Stephen Lane wrote:
Yes it is hard to find a paint that evaporates cleanly, I haven't found one yet but I agree that good extraction or whats called air assist would probably help alot but I haven't been able to make that work on my laser (yet).
By paint thinner I mean what ever is the thinner for the paint you use for most tinned spray paint MEK or Acetone will work the point is if the paint has gone on relativly thick after its been Lased off the residue is very thin so a quick wipe with whatever thinner works usually cleans it off without taking the lot off.
The Cermark paint listed in this thread allows a CO2 Laser to mark metal but I wouldn't bet on the marking being etch resistant but I would love to hear if it is it would make doing this alot easier.
By reasonably etch resistant is as you allude to it will lift easily causing pits etc with the Acid/H2O2 mix but some times depending on the amount to etch off its not in it long enough to matter.
I hope that helps
Regards
Stephen
--- In Homebrew_PCBs@yahoogroups.com, Kamal Shankar <kbshankar2000@...> wrote:
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> >beam (CO2 Beam is an infra red one) as to resist I have use plain black matt pressure pack spray paint to create brass stencils by this method it is a little hit and miss in that the paint sometimes does not evaporate cleanly but if you wipe it over with a paint thinner quickly you can tidy it up. Then I
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> Hmm.. so it seems that getting a spray paint that does not leave any residue behind after laser cutting is extremely difficult to find!
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> One member, either here or some other forum, had posted that they had found a paint that left no residue, but I did not get any answer when I asked for a model number.
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> > etch it with the acid/peroxide etchant the paint is reasonably etch resistant to this & I have also had great results with the persuphate etchant as well.
> >I use a 40W CO2 Laser for this
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> When you say "reasonably etch resistant", does it mean you get pitting on lost thin traces?
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> Also - I noticed that Home Depot carries "Acetone" and "Paint thinner" as two separate bottles.
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> Is there a difference between the two regarding using them to clean up residue from a laser cut board?
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