Soldering a tractor radiator

Ive repaired just this joint for a friends identical tractor.

1. you take the rad out 2. you lay it on its side. 3. you clean up all around the joint so its scraped clean. 4. you flux it with killed hcl which has all the zinc it can take dissolved in it 5. you heat with your small torch gently so you see the solder just start to flow,. then add some more flux and solder. Dont try to reflow it all around in one go. Just about a 1/4 at a time. Work all around the filler pipe,

1. sprinkle with cold water to draw all the heat. then test to see if the joint is sealed all around. this joint is badly designed as folk put strain on it when pressing down on the filler cap to unscrew it to take it off. thats what splits the seam. you can take a strip of brass and make a gussett to support this design fault.

Hope this helps. Ted Frater Dorset UK.

Soldering a radiator isn't hard, it's just one of those tricky jobs that are best approached as if you know what you're doing. I've done at least fifty, dunno how many really.

The best torch for the job is an air-acetylene unit, the old Prestolite sort. It's worth buying one just for the job if you can get it for a reasonable price, check ebay for that. No big deal if you can't get the regulator and all, just press the hose onto a welding tip on your torch and go to work. I would say second best is a cutting torch and third best being the typical propane torch.

Use an aggresive flux and a 60/40 lead solder, preferably an acid core that agrees with the other flux- if you're not sure they'll get along, just use the acid core. Don't even try it with the new plumbing solders. As has been stated, cleanliness is the trick. If you're using a cutting torch, use your smallest tip and just enough flame that it won't pop out. Get the heat in quick, get out and touch the solder to the joint and get the heat back in to flow the solder. Move quick and keep the flame away from the fins. If the solder won't flow, stop and clean better.

The Prestolite torch is just the berries, perfect combination of temperature and BTU. You can do a good job with the propane torch too, it's no big deal any way you do it.

Make sure your solder is clean. If it's old, polish it with steel wool or something that'll remove the oxide. If it's an old acid core, melt enough off the end to get to fresh core. Rinse the joint well, the permanent anti-freeze can cause problems. You really don't need to fill the radiator with water but you can if you want. Attitude is much of the job- too much hesitation can be a source of trouble.

Rinse well after you're done, a little baking soda is OK if you're concerned about the flux. Spend the time it takes to straighten the fins nicely and don't blow the crabs out of the fins with a power washer..

John

I used to build and/or rebuild expensive radiators for antique autos. The key is to use a 60/40 Eutectic solder, as Stan said. It is hard to find the right solder, unless you are buying a 15 Lb roll, so take a jar with you to the nearest rad shop and buy at least 25 feet of solder and a pint of organic flux. This elusive stuff is handy for many projects, and does a much nice job than the electrical/plumbing solder most people use to foul up the job. I use a propane torch or an acetylene/air torch, you want small to medium soft flame, so the welding torch is out. If anyone has used stop leaks, glues, eggs, etc, or it just has many years of corrosion, you will never get the joint clean enough to solder, so take the tank off, wire brush (by hand) all joint surfaces while hot, then re-assemble and float the solder on. Prop the rad up so each joint is as level as possible while soldering, or so gravity will help while de-soldering., and when done pressurize to about 5 PSI over cap pressure, or 5 PSI if its an open system, and dunk it in a trough and check for bubbles.

I go along with the advice given about taking it to a radiator shop. I attempted to repair the rad on my JD 4010. Did a fabulous job on the cleaning, degreasing etc. I got to practice my skills every two years. It just wouldn't last. If you want the experience, go for it. If you want it "fixed", the rad shop.

Eutectic is 63/37, and it's commonly available.

Won't work for THAT particular leak. I've tried them all over 40+ years. They are good for core leaks, but not "stressed" seams.

Greetings Chris, I filled holes in an 1939 Ford 9N radiator with solder that were 10mm in diameter using lead free plumbing solder and flux. The repair lasted at least 100 hours before I had time to come back and use some brass sheet to solder over the holes. Soldering your radiator is actually pretty easy. It must be dry and clean. After cleaning to bare metal the areas that need solder apply flux and gently heat. There is a good chance that stuff will come out through the cracks and firty up the just cleaned area. After this stops make sure once again that the metal is clean and fluxed. Use a hot flame so that the metal will melt solder where you want but that distant areas don't. Keep a wet rag handy in case you need to cool off something in a hurry. Start in a small area and touch the solder frequently to the metal so that you know when it is just hot enough. Remove the flame when touching the solder to the metal. Only re-heat the area when it cools enough that the solder won't flow. If the repair tales too long cool the radiator and start over. If the holes or cracks are long are big consider soldering brass or copper sheet to the area as reinforcement. Add flux often enough to keep the area clean. The flux absorbs oxygen and can only absorb so much. If it starts turning black it is too hot. Don't use the water based plumbing flux. Remember that you want to only heat the area to be soldered so a hot flame that heats quickly will enable you to keep the temperature hot where you need and cool where you need. ERS

"Larry Jaques" wrote: If you want to learn about steam pressure, go ahead and do that. ^^^^^^^^^^^^^^^^ I think Chris is smart enough to leave the radiator cap off.

Eutectic is 63/37 and is commonly found at stained glass supplies stores/outlets.

My preference of heat source would be an OA torch, it is my preferred tool for soft soldering some items as it gives me the greatest control. For plumbing I would use a standard propane torch but that's plumbing. I would go with a 60/40 solder as you get a mushy stage when the solder is between the solidus and liquidus temps, a eutectic will melt at the minimum temp and all at one temp so can be more difficult to control, much like lead free solder which IIRC is near enough pure tin at least in the UK . As for burner size that is not necessarilly the issue, I go for OA because it give very local heat rather than a large general heat that you get with a larger burner, this gives me fine control of the local solder melt, requires practice, but can be worth it. Now I was showing a friend to solder the other day and she was concentrating on the solder melt so much she forgot the flame and nearly over heated the piece, I explained to her what she had done wrong and realised that I do the same thing. She is my main glass blowing tutor and knows glass whereas she is getting into doing some metal work which I can help her with, one can get so focused on an individual aspect of a process that one neglects the other parts, hence she was viewing the solder melting and completely forgot the torch playing on and heating the workpiece, I do the same thing when glassblowing on many occasions.

The Prestolite air acetylene torch is nice, I used some when in high school in the US doing a metal smithing class, but I have never seen the likes of them in the UK which is where Christopher is located. I wonder what the equivalent is, compressed air fuel, oxy fuel, I would suspect a compressed air fuel unit as used be some jewelers on larger pieces.

Chris

I did the entire top tank seam about 25 years ago, and several patch jobs since. My experience matches up with Stan's recommendations. Good acid flux is required, but is not a substitute for physical cleaning. You need to disassemble, clean to shiny bare metal, apply flux, assemble, heat, apply more flux, and use the 60/40 tin/lead solder others have mentioned, the lead free will drive you crazy.

Carl

Greetings Chris, Others have said here that they don't like the lead free solder. I haven't had any trouble with it. The stuff I use is 94% tin and 6% silver. Whatever you use be sure to remove the flame from the work when applying the solder. This is what works for me. Sometimes, when the solder is really thick, you can leave the flame on the solder when applying more solder. After the first layer of solder is applied and has cooled it will be easier to add solder to that area again without causing too much of the first layer melting too much. This is because the solder will have alloyed with the copper a little and the melting temperature will have risen some. If you can practice on some copper or brass sheet first that would be good. Especially copper. Copper transmits faster much faster than brass so if you can solder copper sheet then a brass radiator will be easier. Start the soldering as far away from good soldered joints as possible. Then heat just enough to get the solder to flow in a small area and work your way along. Others here have mentioned cleanliness. Having clean metal cannot be overemphasised. The solder will flow remarkably fast over clean fluxed metal and can balk at surfaces that have a little tarnish. Eric

Just grab a small bottle of MURIATIC ACID (HYDROCHLORIC) and a few hunks of zinc and make your own.When the acid won't eat any more zinc, you are done.

Hi folks,

Thanks for all the advice. Thanks especially to those (Ted, Eric and a few others) who've done it before and know that it can be done.

I had a look at the radiator again today. I don't think I'm going to try and solder it in-place. One of my reasons for doing this was to save the cost of new anti-freeze. I'm now thinking that on the whole this is a pretty bad reason. I had also thought it might be safer to leave the radiator partially filled to protect it from heat, but I think the poor access for cleaning and doing the actual soldering mean that it isn't a great plan. The radiator needs cleaning pretty badly.

So if I'm going to do it, the radiator is coming out. There are a couple of features of the radiator which concern me, though. The first is that the bottom of the joint I need to repair is only about 1 inch above the top of the tubes. Is this similar to the radiator you repaired, Ted, or is this one going to be extra risky?

Secondly, there is a previous repair on the top side of the joint. It's rather over-filled, so I think I'm going to need to get the solder off. Any ideas on how I might achieve this, apart from heating it carefully with the top pointing downwards?

Then there's the question of flux. I had a look in the workshop and I have three fluxes, together with lead-tin solder (which I think is

Templer's "Telux", marked as "milder" and seems waxy, so I don't think it's water-based.

Laco "Regular Soldering Flux", marked "non-toxic and non-acidic". Less waxy that the Telux, but I don't think it's water-based.

Fry's Metals "Powerflow" Flux. Apparently it offers "good penetration of surface oxide with no pre-cleaning necessary". It's the only flux I have which might be acidic, but I'm not certain. It looks like it probably is water-based.

Any hints and suggestions? I might get the radiator out this coming weekend if I have time.

Best wishes,

Chris

Perhaps easier said than done. I have some phosphoric acid somewhere, but I don't have any hydrochloric, and I don't have a chunk of zinc I want to destroy!

Chris

Greetings Chris, Why do you need to remove what looks like excess solder? Is it in the way? With your inexperience the 1 inch distance is a little problematic. To help with this start heating farther away and chase the heat to the repair site. It won't hurt to have a little extra solder somewhere if it just sits in the wind. I don't know anything about your fluxes but the stuff I use is (I think) a petroleum based product with some type of acid in it. Just regular plumbing solder flux. It has zinc chloride and ammonium chloride in it. It has a longer working life and stays on the metal than the water based plumbibg fluxes sold here in the USA. It is a paste which also really helps it stay where you want until it gets hot and starts to flow. Eric

Once you remove the radiator, heat the tube and remove it. Once you remove it, it will be a lot easier to clean everything that needs cleaning.

If you really want to save the anti freeze drain it into a clean container for re-use.

A good way to manage the radiator under repair is to place it between two pieces of plywood and clamp the sandwich together. This is helpful when things get hot and prevents damage to the core if the unit falls over.

I will leave it to others to recommend the best flux.

In reverse order, thew flux to try is the fry's powerflo. The previous repair of oversoldering will come off with your flux brush a 1/2in paint brush will do. Use your small but hot flamed torch to localise the heat to melt this area Always flux plenty you cant over flux . as soon as you see the soldermelt, just brush it off onto the floor. Make sure youve proper boots on!!. If you watch where your heating and have a wet rag on the seam by the tubes youll be ok. Finally, take time to clean everything well. you may need to flux and heat then flux again then reheat then repeat till the flux dissolves the remaing oxides and the solder wets the metal. Obviously you need to hold the flamme away from the brush otherwise youll be looking for another. Push the solder about with the flux brush. your better to use a thin length of 1/8th solder it melts easier than a thick stick. Tin lead Solder joint construction is quite different to silver solder joint design which is different again to welding.

Well be thinking of you this weeked.