Black Tank Repair-- It's NOT ABS. HELP!

[tireman9]

Am trying to do a repair on the black tank but it appears the tank is not ABS but some other type of plastic. How do I glue ABS to the tank?

2008 Coachmen Freelander. Dump valves not installed correctly so handles pointed down and have been broken twice by road debris. So am replacing valves & lines.

Have ABS pipe & fittings to go from tank to new valves and while removing old ABS pipe it appears the neck of the tank is NOT ABS as it doesn't melt like ABS does from heat of the saw or soften when ABS solvent glue is applied.
So now I have a real problem as I have no idea how to properly glue ABS fittings or reinforcement panel tot he side of the tank.

Coachmen did glue some ABS pipe into the tank but the glue they uses didn't fuse the tank plastic.

Ideas appreciated as it appears my only option now is a new tank assuming I can get one as I find nothing similar in size & shape from businesses selling holding tanks and there is no identifiable part number on the tank.

This job is going downhill fast. help is needed.

[huffypuff]

I can only think of hoses and clamps from Home Depot plumbing department. It would help to have picture of tank neck. Sorry

[ClayL]

It may be polyethylene which is almost impossible to glue. It can be done but requires some nasty solvent and surface preparation as I recall. Usually repairs are made by a plastic welding technique using polyethylene rod. The welding set up can be bought pretty cheaply at Harbor Freight.

EDIT: It appears that there are some ways to glue polyethylene now that didn't exist 50 years ago. Take a look at HERE

One site I looked at said the surface had to be prepared for the epoxy adhesive as follows.

"Directions for bonding polyethylene using flame treating:

1. Fit a propane torch with flame spreader.

2. Following the operating cautions of the propane torch, ignite the flame.

3. Observe the flame in a darkened room, noting the primary (bright blue) and secondary (faint yellow) portions of the flame (see drawing).

4. Adjust the flame so that the primary flame is contained within the spreader, and the secondary flame is 1-1/2" beyond the spreader (see drawing).

5. Treat the polyethylene to be bonded with the tip of the secondary flame by passing it over the polyethylene in 5 gentle strokes. Total exposure to the flame should be 2-3 seconds (.5 second per stroke.) This light exposure should not deform or melt the polyethylene in any way.

6. Test the polyethylene for bond readiness by wetting it with water. If the water runs off immediately, the treatment was not effective. If the water sheets on the surface, the surface is ready for bonding. If unsure, compare the water's action on the treated area with the untreated area.

7. Bond joints per the above directions within 1 hour after flame treating. Always prepare test bonds to be certain that flame treating is effective with your material.

[dickandlois]

This is a link to another product that will weld Polyethylene or High Density Polyethylene

http://www.tapplastics.com/product/repair_products/plastic_adhesives/tap_poly_weld_adhesive/435

This product also uses the flame treatment mentioned in Clay's post.

Have not looked around yet, but from looking at just the portion that is broken off the tank, would a swage type fitting work that would allow you to then attach the valve tree in a different orientation ?

By chance is there a plastic welding shop in your neck of the woods ?

Coaches do not do well when Off Roading ! BTDT and its difficult to fit them with skid plates.

You might look at Polypropylene Bulkhead fittings-3in.,3 1/4in and 4 1/2 in. for water and storage tanks. Trick might be getting the internal portion inside the tank and would there be enough shoulder to get a good seal ?

Kind of need a flat surface to get a good seal.

Rich.

[tireman9]

Found a 2 part epoxy from 3M #8115 that will bond with LDPE. Will look into the flame prep as extra insurance. Think I will do a test panel.

[jleamont]

Tireman9, How did you make out with the repairs?