waste tank

[Johngould]

I am working on the rear floor and waste tank in our 1967 airstream over lander. the waste tank is white and I used a black car epoxy to seal some cracks and it worked well. I thought the original tank was black??

John

[AnnArborBob]

No. The term "black" refers to the kind of water that goes in there (e.g., black water vs. grey water.) Most Airstream holding tanks are a white plastic be they designated as "black tanks" or "grey tanks."

[cwf]

Neighbor's brother across the street from me just had his cracked 'black'/white tank 'plastic welded'.. seems to be the way to go...

good luck with the Epoxy.. it doesn't seem to flex as well as a loaded tank... and could peel away from the plastic tank material... hope I am wrong...

[AnnArborBob]

Personally, if I was going through the trouble and expense of restoring/repairing an old Airstream and had access to the tanks, I would replace them. They've given fifty years of service, why take a chance?

[airdreamers]

If the decision is to repair the tank, I have used JB Weld, great product! Flows to seal 100%. If major leaks etc, I agree with AnnArborBob. Dedending on the renovation and access to the tank, replacement is definitely an option while you can get at the tank or tanks. Good luck been there done that!

[Protagonist]

Originally Posted by AnnArborBob

No. The term "black" refers to the kind of water that goes in there (e.g., black water vs. grey water.) Most Airstream holding tanks are a white plastic be they designated as "black tanks" or "grey tanks."

For the newcomer to RVing, the term "black water" refers to water that contains human or animal waste, including urine, feces, blood, whatever. "Gray water" is any water that is not fit to drink and does not contain human waste. "White water" is drinkable water, but that term is hardly ever used because river runners use white water to mean something different. Instead it's called "potable" water, while both black and gray water are "non-potable."

So by strict definition, if you've got a dog that piddles in the shower when he can't go outside, your gray tank would actually contain black water (animal waste) until it's emptied and rinsed. If you cut your finger and hold the injured digit under cold running water in the galley sink, your gray water tank would actually contain black water due to the presence of human blood.

[robwok]

Dang, so no more peeing in the shower?

[dbj216]

I worked in a plastic "rotomolding" shop for a number of years. This process is similar to making waffles. A hot mold, pour in plastic powder, tumble the mold over and over, and the plastic melts and sticks to the inside walls of the mold, kinda like a waffle does. Open the mold and out comes the part. It is a great process for making low volume, odd shaped hollow plastic parts, like RV waste water tanks. Inca Plastics in California is one of the original rotomolders and have made who knows how many boo coo tanks through the years. Inca invented the spin weld process by the way (my understanding).

The plastic used is typically polyethylene. This is a thermoplastic material. I comes in a natural color (white), but can be mixed or blended with dyes for black, gray, red, what have you.

The polyethylene is "weld-able". You can repair leaks and cracks by heating the affected area to about 350 degrees and then heat a polyethylene "stick" and puddle the two together. Like welding steel, but much lower temps. Polyethylene melts at about 400 F.

I am not aware of any epoxies or adhesives that will stick to polyethylene. It has to be remelted to repair. Your tank may be some other type of plastic, or maybe even fiberglass (usually earlier trailers than 67.)

I note my 66 Trade Wind had what appeared to be a thermoformed tank. It looked like two pieces that had a seam around the top. See photo.

Direct replacement tanks are available from several sources.

Hope this helps some.

David

[Inland RV Center, In]

Originally Posted by Johngould

I am working on the rear floor and waste tank in our 1967 airstream over lander. the waste tank is white and I used a black car epoxy to seal some cracks and it worked well. I thought the original tank was black??

John

Epoxy does not stick to plastic very well.

You will find that the epoxy fix, will simply separate from the tank.

Fiberglass replacement tanks are available, that will out last most owners life time.

Andy