928ntslow

My process was tank removed and set upside down on a bench to get to the leaky area. Crack filed to create a nice valley for weld. Cleaned with MEK. Area heated to semi soft with air welder. Soldering iron to melt polyeth. rod and creating a bead swirling the rod and material from tank to mix together. Built area up as if scared.

Filled tank with H2O and let sit for a day. NO LEAKS. Emptied, dried out, set tank back in car, filled tank with petrol 1 day later...leaky leaky.

neilh

Picked up tank from 928intl, thanks Jim.

Now, my wife keeps complaining I don't involve her in 'my hobbies', so guess who is going to be underneath holding the tank while i bolt up!

Anyone ( local! to San Diego) need a tank to try and repair, email me, we can work something out, or i chop it up and make an interesting planter in the yard!


Neil

Bus

Just a quick note to say that I seem to be succeeding in my effort to repair the tank.

Had a common crack next to the strap nearest the transmission. Drilled out the ends, dremel'd a nice groove to weld into, then:

I tried a weld, with the right rod. Welded with my cheap hot-air welder, it failed quickly.

Rewelded with my high wattage soldering iron to get better penetration into the tank. Burned my crack into a hole, didn't hold.

Used the expensive Steinel hot-air welder at work. Got great penetration, got big hole, but filled it in. Covered the weld repair with PC11 marine epoxy for a secondary cover. Lasted three days, then failed.

Did some research, obviously most folks know that every epoxy says "wont bond to polyethylene(PE)" on it... found a 3M product that does, DP8005 http://cms.3m.com/cms/GB/en/0-131/kkrzcFW/view.jhtml

This is an acrylic,that bonds to PE. I had some test PE at work, so I bonded a few things together, and sure enough, you can get it to yield, but it does not tear at the attachment point to the PE.

Since I had a hole now instead of a crack, I had to bond a piece in from the back, then fill and sand the hole. This stuff shrinks when it cures, so it took me a couple of days to get everything cleaned up. There were a couple of other surface cracks that I dremeled out and took care of at the same time... oh, and I put a coat of "Seal All" gas and oil resistant adhesive on the inside too, just for insurance, but I don't think it needed it.

Grainger sells DP8005 for about 18 bucks a package. It's a ten to one mix ratio internally, and the 35ml package is good for the large repair that I performed. There is a special application gun, plunger and mixing nozzles that could add about 70 more bucks to that if you don't have one that you can borrow... I'm looking forward to using it in some work projects also!

Successful repair for about 10 days now... and I'm not anticipating any more trouble.

Michael

Peter F

That is good news,

thanks for the information sharing on this.
Please keep us posted on the development.

Cheers/Peter

Jim bailey - 928 International

Michael somehow the "Successful repair for about 10 days now" reminds me of the story of the fellow who fell of the top of a 50 story building and as he flew past the 44floor was heard to say "So far so good". Here in California they put the gas water heaters in the garage and in one instance a leaking gas tank burned up nearly the entire house. I really hope your repair does work because at some point in time you have to figure new gas tanks are not going to be available.

neilh

Exactly what Jim said, and thats why I bought a replacement from him rather than try a repair.

Rufus Sanders

I didn't bother to read everyone else's reply because I've done this repar and it's held or 3 years w/o a single drop or odor of fuel. I had a strap-induced crack in my fuel tank and fixed it with ..wait for it... concrete crack sealant.

PL brand Polyurethane Concrete & Masonry Sealant to be exact. It' s moisture curable polyurethane and is super tough, and flexible and resistant to solvents, being PU. it comes in a cauk gun style tube and just squeeze it into the crack, work it in with your fingers to get it through to the inside, and let it cure for about 2 days at room temp. Don't put heat to it, or it won't' cure as fast.

This works. Try it. - Ruf

Bus

Thanks Rufus! Where were you after the second or third tank r&i??

Jim, You appear to have picked up the slight scepticism in my typing? I couldn't swing a new one($950 + $52 shippping), and I worried that any used one has to eventually fail in the same manner?? (although I'm still planning on picking up a spare while it's cheap). Plus, I'd already had this one dipped and it was perfectly clean... I was determined to find a fix! I work in a darn polyurethane foam plant... with several chem engineers around I kept pestering for help too (no help though).

I understand the worries with the gas water heaters in the garage... I used to have the same thing in my house in Indiana. I would have to shut off the tank and then relight the pilot after I'd finished painting in the garage... luckily now I'm in a total electric house.... but, if one drop of fuel hits the garage floor my wife can smell it two stories up... I have to fill the lawn mower and the weed wacker outside!

Just a question... there's a place in the Midwest that makes custom polyethylene tanks... they could make a run of say a 100 pieces and you could create an aftermarket new option:
http://www.mtscompany.com/custom.htm

neilh

Anyone else need a tank to try and repair, pm me, $100 or best offer + shipping about $45 UPS surface to most of US.

Randy V

No, no. It should be:

"Aged, time-proven gas tank with a small crack, successful repair of which will increase your pride-of-ownership and convey a sense of satisfaction from your skills, and earn you extensive bragging rights within the 928 community. While that type of self-esteem cannot be purchased at any price, I will take $300 - firm, plus shipping."

neilh

LOL,
Randy, was that an offer!

Bus

Thanks Randy!

I had no idea that I had: I'll be beaming all day... unfortunately, I'll still be removing an old timing belt!