Should we worry about water leaks with an aftermarket roof rack?

[TheComedian]

For sealing (and gluing) things on the car i would always preffer Sikaflex -> Sikaflex®-521 UV - https://industry.sika.com/en/home/renewable-energies/wind-energy/nacelles-and-machineparts/weather-resistantsealing/sikaflex-521-uv.html
Especially with a tensile strengh of 1,8MPa you glue many things instead of drilling holes…

 

[TheComedian]

Some folks herein have suggested using silicone for sealing hardware in or near painted steel. Many silicone sealants essentially promote rust in painted steel. I found this out the hard way on my Tundra. The problem: some silicone caulks and sealers release acetic acid during curing, which can react with certain metals and cause a galvanic reaction to the sealer, or trap moisture under the sealer.

I suggest using other products besides silicone for sealing surfaces in contact with or near painted steel. I mostly use polyethylene sealers for these situations.

For sealing roof rack hardware holes in the body on my 80 and my trailer I have used:

Permathane -- a polyethylene sealer; it may be hard to find. I got it at Dixieline. Can be messy.
Loctite 565 -- is rated to specifically seal threads in hardware; I have used it on all my roof rack hardware threads.

Factory Rack Removal Options?

forum.ih8mud.com

Tons of info here:

Galvanic Reaction to Caulk | All Metals Fabrication

All Metals Fabrication has spent years developing core competencies in all types of metals including galvanic caulk. Galvanic reaction to caulk is dependent upon the type of metal used.

www.allmetalsfab.com

Silicone sealants and rust

Silicone sealants and rust

forum.w116.org

What metals does silicone corrode? | ContextResponse.com

According to Silicones: Chemistry and Corrosion, “Single part silicone sealers generally contain a cross-linking catalyst (such as a tin compound) that is activated upon exposure to moisture in the air.” When acetic acid is released, it attacks and corrodes metals such as copper, zinc, brass...

everythingwhat.com

Waterproof sealant for metal: Stops leaks in tough places

Waterproof sealant for metal – the DIYer’s choice for sealing metal surfaces. It protects against moisture and leaking even in harsh conditions.

www.loctiteproducts.com

What Type of Metal Sealant to Use for Painted Metal | DoItYourself.com

A metal sealant can help protect metal products and surfaces.

www.doityourself.com

Cheers,
Jon

Better you use 243 instead of 565.
The 565 prevents from rust but it has less tolerance to oil and do not secure the screw in position.

565 is a good for fittings where you need a direct sealant against pressure and on a roofrack its more important to secure the screw.

Both types prevent from rust and water

 

[bloc]

I shied away from the installation of the K9 roof rails for this exact reason. I wasn't comfortable with a "daub of silicone" and a stack of washers to keep water out. I'm sure that method is fine for most people and I'm sure that they've "never had anyone come back with complaints or water intrusion issues", but I felt like there had to be a better solution out there.

The approach that Rhino-Rack takes seems at least a little more methodical: foam coated copper washers and an o-ring around the bolt head going down. It may not be perfect but I felt better about it.

View attachment 2853390

Have any pictures of this oring setup?

 

[TheLCProject]

Have any pictures of this oring setup?

I'll have a video of it up at some point.

In the meantime, you can look up the install instructions for the RCP17-BK (200 series rhino rack feet kit)

 

[DadWagon]

I shied away from the installation of the K9 roof rails for this exact reason. I wasn't comfortable with a "daub of silicone" and a stack of washers to keep water out. I'm sure that method is fine for most people and I'm sure that they've "never had anyone come back with complaints or water intrusion issues", but I felt like there had to be a better solution out there.

The approach that Rhino-Rack takes seems at least a little more methodical: foam coated copper washers and an o-ring around the bolt head going down. It may not be perfect but I felt better about it.

View attachment 2853390

Did you add anything in addition to the RR washers? How's it holding up? I'm starting my install on RR goods tomorrow.

 

[TheLCProject]

I used some urethane sealant on my install on my old 100 but nothing on the 200.

I haven't noticed any water intrusion and it's been in some good rain and also washed. It's not to say that there isn't any coming in, but carpets and headliner have been dry and the interior isn't musty.

I'd add some sealant to the bolts/threads if I were to do it again.