Petrol tank repair

[Aussie]

Cleaned a Saladin petrol tank (LHR) and discovered half a dozen pin holes (under the hydraulic oil tank so I guess rusted from outside in, rather than the reverse). I have a POR-15 kit to clean, derust and reseal the inside, and the kit includes a patch for holes but I'm a bit wary of relying on that. So, my plan was to fill the holes with solder then perhaps solder a plate over the area. The affected area is around 3" across.

However while someone told me to use silver solder, a plumber told me today that silver solder isn't for steel and that I should use normal solder. What should I use?

Or, would it be better to MIG weld a patch on? And if I go with welding, could I also plug the pin holes with that, or would I just blow bigger holes in the tank? (You can see I'm not an expert with either welding or soldering!)

Whatever I do, I'll put the POR-15 patch on top of it.

Thanks, James.

[Richard Farrant]

However while someone told me to use silver solder, a plumber told me today that silver solder isn't for steel and that I should use normal solder. What should I use?

.

 

Hi James,

you can use silver solder on steel, for more info, check this out ;

http://www.cupalloys.co.uk/best_practice/

[Hoseman]

Hi James,

you can use silver solder on steel, for more info, check this out ;

http://www.cupalloys.co.uk/best_practice/[/QUOT

Silver solder is ok on steel and other metals, even dissimilar ones.

I have used it even on hydraulic fittings, good pressure ratings.

Secret is cleanliness, clean and flux the area well!

Don't mig it as it will open a can of worms, steel will be a lot thinner inside and you WILL blow holes in it.

No professional tank repairer near you, even just to advise? I have a good one here that does tank and radiator/cooler repairs, a lot do both!

Where in Vic are you? My brother in law is a hydraulics engineer there, lives in Geelong area, he will know the local repairers and can reccomend!

Edited August 27, 2013 by Hoseman

[Savarus]

Agreed, don't try to MIG it unless you're hot-hot-hot on your welding; IE coded. Tanks of any kind are jobs for pros as the welding has to be flawless, especially if it has to pass a ministry inspection. As a professional welding engineer of nearly 17 years I still wince when someone asks me to repair a tank... even then I tackle it with gas, never a MIG plant.

 

Can't honestly say much about the suitability of silver solder on a tank but yes, it does adhere to Steel just fine.

Hoseman's point about cleanliness is the key. It's all in the prep.

 

Good luck with the repair!

[Aussie]

Thanks so much for your replies guys. MIG is out, and having looked at the (great) web site suggested by Richard, I've decided that I should practise on something a bit less important than a petrol tank, rather than thinking "how hard could it be?". Needs to be a safe job so have handed it on to a tank repairer to solder and test for me. Your replies have most likely averted a disaster! James