OK, I just spent 2 hours googling because I didn't want to annoy youse guys by asking too many questions. There is way too much info out there and I don't know who to believe. I trust you guys.I have about 10 unused screw holes in my roof, and another dozen holding down some old but useful tech. I want to plug the unused ones and seal the useful ones.On another thread, DrewE said, 'epoxy mixed with a filler of some sort,' for the unused ones. So I was trying to figure out what filler. Hoo boy.For the useful ones, should I remove the screws, scrape out the old caulk, and replace the screws, bedding in dicor? 551?

do we have to check back in prior posts to relearn what the top is made of?amateur epoxying looks like, well amateur epoxying.bumpy

Bumpyroad wrote:do we have to check back in prior posts to relearn what the top is made of?amateur epoxying looks like, well amateur epoxying.bumpyFiberglass

If it is fiberglass I would go to the auto parts store and get some fiberglass fabric and the resin and hardener and use that to patch, cut small squares of the fabric just larger than the holes, sand off the paint in the repair area, re-glass is then sand and prime to seal it.

Thanks Chris, that does sound more waterproof than filling. Lot of work, tho! There is gelcoat under the paint. Do I need to sand that off, too?

The commonly available 5 minute or 1 hour epoxies are not really waterproof.I'd say for just a few screw holes use JB weld. Epoxy must be painted over, it is not UV resistant.Sometimes paint does not like to stick to epoxy, sand it and wipe it to remove any blush or shiny spots.I use a lot of 2 part epoxy, of the type for laminating surfboards. To thicken this epoxy I use wood flour, which is basically sanding dust I collect in my belt sander from a 120 grit belt.It turns the epoxy into various shades of brown depending on the wood the dust was colected from. One needs a lot more dust thean they would expect to use until the epoxy is about a peanut butter consistency. There are dozens of thixotropic agents one can add to epoxy to thicken it up, but wood flour/dust is free and more than effective enough for this task.One other possibility is mixing the epoxy, then waiting on it to start thickening, and then once gooey and thicker, mush it into the holes with a straight edge, but this can get messy with stringy epoxy leaving hairs from cup and straight edge. One also needs to saturate the fibers with unthickened epoxy first.If there is paint in the screw holes, I'd want that paint out of there first

Filling screw holes in roof | Good Sam Community

MrWizard
Moderator
Aug 23, 2017
Naio
di you ever get your new vent & fan installed
Bill_Satellite
Explorer II
Aug 08, 2017
Naio wrote:
Maybe I am wrong, but I am just uncomfortable with anything involving putting screws back in the holes. It just seems like a bunch of spiral pathways for water to get in!

It is not. Since there is Dicor in the hole and a bit on top, the threads of the screw become wrapped in caulk as it is screwed in. I have removed screws that I had installed years earlier and they still looked like the day I screwed them in. There is no way for water to get past the head of the screw with the caulk under the head and over the top and the threads themselves are also wrapped in caulk. Heck, look at all the roof vents and similar things on your roof. They are all screwed down and don't leak.
suprz
Explorer
Aug 08, 2017
Naio wrote:
Ok, added waterproof JB weld to my amazon order. Shockingly cheap!

Course I guess a tube of dicorbis 5x the amount for 2x the price ;). Anyway, I am happy to have a plan.

Thanks very much, all of you. I was not happy to find all these holes in my roof, but I now have hope of not getting wet :)

Good suggestions on the JB weld ( the stuff is amazing) and the 3m sealant. Just to be a bit more sure, use Eternabond tape over that stuff too. Water is the killer of RV's
Naio
Explorer II
Aug 08, 2017
Ok, added waterproof JB weld to my amazon order. Shockingly cheap!

Course I guess a tube of dicorbis 5x the amount for 2x the price ;). Anyway, I am happy to have a plan.

Thanks very much, all of you. I was not happy to find all these holes in my roof, but I now have hope of not getting wet :)
landyacht318
Explorer
Aug 08, 2017
3m 5200 is certainly good stuff, but people seem to think it is unable to be removed once applied. This is far from true. I;ve used a lot of it and removed a lot of it. Compared to regular caulk it is more difficult, but by no means impossible, adn in reality not all that difficult. Backing a potted screw out of it, is simple, once one gets access to the screw head. Couple seconds with a wire wheel and a dental pic.

I think Naio's best option it the waterproof JB weld. Do your best to mix it properly, ratio wise, and completely and perhaps get a Q tip and some DNalcohol inside the threads.
Naio
Explorer II
Aug 08, 2017
Maybe I am wrong, but I am just uncomfortable with anything involving putting screws back in the holes. It just seems like a bunch of spiral pathways for water to get in!
dons2346
Explorer
Aug 08, 2017
I would get stainless steel screws one size larger than the holes, fill the holes with 3M 5200, insert the screws and then cover the screw heads with Dicor after the 5200 has set.

Just make sure you don't want to use those holes again.
coolmom42
Explorer II
Aug 08, 2017
MrWizard wrote:
JB Weld
has a water proof expoxy putty, i have used on a variety of things
including a leaky A/C on my first class A, that leaked water in the rain
it is so water proof, it cures in the rain or under water

it would be my goto for those screw holes
clean both inside outside and in the hole
roll up a little like playing with 'clay'
push it in the hole , and squish it on both sides in and out
mushroom style like a rivet
once its dry (24 hrs ?) paint it or seal it with anything you like

JB water weld
i try to keep a tube on hand, great for leaky water lines
just turn off the water pressure for a few hours, to let it set up

I was about to suggest this stuff. It's amazing. And given that it's on the roof, I wouldn't be overly concerned about appearance.
Bill_Satellite
Explorer II
Aug 07, 2017
Naio wrote:
OK, I just spent 2 hours googling because I didn't want to annoy youse guys by asking too many questions. There is way too much info out there and I don't know who to believe. I trust you guys.

I have about 10 unused screw holes in my roof, and another dozen holding down some old but useful tech. I want to plug the unused ones and seal the useful ones.

On another thread, DrewE said, 'epoxy mixed with a filler of some sort,' for the unused ones. So I was trying to figure out what filler. Hoo boy.

For the useful ones, should I remove the screws, scrape out the old caulk, and replace the screws, bedding in dicor? 551?

Get some Dicor caulk and squeeze a bit into the hole and let a bit ooze out onto the roof. Now, screw in a screw of the appropriate size or even a tad bigger. Caulk over the top of this and you have a nicely sealed hole that will last for many years. Check the caulk every couple of years and add a bit more if necessary.
MrWizard
Moderator
Aug 07, 2017
JB Weld
has a water proof expoxy putty, i have used on a variety of things
including a leaky A/C on my first class A, that leaked water in the rain
it is so water proof, it cures in the rain or under water

it would be my goto for those screw holes
clean both inside outside and in the hole
roll up a little like playing with 'clay'
push it in the hole , and squish it on both sides in and out
mushroom style like a rivet
once its dry (24 hrs ?) paint it or seal it with anything you like

JB water weld
i try to keep a tube on hand, great for leaky water lines
just turn off the water pressure for a few hours, to let it set up