Marking out

Hello fellow travellers,

Can any one remember the formulae for making copper sulphate marking out fluid? I seem to remember that it included copper sulphate crystals dissolved in hot water with the addition of dilute sulphuric acid but I have forgotten the ratios.

Can anyone help ?

Tony Daborn

Quite a long thread on the subject here

I don't think its a fussy formula. Just dissolve as much copper sulphate as possible and don't worry about the acid. I cant remember ever putting any in. Bright steel with emery and dab a bit on.

SteveW

Brings back happy boyhood memories of "growing" huge blue crystals by dangling a tiny crystal tied to a cotton thread into a concentrated solution of copper sulphate!

Martin

When I first started up my home workshop (this century, not last ), I did make up some concentrated copper sulphate solution and put a few drops of battery acid into the mix. (100mL of solution or thereabouts).

One side effect is that clean steel does get a nice copper coat which prevents rusting...

I only ever use permanent spirit markers (Pentel, Sharpie...) now as it's just cleaner and simpler. There is also a choice of colours too-

Steve

Many thanks all. I shall go the straight forward route and dissolve the crystals and then if not successful add some acid based compound. I tried the permanent marker again yesterday but again found that unless the scribe was not at 90* to marker fluid as applied it was not easily seen.

Will let you all know the result

Tony

I used so-called permanent markers, but found they weren't so permanent as they rubbed off easily especially if there was any oil around.

I have been recommended etch primer spray paint - have found that works well, stays put, marks are clear, and is no problem to remove when required.

The only problem I'v had with marker pen is getting it all off again before painting, on the Stuart turner S9 the paint I used, and the (I thought) cleaned off marker disagreed with each other, requiring stripping, and repainting of a number of parts.

Ian S C

I use these, they're very good and come off with meths afterwards. Far less messy than layout fluid.

http://www.cultpens.com/i/q/PL01790/pilot-super-color-marker-pen-jumbo-wide-broad-sc6600

Whats wrong with traditional blue layout fluid,its been used for donkeys years and there was a lot of it spilled on benches, I travelled extensively around various machining ,and sheetmetal contractors plus a lot of toolmakers and never saw any copper sulphate used though its use was mentioned in various older tech books.For black plate whitewash and chalk were used though when the work was centre punched the chalk fell off. for black flat ,plate and angle ,grey aerosol primer really shows up scriber marks and primer can be painted over as most black iron finishes up painted.

I recently purchased a litre of traditional blue layout fluid. This much more than I will ever use. Nearly 80 in age.

Perhaps others may be interested in 20 ml or 100 ml plastic bottles.?

I buy a sachet of copper sulphate from fleabay and dissolve a little in hot water. Store in 35mm film plastic storage pods and shake well before use - lasts ages.

Rik