Using Eternabond Over Old Dicor Sealant

[pshipsey]

My leaky cabover is opening a can of worms, as expected. I'm watching videos and I see people using eternabond over old cracked sealants, such as Dicor. They remove the chipped material and tape right over it without sealing or filling in the cracks. What?! Is this OK? An associated question:
Can you put eternabond over Dicor self- leveling or no sag sealant?

Thanks in advance

 

[Kirk]

Putting anything over the top of the existing problems is just living in denial of the problems. If you have rotting that has started, putting more of anything over it will not resolve the question. You can either fix things right, or hide them and hope for the best.

 

[Gary RV_Wizard]

Can you put eternabond over Dicor self- leveling or no sag sealant?

Yes you can, but putting it over uneven or loose/peeling sealant is a waste of time and money. Good prep work is essential. First remove any loose or peeling sealant. Then smooth off any ridges or deep valleys (a hair dryer and stiff putty knife works well) and clean the area with a cloth dampened with mineral spirits. If the sealant is narrower than the width of the tape, you can bridge over it and make a good seal to the adjacent roof material. If not, you need to make the entire area smooth enough that the Eternabond can adhere well and then overlap strips until both edges reach the original roof. That seals the edges of the old caulk so that water cannot seep underneath.

And none of the above is worthwhile if the material under the old sealant is rotted. As a minimum, the edges of the tape have to cover the entire hole and reach surrounding solid roof. However, rot near always continues and eventually swallows the patch. Best to fix the rotten substrate and then tape over it.

 

[TheBar]

As Kirk said if you hide rot you will be living in denial of the problems. But if you don't have the money, skills, time, or if the RV is already living on borrowed time, do what you can to get a few more years out of it. Do treat any rotted wood you can get to without tearing things apart. A product like Minwax wood rot treatment may add a couple more years. It will soak into rotted wood and turn it into a plastic that will even hold a screw.

Do the prep as Gary said. You can put Eternabond over everything but dirt, oil, and a wide area of silicone - - you can put it over a narrow strip of silicone caulking.

You can put Eternabond over old cracked caulking and gaps if they are about 1/8" or less, but anything wider should be filled first. Like with aerosol low expansion foam. Any kind of filler (except silicone) is ok under Eternabond since it will not age further with the Eternabond over it. I would let the caulking dry first.

 

[John From Detroit]

product like Minwax wood rot treatment may add a couple more years. It will soak into rotted wood and turn it into a plastic that will even hold a screw.

I used a product called "Water putty" it's a powder you mix with very little water and mix.
First you dig out all the rotted wood.

I made a floor out of the stuff.. Rock solid but drills and cuts like wood.. WILL NOT ROT.
For assorted reason I'd not recommend it save as a last resort double for roof but man did it make a floor.

 

[RV_Lee122]

Removing sealant is easy. Get some mineral spirits, pour on a rag, then wipe the old sealant with it and use a scraper to remove. Then put on new sealant

dont put eternabond over the old sealant

 

[TheBar]

Removing sealant is easy. Get some mineral spirits, pour on a rag, then wipe the old sealant with it and use a scraper to remove. Then put on new sealant

dont put eternabond over the old sealant

Anybody can make a youtube video. That doesn't make it true. That guy probably had no idea what kind of tape it was.

That is NOT genuine Eternabond in the video. It might be a knockoff brand like FlexSeal or Dicor. Eternabond is 1/8" thick not paper thin like that. That video looks like someone painted over masking tape or duct tape.

After 12 years in full southern sun my Eternabond has never needed repairs, has never come loose, is still stretchy, and is still looks like new. I guess I need to make a video for people to believe it.

 

[Gary RV_Wizard]

Agree with TheBar - that's not Eternabond (nor Dicor Seal-tite either). And whatever it is, it was applied in a very shoddy manner. I'd ignore that video entirely.

 

[RV_Lee122]

Video was more to not put it over worn out sealant. Plus, its the sides of the overhead bunk of a class C. Eternabod will look terrible up there in plain view. Its a simple job of remove and replace. I'd reseal the entire front bunk. Top, sides and bottom.

 

[TheBar]

Video was more to not put it over worn out sealant. Plus, its the sides of the overhead bunk of a class C. Eternabod will look terrible up there in plain view. Its a simple job of remove and replace. I'd reseal the entire front bunk. Top, sides and bottom.

We are not talking a $200k RV here. It already has rot and she just needs it to survive a few more years. I put Eternabond over 17 year old cracked factory sealant. 12 years later it still looks and is as flexible as new. Eternabond looks much better than the sloppy factory caulking job. Whoever applied that just finished a 48 hour shift or a bottle of Jim Beam.

 

[pshipsey]

Yes you can, but putting it over uneven or loose/peeling sealant is a waste of time and money. Good prep work is essential. First remove any loose or peeling sealant. Then smooth off any ridges or deep valleys (a hair dryer and stiff putty knife works well) and clean the area with a cloth dampened with mineral spirits. If the sealant is narrower than the width of the tape, you can bridge over it and make a good seal to the adjacent roof material. If not, you need to make the entire area smooth enough that the Eternabond can adhere well and then overlap strips until both edges reach the original roof. That seals the edges of the old caulk so that water cannot seep underneath.

And none of the above is worthwhile if the material under the old sealant is rotted. As a minimum, the edges of the tape have to cover the entire hole and reach surrounding solid roof. However, rot near always continues and eventually swallows the patch. Best to fix the rotten substrate and then tape over it.

Agreed and thanks . I'm doing repairs in stages or I'll nvr get on the road this year.

Btw everyone, I found a great silicone remover called Acrysol. It's not cheap but it's great. No damage to exterior and does the job!
I'll post updates. My old camper is looking good!!!

 

[Gary RV_Wizard]

Acrysol is great stuff, but still not safe to use on EPDM roof material. It will surely remove whatever is stuck on top of the EPDM, but it will also penetrate the EPDM fabric and it WILL dissolve the adhesive underneath. Use sparingly, wiping with a dampened cloth and quickly removing any excess.

 

[RayIN]

Eternabond video library

 

[pshipsey]

Acrysol is great stuff, but still not safe to use on EPDM roof material. It will surely remove whatever is stuck on top of the EPDM, but it will also penetrate the EPDM fabric and it WILL dissolve the adhesive underneath. Use sparingly, wiping with a dampened cloth and quickly removing any excess.

Thanks. Thanks and good to know. So far I've only used it on the fiberglass sides where there was a lot of old silicone caulk and spray. I was planning to use it on the roof as I need to remove and replace the seal where the cabover meets the roof on the top.
Thanks for the save!

 

[Gary RV_Wizard]

You can use it, just don't slop it on the rubber roof. Damp-wet a cotton cloth with the acrysol and wipe off a layer of the gooey stuff. Repeat until the surface is clean enough for the next steps.

 

[pshipsey]

What other solvent could I use for that top piece? I've read mineral spirits? I'm thinking I don't want to go all the way down to the rubber and the trim piece that joins the roof to the cabover, but there are cracks and holes around some screws. Thanks

 

[Kirk]

You definitely want to get as much of that as possible off. If it were me, I would use mineral spirits but even then wet a cloth and don't pour it directly onto the membrane. With so many layers, it is not likely that adding more would help for very long as a loose layer under new make the new do nothing. I always began by using a plastic scraper to remove as much as possible as the first step. An RV tech that I know uses a metal scraper but his has been rounded off on the corners of the blade.

 

[rpnelson]

Naptha works good to help remove lap sealant which it looks like a lot of that is. It also works good to clean the surface you are applying eternabond tape to. I would want to remove as much of that old sealant as you can first though. Also, if there are windows, skylights or other openings near this area check them for leaks too.

 

[Gary RV_Wizard]

Naptha works good to help remove lap sealant which it looks like a lot of that is.

On an EPDM roof, Naptha is a worse choice than either mineral spirits or acrysol. Naptha is highly volatile and flammable. It's a terrific solvent, though, as is acetone and MEK. Just not wise to use over EPDM fabric.

To remove thick layers of old lap sealant, try a hair dryer to warm it up and a stiff putty knife to peel off the thick stuff. As you get down near the EPDM fabric, I suggest a plastic putty knife rather than metal. Then use mineral spirits or the acrysol on a cloth to wipe up the residue.

 

[Adventurous Traveler]

I think if the OP follows Gary's post-19 suggestions, she should be good to go with her repair.

I've used Eternabond Tape on two of my motorhomes to seal the front cap on one and the rear cap on another. Great stuff. I used a combination of carefully using a razor knife, then a plastic scraper to remove the old Dicor. I wiped the area clean with Acetone on a rag. You want to make sure you lay the tape as flat and smooth as possible without bubbles or bunched tape. I used a wallpaper roller to smooth the tape and get a great seal. The finished job looked better than the factory Dicor sealant.