Nicked radiator hard line with angle grinder

Quantumkiwi

New member
While cutting my frame endcaps off the put a bumper on, bumblefinger me nicked one of my radiator hard lines with a cutoff wheel. Its seems to be at least 1/2mm deep. Should I immediately replace this line, or can I just JB weld it a bit and replace it with my radiator in the next few months? Alternatively, can I just slap a tack on there (assuming the line is steel) with my mig, or is the risk of burning through too high?

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I nicked my ac line in the exact same spot when I was cutting the frame for my front bumper.. I just painted it and it’s been fine since, I wouldn’t worry about it at all.
 
AC line, not critical, but it is near the bend which is a high (thermal) stress area. I don't see JB weld as being good under pressure, but what you could do is JB weld it + put a small screw type hose clamp on it which should hold. A better option than JB weld would be to braze it, but practice on some scrap aluminum first!
 
AC line, not critical, but it is near the bend which is a high (thermal) stress area. I don't see JB weld as being good under pressure, but what you could do is JB weld it + put a small screw type hose clamp on it which should hold. A better option than JB weld would be to braze it, but practice on some scrap aluminum first!

I don't think it would be a good idea to braze on that while it is under pressure!
 
If its not leaking now, it unlikely to in the future... just leave it. Worst case is you lose your AC for a while.

-Charlie
 
AC line, not critical, but it is near the bend which is a high (thermal) stress area. I don't see JB weld as being good under pressure, but what you could do is JB weld it + put a small screw type hose clamp on it which should hold. A better option than JB weld would be to braze it, but practice on some scrap aluminum first!

Excellent answer, for jerry-rigging it. That's what I would do, and I am a master at jerry-rigging (fixing my effups).

JB Weld alone wouldn't really do anything. If the pressure inside would rupture the metal, even a pin hole size, the JB alone would not hold it. But if held in place by the hose clamp mentioned, it just might hold. Not much to lose in trying that, except maybe $5 in supplies. JB Weld is miraculous stuff, if you keep in in compression (never, ever in tension), and roughen and thoroughly clean the metal.

If there is any liquid inside that line (even liquid refrigerant), it would be impossible to braze it. I have brazed aluminum numerous times. It really isn't difficult to do, as long as you follow the instructions and think about what is going on. And you get almost a true weld. But difficult to do that with it in place, and again, impossible to get it to temperature if there is any liquid inside it.

The best option would be to just replace that line. Of course.

I have only stayed in Holiday Inns once or twice in my life, but I am a master at fixing screwups, and I really have been a mechanical engineer for 28 years.
 
Too far away from me, but you could use a rod of blue demon triple play to braze over it and it would be good to go, and even stronger in that area. If it concerns you, a welding shop can do it in about 5 minutes, or grab some of them yourself and do it if you have any welding or brazing experience. All you need is MAPP gas. Practice on some stuff, watch a few youtube vids on how to do it, and learn a new skill. YOU CAN DO IT!

Also, Amazon will try to sell you flux with it. You don't need flux with this rod.


https://www.amazon.com/Blue-Demon-BDTP-125-01T-Aluminum-Zinc-Brazing/dp/B01MCTUIUN

Blue Demon Triple Play Brazing Rod! – Works By a Hurst
 
If there is any liquid inside that line (even liquid refrigerant), it would be impossible to braze it...

Yep thats right. Saturated gas goes in top of condensor liquid out bottom.
There will be liquid there, thats also a high side line with the most thermal expansion and contraction.
I'd braze it on the bench since it's a one shot deal.
If AC is working now recover/filter whats in system replace line pull vacumm
check for leaks charge with a bit of PAG oil and seal conditioner leak dye.
The freon is what drives up the cost.
 
Yep thats right. Saturated gas goes in top of condensor liquid out bottom.
There will be liquid there, thats also a high side line with the most thermal expansion and contraction.
I'd braze it on the bench since it's a one shot deal.
If AC is working now recover/filter whats in system replace line pull vacumm
check for leaks charge with a bit of PAG oil and seal conditioner leak dye.
The freon is what drives up the cost.
Or just leave it alone since it isn't leaking?

-Charlie
 
Yep thats right. Saturated gas goes in top of condensor liquid out bottom.
There will be liquid there, thats also a high side line with the most thermal expansion and contraction.
I'd braze it on the bench since it's a one shot deal.
If AC is working now recover/filter whats in system replace line pull vacumm
check for leaks charge with a bit of PAG oil and seal conditioner leak dye.
The freon is what drives up the cost.

I learned that pesky fact about liquid in a pipe while trying to solder a fitting on copper house plumbing. If there is any water at all in the tube, it is impossible to get the metal hot enough to solder or braze it. I burned through a few propane canisters, before I learned that you must get all of the liquid out of the working area.
 
Or just leave it alone since it isn't leaking?

-Charlie

True dat, but if you get a highside leak that big you lose all freon real quick plus most of PAG, his money.
I live in the south so AC high priority.
Be a good time to change drier, if drier desecant cartridge breaks apart gets into system your f..kd
Driers do have a life span, cost me $1200 how I know.
 
I learned that pesky fact about liquid in a pipe while trying to solder a fitting on copper house plumbing. If there is any water at all in the tube, it is impossible to get the metal hot enough to solder or braze it. I burned through a few propane canisters, before I learned that you must get all of the liquid out of the working area.

Yep I've gone as far as shoving bread into pipe to plug it to make joint with house plumbing.
 
You gotta be real good to braze aluminium, real good. Being that system is pressurized even when not running it's going to blow out right about the time
it goes molten to bond.

Yep thats right. Saturated gas goes in top of condensor liquid out bottom.
There will be liquid there, thats also a high side line with the most thermal expansion and contraction.
I'd braze it on the bench since it's a one shot deal.

I learned that pesky fact about liquid in a pipe while trying to solder a fitting on copper house plumbing. If there is any water at all in the tube, it is impossible to get the metal hot enough to solder or braze it. I burned through a few propane canisters, before I learned that you must get all of the liquid out of the working area.

Afaik when brazing, you don't actually melt the surface, just the filler. Seems like the problem with brazing that line is the thin walls and the low specific heat of aluminium means it would be easy to blow through, especially if you are using something as indiscriminate as a gas torch.

So, reckon I can TIG braze it on the car? I maybe could crank the TIG heat up enough to get it hot without really heating up much of the liquid. Failing that, I can just bribe my welding teacher to braze it. But thats a bit silly, since I don't even think its leaking, so I will probably leave it until it explodes int he summer heat or something.
 
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