Alu rad seeking God

[Pc Plum]

Ok, so its not getting religious on me. Its just slightly holy

I have a new (second hand) rad for the Supra and it has a tiny pin hole in one of the tubes. Looks like something has been forced into the rad and flattened a tube slightly, causing a tiny hole.

I've ordered some aluminium soldering rods (Bernzomatic Alu soldering rods), but I'm a bit apprehensive about overheating the delicate tube and melting the whole lot.

Anyone any experience of this?? Is fluxing advisable?? Are there temperature indicator crayons available?

I'm slightly peed off as this rad was supposed to be perfect condition from a 30K mile car! I'll be getting my money back whatever happens!

 

[weldequip]

I think you'll find that by the time the Bernzomatic rods have got up to temperature the rad will have collapsed (especially if using MAPP Gas/Propane on it's own without oxygen). Is there not radiator sealant stuff that you pour in to seal leaks, or is that only a temporary cure?
weldequip

 

[Drains]

I presume the rad is made from copper, so get an old fashioned soldering iron, a big 'un, and solder it up with lead solder.

 

[Drains]

Woops, sorry, my mistake, wasn't paying attention. It's an ally rad. I'll shut up

 

[Hitch]

I never mess around with radiators, take it out and take it to your nearest rad specialist. They work mirracles on them!

 

[weldequip]

I supply a local company who specialise in restoring radiators, particulary for classics - ALVIS etc. They use a lot of silver solder & copper phosphorus brazing alloys.
weldequip

 

[Pc Plum]

Thanks weldequip. It probably will go breasts vertical, but if it does I've not lost anything Maybe I'll look for a lower temp alu solder rod though. The Bernzomatic ones melt at 350 deg C I think. There are ones that flow at just under 200 but are mostly tin.

If it all goes wrong I'll get the old brass one out and silver solder the header tank that's leaking on that one!

 

[weldequip]

You can get precise temperature crayons but it's finding a dealer that stocks them - they are a tenner a piece & there's scores of temperature ranges & applications so I don't even bother!
weldequip

 

[Lippyp]

JB Weld would probably fix it, it seems to fix most things!

 

[aero]

JD weld!! On a rad!!!! Wash your mouth out!

A rad specilist is the way I'd go. Simple, no hassle and with a guarantee.

If you insisst on messing about with it yourself (oh-er matron ) rub some soap around the area ( ..... ), when it goes black ( ) you'll have a pool of ally where once a bit of radiator was. Yes a caustic flux is recommended. But you really should pay a visit to your local radiator people as it sounds like you have no experience doing this sort of thing

 

[bump]

Never use the Rad Weld temporary fix stuff, as it collects in the water galleries in the head and is a real pain to get rid of. The only way I've found is take the head off and hand clean it.

 

[Pc Plum]

JB Weld would probably fix it, it seems to fix most things!

That's whats on the rad thats in the car at the moment. It lasted for three months then split again (mind you it was on the plastic header tank, and it doesn't bond well to plastic).

I've found some aluminium solder paste. Its solder dust/filings in a flux. Just dab a blob on & head it up and it flows and fluxes at the right temperatures. May get some of this. https://store.sra-solder.com/product.php?xProd=6141&xSec=21

 

[Pc Plum]

Never use the Rad Weld temporary fix stuff, as it collects in the water galleries in the head and is a real pain to get rid of. The only way I've found is take the head off and hand clean it.

Never would! I don't want my heater blocked again. Luckily last time it was in a mini so it only took 20 mins to remove & clean it out.

 

[malcolm]

I've used Easyweld on aluminium sheets (similar to the 400 degrees solder, and that works quite well. Although the first couple of times I tried it I melted the aluminium a bit.

I think it helps with that stuff to have the heat conducting away making it easier to control the heat. Wonder whether the thin fins on a radiator might melt off before the core gets hot enough - nothing to conduct the heat out of those fins.

Interested to know how you get on if you do try it.

 

[Pc Plum]

I think I'll place some shielding plates over the fins and just leave the tube exposed. The hole is only a pin prick if that, so hopefully just flowing some solder over it will sort it for good. The tubes are deep, so should conduct well keeping the temperature manageable. I'll let you know how it works out with pics if possible.

 

[Pc Plum]

Got it done tonight. Took approx 10 mins and was dead easy.

Lay the rad flat & use a stainless wire brush to clean up the damaged area. Hit it with the Bernzomatic TS7000 running on MAPP and slowly heat the area (I didn't bother covering up the fins, a couple of burnt ones doesn't bother me too much). Took about 20 seconds heating it up gently and testing with the solder rod to get the rod to start to flow. Rub again with the stainless brush, dab the solder on and a bit (2 seconds) of steady heat and it was done.

It seems the cleaning with the wire brush while heating is vital in getting getting the oxide off and ensuring a good flow & bond.

Really pleased with the result even if a few fins are a bit burned. Scrap rad converted back to fully functional item

Now looking for other alu/alloy things to repair! I have a compressor housing from my Supra hybrid turbo that needs some repair where the compressor wheel has rubbed the alu away.

 

[Pc Plum]

But you really should pay a visit to your local radiator people as it sounds like you have no experience doing this sort of thing

I have lots of experience melting and even burning metals, with varying degrees of success Seriously I wouldn't attempt it if I didn't think I could do it.

TBH its so easy anyone could do it.

 

[aero]

Well bleathering on here and get on with it man!

 

[Pc Plum]

Well bleathering on here and get on with it man!

'Tis already done my friend. Lovely job