Sealing Screws

[shortgmanp]

I have alot of screws to seal. I am having a hard time deciding on the best way to do that. I am not sure weather to butyl tape the holes or something else. How about some expert ideas. Thanks Greg

[madjack]

...first I predrill all screwholes...if I use a sealant caulk, I squirt a dab into each hole before the screw goes in...if I use butyl tape, I just insert the screw thru the butyl tape and fasten it down.....
madjack

[shortgmanp]

I have used butyl tape on most seams on the camper. I guess the compresion of the butyl seals up the screw. I just wasn't sure if i should pull those screws out and put some clear silicone down in the hole or something. Love to read your postings madjack. I appreciate the education. People who have experience in things (such as teardrops) have been crucial in my not making too many mistake yet. Thanks Greg

[48Rob]

Greg,

Butyl tape is a good sealer, and does a nice job most of the time, for a period of time.

On rough uneven surfaces such as are found on some trailer skin patterns, more than 1 layer is needed to fill the gaps.
Over time, butyl tape can/will dry somewhat, causing it to shrink.
Uusually this occurs along the exposed edges, and around the screw threads, as there are the areas that absorb the most heat and have the most exposure to the air.

Once the tape dries and shrinks slightly, the screw heads are no longer tight against the trim or mounting flange, and water can get under the screw head.
Since the tape has also shrunk around the screw threads, water now finds its way into the wood framing via the screw threads.

If you prevent the butyl tape from drying, you can prevent a lot of damage.
After trimming off the excess tape that squeezes out after install, apply a thin bead of sealant over the butyl between the body and trim.
This will prevent air from reaching the butyl.

I also inject sealant into each screw hole, as added insurance, since the screws can also allow water in over time after becoming loose from road travel.
I've had better luck installing the screws, then removing a few at a time, injecting sealer in the hole, then re installing the screw, than simply placing a dab in the screw hole in the trim and then running the screw in.
The latter method doesn't allow enough sealer to completely fill the hole to give full protection.
The idea is that sealer fills the screw threads all the way to the bottom, also making full contact with the wood, all the way to the bottom, and the little bit of excess that squeezes out at the top forms a gasket that allows a little movement while preventing moisture intrusion.

Rob

[ajricher]

Re: Sealants:

If you want to use a like sealer, butyl is available in a liquid caulk form. I found it at my local Ace labeled as gutter caulk.

In hindsight I should not have used it under the edging on my TTT rebuild as the stuff was just such a monumental pain in the posterior to work with, but it did do the trick.

WHen putting in screws I did two things (thios was on the roof, where a leak would be a Very Bad Thing). I predrilled the hole, added caulk, then put in the screw, then put a covering of caulk over the screw head, smoothed and feathered with a finger dipped in kerosene.

Paranoid, me? Most certianly, after all the work I put into that verdammt trailer.

Alan

[planovet]

...first I predrill all screwholes...if I use a sealant caulk, I squirt a dab into each hole before the screw goes in...if I use butyl tape, I just insert the screw thru the butyl tape and fasten it down.....
madjack

That's what I did. The butyl tape may shrink some but you will carry some of it into the hole while you are screwing it in. Is it enough by itself? Time will tell.

[b.bodemer]

I'll second that.

Any exposed screws got a dab of silicone!

Barb

[Arne]

i caulk item, put screws half way in, and put a dab of caulk at the bottom of the screw head, then put screw all the way in and wipe off extra..

[Mightydog]

i caulk item, put screws half way in, and put a dab of caulk at the bottom of the screw head, then put screw all the way in and wipe off extra..

+1

Works like a champ!