marking / layout blue

If you have a rather complex marking-out task, it can help to buy a pack of six OHP pens. OverHead Projection, that is - for writing on clear film. They are better for some jobs than ordinary markers as the colour is stronger, and the marking 'point' is thinner. And of course, a pack of six gives you, well, six different colours so you can mark the stages in a job, etc, avoiding confusion. And being pen-size rather than Marker size you can carry them in an overall top pocket.

Cheers, Tim

'Stuart's Micrometer Engineers Marking'

I have an elderly tin and it's still available.

Neil

Yes, Peter, I use marking fluid the blue Dykem version, it isn't expensive Walters&Walters sell it at something like £15/litre. . I use an aeromodellers ''flattie'' doping brush to apply a nice even layer over each piece of bright steel as soon as it's sawn off of the oily stock length. I have never bought the spray cans which are relatively expensive nor the small bottles, it makes economic sense to by a larger size and perhaps share with someone else.

For folks like me with less than perfect vision, and lacking machines with DRO, I find that it helps immensely especially in poor light conditions.

It does have another very useful attribute for those of us that cannot run a fully heated workshop, in that it keeps rust at bay when working on long term projects where covering the project in oil might not be desirable.

Trevor

Thanks gentlemen.

So micrometer blue is just "scraping" blue. I have plenty of the stuff, having done a fair bit of scraping. I just didn't know it was referred to as micrometer blue. I thought it had something to do with micrometers which in a way I suppose it has.

Andrew.

Used to have some White, Grey and Blue marking blue.

My two penn’orth goes like this …

Up north t’other side of Manchester we called the greasy blue stuff ‘bedding blue’. (Nothing to do with nuptial discord.)

On page 2 of this thread (about five years back) I related a story that went like this …

When an apprentice was learning to read a Vernier [scale], bedding blue was often [discreetly] smeared inside a doll’s eye magnifier for the unsuspecting learner.

Getting them to change eyes for a better look brought on more laughter. If you haven't seen a doll's eye magnifier (jeweller's loupe), they look like this.

‘Marking out blue’ is commonly used as a very quick reference by Chris of **LINK** especially when he is setting shoulder lengths on the lathe. However, as can often be seen, marking out blue will flake and rub off quite readily.

For extremely fine, close up work, toolmakers in my apprenticeship era would apply copper sulphate to steel. It allowed a much sharper scribed line and, although less clear than marking out blue, the copper coating didn’t rub off easily.

Sam

In the olden days ( back when Adam was a lad! ) I went to a new (then) secondary "Technical School". We had engineering lessons in a properly equipped mechanical workshop ( 6 lathes, two shapers, milling machine, drills, oxy/acetylene etc. For marking out there was a tank of copper sulphate solution to coat the work piece first. It was effective ( as long as the metal was cleaned first) and a very fine line was possible with a sharp scriber. Within reason, it survived the construction process!

Having said that - now I use the "proper" marking out fluid or, as has been suggested, a broad tipped permanent marker pen - both work well for me though the marker is better for small bits.

Norman

Marker pen will leech through undercoat paints even when removed with thinners

Yes, I've had that problem repeatedly. Amazing how persistent that stuff is. Just seems to keep coming up through the undercoat. Anyone found a cure for this?

I also find that marker pen gets rubbed off by swarf and fingers during machining or drilling or whatever. Sometimes I just use a handy spray can of blue hammertone paint as marking out blue. Without undercoat or surface prep it seems to stick well for marking out purposes but is easily enough removed when its time for finish painting. Cheap as chips compared with "proper" marking blue spray too.

Hello Hopper,

A quick flash coating of emulsion paint will 'stop' the leaching through of things like rust and water staining which is another manifestation of the same effect.

Brian

Layout fluid is button polish with a dash of gentian violet to make it colourful. If your bottle dries out, add metylated spirit. Gentian violet is on eBay at £20 for 10 grams, seems a bit pricy. Has a lot of Health and Safety warnings attached but people use a 1% solution to kill infections in baby's mouth. Can't both be right, can they?

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.

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.

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.

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.

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

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

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.