How to Solder and Repair a Leaking Radiator 

I know there's alot of hate comments on here but I don't think he deserves it guys. He did an ok job for an amateur, and if it didn't leak, who cares if it's pretty or not? It's all up to personal preference. Thank you for making this video sir, I've got the same problem and I haven't got the money for a new rad

Key to soldering radiators or anything is having the spot your soldering super clean. And tinning before you solder something.

Cleanliness is key to any radiator repair. Use a stiff brush after heating to help cleaning the metal. Use lead based solder not plumbing solder. Heat then apply flux the help clean the metal. Heat the area then apply small amount for flux and solder. if the solder runs off without bonding it most likely is not clean enough.

Oof. You likely made the leak worse by flowing more old solder out of the seam than new stuff you were trying to get in. I would heat the neck until it separates from the body of the radiator, clean both surfaces thoroughly with acid flux like Harris Stay-Clean, then I would "tin" both mating surfaces with a thin film of solder, then place the two together and heat them up to allow the solder on both to melt together. That would leave a tight seal that looks fac-tree!

A tip, absolute clean, bare metal is a must and solder always flows towards the heat, so if you were putting the solder on the outside of the filler neck, you want to hold the torch on the inside of the joint letting it flow in. Good luck, if you need a hand let me know.

You have to heat the metal until it's red hot if you have to continue adding Flux that's not a problem it will literally melt into the crack. You didn't heat up the metal long enough

im so happy his bench looks like mine. a total mess. must be a hell of a mechanic

Thanks. I hadn't done much of this but I got my John Deere radiator inlet crack fixed today. No more leak

I was taught a long time ago to let the metal suck the solder in not blow it in with the heat. You did good not being a plumber or a pipe fitter. I've done a shit load worse trying to do that.

Thank you. The good thing about you tube, if you do anything, every one will chime in how to do it better. I’m trying to straighten the neck on mine. I ordered a new one but would like to repair the one I have. Thanks for showing it’s possible.

Like the old saying goes,you gotta do what ya gotta do and use what ya gotta use, i do this for a living and would say heat your base metal instead of the filler neck as it is thinner than the radiator tank. Overheating the neck will cause the flux not to activate properly and the solder not to flow properly. Overall no leaks means a good repair!

Thanks for this I have to do a rad in my cavalier. I wonder if straight lead would work. I know it melts super easy. I done copper in house many times. So the solder has no lead. Of course, it was always the best. Thanks again. BTW the more you do something, the better you get!

Hi thank you for the video well done sir 👍🏻

Nice, I used to solder lead cable sheaths back in the 80s its an aquired skill, also we had wiping pads and great flux. I gotta do a heater core on my AMC wagon trying to clean it now dont think its gonna go good.

Take the fillerneck off (make it hot) clean it and put it back and then solder it.

few things can explain that you have difficulty to touch up the solder bead 1) the wire wheel is good for rough cleaning, use a file and a scotch brite pad to find clean bright metal 2) use liquid flux as STAY CLEAN, it is far superior to paste flux sold to solder copper pipes. 3)on such an old radiator, the solder used is usually lead based so better use lead based filler material, it blend better to base filler 4) use a concentrated heat source, much, much easier to control the solder bead and to avoid desolder surroundings solders, usually, oxy-acetylene or oxy propane with a very fine torch tip does very well in this type of applivation.. A torch as you used is fine to solder copper pipes but the heat source is too blunt and poses the risk of damaging surrounding soldered joints.

The metal surface may be contaminated with oils, your dremel wire brush may not have been enough. Using a solvent like acetone would probably work, then the solder will melt onto the brass.

First and foremost is clean, clean and clean again. Then apply heat to where you want the solder to GO, not above it unless you want the solder to flow up. After it is heated, apply flux, then heat all around the tube and blow pressurized air to remove the old solder, then yep, clean, clean and clean again. Then apply heat, then flux again heat all around and keep the heat below the top to draw the solder in. Next I suggest you use SILVER SOLDER as it is more tolerant to different metals and stronger than lead. The solder will follow the heat source so pull the solder in with the torch, do not try to push or flood the solder into the groove. Brush on flux as needed to remove slag (dirty old solder) as it rises and finally wipe the joint with a wet cloth. PLEASE WEAR THE PROPER EYE, FACE, and RESPRATORY PROTECTION WHEN WORKING WITH SOLDER AND FLUX !! One pop of molten flux and solder into your eye and it's all over !!

I know this is from five years ago, you may be better at soldering now. I suck too. One thing I have learned is the molten solder on the joint will follow the torch heat to make it look nice and lay down better

Probably not clean enough but for not ever doing it before I say good effort! To remove the soder I heat till melted and blow off with air gun.

give it a wipe with some wire wool just after melting to clean away excess solder

I was just waiting for you to catch your sleeve in that wire brush. If you do, it will get your attention real real fast. Also, it shouldn't take to long for you to realize that the solder will FOLLOW the flame. Cleaning and fluxing is paramount. Even if you have to wirebrush the heck out of it as you get the old solder to melt.

Cool

The leak is between the top of the rad and the filling fiting. The best way would be to heat the fitting and the rad around it and use pliar to remove the fitting and clean the fitting and the rad of excess material with a rag before it cools. Clean the parts to be joined. Then reinstall with freash solder flux and paint. Job done.

hi ..... there is 2 issues ....... the item isnt clean enough , and you are using to much heat ...... for better cleaning , you can use the solder paste and heat it up and then use the wirred wheel again , (no tin ) remember to clean inside aswell because , you are pulling the dirt from the inside and out with the heat ......... the solder would flow when its clean enough .......... nice work though

How long will this solder last? Is this a permanent fix?

thats a good example how to not do it.

I thought you heat it up the that you were trying to repair until it would melt the solder on its own when it was heated

Leadless solder is a pain to work with.

Heat it first to clean out the old solder. Let it cool flux and then add solder . more lead base solder is better . good luck !

Take it to a Radiator Repair shop! And do it right that classic car worth it 👌!

This is an interesting repair video. Maybe you should have removed the filler neck and thoroughly cleaned it and the hole it fits inside and used a different flux for better adhesion. I was the mechanic in a radiator shop for a short time, removing and reinstalling radiators and heater cores. I thing that the gents who did the repairs used an acid sort of cleaner. I don't recall the type of solder they used 48 years ago.

Silver soldering on clean surface

Brassworks makes new and repairs these old radiators

Definitely wasn't clean enough. After the wire brush it should have been clean shiny copper

i file the surface then flux then solder , thats a far more easy way any wire wheel will just contaminate the work from an old job you wire wheeled last that may of had oil and what not when you file it will be 100% new clean ready to flux then solder

man, that was a disaster

Obligatory negative comment

Clean with muraticacid

It keeps pooling because you're not level and you're putting too much heat into the part and not warming the solder.

dirty joint to much heat.. fill thr rad up to the level your working or you will make leaks elsewhere/..

You need solder with lead in it.

I clicked on the video cause it said radiator repair not participation trophy.

Its not clean

need to use silver solder

Too hot.

you got it so hot it's like liquid, so you keep laying the flame on hoping it will thin out? You got it so hot you could probably have soldered it after 5-10 seconds and just touched the solder to the super-heated area. You keep using too much heat, like 95%+ of the time when you're using heat you shouldn't and you would have had a much much quicker easier time and a better solder.

I couldn’t continue listening to this. I had to use subtitles with no volume. I know it’s a US thing, but there is a letter ‘L’ in solder!!!

Brazing it may have worked better

can better with bronze

🤦🏻‍♂️

You are heating it up far to much.

Don’t quit your day job 😂

Dear America, SOL-DER Not SA-DER. Thankyou

I don't mean to be critical, but you are promising how to, and you don't have experience in your topic. I kind of feel like you wasted my time just to sell a few commercials.

your making a right pigs ear of that

Well. That's 6 minutes I'm never getting back. I'm aware that the video goes for 11 minutes long but I didn't finish it all. Why is this crap content at the top of my feed when I legit want to fix a radiator?!