Community Forums

ArkRVHog · 10-05-2022, 02:44 PM

Here's a pic of my Dicor sealant (I assume the factory originally used Dicor) that is around my fiberglass roof intrusions such as A/C, vents, fans, antenna, etc. The tiny cracks don't appear to be deep but they are numerous at this point...my unit is going on about 5 years old and has never been re-caulked.

I will admit to smearing some silicone on the Dicor is very small amounts in some places in the past when I'd see a small hole in the caulk that worried me.

All of the Dicor is still firmly on the fiberglass surface...not peeling up...and doesn't appear in bad shape other than the surface cracking as shown.

What's my best pro-active fix on this that is a do-it-yourself project? I'm wondering if cleaning the Dicor first (with what?) and either applying wide Eternabond tape over the Dicor OR can I use a product like Lexel and sort of smear that over the top of the Dicor and not cause a negative reaction to either?

I don't want to spend hours doing something wrong so all opinions with experience are appreciated!

NV_Camper · 10-05-2022, 03:05 PM

Basically this... I've used mineral spirits instead of denatured alcohol before putting on the new, but the idea is the same. Not sure about spots you've used silicone however. Probably scrap the dicor off a bit in those areas and top with new.

https://www.youtube.com/watch?v=WStVHmP9HIk

shootist · 10-05-2022, 03:40 PM

I've taken a wire wheel to the cracks before ( makes a tremendous mess, don't do it) and found they don't go very deep. If you can't buy denatured alcohol go buy some everclear 190 proof. Same thing with out the added toxins in denatured. Scrub the stuff clean with a rough cloth and add some more divorce.

USMCRET · 10-05-2022, 05:26 PM

Be certain of the type of sealant already there. My DS has no dicor anywhere from the factory. It’s all silicone.

Dav L · 10-06-2022, 07:30 AM

Remove all that old stuff (this is the hard part), clean the base, put new Dicor above that just on the gaps, let that cure (days), reclean, put Eternabond over the whole thing. Double the protection, and will look much cleaner.

mistercee · 10-06-2022, 08:31 AM

Plastic scraper to gently remove any loose and/or compromised
Dicor.

Fantastik brand spray cleaner does a great clean-up job.

Dicor right over the cleaned area with self-leveling on horizontal areas and non-sag for any vertical.

SJ-Chris · 10-06-2022, 09:46 AM

My Class C RV that was 6 years old had a lot of dicor cracking. It has been drilled into me that water is one of the worst destroyers of RVs. And, I was planning on putting up solar and I wanted to start with a "clean canvas" so I went ahead and recoated my entire roof and dicor seals. Gives me great piece of mind and 2 years later still looks great. Total cost was ~2 gallons of roof sealant and some of Dicor's Step 1 cleaner. Was easy (and satisfying) to do. You can read about it here:

https://www.irv2.com/forums/f87/rv-r...ct-524232.html

There are some good Before and After photos of the cracked dicor.

Good luck!
Chris

153stars · 10-06-2022, 01:22 PM

It doesn't look like like sealer was silicone based.
Spray9 is a beast of cleaner to scrub off nastiness before using solvents those seem to embed the old dirt , it leaves white stuff nice and white again...its like 409 but better IMHO just harder to fin

glwinger · 10-06-2022, 05:09 PM

Quote:

Originally Posted by ArkRVHog

Here's a pic of my Dicor sealant (I assume the factory originally used Dicor) that is around my fiberglass roof intrusions such as A/C, vents, fans, antenna, etc. The tiny cracks don't appear to be deep but they are numerous at this point...my unit is going on about 5 years old and has never been re-caulked.

I will admit to smearing some silicone on the Dicor is very small amounts in some places in the past when I'd see a small hole in the caulk that worried me.

All of the Dicor is still firmly on the fiberglass surface...not peeling up...and doesn't appear in bad shape other than the surface cracking as shown.

What's my best pro-active fix on this that is a do-it-yourself project? I'm wondering if cleaning the Dicor first (with what?) and either applying wide Eternabond tape over the Dicor OR can I use a product like Lexel and sort of smear that over the top of the Dicor and not cause a negative reaction to either?

I don't want to spend hours doing something wrong so all opinions with experience are appreciated!

If you have used silicone, it needs to be removed before applying anything else. Nothing will stick to cured silicon. Not even silicone.

chindog · 10-06-2022, 07:39 PM

Ditto on removing the silicone. Scrape off any that you applied. Clean the remaining dicor with mineral spirits or denatured alcohol with a rag, and then just apply new dicor over the old. You don't need to remove it. Check all your roof sealants annually, and apply new dicor where needed.

slowlanelife · 10-06-2022, 08:32 PM

After our unit was 8 yrs old it was staring to look like your photo, maybe not quite as bad. After some research I did as some others here-cleaned with mineral spirits. That won't get it back to white but definitely helps. Then I applied the Dicor self leveling which really doesn't self level very well in my opinion. I wound up using disposable latex gloves to smooth/smear it around. It came out pretty good. I have 3 skylights, 3 roof vents, and lots of seam around the perimeter on a 32' Class C. I think I used 8-10 tubes. On Amazon you can get a better deal on multiple quantities. I think I spent 8-10 hours over 4 days. I'm glad I didn't try to do it all in one day. Take your time and be careful up there. It will give you good peace of mind when done.

bhammond1980 · 10-06-2022, 09:17 PM

I wash it with mineral spirits then scrape any loose material off. After I have the prep done, I use the self-leveling type. Attached is a pic of the final result.

fatsurf · 10-07-2022, 10:37 AM

I used my harbor freight multitool (oscillator)with a scraper blade. This tool was awesome for removal of the Dicor. Made hours of "gentile scraping into minutes of easy work. Scrap off the bulk of the old sealant then reapply.

Gary RVRoamer · 10-07-2022, 11:35 AM

Quote:

If you have used silicone, it needs to be removed before applying anything else. Nothing will stick to cured silicon. Not even silicone.

True for pure silicone, but false for most any silicone blend, e.g. silicone-latex or silicone-acrylic. How do you know what's in the tube? If it says it is paintable, it's NOT pure silicone and perfectly safe to leave in place.

Dicor lap sealant continues to shrink over time, causing the surface cracks. Those are harmless, but if unsure how deep they go, you can apply more sealant over top of them. Leaks are more likely at the edges where water can penetrate underneath.