Sealing Screws in roof / solar panel prep

[A.Smith]

I saw it somewhere .
Suggestions for re- installing screws before the solar panel gets installed.
3m 4200 ? Dicor lap cement ?

Denatured Alcohol is not available in Oragnge County, Ca. Suesstions for alternative solvent for prep before adhesive or sealant ?

Thanks
Fred
A.Smith

 

[fish more]

Use rubbing alcohol and 3M 4200

 

[Vic Harder]

+1 for 3m 4200. I've also used brake cleaning spray to clean the area

 

[Beach]

Same as above but i used toluene for a solvent. squeeze a small amount into the hole. not just a dab on the surface.

 

[ntsqd]

I go for broke and use 5200. I have not experienced the horror stories that others tell of in using it and am unrepentant in continuing to use it.

 

[ri-f]

Sikaflex with acetone for prep and cleanup. i've used it in place of 3M 4200 and 3M 5200 on boats, in harsh environments, for years. It won't crack under stress or extreme heat. It takes a few days to fully cure, but worth the wait.

 

[A.Smith]

Sikaflex with acetone for prep and cleanup. i've used it in place of 3M 4200 and 3M 5200 on boats, in harsh environments, for years. It won't crack under stress or extreme heat. It takes a few days to fully cure, but worth the wait.

Seems there are a few different Siksflex products, which one is your preferred ?
Thanks,
Fred
A.Smith

 

[ri-f]

Seems there are a few different Siksflex products, which one is your preferred ?
Thanks,
Fred
A.Smith

Fred,
There are quite a few numbers in their lineup. In the marine world, Sikaflex 291 is a very popular, all around sealant and available at most marine supply stores and of course on Amazon, etc. The RV crowd seems to like Sikaflex 221 and also Sikaflex 715, specifically for RV roofs. I'd probably choose 291 or 715. Read the descriptions on those two and see what seems like a good fit for you. If all else fails and you get tired of reading specs, you can't go far wrong with 291. It works abovedecks on ocean-going boats in really harsh realms. There is nothing a truck camper will be exposed to that will be more destructive than what an ocean cruiser deals with, both in the Tropics and in the high latitudes.

Sikaflex 291: https://usa.sika.com/content/dam/dms/us01/2/ipd-pds-sikaflex291-us.pdf
Sikaflex 715: https://usa.sika.com/content/dam/dms/us01/d/sikaflex-715.pdf
Sikaflex 221: https://usa.sika.com/content/dam/dms/us01/f/ipd-pds-sikaflex221-us.pdf

Best,
Rich.

 

[BFH4N]

Acetone is my preferred cleaner for such jobs.

 

[A.Smith]

Thanks to all. Oh I hope I am doing this right. The previous owners found a sale on Silicon, and bedded the screws and covered the washers and screw heads with liberal amounts. It is amazing I have not had leaks before, but then it does not rain in Southern California.

I am slowly removing all traces of the silicon from the roof top. I am sitting on a sheet of plywood to disperse my weight and as a flat work space. I am replacing the screws and washers with new stainles. I am coating the screw threads with 3m 4200,and making a small mound, then placing nylon and metal washers atop the mound of 4200. Then placing and tightening the screw, making sure sealant flows out from under the washers. Then when the screw is snug, I create a covering of washer and screw head with more 4200.

The only solvents available are paint thinner and acetone. 4200 does not like rubbing alcohol. I clean the silicon off with paint thinner and vigorous rubbing. Then I wipe the area with acetone, wait till dry then apply the 4200.

Any suggestions are welcomed.

Fred
A.Smith

 

[ri-f]

I am coating the screw threads with 3m 4200,and making a small mound, then placing nylon and metal washers atop the mound of 4200. Then placing and tightening the screw, making sure sealant flows out from under the washers. Then when the screw is snug, I create a covering of washer and screw head with more 4200.

Any suggestions are welcomed.

Fred
A.Smith

Don't over tighten the screws until after the 4200 sets up a bit, you'll wind up removing more than you put down if you over tighten right away.. After it set up some, then tighten them down. You really shouldn't need to overcoat the screws on the second round if you do the initial step properly.

Good luck.
Rich

 

[A.Smith]

Don't over tighten the screws until after the 4200 sets up a bit, you'll wind up removing more than you put down if you over tighten right away.. After it set up some, then tighten them down. You really shouldn't need to overcoat the screws on the second round if you do the initial step properly.

Good luck.
Rich

Thanks Rich, I will modify my techniques.

Oh the Adventures
Fred

 

[ntsqd]

Auto body shops have a product that is specific for removing silicone. It probably won't do much for the globules, but it should help with the trace bits left behind. If you have a real auto parts store that also mixes automotive paint or an automotive paint supplier in your area you might go see what they've got.

 

[kmcintyre]

Not to highjack this thread but how often does everyone re-seal their roof screws? On my 2001 Eagle, I did it around 2012 and have no issues. I can't remember what product I used, could have been Sikaflex.

The thought of having to clean all those screw heads off seems a bit overwhelming.

I put some on the threads, etc. Let it setup and put a dab/mound/dollop on top of each screw head. Looks like a polka dot up there but it doesn't leak!

 

[ntsqd]

I re-sealed the Phoenix when it started leaking around the vent. Hasn't leaked on those screws since.