One way to get rid of “pinholes” in the toner is to put the board in acetone vapor for 30 minutes or so. The toner will melt and fill in small gaps and pinholes.

I routinely get 6 mil (.15 mm) traces using my modified laser printer that deposits toner directly on copperclad boards. The printer works first time almost every time, even if it’s been sitting on the shelf a few months.?

Mark

On Jul 1, 2018, at 6:24 PM, groupsio@... wrote:

I think most proponents of toner transfer would agree that this is a dark art.

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Rob has described a method that works for him and you tend to stick with what works - which makes good sense.

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There are many variables which make for a different result in your situation. First most would be the printer that you use and the toner characteristics. The best thing is to experiment but not take what works for one person as gospel so that you are disappointed with the result. Experiment.

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I don’t use special paper. Glossy travel brochures are free ?and work with the HP printer that I use.

I do not scratch my copper board or clean it with chemicals at all - or even wipe with a damp spaniel.

I have a large and fairly “hard” eraser originally intended for carpentry use which has fine particles so that I get a good clean shine.

Under the microscope there are fine scratches but I don’t need to score it.

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I use a laminator, albeit a heavy job intended for office work and not a ten quid cheapie.

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I have never needed to go over the toner with a pen and I use Ferric Chloride as etchant.
I can get consistent results of track widths to 0.7mm

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So what that all says is that Robs method works for him and mine works for me and he is right when he says ?“It’s a real crap shoot where you NEVER will get the desired results UNLESS YOU EXPERIMENT AND DOCUMENT”.

Start with what you have to hand - and what is free - like paper. Work up from that and don't be discouraged if the first few attempts fail. Try all the methods that have been suggested. It's worth it in the end.

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Here are some examples of my boards:

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72/73

Tony G4WIF