gun trigger a couple inches before stopping which creates a thiner tapered end - then I smooth out what I've applied.

Repeat this until done.

A bit of the Dawn and water mixture does not hurt the end joints of caulk when you join them together.

Proflex stays workable for a few minutes but the workability only applies to pressing down on a lump not smoothing a second time.

Drawback of Proflex after a few years it does get hard but not so hard you can't remove it in a string. It also gets dirty and I use mineral spirits to take off the grime. I'd say 5 years then I redo it.

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[ChrisParise]

Originally Posted by BriaBeck

I asked Sashco directly through their website about Lexel being compatible with TPO or EPDM... here is the response I just received:





So, don't use Lexel on TPO or EPDM rubber roof.

Thanks for the research!

I'll be sticking with Dicor self leveling lap sealant for touchups. Any touchups I've done show no sign of degradation after a few years.

Sikaflex - my dealer used it on my roof when they installed my T4 Inmotion Satellite Dome. That was in 2019 and the Sikaflex looks bright white as the day they put it down.and it must be self leveling cause it's flat as a pancake. I've never asked my shop if Sikaflex can be applied ovee Dicor self leveling lap sealant but even if it can I'd prefer to keep the two separate. The Sikaflex is impressive looking.

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[Larry-NC]

Originally Posted by ChrisParise

Trying to find out about Lexel. It seems it's more of a exterior door and window caulk. Is that correct?

I think this is the manufacturers website please correct me if I'm wrong.

They don't explicitly say it's for campers and rubber roofs are not listed as where to use.

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They explicitly say it's NOT for rubber roofs.

Here's an explicit quote from their tech datasheet:

• Will not adhere to or is incompatible with
Aquaseal®*, cultured marble, Kynar®*,
polypropylene, polystyrene foam insulation,
polyethylene, rubber, silicone, styrofoam (it
dissolves it), vulcanized rubber, waxes

[ChrisParise]

Originally Posted by Larry-NC

They explicitly say it's NOT for rubber roofs.



Here's an explicit quote from their tech datasheet:

Thanks for confirming, I won't be using it on my epdm roof. Sticking with Dicor self leveling lap sealant for any touchups

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