Originally Posted by Humble Leader

this is probably the best way to handle this. you could use butyl tape as well. you live in texas where you don't have very cold winters and then pretty hot summers so freeze and thaw is not a big concern. but sealant is not permanent and you should inspect annually to make sure it's holding up

my concern would always be water in that channel hanging out near the block spacer that is used and getting past the sealant

rageandlove basically has the best way to avoid this but not everyone wants a sherpa rack which is understandable. when you apply the silicone or tape don't overdo it. you don't want the spacer to be resting on a thick layer of silicone

if the SEMS screw has a removable washer then just remove it and use the EPDM washer. if the washer is fixed to the screw you can still use an EPDM. EPDM will help stop vibration due to the rubber component so you don't need to have an anti vibration or lock washer on top of the EPDM one

I would like to make one edit: EPDM washers are only effective when used correctly. over or under tightening will result in poor waterproofing. the washer is convex and needs to be tightened until completely flat, no more, no less. this may conflict with torque specs

Originally Posted by LeesWagon

Thanks for your help bud. i got the 3M stuff on order, along with some bonded washers from McMaster-Carr. hopefully should have everything arriving Sunday for the install!

Originally Posted by Humble Leader

which rack did you get? I have been thinking of a rack system. I like LFD because of how clean it looks and installs. I don't have any plans for a roof top tent so weight is not an issue (just 2 pelican boxes). anything steel though my concern is rust up here in Canada

Originally Posted by LeesWagon

I got the LFD 3/4 rack. Looks like it is about 3-4" shorter than my tent, but should be ok.

If rust is an issue they do offer stainless steel versions of their racks. They also have a forum discount if you mention it when ordering.

Originally Posted by Humble Leader

oh nice, I was looking at the LFD cross bars. was going to pickup a couple of them in stainless