Fiber brush for circuit boards

Looks like Chemtronics sells a flux cleaning system based on that brush but doesn't sell the brush separately:

If it's fiberglass bristles, you could just buy some "acid brushes":

This might work, but the bristles appear to be too large diameter:

amazon.com/Fiberglass-Scratch-Brush-Pen-applications/dp/B07S3RCTGZ/

The Amazon link is for reference. Auto body repair shops use scratch pens for cleaning up stone chips and so forth so you can find them at any autp parts store.

We bought some of those, they are somewhat soft, like paint brushes, not very stiff as the OP is looking for.

John :-#(#

Any good?

Not too sure what the exact material composition of the fibre you are referring to, but I've used glass fibre brushes in the past which create dusty sharp particles that are very painful if ye are unlucky to get them trapped in ya skin. Not my favourite tool.

This venue exists to offer the most complicated process for the simplest problem, often not even related to the original problem, and then only after endless discussions on irrelevant sidebars.

Ladies and Gentlemen, boys and girls and children of all ages: Go to a decent plumbing supply house, and or an old-fashioned hardware store (even an ACE). Ask to see what they have by way of small brushes, The ACE nearest our summer house has at least ten (10) options, from very soft spring-brass bristles to peel-the-chrome-off-a-trailer-hitch steel bristles, both in toothbrush and paint brush configurations, metal, wood and plastic, and, for the record, including some natural bristle options as well. Then, using your eyes and fingers, choose the best option(s) for your specific need (or needs).

Peter Wieck Melrose Park, PA

All I can tell you is the material is black, it's not metallic, it's not natural hair, it's very stiff, and not only does it not shed any particles whatsoever, it doesn't wear out. A bit. At all. It also doesn't react to IPA, acetone, or toluene. I've seen those fiberglass pens that come with 10 refills. The Chemtronic brush bristles are only a few mm long but they don't wear down.

Chemtronics answered my email and said they don't sell the brushes separately as I suspected. I have been unable to find them by searching images or found any other product that uses them.

For now I've cut some acid brushes down to about 5 mm to duplicate the stiffness (more or less). I guess I'll have to buy some cans of Fluxoff to get a couple more. I think I'll drill them and attach a long lanyard to them so I'm less likely to misplace them in the future.