let's talk about metal markers!

 In which your author core-dumps more information than you
probably wanted to know about Sharpies™, flow pens, soapstones,
and other markers one finds around a typical metal shop...
plus: a Recent and Significant Development of Marking Technology.

 

 Carpenters, framers, cabinet-makers, and other wood-workers got it easy: with the exception of weird exotic woods, they can nearly always make the marks they need to make on wood with either a pencil or a traditional marking blade.

 But wood doesn't often come covered in rust or oil, wood is never heated to thousands of degrees, and so on.  Marking metal for various purposes around the shop (or worse, the metal or scrap-yard) can be quite challenging.

 Let us review some traditional methods, as depicted in this photo... except this is missing a paint marker, because the last one I had vanished somehow and hasn't been replaced...

 

0. paint markers (not shown)

 There are several sorts of object known as "paint marker", containing a variety of inks or paints, for a variety of purposes.  There are even some available at craft and fabric stores for marking fabric. (spoiler: if you need those, you are reading the wrong blog)

 The ones with oil-based, fast(ish)-drying paint which are best for metal come with two flavors of tip: a coarse flow-pen nib AKA "felt tip", and a ball-point design. My experience is that the latter are far more durable, and the former must be babied to last.

 Paint markers are popular with iron-workers and people who make big cuts and holes in big pieces of metal, but I have found them available in most hardware stores.  They are a bit expensive, usually at least $5 ea in 2022.

 As for heat resistance, the common paint markers use an remarkable paint which is destroyed by welding heat or higher.  I have heard for years that high-heat version exist, but I've never seen them sold, even in welding shops.  A quick web search reveals that Dykem (the layout dye people) make a "high heat" marker good to 1093ºC / 2000ºF.  In my opinion, for $13 each, they can go piss up a rope.

1. soapstone

 The traditional marking tool of welders, iron-workers, and metal-workers.  It's most important feature is that the mark is virtually heat proof.  The marks will withstand the 1100ºC heat of yellow-hot steel.  I honestly don't know what kind of heat it takes to vaporize soapstone (AKA talc) but I'm fairly certain you'd need a steel-worker's reflective suit to be in the same room with it.

 Soapstone will write on some slightly oily surfaces... depending. On thick oil, no.  On grease, no. On very thin layers of very light oils, yes.  On mill scale certainly.

 

 Very inexpensive, lasts a long time, "sharpens" with any belt sander, sandpaper, or file, replacement stones are very cheap, and available at virtually any hardware store in the CONUS.

 

2. The Sharpie.

 AKA 'flow pen', sometimes 'marker pen'.  

 

(the genericized trademark "Magic Marker" is a storied brand now in use by more than one company, to refer to different products, for different end-use purposes, which originally belonged to The Magic Marker Corporation of Cherry Hill, NJ, now defunct.)

 The Sharpie (originally the creation of The Sanford Corporation, now held by Newell Brands), was such an extraordinary success story in terms of market penetration and domination that it is completely ingrained into American manufacturing and office cultures as well as the common vernacular, so much so that it actually is tested to meet a standard (ASTMD-4236)*.  Everyone in America knows what a Sharpie is, although most never think about that fact.

 

 The Sharpie and its imitators are popular in every business sector because of their finely-pointed tips, permanent ink, and choice of colors.

 But in the metal shop, standard Sharpies (including the new ink, more about this development later) have one singular problem: they don't mark well on oily surfaces.  As it happens, a surface in a metal shop which is NOT oily, is a rare thing, so they're restricted to cleaned or dry mill-scale surfaces.

 One limitation of flow pens has - until recently - been the "ink" they use.  Historically, a dye was used, which contained no particulates (ie; traditional - and opaque - pigments) which might clog the fine pores of the "felt" tips.  Once the carrier solvent evaporates, dyes dry to a very thin film indeed, which tends to be a bit transparent even with the best of mixtures.  With colors this is probably desirable, but not when we are trying to make opaque marks on metal.

 Some time in the early 2000s†, the Sharpie Extreme came out, which promised much darker marks, and lo, this proved to be true.  Someone on Reddit claims to have examined the new ink under a microscope, and found it to contain extremely fine solid pigment particles, which are apparently fine enough, or smooth enough, or both, to pass through the porous tips without clogging them.  I can tell you that Sharpie Extreme make darker marks, but performs no differently - ie; not well - on oily metal.

3. A Contender Appears

 A few years ago, the Milwaukee Tool brand brought out their own fine pointed permanent marker called, unimaginatively, INKZALL™ (yes, all-caps), had one big bragging point on all their marketing and store stocking materials: "even marks on oily surfaces".  I was moonlighting in a hardware store when they hit stores and I immediately ran around testing the thing on everything I could find.

 I am here to tell you that the claim is true: unless the surface is so swimming in oil or grease that the only thing capable of marking it is a rag, INKZALL™ markers will, in fact, cut through the oil and make a permanent mark on the metal.  Wipe with a dry rag and the oil will be reduced, but the mark remains.  This is a fairly impressive achievement.

 Interesting little tid-bit on all of their labeling: "ink made in Germany, pen made in China".

 So I habitually keep all of these around my shop, and use all of them for different things.  I haven't really been missing the real paint marker, which is probably why I haven't bought one from the hardware store right down the street (where I used to work).  I just don't need one very often.

______________________________________________________________
*this fact is almost certainly to enable its purchase by the US Gov't & DoD,
because the GAO wants EVERYTHING the gov't buys to meet SOME
standard of SOME kind or they won't put it on the approved list.

† at the same time the brand was sold to a Chinese firm, manufacturing
moved to China, and a bunch of new, non-tool products were floated
in markets the brand had never moved in before.