I couldn't easily get hold of marking blue, but discovered a recipe in SParey for an acidulated copper suplhate solution which works quite well.
The recipe is really easy - a couple of teaspoons of copper sulphate in a medicine bottle of water and make acid with a few drops of sulphuric acid.
THe metal has to be oil free or it doesn't work. On clean steel you get a very durable copper finish, which has a second advantage of keeping out the corrosion in damp workshops...
Steve
sulphuric acid.
Steve,
Our 'Pound Shop" here in Bromley occassionally has broad tipped felt tipped marker pens with spirit ink, and I find them excellent as marking out backgrounds prior to scribing - I try to keep to blue but other dark colours also work well !
I have a bottle of 'proper' blue but the pens are so much more convenient.
AWEM
Just make sure it is a saturated solution.
Its saturated allright - you should see how much water he puts in it... ;-)
Regards, Tony
I use those big fat Eddings 200 or 2000 marker pens, handy quick to apply and not as messy as marking blue
-- Regards,
John Stevenson Nottingham, England.
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very interesting , i always thought it was done by using electrical current.. tell us more .. where you get the sulphuric acid from?? what u using? how much sulphuric do you have to add???
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