Does The Replacement Rubber Grommet for RV Gray Water Tanks # F02-2105 Require Sealant

Question:

Hello, I installed the 1.5inch gray tank grommet into a polyethylene tank. I cut out a 2.5inch hole and the grommet feels loose after it was placed. I can easily spin it around within the hole. My question is should it be this loose? Do these grommets require silicone?....because this 2.5inch hole is obviously too large and water will leak thru. Thanks for any help you can offer.

asked by: Steven T

Expert Reply:

Hey Steven,

The tube portion of the Replacement Rubber Grommet for RV Gray Water Tanks # F02-2105 is 2-1/4" and the lips stick out 3/8". If you cut the hole to 2-1/2" you've got a 1/4" gap from the inner tube portion to the edge of the hole in the tank, which is a bit more than I'd personally like for a grommet that's supposed to hold water. Like an 1/8" of space should be enough to get the grommet in place and form a tighter seal.

This is intended to be used without sealants as the weight of the water pressing against it should help seal the lip to the inside of the tank but with yours being so loose it wouldn't hurt to use some silicone around the outside of the lip as a backup and prevent it from moving around.

expert reply by: Kevin C