Sealant for Aftermarket Roof Rack?

sharky

New member
Just received my Victory 4x4 roof rack and trying to understand what the best way is to seal the mounting holes to prevent water intrusion. Their instructions were to use a generous amount of black RTV around and in the factory mounting holes. I was planning on going this route, but wondered if there was a cleaner alternative to seal it?

Watching and reading other roof rack install videos seems that the norm is RTV, but the reason I am hesitant with glooping RTV everywhere is because I read that:
  • it's a pain to clean if you want to remove it
  • it needs to eventually be reapplied because of the constant exposure to the sun
  • filling the mounting hole with silicon sounds like a pain to deal with if I wanted to go a different route later on
Found this great post where it was suggested to use butyl tape and silicone washers, which I am leaning towards.

Any insight is appreciated. Also, recommendations on thread sealing for the bolts... thought of pipe dope or teflon tape, but sounds like blue loc-tite would work?
 
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I used a small amount of silicone sealant, and sourced some rubber washers in addition. If you look at how the roof rack mounts and the holes, the real risk is water in the rain channels going in between the plastic bolt guides and the roof, not down through the nut and bolt threads.




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Roof rack that do not require sealant

I am aware that there are a few racks on the market that do not depend on silcone, butyl, RTV, or any other offensive, goopy, sticky, messy stuff.

I know ARB and Sherpa rack are designed in this way with OEM style rubber seals.

Are there any other racks that I could add to my list?
 
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None that I've seen and I've read a lot on the subject. And the Sherpa racks are on sale 12% off for the next two days, so a good deal.

I am aware that there are a few racks on the market that do not depend on silcone, butyl, RTV, or any other offensive, goopy, sticky, messy stuff.

I know ARB and Sherpa rack are designed in this way with OEM style rubber seals.

Are there any other racks that I could add to my list?
 
Silicone caulks that release acetic acid during the curing would potentially be corrosive to the metal roof or rack. Butyl caulk does not release it.
 
There was a recent Roof rack thread where a guy used silicone and over time it contracted and allowed water penetration... his roof had rust holes and was trashed. A member posted that through his extensive research found that butyl rubber sealant, like what is used to affix windshields, is best as it does not contract. Just an FYI. You might search out that thread.
 
Here's lots of info.

Non Drill roof rack (no silicone)

I'm building my own spacers for the roof rack to sit on with a combination of 3/4" thick plexiglass (making a big ol rectangular block and drilling 2 holes into it), butyl rubber, and a sheet of 1/8" high temp silicone (Red Silicone Rubber Sheet Roll High Temperature Thick Commercial Grade 8" x 8" x 0.12": Amazon.ca: Tools & Home Improvement)

I'm using cutting some silicone sheet to size to sit between the roof itself and the spacer -i.e. I made a silicone gasket which also helps protect the spacer from damaging the paint on the roof. Butyl on both sides of the silicone to be super safe -not a lot but enough to squeeze and fill into any spaces or gaps. I'm also adding a silicone gasket on top of the spacer where the roof rack bracket sits on top of the spacer (it's hard surface on hard surface so it's not water tight).

Lots of ways to skin this cat.
 
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My Prinsu rack should be here in couple of days and this I'm planning to do the following from bottom up:
Butyl tape around the factory white washers/holes
Silicone Rubber Sealing Washer McCaster 99604A123
SS Washer
Silicone
Prinsu Washer
Silicone
Rack.

Not planning on putting any silicone in the holes of the roof but will be wrapping the bolts in blue monster pfte tape. Hopefully this will do it.
 
Here is what I did with my Gobi rack. Used Butyl tape. So far it has been 8 months with no leak with heavy rain here in South Fl. Very happy with the outcome
 

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Make informed choices when deciding what to use when sealing roof rack mounts.

Destroyed Factory Roof Mounting Locations

This is a bad reference though. The OP later explained how the damage in the initial post happened.

He never once inspected the seals after putting the rack up. This happened more than 5 years after installing the rack. He linexed the roof up to the seams of the rack. He kept it outside in Hawaii for 5+ years, and had annual periods of up to 6 months at a time where it was never moved.

I'm installing my full length victory 4x4 rack today and plan on using the black RTV as they recommend. My 4runner stays garaged in the PNW and serves as my daily driver to and from the garage at work when not out on weekend trips.

For those that fear water intrusion despite following the installation guidelines, maybe you should reconsider the necessity of an after market rack.
 
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