Can JB Weld withstand the high side pressure of an aluminum A/C line?

My daughter's 2010 Accord has Zero pressure in the air conditioning system. I vacuumed it down, but the pressure neutralized immediately after I turned the pump off. I think I've located a pinhole in the high side line, which would not be even remotely easy to replace. I can't be 100% sure without sacrificing another can of stuff, but it looks like a likely point of failure. Refrigerant was blowing out when I tried to add it, but it was under the coolant reservoir and I couldn't get a good look at the time.

After breaking the news that she was just going to have to deal with it, I started thinking about JB Weld. What do we think? Would it hold back the pressure? Would JB Stick be a better choice? Or would I just be wasting more time on this project?

Its JB Weld, is it really wasted time to slap some on?  I'd reinforce it with some sort of matrix so you aren't relying just on the JB Weld

IIRC JBweld is like 4000psi in strength so it should be strong enough.  

My concern is surface prep and porosity.  I don't know how porus to gases JB weld is.  It's epoxy so I believe it's fairly solid but just not sure.

Those look like corrosion holes, which means its probably going to leak somewhere else.

And no, I don't think JB Weld is going to fix anything.

Okay, I did a little further investigation. That's not the leak. It's close, but more difficult to access. 
 

There's an unfastened clip next to the pressure switch that's supposed to support that line, and I can't get it in place. I suspect that the two hard lines are supposed to be on opposite sides of each other. (The car had some minor front end body work in the past) The high side line has been rubbing on the sharp edges of the radiator and there are two points of failure. 
 

I may be able to remove one end of that line and swap their positions, and then try the JB fix. 
 

I have JB Weld, JB Quick and JB Stick. I figure that I only have one shot at this so I need to choose...

If you want to try this, I would recommend putting some sort of patch on top of the JB Weld (e.g. ideally a cut piece of tubing) then strap the patch via a hose clamp.  That way you will not be depending on a dab of JB Weld to hold back 300 psi, just to seal the edges.  It will also help if the area around the hole is weakened and protect from further damage.

In reply to aircooled :

Excellent idea. Thanks.

Does original JB Weld set up without oxygen?

Can I just slather it on the inside of an aluminum patch and clamp it tight?

As long as the mix of the JB weld is really good you don;t need oxygen. I have seen it setup underwater. 

wearymicrobe said:

As long as the mix of the JB weld is really good you don;t need oxygen. I have seen it setup underwater. 

Yup. 

JB is an epoxy. Provided it is warm enough to not hinder the reaction it should set anywhere so long as the proportions are right.

Oh!  If it has been dumping freon, it has also been dumping compressor oil.  If you don't clean it real well nothing will stick. 

Acetone would be my recommendation, followed by some light sanding to promote adhesion, then more acetone.

I have used these to repair the rear ac hard line on a van. They are compression fittings and seal well. Just cut out the bad spot and replace it. They available in several different sizes. 

There are also individual fitting that you cut in at the damaged spot. I haven't used these before but they look like they should work as well.

Amazon carries them. 

Toyman01 + Sized and said:

I have used these to repair the rear ac hard line on a van. They are compression fittings and seal well. Just cut out the bad spot and replace it. They available in several different sizes. 

 

There are also individual fitting that you cut in at the damaged spot. I haven't used these before but they look like they should work as well.

 

Amazon carries them. 

I have used them.  They work fine, as long as your wear point is on a bit af straight tube.

Also, if the line is removable without lifting the engine out, anybody with a tig and a bit of skill can fix you up.

JB weld will not seal it, it can't handle the pressure or the expansion with heat.

+1 for cutting the tube at the leak and installing a compression fitting.  it works.

Part of why I really hope Mazda's NA parts reproduction includes A/C lines is that I have one customer with like three of those in the low side line coming off of the evaporator, and another with a heavily shortened high side line off of the condensor.  Both sub-60k mile NA6s.

I have fixed one with the aluminum brazing rod from HF.  Scuffed the tube with a Scotchbrite pad and got it perfectly clean.  Brazed it with a MAP gas torch.  Has been holding for 5+ years.

I tried JBweld way back on an AC line on my first Integra b/c of a short ram intake piercing the line, it didn't hold. 

Ended up buying a used AC line to fix my problem. 

Scott_H said:

I have fixed one with the aluminum brazing rod from HF.  Scuffed the tube with a Scotchbrite pad and got it perfectly clean.  Brazed it with a MAP gas torch.  Has been holding for 5+ years.

I did the same with a condenser that had a small hole.  The patch + JB Weld + clamp has potential though, especially in what looks like very poor access.

Of note, yes, R-134 is flammable.  The residual pressure resulted in a nice flame when I started brazing.