Fuel tank hole

[Postman]

 Greetings from Finland!

My tank is leaking! There was an old repair with plastic padding or something. When my K100 was in garage there was a smell of fuel and left side under the tank was wet.

What is the best choice? Chemical metal vs. welding?

I removed fuel pump and filter. You can see a hole under the fuel pump.

There was lot of grab in the tank. Plastic, aluminium and old fuel hose[emoji2]

Lähetetty minun SM-G800F laitteesta Tapatalkilla

[Chaos]

I used 2 part Permatex epoxy made for such repairs and it has held up well over the years.  Not sure what is available over there where you are. Welding would probably be a better option but more hassle and expense.

[Inge K.]

The short piece of fuel hose could be the one that's between the fuel pump bracket and the sidewall of the tank.
It's should be cut open along it's full length. You should have two of this, front and rear end of the bracket.

[Postman]

Ok. Thanks for replies! I need to ask welding tomorrow. It is good to know that extra hose inside the tank is not left over. Maybe there was only one hose but i have to check it..



Lähetetty minun SM-T560 laitteesta Tapatalkilla

[Postman]

I didn't find other hose in the tank. Inge can You explain some more where this rubber hose should be? I didn't see it when I took fuel pump off.


There is nothing about this hose in Haynes or repair manual???

[Inge K.]

At a closer look at the piece of hose in the picture isn't cut open lengthwise, so then it's not from the
fuel pump bracket.
Maybe it was intended to be between the metal tube and the fuel filter and some PO dropped it into the
tank......and just cutting a new piece instead of search after the one in the bottom of the tank.
(it seems to have the correct length for this....and if the inside dia. is 8 mm).

[Postman]

I'm quite sure there should be only one hose between wall and bracket. There is a shape for hose in the front of the bracket. You can see it when zooming the photo. I put hose back its place and now it is somewhere under the bracket and wall. I can't take it off so it can stay there.

I got some chemical metal from local bike builder. He said it is hard to weld because  thickness of aluminium.

And there was one month que in local aluminium welding company.

Hope this works!

Lähetetty minun SM-G800F laitteesta Tapatalkilla

[Vespa no more]

I have a tank with a leak in it
I have bought some JB Weld
But then I saw this and have some rods on order from China



Has anyone tried this? How does it hold up to pressure and general wear and tear.
If I'm not mistaken, the K tank is not pressurized - it is the fuel line (pulled into the fuel pump, then pressurized through the filter and onto the injectors and back to tank through fuel regulator).


Had a win with my daughter's Rover 75. Fixed broken injectors by replacing with ones from wreckers yard (s'pose tip here is to identify the expensive injector (eg $475 each) and work out other applications that might be significantly cheaper (eg 3 for $40)), then more bloody fuel leaks... turned out to be o-rings not seated right. Now the car goes fine. Time to sell it before British engineering cases more angst.

Guy

[Laitch]

Has anyone tried this?

It is possible to weld an aluminum tank with holes in it depending upon the extent of the corrosion surrounding the holes. These and other aluminum tanks have been welded successfully.

The demonstrator's successful technique with that soda can comes both from years of experience and also from using a clean, uncorroded surface on which to make the repair. Finding the uncorroded portion of a deteriorated fuel tank and building from it is the challenge. The surface must be cleaned of corrosion. A hole might be small to start but it could be several times its original size by the time a stable place is found on the surface to start the weld. Heat will burn through aluminum panel and/or distort the whole surface of the base material if it is concentrated in one area for too long a time. Speed is critical; safety awareness is critical.

If the cans are made of aluminum, a few cases of Illawarra could provide refreshing practice material but welding on a partially corroded, thin sheet would be particularly beneficial for experience.

[bmwpyro]

adding to what Laitch said. it has to be clean. freshly scrubbed.


and just for safety sake, it bears repeating, tank needs to have no gas, vapors or fumes. if you can smell it. then don't weld it. (unless you have a cold  :yes )
and since the tank is aluminum, you will needs lots of heat or it wont be hot enough to braze properly. suggest a oxy acetalene or at bare minimum, a oxy mapp torch.
i used muggy . SA5. pricey , works good. the nice thing with muggy is their flux will indicate to you when its hot enough.
i don't know if they are diff from the ones from china. lots of videos on how to use...

good luck!

[Martin]

I bought some aluminium solder rods, but I didn't have much success. I tried a couple of gas's Oxy Acetylene worked the best, but it was very hard to gauge the heat. It was a bit like Goldilocks too little heat just made little blobs that did not stick real well, too much and it just blew holes,
and just enough heat it soldered. Unfortunately it was extremely hard keeping it in the zone, and a lot of practice would be needed. I have a couple of Son in Laws who are welders who I keep forgetting to ask about it.
Regards Martin.