8 replies to this topic

[Monty_Jon]

I’ve acquired a nice alloy fuel tank for my bantam, but it has a small crack on the underside next to a weld (aprox 15mm long)

Is there an easy fix for this, or does it need to be re-welded?

[petwar]

Monty_Jon, on 11 January 2011 - 08:08 PM, said:

I’ve acquired a nice alloy fuel tank for my bantam, but it has a small crack on the underside next to a weld (aprox 15mm long)

Is there an easy fix for this, or does it need to be re-welded?

you could use metal epoxy. You can buy it from most car spares shops and halfrauds ect. Ive used it to repair allsorts even crank cases.

[ormplus]

better getting it tig welded.

[TrialsRfun]

I would get it welded, drain the fuel, remove the tank, remove top, taps, everything, then hold the tank filler top up to a car exhaust while it is running either petrol or diesel will do.
The tank will warm up quite quickly, hold it there for several minutes it will then be totally safe to weld/ have welded. tell the welder what you have done to the tank.

[HAM2]

Look for the product name Durafix?Aluminium soldering.
It's like brazing but for Aluminium,I referred to it before on this forum....somewhere?
There's a video on Youtube where the guy solders up a punctured aluminium coke can.

[Monty_Jon]

HAM2, on 11 January 2011 - 09:45 PM, said:

Look for the product name Durafix?Aluminium soldering.
It's like brazing but for Aluminium,I referred to it before on this forum....somewhere?
There's a video on Youtube where the guy solders up a punctured aluminium coke can.

Just had a look on youtube, that Durafix looks pretty good stuff!

I’ll have to remember to get the petrol out first

[1oldbanjo]

Monty_Jon, on 11 January 2011 - 10:19 PM, said:

Just had a look on youtube, that Durafix looks pretty good stuff!

I’ll have to remember to get the petrol out first

It should not be a problem to get your tank safe to weld - the tanks are small and do not have any baffles in them. Dump out the gas, then rinse the tank out with a detergent and flush with water. Then let the tank air out or sit in the sun. Just prior to taking a torch to the tank blow some compressed air to flush out any vapors.

The aluminim repair products are very particular about the metal being clean or it won't stick. Also the repair is not very good at filling gaps - but do fine on cracks or splits.

[alan]

I have played around with durafix type products without too much sucess. I think your best approach would be to recess the split slightly and fill the recess with the filler rod after thorough cleaning. Note all the videos show horizontal repairs where the filler rod is puddled in. if you try anything vertical the filler runs away!

I would also be looking to see why the tank split in the first place. Is it mounted properly ? My experience with durafix type products is that it tends to crack especially if subject to vibration.

my recommendation would be to have it tig welded, if the durafix type stuff doesn't work i think you willl struggle to tig weld it afterwards.

Edited by alan, 13 January 2011 - 08:15 AM.

[Monty_Jon]

alan, on 12 January 2011 - 06:11 PM, said:

I have played around with durafix type products without too much sucess. I think your best approach would be to recess the split slightly and fill the recess with the filler rod after thorough cleaning. Note all the videos show horizontal repairs were the filler rod is puddled in. if you try anything vertical the filler runs away!

I would also be looking to see why the tank split in the first place. Is it mounted properly ? My experience with durafix type products is that it tends to crack especially if subject to vibration.

my recommendation would be to have it tig welded, if the durafix type stuff doesn't work i think you willl struggle to tig weld it afterwards.

Yep, I think you are right. I will try a couple of local fabricators tomorrow see if I can get it done

It’s split because it was incorrectly mounted, it’s a new tank but someone has been heavy handed with it!