marking / layout blue

[John BaronParticipant @johnbaron31275]

Hi Guys,

A small tube of Prussian Blue artists oil paint diluted with linseed oil and white spirit works well but it takes a long time to dry off. Though personally I prefer to use a permanent marker.

[mechman48Participant @mechman48]

I recall using Copper Sulphate when I was apprentice; then along came blue 'Layout fluid' which I used in the tool room. I also remember, when marking out on castings, using 'leaded' white wash, until the H & S gremlins came along. Didn't someone say on here that you can still get Cu sulphate solution from garden centres ?

George.

[pgk pgkParticipant @pgkpgk17461]

Posted by mechman48 on 01/09/2018 14:35:55:

…. Didn't someone say on here that you can still get Cu sulphate solution from garden centres ?

George.

I make my own bordeaux solution from copper culphate crystals and lime, both bought on ebay (to protect my citrus from fungal disease prior to their winter greenhouse quarters)

Of late i've been using more layout blue despite DRO if only to help keep the gremlins away.

[larry phelan 1Participant @larryphelan1]

Came across a tin of Stuarts Micometer blue,while looking for something else,so it,s still around.

Bought it years ago,dont remember when I last used it.

[SillyOldDufferModerator @sillyoldduffer]

Quite a few disadvantages with Copper Sulphate:

• Has to be made up and acidulated with Sulphuric Acid.
• Only works on clean steel, and not all of them!
• Best applied by dipping in a tank for a few minutes, not by brush
• Work should be rinsed and dried after application. Slow.
• Messy & corrosive (acid drips)
• Degree to which the copper coat sticks to the steel varies between flaky and semi-permanent
• Relatively poor contrast between scribed line and the background colour
• Mildly poisonous, you don't want it in a cut or your eyes, or have a pet drink it.

Blue dye marking fluid is fast drying, safer, easily removed (apart from some plastics), and can be applied by brush to almost anything. It makes a fair fist of coating dirty metal. Much less fuss. Mind you, dropping the bottle with the cap off turns you into a smurf. I used to own a mini-lathe painted green and yellow plus many blue camouflage blotches.

Got a recipe somewhere involving ground up chalk and Gum Arabic. I'll see if I can find it.

Dave

[Nick Clarke 3Participant @nickclarke3]

Posted by SillyOldDuffer on 01/09/2018 18:11:06:

Got a recipe somewhere involving ground up chalk and Gum Arabic. I'll see if I can find it.

Some recipe! These TV cookery programmes are really getting a bit weird – bring back Delia I say!

[Pete RimmerParticipant @peterimmer30576]

Posted by larry phelan 1 on 01/09/2018 18:08:05:

Came across a tin of Stuarts Micometer blue,while looking for something else,so it,s still around.

Bought it years ago,dont remember when I last used it.

Stuarts is still around but it's not layout blue, as I'm sure has already been pointed out. Layout blue dries out fully so it can be handled, engineer's blue is designed not to fully dry out, though if left on over several weeks can be a bit of a bind to remove.

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