Hi all , have had a spun stainless fuel tank sat in the buggy for over six months with fuel in it , I have just noticed a weep in the welded seam around one end of the tank, I really don't want to have to strip it all out and I don't suppose the rod shop would even swap it after all this time. Probably sh..e Chinese welding to blame, when I wipe it , it takes a fair while to be able to see any wet on my finger again so a minute leak. Any product anyone can suggest that may seal this, as it is on the underside and not seen  , I thought maybe empty tank , degrease the weld and brush some fibreglass resin along the weld. I have Seen various tank sealers but these are usually internal and would still mean removing tank to swirl it around the insides. Anyone had a similar problem or suggest a fix. Many thanks.

http://www.ebay.co.uk/itm/PLASTIC-PADDING-LEAK-FIX-RADIATOR-PIPE-WATER-PETROL-TANK-REPAIR-KIT-/302004634263?hash=item4650e10297:g:fxQAAOSwl8NVVLSC

Personally (just my opinion) if it is such a slow leak anything applied on the outside will work more as a patch and is unlikely to last and would work better if there was a gap to fill.
If there is an internal goop available that will withstand modern fuel then that is more likely to seal it better, but there is the risk of it detaching and clogging up the system, I have never used it. Ask  on here and maybe someone has experience of these.

The other thing is that with such a slow leak are you certain you have found the leak site, the entire weld could be porous and gravity makes it look like it is near the bottom.  Hope you are a non smoker 

My 2 cents here

Don`t use the internal tank sealant chemicals - they break down with modern fuels and have ruined the inside of my own tank inside a couple of years.

I have had good success with some of the fuel patch products sold commercially, but they aint pretty and at the end of the day, its still masking the original fault.

If a weld is suspect, then the only real way is to get someone brave enough to re-weld it - there are some out there that fill tanks with water and happy to do it, but you may have to hunt about a bit - but if it were my tank, then I would probably be googling for a welder as we speak

There are tank sealers available for modern fuels, I did the Jas tank before fitting as ethanol fuels will rot it from the inside out.

I used one of the Ethanol ones from Flatlands when I bought a brand new tank from them - worst move I ever made, and have been picking bits out ever since

Hmmm , the only way then I think is probably a new tank, will speak to the supplier and see what they have to say. Damn annoying though.

Hi.
I can get you some sealant that should work just fine. It called PR 1826. A company called kem fast  stock it. I used to use it to fix aircraft fuel leaks, most of the time on the inside but sometimes from the outside. Do a goole search on it and if you want to give it a go let me know.

Testa

I'd feel safer knowing the weld was fixed, and by that I mean buying a new tank from somewhere with proven results if you suspect its because its cheap mass production. If you can't find someone to re-do the weld.

Phoned the supplier and not a lot of help really, say's he's out of stock with no sign of any on the horizon ,... Hmmm  . Did a bit of googling and spoke to a couple of engineering friends, one of whom said a lot of people use araldite to fix rust pinholes in fuel tanks. Certainly a lot of references to this on Google, being such a tiny weep, I may give this a go before stripping it out, the tank is very thin stainless and probably not that easy to weld, especially since it has had fuel in ! My head says as many on here , welder up or a new tank but I also think if it is only a pinhole in the weld then araldite should plug it easily. 

I have had reasonable success with this stuff before

http://www.ebay.co.uk/itm/VersaChem-HEAVY-DUTY-Fuel-Tank-Repair-Kit-Petrol-Diesel-Leak-Fix-Seal-n-Place-/321814499259?hash=item4aeda38fbb:g:i6wAAOSwmrlUy~Qk