Sealing oil tank

[Sakura]

A10 oil tanks are known to split along the seams, I've seen it a couple of times. Anybody had experience of sealing an oil tank with petrol tank sealer? Obviously inlet and outlet plus breather tower need sealing. Tank is thoroughly clean although there may be some residual in the seams.

[CheeserBeezer]

I wouldn't go down that route. I'd braze it.

[limeyrob]

Agreed, braze or mig.  Braze should be a bit more forgiving.  Its cracked because its stressed and moving so a sealer won't work, you have to mechanically join the two parts.

[Sakura]

I've gas welded them previously.  Mig is hard and more susceptible to cracking again and once brazed you can't go back to welding.  I think you might have a point over sealer. It goes hard and would probably crack with vibration,  although it doesnt seem to affect petrol tanks? Oh well, just a thought.

[CheeserBeezer]

I've brazed a couple, successfully. Pressure test by closing the holes and fitting a petrol pipe to the breather and blowing into it whilst painting the seams with soap solution. It shouldn't crack again if properly rubber mounted. The problem is that many people don't fit the rubbers and sleeves properly. This page might be useful......
https://sites.google.com/site/priorymagnetos/oil-tank-and-tool-box

[sean]

needs to be spotlessly cleaned of any oil as the heat will draw it out but brazing or silicon bronze mig if you know someone with a set up .

[Joolstacho]

Oooh, imagine the problems when the 'liner' breaks up (it will sooner or later). It's bad enough in the petrol tank, but the oil tank?

[limeyrob]

Yes, its a fatigue / stress failure near a bracket that has caused a crack and leak.  The crack has relieved some of the stress but caused a leak.  The crack will continue to grow.  Brazing is a good fix because its a bit flexible and the flame heat will heat treat the metal and relax the residual stress.  Once its fixed the key is to fit it with the least tension on the brackets so its worth fitting it and fettling the bracket and mounts before brazing to make sure the the tank is a good fit before its all stiffened up.

[Billybream]

My oil tanked failed at a very young age, brazing was the solution and it's proved leakage free for the last 55yrs