Does this look like gas or tig rework on the I/C photo. I wonder if the work could be gas/stick soldering versis TIG because of the tight spaces available.

THis is a I/C that failed and was cut open. THe beads look like TIG but I wanna ask someone else's opinion before I am satisfied here.

If its TIG I wonder how they knew where to do this as there are SO MANY welds on the I/C and on BOTH sides of the sample unit.

Does it make sense that there are many cracks to fix up?? Iam assuming that this is an oven brazed Al I/C and they pressure tested it after 'assembly' ??

 

Woody,
it looks to me like TIG, but I can't see in the picture if there is any "scarring" around the welds from flux. If there is-it could be torch/braze repair. If there is no flux pitting, it is most likely a TIG repair job.

As for the manufacturing method-I'd say you are on the money.

As to where to weld? An air pressure/soap solution, and many iterations, would indicate leaks. You just keep doing it until there are no more bubbles!

As to the "why" it fails, the act of welding thin-walled material to a thicker walled material is really hard to do-especially in aluminum. It's very difficult to get the thick stuff hot enough without overheating the thinner stuff. Cracks open as soon as it cools down.

And then there's the temperature differential in operation. That will flex the daylights out of it too.

Very tough job, that...

 

Pretty shabby furnace braze job with preforms is my guess. Leak detection with leaks marked and stick and torch brazed I would guess.

The trouble with furnace brazing is that weak spots with poor penetration are not visible and it all looks rosy. The same goes for general welding or brazing but in this case with a long length of seams to be filled one weak spot leads to total failure.

The large number of touch ups here means many weak spots were not found.This part should have been scrapped just on the percentage of fixes required basis.

 

it looks to thick to be tig welded. tig welds look like a stack of dimes if done properly. same shape each row thin rows stacked not globed on each other like the pic

this is an example of proper tig welding

 

Google is ur friend..

Example is aluminum..