Sewage Holding Tank Sealant

John S

New member
Hello all,

Was tracking down a faint sewage smell and after getting access to my tank noticed a "brown" stain coming from my 3" access hole on my sewage tank.

I want to reseal the fitting and reinstall it. Any suggestions on what would be the best type of sealant to use. I was thinking 5200, but open to suggestions.

Thanks,
 
There is no perfect sealant for a poly tank. There are plastic welding kits available if there is a crack in a tank. I have also successfully "repaired" poly tanks with glass cloth, roughing up with 36 grit sandpaper and epoxy. The best epoxy to use would be the G Flex by West Systems.

5200 may or may not work--it is one of the best sealants, but does not hold as well to poly ethylene or poly propylene tanks. If this just is a plastic access hatch, and is put in with a sealant, often Boat life "life seal" is what is usually used.

Of course C Dory used the ubiquitous "Bostic" sealant on anything which moved or screwed for one period...
 
thataway":1a7r8zvq said:
There is no perfect sealant for a poly tank. There are plastic welding kits available if there is a crack in a tank. I have also successfully "repaired" poly tanks with glass cloth, roughing up with 36 grit sandpaper and epoxy. The best epoxy to use would be the G Flex by West Systems.

5200 may or may not work--it is one of the best sealants, but does not hold as well to poly ethylene or poly propylene tanks. If this just is a plastic access hatch, and is put in with a sealant, often Boat life "life seal" is what is usually used.

Of course C Dory used the ubiquitous "Bostic" sealant on anything which moved or screwed for one period...

Hi Bob,
Thanks for the reply, It is a poly tank, but I don't have a crack.
I just need to seal a screw in plug fitting.


Any thoughts on the best sealant for that? to use on the threads?

Thanks again,
 
If it is a plug, which screws into a spun in threaded fitting (welded into the tank) then the Teflon tape. If it is a plastic ring which has 6 to 8 screws into the tank, and then a plate which which screws into the ring, I would use silicon grease on the threads and "O" ring of the plate. For the screws--probably Life Caulk Life seal, and redo the screws with one size larger than current ones.
 
Back
Top