I have found the old-school radiator shops near me have all closed. Everything is remove and replace these days.

Look in your area for a welding job shop - TIG brazing it would be easy for one of these guys. I found such a one-man shop in my neighborhood - he fixed the broken window regulator brackets for both windows for a grand total of $50.

 

JC '78,

Continue using Google or Bing search.
Use key words such as S.W. or N.E. (then your state) to narrow down the region you are seeking.
Don't be surprised if you have to drive 100 - 150 miles to find a Rad shop. No big deal. Better than paying for a new unit.

I would not trust just any ol' auto-repair shop. The Rad should be acid dipped and cleaned by a specialist.
Keep searching.

 

Did find a rad shop, seems pretty old school and as I explained sounded like it would be simple repair, didn’t flinch much. Rad will have to come out though. I’m leaning towards sealing shut rather than another petcock and draining from lower hose in future

 

Great!

If they can solder a female thread to the radiator, then you could install a plastic petcock that won't corrode like the original metal valve. Just an idea to allow draining without the risk of breaking loose a solder joint.

 

I hate petcocks. Seldom open when needed. Flimsy, crap. Snap off. I have none on the block either.

However, my drain, like yours did have a bolt. Easy-Peezy with a socket / ratchet.
Like I said earlier. Just put some sealant on the NEW drain plug threads.

If you have the shop block off the drain completely, to me that is a bubba fix.
My morals say to do it right for my sake and the next owner.

And really consider a Sacrificial Anode Rod for a drain bolt.
Just found it on Amazon. This is the one I bought.
Made by Flex-a-lite. Item # 32060
$21

 

Like I say, just make a brass patch to cover the hole and solder in over the hole. The whole radiator is soldered....you don't need TIG (whaaaat??!). You need to remove it, wash it out, tip it upside down (repair-side-up). Clean the paint away around the hole with some steel wool. Degrease the area. Apply the flux and have at it. If you don't get it satisfactory the first time, clean and try again. I bet there are probably dozens of videos on how to do it.

I've soldered lots of radiator leaks in the last 30yrs. Just did one in my skid steer not that long ago. Not that difficult. I'm telling you this from experience. Why drive all over town and wait, go back...all that running around and pay a shop for something you could literally do in 20 min?

 

Glad you found a repair shop. Personally, I wouldn't seal it shut. My rad has a plastic screw in plug, with a rubber washer, which has lasted years. Being plastic it "reminds" you that you don't need to wind 50 lbs ft on it when it goes back, just finger tight is plenty! 😄 I put a new washer on each time I remove it.

I drain the rad each year and refill, the thinking being that doing it each year will change out most of the coolant over a couple of years - there's no way I'm getting into removing the block drain plugs!😱

 

You can't have enough Drain Plugs on a C3.
It's a burden not to have one on a manual transmission.
It's a burden not to have one on automatics pan.
It's a burden not to have one on the differential.
It will be a burden not to have one on the Rad.

 

Probably dumb question, but in that case would I even need to remove Rad? I feel I could probably do all that with it in?

 

Definitely! You want to turn it repair-side-up. It has to be dry. You want a good work area...so you're working on it and it's not going to tip over or moisture drip down. You can't solder anything when there's even a drop of two or three of moisture. And coolant has inhibitors in it that aren't helpful for soldering too. So I would rinse the radiator out with water a couple times and let it sit and dry for a few hours...with the repair area 'up'.

The best would be to heat the hole up a bit with your propane torch ...to cook the paint around the hole (5-10 seconds), and then clean the paint off with steel wool once it cools. I would personally put some phosphoric acid cleaner HERE to the brass around the repair area (not whole radiator). Put some on a paper towel and get inside the hole to clean the underside (using yer finger or some tool). There could be deposits, etc. on the underside of the hole. The Phosphoric acid...will 'eat' away deposits, etc. It's similar to a strong bathroom cleaner only stronger. Not like battery acid. Won't hurt ya. I use it all the time. It'll eat away and deposits on the underside of the hole. Use a brush or paper towel maybe a rubber glove. Might sting yer fingers. I put it on the sinks and bathroom fixtures of our rentals (renters aren't the cleanest) and man it eats away all the lime etc with a little brushing and makes them look like new! It'll take rust of bolts if ya soak them. Good product. Hundreds of uses. Rust-Oleum has a similar gel product. Both are good but for different applications. Then neutralize the phosphoric acid and clean the area with some water on a sponge.

Then dry it. It has to be dry to do soldering. Put some soldering flux around the hole and the patch...and heat it up and apply your solder. Watch some videos on soldering copper pipes. It's easy. Go buy a couple copper pipe fittings at the home center and practice.

I'll make a plumber out of you yet! LOL

 

I guess regardless the rad is coming out!

 

Oh yeah...w/o a doubt. When you do the solder job you want to do things in accordance of what will give you the greatest success and longevity. Get it 'right' the first time....so you don't have to ever mess with it again. Trying to do it in the car is asking for trouble.

Did you ever find any radiator shops? If you called a salvage yard, they'd probably know too.

 

Does anyone else reading this topic see a "Lost Logic"?

OP pulls the rad. Then tries to patch a fairly large hole, that the OP has never attempted, this procedure before.
Then install the rad. Hook up all the water hoses and trans lines, bring the engine temp up to 200 degrees. Cross fingers.

A radiator shop would not allow the Rad to leave their shop without an extensive pressure test for several minutes.
The OP has no way of performing this test accurately.
The radiator shop would clean the inside of the Rad, which considering the age, is a great idea.

Unless you are flat broke.
Unless the radiator shop is 300 miles away.
Unless you enjoy losing your coolant.
By all means, repair it yourself.

Not trying to be a pessimist, but this is one of those repairs where the outcome of success (or failure) is not known until lots of labor and hours have passed.
Some repairs should be left to those with experience.

 

I actually am planning to bring to shop. I figure if I take out rad, it should be simple fix for THEM, and I don’t want to be stranded in the future with a pool of coolant on the ground

 

Just throwing this out there...
I would thoroughly inspect that radiator inside and out before getting repaired. If really good then repair it, if not...
i like to keep mine original but with newer aluminum radiators with higher efficiency and reliability (peace of mind not watching temp gauge) , i would seriously consider replacing it. You can store the old one in the shed .
here is my 40 year old radiator thread if helpful. Note the DeWitt's universal rad from USA made Zip is pretty good value for the 78-79 if still around (insert choice of rad suppliers) . For as bad as mine looked.. the drain opened right up. your metal may be thin?

https://www.corvetteforum.com/forums...nt-79-l82.html

 

Thoughts on condition? Not sure how much rad shop will charge, yet.

 

inside view

 

Looks like some accidental overspray GM Corporate Blue engine paint on the back.
Looks like 20,000 miles of dirt roads on the front. Yikes! But will clean up easily.

Inside looks like somebody changed the coolant regularly and used distilled water mix.
That's good.