Thread: Radiator Soldering Repair

That should do the job. However that appears to be hard solder(?) You want soft solder - that is all that is used on radiators (the same as used for wiring). Lead-based is best.

Just remember that:
1. The radiator should be clean (and wire brushed)
2. Use plenty of flux
3. The radiator is THIN - be careful with the heat...

I was part way through repairing a RRC rad using a large screwdriver heated in a campfire when a kind soul turned up with small blow torch like you have posted...

Once again, thanks for your help. I did see it, or another solder in the shop, was labelled as "soft" and wondered what that was about. And I have a few spare radiators to practise on.

And I never thought about carrying a little blowtorch in the bush but it would actually be quite handy!

My radiators are now aluminium so no use to me but "back in the old days" I would always travel with an old soldering iron (big hunk of pointy copper on one end of a steel rod and a wooden handle at the other end) and propane gas torch. If you are not an old hand with soldering then good idea of yours to have a go on some old ones first.

First sheet metal work project at school as I remember was to cut out a kitchen scoop, bend and solder the bits together, good practice for radiator work.

That's a good point. In all these years, I never have learned to solder. I might get some sheet metal and do that as well.

There was an episode of 'Bush Mechanics' where they fixed a holed radiator by finding a battery and a hubcap (both within a few feet of where they'd broken down), tipping the battery acid over the radiator as flux, then breaking up the battery, melting the lead in the hubcap over a nice little mulga campfire, and pouring the lead over the leak. I thought this was standard practice around the Crossing!

Yes, I saw that one. It would be worth trying, too! I wonder what you'd use instead of a hubcap these days?

Wheel weights instead of hub caps...

I carry a little Weller Portasol kit with blow torch/heat gun/soldering iron tips, solder and phosphoric flux, also good for loosening nuts and bolts, particularly nylocs on propshafts that have started rounding off.

I knocked a hole in my radiator while doing my timing belt.... I fixed it using the two part putty that you mash together.... 6 months later still works a treat definitely the easiest fix I have ever done!