Roof Rack Threads Messed up

You have very strong feelings towards silicone. Might I recommend professional help.

 

Thank you, I'll take it under consideration.

 

If you needed the hitch to install your rack, it probably wasnt installed right to begin with...

 

The 3M Marine Grade silicone I used to seal the top of the transom (where wood meets aluminum) on a canoe is still good as new after 8 years. And it's outside 24/7/365.

Used the same stuff for my Rhino Rack install, in addition to the included butyl pads. Silicone is not exposed.

 

Ok. I still wouldn't use it as a roof rack sealant.

 

I'll sell it in California to make up for the loss I took from the dried goop all over the roof.

 

They do seem to hold their value out here.

 

Give me the name of the therapist you find @mynameistory -- I probably have the same issues to work through.

My career in polymer science and technology for more than 40 years now, especially in coatings and adhesives, has given me a chance to work around all kinds of polymers. I'm not sure there's a class more broadly used in questionable applications than RTV silicones. People seem to think it's an adhesive, a filler, a mastic, a jack-of-all-trades where it's really not that good. Sorta like duct tape in a tube.

I'd definitely go for a butyl rubber strip-caulk (or dum dum, if you like) over silicone for a penetration in a vehicle roof.

 

I think the aftermarket rack manufacturers are mostly to blame. They should really provide correct mounting sealants and instructions with their rack kits. Instead, most of them barely include a footnote about it. When they do, they tell you to slather on whatever you can find at Home Depot. Just a shame that so many trucks will see chronic rust damage and electrical gremlins because of it.

 

I had the same problem, part of the roof metal covered up the threads and I couldn’t get a bolt in there. I took a dremel and grinded down the metal and made the opening bigger. I did not touch the threads or tap anything, just grinded down the metal

 

I just tossed on an OEM rack a few days ago and you two are really making me plan on taking it off and re-mount it using some butyl rubber. Thanks for the heads up

 

If you installed an OEM rack and used the factory supplied mounting pads and hardware, you should be okay. The mounting pads should have had a tacky, pliable rubber substrate, and the bolts/washers have a rubber layer as well.

 

Bought it used, no rubber washers. Got new hardware but used clear RTV

 

For reference, here's what the butyl pads look like. My Rhino Rack included them for every hole.

 

Ah. Go carefully, that stuff can be a real bear to chisel off.

 

Thanks everyone. Went out and bought an M6x1.00 tap and chased the threads. Everything working great!