Replaced city water SHURflo pressure relief valve fitting

[silverback]

Ours was leaking after (only?) 4 years. I found the metal version for 65 PSI is a standard SHURflo RV part so we put a new one on this morning. The original had plumbers putty around the inside plus what looks like silver silicone around the outer edge. Easy enough to find the plumbers putty but does anyone now what I should use around the outer edge where the fitting meets the trailer skin? I'd like to use the same silver stuff. I guess I could use regular clear silicone too. I want to make sure water doesn't get in between the walls (again) from the outside elements. Like me washing the trailer.
Thanks,
Ken

[ts8501]

Also known as Vulkem, but the link is here.

[wayner61]

Hi Ken -

Silicone and aluminum don't mix. It will never stick well enough to keep the water out. I would guess it is either Acryl-R or Sika Flex. Sika Flex is a caulk that you can get in a lot of places. The gray color is what Airstream uses. Acryl-R is meant to fill much smaller gaps. It is what A/S uses typically as a seam sealer. The bead can be very small. The only place I know to get it is either from an A/S dealer or from the A/S store. It is in the maintenance product section.

Hope that helps.

[silverback]

Thanks guys. I will get some.
-Ken