Soldering a tractor radiator (disaster story)

Sorry to hear this sad story. Since radiator shops do such repairs for peanuts, comparatively speaking, I do not even consider any DIY radiator repairs. Once I had a very broken radiator (off of a cummins L 4 2 3 D engine) that the radiator shop fixed in a day for $45.
i

A radiator shop will probably 'dip' it for you, or maybe a machine shop with a hot-tank.
A high melting temp solder can't be that hard to find- maybe some 'lead free' for one and 'lead' solder for the other?
We just don't give up here- but hey, you knew that when you posted... ;)
Dave

Hi folks,
Some of you may remember that about a year ago you gave me some advice
about repairing a leak in my Fordson Super Major tractor radiator. It's
a long story, but I only just got round to having a go.
The filler cap isn't on top of the radiator. It's on the end of a
horizontal pipe about six inches long which protrudes from the back of
the radiator. Where the horizontal pipe is joined to the radiator there
was a leak on the underside. It had been badly repaired by dumping lots
of soft solder on the joint in the past.
I drained the radiator, took it out and laid it flat on the workbench. I
put some wet rags around the top of the tubes to protect them from the
heat. I used a medium sized burner on my Sievert propane torch, and
began to gently heat the joint. I applied some Fry's "Powerflo" flux
with a brush. The solder started to melt, and I flicked it off with the
brush.
All very well and good, but there was a lot of solder there. I kept
flicking it off. The gap got larger. After a minute or so it looked like
I'd cleaned it all out, so I started wiggling the pipe. I wanted to
disassemble the joint, as it was filthy. It wouldn't come out. More
heat, more wiggling. At this point disaster struck. I hadn't realised
that the pipe was in fact made from two pieces of pressed brass sheet
soldered together. The melting point of this solder must have been the
same, as it popped open along the side seams.
I switched off the torch and starting thinking about what to do next. At
this point I noticed that the pool of excess solder on the bench had
turned into the shape of Pac-Man, who appeared to be laughing at me. You
can see the solder Pac-Man here:

Pac-Man, you cheeky blob, I am going get revenge for this!
I looked at the joint for the few minutes. I noticed something which I
had not seen earlier. There were two rivets under the grime on the top
surface of the radiator holding the joint together, which was why it
wouldn't come apart. I should have seen those earlier. I should probably
also have figured out, from having visited a car radiator factory in the
past, that these things are soldered in ovens when they are ultra clean,
not with a propane torch in a shed.
I gave the joint a good clean with a wire brush, held it all together
with some G-cramps, and had a go at soldering it back together. It
wouldn't work. The gap was too large (well over 1/16") and most of the
solder fell inside the radiator. That which didn't was only wetting the
metal in patches, despite an abundance of flux. Perhaps the gap was
bigger than it should have been. Maybe this explained the cracked solder
and the leak, or maybe it happened while I was wiggling the pipe.
At this point I gave up. I guess I could have drilled out the rivets and
taken the joint apart to clean it, but it was filthy and looked like an
impossible job to get it back together.
I wish I had seen the rivets beforehand. I guess the moral is that you
need to clean and inspect a job really throughly, and avoid making
assumptions. As one of my schoolteachers used to say, assume makes an
ASS out of U and ME. Even if you don't often screw up, it's still
annoying when you do. Perhaps even more annoying. We live and learn, I
guess.
On the plus side, I didn't ruin a good radiator. It was a fairly crappy
radiator anyway. And it was interesting to see that the wet rags kept
the tube and manifold joints cool enough to keep them from melting
(perhaps they are also made with a higher melting point solder). To be
honest, I'm not sure I would have been able to fix the joint even if I'd
seen the rivets first. There was such a heavy layer of grease and oxides
on the metal.
So it looks like I'm going to have to buy a new radiator. Damn. Or I
could look for a second hand one, but I'm not sure second hand radiators
are worth the effort. Any thoughts?
Radiators are clearly not easy to fix :-(.
Best wishes,
Chris

I had this idea. Hadn't had the idea of holding the sheet in place with rivets or the screws, though. I have some copper sheet, but it's not thick enough to fill the gap in one go. The gap is over 1/16" wide.
I am doubtful that the repair is possible without two different solders which melt at different temperatures. It's also riveted together and rather dirty.
My gut reaction is that even though I really don't want to buy a new radiator (fortunately they are available, but how good they are I don't know), this one probably isn't worth the effort of trying to fix, especially when I don't know how long it's going to last
Probably I will keep the cowl and give the radiator to the neighbour's grandson for scrap. Someone will be pleased with it that way :-).
Chris

I asked around, but couldn't find anyone locally. Everyone just said chuck it and buy a new one. Maybe radiator shops are an American thing?
At least I tried :-).
Chris

Possibly a US thing, but if you can find one they sure save a lot of hassles. I had a radiator on an old backhoe with several leaks, etc. that I took to a local radiator shop. They returned it repaired, pressure tested and spotlessly re-blacked in a day for like $80. Come to think of it, I believe that $80 also covered the hydraulic oil cooler too. Having the right skills, tools and materials makes all the difference.

I'll go and look at it again tomorrow. If it looks any better than I expect, I might have another go.
Chris

I think this is easier than you think it is
1. clean joint well. use files, sandpaper, wire brush, whatever you can to get it clean 2. clean an area about 1/2 inch around it also - get it really really clean. And on the tube too 3. tin the areas you just cleaned - use lots of flux, get a nice layer of solder on all the cleaned surfaces 4. make an L shape out of copper and heat it red hot, let it cool (anneals it), wrap it around the joint where the tube joins the radiator 5. remove it and tin it inside and out 6. put it back and pull it tight, heat and solder the L, at both edges 7. finsh off any open seams on the tube 8. drink warm beer and celibrate... ** Posted from **

Note: "clean" means "looks like virgin metal and has nothing oily at all on it". I have had minutes-old fingerprints fail to tin at times like this -- I do all my cleaning/soldering wearing disposable rubber gloves. If I can I use fine sandpaper to make absolutely sure that I've gotten through all the oxide and crud, and I tin _soon_.

Others have pretty well covered the basics. Don't give up yet. A piece of copper wire formed into a ring can bridge the gap around the pipe. Do not use 60/40 or 63/37 solder if you can help it. Radiator shops generally would only use these for tinning the surfaces. The 63/37 goes directly from solid to liquid and the 60/40 is almost the same. If you get some 50/50 or 40/60 it will have a pasty or mushy state that is easier to control. Warm up the entire area but do not try to melt all the solder at once. Using a soldering iron (or copper) is easiest but a little practice with a small torch will enable you to solder a small part of the area without the rest coming unsoldered. It just takes a little practice to get the hang of it.
(One of my current projects is repairing the severely broken, welded, reinforced, and rebroken frame rails on a 1962 Super Major with Ford 712 Loader and 723 backhoe.)
Don Young

I'm with Iggy. If you can find the suitable repair shop, they can do this easily, cheaply, and well.
As an aside, there has been a periodic listing for a full set of radiator shop tools and tanks for a very reasonable price in the local craigslist. The non repairable aluminum radiators in the late model vehicles must be taking a toll. :(
Christ>> Sorry to hear this sad story. Since radiator shops do such repairs

What Tim said. But the flux must be ACID. My local weld shop has some proprietary formula stuff that works great but good old HCl has merit.
Tim Wescott wrote:

good catch - I didn't think of mentioning ACID flux - I've had good luck with the paste stuff sold for soldering copper pipes - it's a little easier to work with (well, a LOT easier to work with) than liquid HCL, and with a wire brush (by hand) and some heat it will clean up a solder joint nicely for resoldering.
** Posted from **

And if you have it, use an oxy/ace torch instead of propane. Set it for a gentle, bushy oxidizing flame. I've successfully disassembled, rodded and reassembled two radiators. I tried propane and I found that the heat was too low and not nearly as controllable as oxy/ace.

I repaired the radiator on my Farmall with epoxy; didn't even remove the radiator, did it all in place. Big ugly blob of epoxy, still holding years later ;)
Free men own guns - www(dot)geocities(dot)com/CapitolHill/5357/ ** Posted from **

Caterpillar used to, perhaps still does, make an epoxy kit specifically for repairing radiators. Used one to fix a D-6 out in the jungle and it worked for the rest of the year and was still going strong when we sold off the plant at the end of the contract.
Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)

and concentrated. With regular plumbing solder, silver bearing or not, I can easily bridge a 1/8 inch gap. Bigger too. Not my skill but the way solder melts. The solder doesn't transmit heat as well as brass. So the trick is to use concentrated heat that gets a small area hot fast. Remove the torch and apply the solder. Just keep repeating. As the solder gets thicker it gets easier. Be careful to apply just enough heat to melt a small area. And if the solder starts to look kind of mushy over a larger area remove the heat and let it cool down a bit. Eric

If you were in Perth, West Oz I would recommend AAA Radiators, they put a new core in mt Patrol radiator for $230, new radiator $500+. My youngest sons Super Major also has a radiator leak, repair is on the round tuit list after his project Gemini gets its beefed up rear axle & diff so it does not break every time he goes to the drags. Only 230 kW at the wheels, single turbo Isuzu 2 litre as against 800+ kW on the drift racer he built for work demo. Stock Gen 3 5.8 litre V8 with twin turbos, intercooler at front, radiator in boot/trunk.

Annealed copper water pipe is easy to flare with a hammer and anvil. Once the flare is almost perpendicular to the pipe you hammer the pipe straight down to finish the end into a flat, even flange that could be soldered to the tank.