DIY Rack Mount Seal?

[Silent Neuroman]

Searching did not give me good info, so here is the question.

I am working on a DIY roof rack that has basic spacers holding up 3x3 Aluminum angle which are through bolted to the factory mount positions. I noticed the factory rail bolts use rubberized washers and the rails have rubberized seals along the edges. These look to provide defense against water intrusion.

Does anyone know if the factory mount insets open to the interior and need seals as described above to prevent leaks on the interior?

Do I need to get busy with butyl tape to keep water off my headliner?

Thanks
S

 

[jdam]

The third party modular aluminum extrusion rack that I have (looks like all the others) have spacers that they ask you seal with silicone, both in the tube/spacer area and around it. I haven't had any leaks yet using that method, but I did reuse the rubberized washers along the top to try and help as well.

 

[URJ150L]

Giant blob of RTV on each hole with spacer placed on top of it is how I did it

 

[r2m]

Generous amounts of silicone.

 

[Silent Neuroman]

Generous amounts of silicone.

The suggestions for RTV must mean that it will leak to the interior if it is not sealed in some way.

S.

 

[jakemccurdy]

Id go RTV. No, its not sealed. Thats why there was a factory gasket. I used silicone on the first one and changed my mind after thinking RTV would hold up to vibration better. When I removed the silicone, it took the paint off : /

 

[URJ150L]

Id go RTV. No, its not sealed. Thats why there was a factory gasket. I used silicone on the first one and changed my mind after thinking RTV would hold up to vibration better. When I removed the silicone, it took the paint off : /

This. The removal of the factory rails reveals gaskets. They’re sticky and tear upon removal of the rails.

 

[r2m]

The suggestions for RTV must mean that it will leak to the interior if it is not sealed in some way.

S.

When I first had my rack mounted, it was on a little crooked and it leaked. Took it back to YotaMasters (who put it on) and they straightened it and silicon everything. Never leaked again!

 

[Banandalorian]

I used butyl tape and silicone on all the mounting bolts for my roof rack. It might be overkill, but I'd rather just do them at initial install then take the whole rack and headliner apart chasing down a leak later.

 

[Silent Neuroman]

Butyl has always been my preference, but I have the additional challenge in this being a DIY rack and it is going through iterations. So what is better for multiple reinstalls? Super sticky butyl or hardened RTV?

S.