By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

Marking out blueing or pens?

All Topics | Latest Posts

Search for:  in Thread Title in  
jon hill 316/09/2020 22:14:19
63 forum posts
14 photos

I often use a solvent marker pen so my marking out shows up better, however solvent pens don't take well on oily surfaces. Are there pens that will take to any oily surface?

Also I vaguely remember using a bottle of blueing for the same purpose many moons ago, having made a quick search there are a bewildering variety of different products. Can someone explain the difference in these products... Eg engineers blue in a tin, bluing paste, cold blue etc.

Andrew Johnston16/09/2020 22:28:21
5657 forum posts
653 photos

There are two basic products. Engineers blue in a tin is a sticky paste used to identify high points when scraping. For instance if one wants to scrape a surface flat against a reference (surface plate) the work is smeared with a thin layer of engineers blue. The work is then pushed across the reference surface. The points where the blue has been rubbed away are high points and need to be scraped. Then repeat as required. The watery blue liquid in a bottle is for marking out. It's painted or wiped on where it dries and leaves a thin blue sheen. Scribed line then show up more clearly.


Nigel Graham 216/09/2020 22:51:02
748 forum posts
16 photos

Normal fibre-tip pens won't work on oily surfaces, no, in fact it will harm them.

Neither will marking-out fluid, which is what you are asking about; but in both cases, clean the surface first with a suitable solvent such as meths, which will also remove the ink afterwards.

When marking out rough or dark materials like hot-rolled steel, I sometimes clean the surface, spray it with a couple of coats of grey primer and mark out with a sharp pencil.

IanT16/09/2020 22:52:22
1611 forum posts
151 photos

I use both Jon

For quick jobs, then a black 'Sharpie' works well on both steel and brass. It's convenient and quick - so a quick dab on a turned part to mark (say) the length of cut - is very handy. It does rub off fairly easily though, so it's not quite as "permanent" as the name suggests - at least on metal.

For larger/more involved work I still use Marking Out Blue - my small bottle of which I purchased from GLR donkeys years ago. You just paint it on with a small paint brush (I use children's ones). After use just let them dry out - they will soften very quickly when re-dipped in the blue. This blue stays on a lot better than Sharpies but can still get worn/rubbed away as the work progresses. So quite often I will place a few punch marks on marked lines for instance to keep the important reference points even if the marking wears off.

Many here will just drill/cut straight from DRO readings these days of course but I still like to see parts marked out.



Mike Poole16/09/2020 23:21:20
2739 forum posts
64 photos

Dykem layout blue is an excellent product for marking out, scribed lines are clear and crisp. Permanent markers are very convenient but the durability is not very good if the item is handled very much. Dykem takes handling much better. Engineers blue is for checking fits or against a reference surface.


Mike Poole16/09/2020 23:33:28
2739 forum posts
64 photos

If you mark out you get a chance to think about whether it’s right before you cut metal. If you are confident then a DRO and diving straight in is a quick way to work but a mistake can be more difficult to rectify than rescribing a line.


Ian Johnson 117/09/2020 00:51:33
288 forum posts
82 photos

Try the new Sharpie 'Pro' felt tip marker pen, it writes on oily or wet surfaces. Bought one today from the local supermarket £3


Tony Pratt 117/09/2020 07:14:24
1225 forum posts
5 photos

Clean the oil off

Thor17/09/2020 07:16:04
1275 forum posts
39 photos

I use both marker pens and layout blue. For laying out just a few lines or points the marker pens are very convenient, if laying out lines that will be used later on during several machining processes I use the more permanent layout blue.


Michael Gilligan17/09/2020 07:55:59
16360 forum posts
712 photos

Please forgive the slight digression, but I must mention a recent ‘find’

I was reading a piece about making steel clock-hands, in which it was casually mentioned that the material was ‘blued’ prior to marking-out with a very fine scriber.

Nothing unexpected in that“ you might say : but the author was talking about blueing with heat [as one would normally do when finishing the hand]

This seems an exceptionally good idea, if the workpiece is suitable.


Bo'sun17/09/2020 08:44:46
202 forum posts

Hi Jon,

Like the above, I use both. Permanent marker for small areas, and layout ink/fluid for larger areas. Buy a decent layout fluid such as dykem, I've found cheaper ones take ages to dry and tend to flake off when scribing into them.

SillyOldDuffer17/09/2020 09:55:01
6322 forum posts
1384 photos

Scraping is the classic application of Engineering Blue paste but it's good for identifying any area of poor fit, like checking tapers, or confirming a gib is pressing evenly. A small tin lasts forever.

It's possible to make a 3rd rate layout blue substitute from paste by dissolving it in Meths. Inferior to real Layout fluid and felt-tip, but handy in a pinch.

Before layout blue, steel was dipped in slightly acidified Copper Sulphate solution, which deposits a thin layer of Copper on the surface. Works quite well, but fussy. Dipping tanks take up space and the chemicals are a mild hazard. Mostly I use felt tips. Decent brands work better than pound shop cheapies, but it's not critical

All layout fluids need a clean surface - remove oil first.


Edited By SillyOldDuffer on 17/09/2020 09:56:08

Steve Withnell17/09/2020 10:22:08
815 forum posts
217 photos

I started off using acidified copper sulphate solution, mainly because I was learning from books that came out of the Ark's library. Then got converted to a big fat black Sharpie and never needed anything else for marking out.

jon hill 317/09/2020 10:23:07
63 forum posts
14 photos

I was interested to here about oil resistant makers eg sharpie pro, I just discovered staney make one to. Has anyone used these pens and do they live up to the hype?

Vic17/09/2020 10:42:21
2607 forum posts
20 photos

I switched to using jumbo permanent markers years ago, they work very well. I’ve not done it but I believe some of them can be refilled to keep costs down.

mechman4817/09/2020 11:04:40
2746 forum posts
422 photos

I don't have that many projects on the go, mainly small engines, & then only one at a time; I prefer to use Jumbo markers for any flat surfaces & chisel pointed sharpies on others so find them quite effective.

During my apprenticeship we were taught to use Dyekem layout fluid as the preferred method but we also used copper sulphate mix, whitewash mix ( white lead ) on cast srfaces, now long since banned. I belive Copper Sulphate is still obtainable from some gardening centres if you want to try that out. To date; jumbo & Sharpies do fine for me.


Circlip17/09/2020 11:32:59
1197 forum posts

Tinned "Engineers Blue" - a little goes - - - - - all over the b****y workshop, as many will attest.

Regards Ian.

Robert Atkinson 217/09/2020 12:07:53
768 forum posts
17 photos


You mentioned "cold blue". This is totally different. it is used to produce the protective bluing of steel used on guns etc. While you could mark out through tthis I won't help with your problem because it won't work on oily material. And of course it only works on ferrous metals.


Robert G8RPI

Edited By Robert Atkinson 2 on 17/09/2020 12:11:34

Vic17/09/2020 12:34:06
2607 forum posts
20 photos

I’ve got both Blue and Red markers but not sure I’ve used the red one. It seems the British prefer blue whilst the Americans prefer red. Or am I mistaken?

Howard Lewis17/09/2020 13:27:38
3605 forum posts
2 photos

Prussian blue (Mine is Micrometer Brand   is DIFFICULT to remove from fingers, but ideal for scraping surfaces.

For marking out, Spirit blue is the one to use. Again hard to remove from fingers!

A Sharpie or a blue felt tip (Chisel point) can be used for marking out, but, is not as durable, in my experience, as spirit blue.



All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Support Our Partners
Eccentric July 5 2018
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest