Repairing radiator puncture

[alexiskai]

There I was, refilling my radiator after installing my new cylinder head, and I start to hear drip, drip, drip. Turns out, somehow I must have bashed something into it while doing all my work over the last four months. Or possibly it's a prior puncture that came unsealed while the radiator was dry.

The location is at the lower right corner, if you're in the car looking forward. It's only leaking to the inside, not out to the front, which suggests to me that the hole is toward the inside.

Anyone have any pro-tips for a good epoxy to use for a repair, or what technique to use to get a good seal the first time?

[BRENT in 10-uh-C]

Solder it up. Clean it well, ...then clean it some more. Then clean it with a soft flame and use flux to clean the tube and allow it to stick. I purchase my flux from Johnsons in Iowa.

If you must, tear the fins loose carefully from the tube to access the puncture, then use a small set of needle-nose pliers to move them back into the proper position. A kiddie swimming pool can be your radiator tank, so fill with water to test. Use about 3 lbs of pressure to check. A exhaust on a shop vac will suffice, so just attach the hose to one of the inlets. Install the radiator cap, plug the overflow with a piece of fuel line hose and a bolt, and use your palm to block the other inlet/outlet.

[alexiskai]

If I've never soldered before, is this a good job to learn on?

[kawagumby]

Originally Posted by alexiskai

If I've never soldered before, is this a good job to learn on?

I've been soldering since the dawn of time, and I would not recommend using a radiator as a learning tool...it just takes some practice to get the feel of solder flow and you don't want to inadvertently un-solder what's already there. However, using an epoxy-type product for limited punctures, such as JBweld would work just as well. Cleaning the area and having it dry is critical, of course.



Tom

[BRENT in 10-uh-C]

Originally Posted by alexiskai

If I've never soldered before, is this a good job to learn on?

Depends, ...what is the radiator worth to you? Experience is generally something you get after you need it. If this radiator is really nice, maybe take it to a professional is the most prudent thing. Remind me the next time you are here and I will give you an old A radiator to practice on.

[alexiskai]

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Originally Posted by BRENT in 10-uh-C

Depends, ...what is the radiator worth to you? Experience is generally something you get after you need it. If this radiator is really nice, maybe take it to a professional is the most prudent thing. Remind me the next time you are here and I will give you an old A radiator to practice on.

Thanks! I'm looking for a local repair place now, but I thought I'd ask here in case this is something within my skillset. Probably not!

[Ray64]

As many posts as you do i think you can pull i off .You seem to know alot so you are a good learner Go for it Also a couple of teaspoonful of black pepper will work

[ronn]

heard of a fella who just emptied the rad- squeezed in some black silicone from the back


and 10 yrs later was dry as the desert.............


maybe not as good as solder, but worked well for him.

[alexiskai]

Originally Posted by ronn

heard of a fella who just emptied the rad- squeezed in some black silicone from the back and 10 yrs later was dry as the desert............. maybe not as good as solder, but worked well for him.

That's the kind of thing I might do but then never admit to the guys on this board.

[Tacoma Bob]

Originally Posted by alexiskai

Thanks! I'm looking for a local repair place now, but I thought I'd ask here in case this is something within my skillset. Probably not!

Sometimes my biggest skillset is my wallet.

[alexiskai]

Discretion something something something valor, etc.

[Brentwood Bob]

Your luck its on the inside, black radiator paint is your new friend.

[1crosscut]

Originally Posted by alexiskai

That's the kind of thing I might do but then never admit to the guys on this board.

Okay I'll admit to doing it.

Expose the area that is leaking and clean it well. Cut a piece of black cotton t-shirt material slightly larger than the area of the leak and saturate it with black silicone gasket sealant. Apply the saturated patch over the leak and smooth it on. The thinner the finished patch the more flexible it will be. A thick blob of silicone is not what you want.

I used this fix on my AA radiator 10 years ago and it has not leaked since. I've also use the same type of repair on chest waders, coolers a hot tub etc... with good success.

[alexiskai]

Good to know. I found a place that will try the repair. If I were planning to keep the car awhile, I might do the silicone fix, but I intend to sell this one in a couple years, and I don't want a buyer to see that and think I'm the type to cut corners (not implying that you are, of course).

[Stingray70]

Alexiskai, I just sent you a PM

[Jack Shaft]

You don't want to develop soldering skills on your only radiator. It is an acquired skill that takes some practice and experience to perform...shame you aren't closer, I have some practice dummies. Ive actually saved a few radiators back flushing with an industrial hot water pressure washer with chemical degreaser, and soldering them up where needed.

[McMimmcs]

Originally Posted by 1crosscut

Okay I'll admit to doing it.

Expose the area that is leaking and clean it well. Cut a piece of black cotton t-shirt material slightly larger than the area of the leak and saturate it with black silicone gasket sealant. Apply the saturated patch over the leak and smooth it on. The thinner the finished patch the more flexible it will be. A thick blob of silicone is not what you want.

I used this fix on my AA radiator 10 years ago and it has not leaked since. I've also use the same type of repair on chest waders, coolers a hot tub etc... with good success.

One of the better farmer fixes I’ve seen. Good thinking ! Wayne

[Kurt in NJ]

Most radiator shops will rip out the tube at each end and solder over the hole in the tank, it will look ugly, for a small hole in the tube on the face of it gently pushing the fins away, carefully scraping to bright copper and soldering with iron is something I have done, if the fins are pushed back the repair can disappear, a torch can easily get the area too hot and pop other solder joints,
Not all solders are equal, I have seen a lot of bad soldering, most times there's several factors in the failure, , much of soldering is preparation, choice of flux and solders, getting the surface hot enough, but not too hot, the "no lead" solders melts at too high temperatures for this work, 50/50 solder , or good 60/40 electronics solder would be what I would use with acid flux after scraping with knife and rubbing with coarse skotchbrite piece held in tweezers/ hemostat till bright, then if in middle of tube either weller gun or electric soldering iron.
I have also used epoxy, this repair on my truck is over 25 years old, it was " marine Tex" epoxy, looks ugly, but has worked

[alexiskai]

Follow up: local radiator shop put it under water and detected two additional leaks. They soldered those up, tack welded repairs where the frame had rusted, and gave it a fresh coat of paint. $160

[ronn]

rad looks pretty straight.

[shew01]

Originally Posted by alexiskai

Follow up: local radiator shop put it under water and detected two additional leaks. They soldered those up, tack welded repairs where the frame had rusted, and gave it a fresh coat of paint. $160

You are fortunate to find a radiator shop that actually does repairs. Radiator shops around here just want to replace with a new radiator.


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[Afordman31]

I just finished soldering one of mine. My Dad taught me to use Muriatic Acid the kind that you can clean pools with. He gave me a couple of zinc canning jar lids that you cut up small little pieces and put in the small amount of acid that you will use to clean the spot where the leak is. The zinc will bubble in the acid so you keep adding small pieces until the bubbles subside. I used a knife, sand paper, small wire brushes to get it as clean as I could then used the mixture of acid with a acid brush to clean the area. I use flux and solder that you would use to solder copper plumbing pipes. As stated do not heat excessively as to not unsolder other areas. I use a Bernzomatic propane torch. I have unsoldered the tank tops off a couple of radiators in the past so that I could clean out the tubes, then soldered the tops back on. It is all learning experiance! Also stay down wind of the acid!

[midgetracer]

Originally Posted by Afordman31

I just finished soldering one of mine. My Dad taught me to use Muriatic Acid the kind that you can clean pools with. He gave me a couple of zinc canning jar lids that you cut up small little pieces and put in the small amount of acid that you will use to clean the spot where the leak is. The zinc will bubble in the acid so you keep adding small pieces until the bubbles subside. I used a knife, sand paper, small wire brushes to get it as clean as I could then used the mixture of acid with a acid brush to clean the area. I use flux and solder that you would use to solder copper plumbing pipes. As stated do not heat excessively as to not unsolder other areas. I use a Bernzomatic propane torch. I have unsoldered the tank tops off a couple of radiators in the past so that I could clean out the tubes, then soldered the tops back on. It is all learning experiance! Also stay down wind of the acid!

I do not see how this method would clean the copper tubes. What you end up with after adding zinc until the bubbles stop is Zinc Chloride. Muriatic acid (Hydrochloric acid) plus Zinc yields Zinc Chloride and hydrogen gas. What is the purpose of the Zinc, when the acid will do the cleaning... I don't believe Zinc Chloride will clean the copper, or is my Chemistry training missing something?

[Afordman31]

Old school technology, but worked for me! No leaks when finished!

[alexiskai]

Zinc chloride is a form of liquid flux, right? So it's not cleaning the area so much as assisting the soldering.

[Tinbasher]

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A trick. When pressure testing a rad. Us a motorcycle tube and cut it in the centre. Then take the two ends and attach it to the upper and lower tubes. Put a little air pressure about 3 pounds and do a water check. Simple and works well. Used it many times fixing rads for guys.

[19Fordy]

You were treated fairly by the radiator shop. Well worth it.