Technical How to remove brazed patch panel?

I'm attempting to save a ratty rear fender on the 39 Poncho. It has a large brazed on patch panel no doubt a valiant attempt by some PO...but its gotta go.
I have never brazed and am looking for advice on removing it if possible without cutting away the entire section.
Ideas?

 

it's likely covering something as bad or worse.
I would cut it all out and replace with good

 

Look up the build thread by 39guy. His convertible sedan had that everywhere.

 

Unless the new repair is going to be brazed you need to cut it out or it’ll contaminate your new weld.

 

I did a member search and don't see a 39guy....

 

try The 39 guy

 

Is it a dent or hole that was covered up? If a dent, I can see trying to just remove the patch and get out the hammer and dolly.
But if it’s a hole, I don’t see why you wouldn’t cut it out.

 

Get the grinder out. Looking at the bottom of the panel you are looking at a larger patch to make that good.

Start by grinding back the lumps of braze to get back to the base metal

 

You can get the br*** off the same way it went on, with a torch as the melting point is below the melting point of the steel that it is on. The problem still is Contamination when you go to weld your new patch on.

 

Looks like I'm facing the inevitable. I'll cut it out and fab a repair panel. I was hoping someone had a lead on some "Braze-away" instant braze remover....
The patch is covering mostly good metal on top. It wrapped around the corner to replace the inside flange which was rotted away. Oddly though, that flange was never drilled to allow bolting to the car.
I had similar rot on the opposite side and to fab the rear end of the fender.
I'm no master fab man, but I o what I must. What could possibly go wrong?

 

The most that could go wrong is you might have to do it again at some point down the road. By then you will have more experience and a better understanding of what not to do.
Patch it and move on.

 

Like mentioned before you can cut out around, grind down, or melt out the braze. Either way the metal where it was is contaminated. Easiest way to do it would be to cut around and make a patch. Regardless of if you melted it out, you'd still want to be at least a 1/8in outside where the braze was anyway. Like you said with the inevitable, might as well take the easy route.

 

Could always braze on a new patch lol.