Repairing Solder Mask / Silkscreen Question

[GoldtoneWorkshop]

Hey All,

I'm working on an amp that was was previously worked on by an ambitious owner. There is a good chunk of exposed copper where the silkscreen has been etched away during the previous repair attempt. I was wondering what you all do in this situation. If it was a small bit of the trace I wouldn't be concerned, but this is a good dime sized area of exposed copper that I feel the need to tidy up.

[tedmich]

that doesnt look like copper, its looks like the board material beneath the mask, the copper traces are still black and visible.

I suppose it could be a ground plane; whats the exposed area conduct to?

Is this a multilayer board or anything special like an metal substrate to remove heat?

[GoldtoneWorkshop]

The big splotch on the left is ground, the other splotch is not, that's the negative 15v rail. Not sure what the material is but the exposed bit is conductive and connecting the different components. This is a multilayer pcb, from an Ampeg SVT-CL.

[Greg Robinson]

There are various brands and price-point options, but I keep an MG Chemicals soldermask pen and a bottle of corona dope for higher voltage applications handy for things like this.
Both of those options require extended cure times, but there are UV curing soldermask options as well for faster work.

[g1]

and a bottle of corona dope for higher voltage applications handy for things like this.

That's what I was thinking and remembered one in black, the GC 10-4702.

[Tom Phillips]

An approach that doesn't require the purchase of specialized material is to flow a layer of solder over the exposed copper. In the olden days, all the traces on a PC board were often treated that way and many of them are still perfectly functional.