Gas tank rust holes

[PhilipDrysdale]

Hi All
I am trying to repair rust pin holes in the undersurface of my 1972 CB750 restoration. Nothing I am doing in preparation of the tank surface is allowing good attachment of the solder. I am very open to any suggestions? I think I have tried all the usual fixes and spent a lot of time on you tube.
Thanking you in advance
Philip

 

[grewth]

If it was in the UK, I'd be looking for a better tank without any serious corrosion issues.
I've no idea what the Australian spares market is like, but I've paid between £60 to £120 for solid tanks with a few dents but rubbish paintwork.
The trouble with rust holed tanks is that there are probably another fifty rust pits that are already 90% through the metal.
I'd never spend good money painting a heavily rusted tank.

 

[Loki]

Have it sandblasted then if there's anything left you'll have a better idea as to whether it's repairable or not

 

[PhilipDrysdale]

If it was in the UK, I'd be looking for a better tank without any serious corrosion issues.
I've no idea what the Australian spares market is like, but I've paid between £60 to £120 for solid tanks with a few dents but rubbish paintwork.
The trouble with rust holed tanks is that there are probably another fifty rust pits that are already 90% through the metal.
I'd never spend good money painting a heavily rusted tank.

Thankyou - probably good advice. I will check that out.

 

[hinksy]

I dont know of anyone down there besides pud , and he would outsource it anyway I think . Maybe give him a call or contact a few smash repair guys and see what they use/do . Ultimately you may have to cut out the floor and renew it

 

[grewth]

I dont know of anyone down there besides pud , and he would outsource it anyway I think . Maybe give him a call or contact a few smash repair guys and see what they use/do . Ultimately you may have to cut out the floor and renew it

Would that be worth the effort on a K type tank ?
Pattern ones are being manufactured in several different countries and the knock on effect of this is that used tanks are relatively cheap and plentiful.
Not so with the F1 and F2 tanks (they are slightly different from each other)
Nobody makes replacement copies as far as I know, so I tend to grab them if they come up for reasonable money.
Some optimistic person in Germany was demanding €700 for one that was full of filler.
Didn't sell.
What a surprise !
Meanwhile the last one I bought off eBay (£60) was rust perforated.
Can't win every time.

 

[86FJNJ]

Post some photos of where the rust holes are. You may need to cut out an area and weld in patch panels and do fiberglass and then bondo to smooth out. Or, you may be able to take it to a local radiator shop and they can coat the inside, but that process will destroy the paint and you'll need to repaint...but sounds like you may need to repaint anyway.

 

[PhilipDrysdale]

Would that be worth the effort on a K type tank ?
Pattern ones are being manufactured in several different countries and the knock on effect of this is that used tanks are relatively cheap and plentiful.
Not so with the F1 and F2 tanks (they are slightly different from each other)
Nobody makes replacement copies as far as I know, so I tend to grab them if they come up for reasonable money.
Some optimistic person in Germany was demanding €700 for one that was full of filler.
Didn't sell.
What a surprise !
Meanwhile the last one I bought off eBay (£60) was rust perforated.
Can't win every time.

Thankyou for all the suggestions. I plan on visiting Pud down in Yarram to see what they would do, but also for some other restoration challenges. Its only a few hours drive from Melbourne. The tank is with a panel beater friend at the moment - I hadnt thought of checking with a radiator repairer?