Staining Sewer vent from sewer gas

[TheProfessor]

Hey gang-

What can be done to prevent and clean discolored aluminum around the sewer vent that seems to be related from Sewer Gas fumes. We dump regularly! but the morning dew also runs down the side of the coach carrying what ever it is along with it making Terrible Stains and streaks that nothing cleans up. We always travel with and empty black water tank.

HELP! I just re-polished it, and am cursing these new streaks, which even a good coat of canuba wax failed to guard against.

Any Suggestions deeply appreciated--

Alex 8728

[sequoiacoast]

I have the same thing happening around my oven vent. I believe it's from the "plumbers tape" (I forget the correct term) that I used to seal it. Since my husband cracked it while polishing and I am replacing it, I am only going to use Vulkem when putting the new one on.

Hope this helps (I don't think it's from gas)!

Oh yeah, and the only way I have found to clean it is to polish it again... sorry .

[Frank's Trailer Works]

you might be fighting a loosing battle... On my 62 the vents are cast metal. They are not aluminium at all, but pot metal or iron of some sort. Your vents might be the same and what you are seeing is actually corrosion from the vent itself. A good solution would be to stop polishing and enjoy the growing patina... I am joking, if you find a solution let me know...

[Melody Ranch]

My bet would be corrosion from the vent cap. When you polished it did you polish the cap (stack) too? If so, the corrosion from it (a different metal than the aluminum skin) will form, and do exactly what you describe. Pull the stack (cap) seal it with a gasket or vulkem and paint it with clear or silver....putting a barrier between the skin and its base.

[sequoiacoast]

I didn't even think abot the metal factor as all mine are plastic. Good luck!

[DoorMan]

I have this problem with a 1971 Globetrotter. It occurs only with the black tank vent. I believe it is siphoning out while under way as the pattern is always toward the back of the trailer. I always empty the tank before towing but there is always a little liquid left in it. I am going to bend a small piece of aluminum to change the air flow over the vent and see if this helps with this problem. You can polish off the stain but it is a nuisance

Herb

[overlander63]

We went through this with our '63. It was fumes from the chemicals that were the culprit in that particular case.