Help! How do I remove flux residue from stainless steel?!

**Karbkid** · 11-26-2009, 06:14 PM

We custom make birdcages out of 304L ss rod for exotic birds. After resistance welding, the cross-wire joints are silver brazed for additional strength and to make a smooth fillet so the bird's claws don't get stuck.
Our problem lies with the flux residue cleanup. We are presently removing the bulk of the sticky stuff with scotchbrite pads, and then finishing by manually polishing with a small buffing wheel on a Foredom flexshaft. This is very time consuming.
A series of pickling/neutralizing/rinsing tanks would take up quite a bit of room due to the size of the cages, and also be quite a bit of chemicals, expense, etc.
We can't use the pedestal buffer due to its desire to hurl the cage across the room when it gets a good grip. It also only reaches the outside.
I've considered purchasing some kind of industrial steam cleaner that could get hot enough to remove the gooey flux, but I doubt it would do much for the firescale, which seems to need to be manually or chemically removed. This choice would also be expensive and would be one more machine demanding bench space in the shop. Please help us find a solution! If Caswell doesn't have a product or method for this, can anyone recommend a direction for us to pursue?
Thanks in advance for ANY advice!

**woodjames** · 11-26-2009, 07:01 PM

Firescale can be effectively removed with a pickel, but for ss you'd be using a mix including nitric acid, and it's really nasty stuff. You've already stated you want to avoid more tanks.

What about sandblasting? You could set up an appropriately sized cabinet, with dust collection. With the correct media you'd get a decent finish. Ultimately what are you doing with the cages? such as painting/powder coating?

As far as the flux, I've had decent luck using solvents, such as lacquer thinner or naphtha. If you go the blasting route, you'd at least want to remove most of it before bringing it into the cabinet. Blasting can effectively remove traces of flux.