Agreed. That's a distinct possibility, regardless of how you clean / repair WPC CPUs. I have not declared victory yet - but I also know that I find a lot of those traces under magnification before repair, and any I miss are generally pretty obvious by chasing a circuit out with the schematic to figure out why this row, or that direct switch, doesn't work.

I think anyone who repairs as many boards as Andrew and I do have a pretty good sized stack of 'non repairable' boards that we save for trying 'new things' on. My intention is to rebuild these boards to work 100% - and probably seal one, and leave the other unsealed - to see if the damage returns. I have sealed every board I have done battery rework on for several years now - because no matter how carefully I believe a board was cleaned, it's cheap insurance - no oxygen should mean it can't corrode again?

The cratex method I use on Sys3-7 boards is iffy on WPCs. Traces get blown away so easily with it, even with the least aggressive grit and being very careful. Fiberglass pencil sanding seems to give you more control - but is very time consuming. And you get painful splinters.

There are days when I wish the price of repro WPC CPUs would drop a few bucks and put those of us doing rework out of that line of business. I can't keep up as it is.

Which is why avenues like this have to be investigated. It's got real potential to save time, which in the end would mean saves money, and saves boards - but you can't really declare victory til you've rebuilt a few, and had them stay 'repaired' for some time now.

I've kinda wondered what other acids might work, too. The toilet bowl cleaner is NOT harsh at all. I had a little splash on my skin. I did this outdoors. It had a nice 'wintergreen' scent to it - I certainly wouldn't huff it, but it didn't smell bad I used gloves and a garden hose to rinse when I was done.

My new board repair shop (in progress) will have separate 'clean' and 'dirty' areas. This is something I would probably do in the 'dirty' area in a laundry tub style sink, as long as I can get appropriate ventilation in place. I sure wouldn't do it in my kitchen sink - I'd die a very slow and painful death if I tried