Lettering panels with a Leroy guide - Page 1
Forum section: electronics / projects

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: April 27, 2018, 05:59:57 pm
content: Decades ago I used to work for a company that built one-off prototypes and test equipment. We'd paint the panels and then do the control lettering with a Leroy lettering guide. On light panels the better black (India) drafting inks worked well and were durable. I think we used Koh I Noor ink made for drafting films. The end result was quite presentable after one got the knack of it.Moving to the present, I want to use the same technique to letter ablackrack panel. There seems to be a white Koh I Noor ink, and I've also considered trying some airbrush acrylic paint, possibly thinned.Finally, the question- what kind of ink or pigment do you think would give the mostdurableresults for this?

author: ajb
author_rank: Super Contributor
timestamp: April 27, 2018, 06:12:25 pm
content: That's a really neat idea! I was given a Leroy kit when I was learning drafting, but at that point we moved pretty quickly to CAD, so I don't think I ever actually used it. It's definitely a neat tool, though. I kind of regret getting rid of that stuff.Ink choice will depend partly on how the panel is finished, I think. Powder coat is basically plastic, so maybe you'd want a solvent ink for that? A matte-etched anodize has a bit of 'tooth' to the surface, so that's probably less critical, but depends on the depth of the etch. Paint is probably the easiest, as in theory you should be able to letter with any compatible paint.If you can get hold of the inks used on silkscreening on metal panels, those will probably be ideal, if they can be thinned enough for your purpose. I think a lot of them require heat to cure, though, and if your panel is too big for a cheap toaster oven I'm not sure if you'd want to do that in your kitchen oven.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: April 30, 2018, 05:51:32 pm
content: Finally got back to this over the weekend and learned a few things. There were several choices of white ink/paint available locally, so the first order of business was to test them for opacity and water resistance:Dr. Ph. Martin's Pen White- opaque, but no water resistance at all. Ok flow in pen.Speedball white ink- poor opacity but quite water resistant. Good flow in the pen.Testor's Aztek airbrush acrylic- opaque and good water resistance, but dries too fast and clogs the pen frequently.Uniball white ink pen (won't fit the Leroy, but curious about the ink)- Nice line, nicely opaque but zero water resistance.Daler-Rowney’s white ink- opaque and water resistant, might be the winner.I think white ink is troublesome because a heavy load of pigment is necessary for opaqueness. If enough pigment is present for good opaqueness, it tends to clog the pen. Thinning the heavier materials hurts opacity. Writing on panels worked well enough with black India ink, but the white inks tend to bleed a bit if they're thin enough to flow well. It's hard to do fine lettering without the letters becoming a blob.I'm convinced this can be done well, but the right ink is the key. The perfect ink would have just enough opacity, wouldn't tend to bleed and wouldn't clog the pen. To that end, it could take a long time to dry, even requiring a bake to do so. That's an advantage if an error is made, as it can be wiped off and redone. I haven't investigated solvent based materials because of the more troublesome cleanup, but that's another avenue.More as I try more options.

author: GerryBags
author_rank: Frequent Contributor
timestamp: April 30, 2018, 07:48:17 pm
content: Quote from: Conrad Hoffman on April 27, 2018, 05:59:57 pmI'm a recent convert to the cult of the electron, most of my life I've been an arty-farty type. I've spent the last few years making military models, and painting them in acrylics. I sold lots of my model kits to buy 'scopes, but still have loads of acrylic paints, varnishes, etc., I can definitely point you in the right direction.As long as you're not talking metallics, as they're not durable at all without clear coating, and you're prepared to airbrush, you can't beat the lacquer based acrylics for durability - like those made by Tamiya, Hattaka (orange line), Gunze or MRP - from almost as soon as they are applied. MRP are, in my opinion, by far the best. You can also get transparent shades, which would enable you to tint clear plastic lenses for white LEDs to any colour you like. Their solid colours are very pigment rich, and that pigment is easily fine enough for my Iwata's 0.2mm nozzle.http://mrpaint.sk/I have mainly military colours, but there are two shades that are getting used on a dim bulb tester I've just knocked up which needs its.... plastickiness.... disguising. I'm going for the late WW2 USN Gloss Sea Blue on the top of its box, with white lettering, and Insignia White for the bottom and sides.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: April 30, 2018, 09:04:40 pm
content: Good info! I'm a bit of a hack with an airbrush, though I do enjoy it. The Leroy however, uses a technical pen arrangement, so the airbrush won't help me. The lacquer based acrylics still might be just the ticket- I'll try to track some down for a test.Your model just reminded me that we have a model railroad supply place nearby. It burned down a couple years ago and they lost a lot of irreplacable stuff, but they rebuilt and probably have a much better paint selection than the arts & crafts stores.http://www.despatchjunction.com/

author: GerryBags
author_rank: Frequent Contributor
timestamp: April 30, 2018, 10:43:51 pm
content: Something interesting I saw recently was a British guy's take on Vanta-Black, except you don't need to sell a kidney for a pot and you have to sign a waiver to say that you will never let Anish Kapoor have your pot. It's supposed to be 90+% as black as Vanta. My stupid memory is failing to supply the name so I will have to ask my neice who had bought a sample set of the black acrylic paint and four daylight visible flourescent pigments.This stuff is so black that you could have what you'd normally call black as the panel colour, and have this black for the lettering and still see it. It's like a gateway to the voidHa! I just went to grab a pic to illustrate Vantablack (apparently), and I found a pic of the alternative my neice got (it's far cheaper) It's "Stuart Semple" Black and it's about $20 in the US:This is the Vanta promo shot:

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: April 30, 2018, 11:24:29 pm
content: Really black paint is an interesting topic. One could go down a deep rabbit hole on blackening optical devices. A lot of research has been done in that area. My cans are long empty, but 3M used to make special matte white and black for such things. I don't know about the blacks above, but most really good blacks are also very fragile. A bit of rubbing or trace of oil and they're not so black anymore. My panel is Rustoleum satin black, which looks a lot like black anodize. It's not terribly black, but when you reach a certain age, black on black color schemes leave a lot to be desired. One of my concerns was that a white white might be too much. I did consider going with a light grey or even something like a light green.

author: GerryBags
author_rank: Frequent Contributor
timestamp: April 30, 2018, 11:37:47 pm
content: USN White is a nice off-white. The Navy also didn't want it to be too bright against dark colours. This one is on US Fleabay too. Incidentally, I think that if the technical pens you're talking about are anything like the Rotring ones I think MRP will be fine with it, especially thinned with Mr. Levelling Thinner by Gunze Sangyo (http://www.mr-hobby.com/en/itemDetail.php?iId=158)https://www.ebay.com/itm/Mr-Paint-U-S-Navy-White-FS17875-MRP-99-30-ml-new-/282730683065

author: Cerebus
author_rank: Super Contributor
timestamp: May 01, 2018, 12:33:45 am
content: Quote from: ajb on April 27, 2018, 06:12:25 pmThe problem with the best of those is that they are two part catalysed and as such would be anathema to the kind of technical pen you need to use with those stencils. I know from using technical pens in the days of yore what a *^£%@&@£* they are to clean, and trying to get a catalysed ink out before it set would be one of my ideas of a task suitable for torturing for the inhabitants of hades.Also, screen printing will handle, and to some extent requires, much higher viscosity inks than one could ever persuade to flow through a Rotring pen or similar.

author: GerryBags
author_rank: Frequent Contributor
timestamp: May 01, 2018, 12:52:18 am
content: Quote from: Cerebus on May 01, 2018, 12:33:45 amMy Mum was an illustrator who used the Rotring technical pens for years. We always had a supply of new nibs (most of the pen) because of the difficulty in cleaning them after even water-based inks had dried in them, or if they'd been used on a fibrous paper rather than a heavily clayed board. Fairly recently My Dad got into doing caricatures and bought a Rotring pen but this one had fountain-pen like cartridges (still refillable with a syringe) and seem to have had an internal redesign that makes them much easier to clean by squirting a solution in to the cartridge end after a soaking. From the smell, the solution is mainly IPA. If it's been a while since you played with a Rotring, they are a big improvement over the previous generation.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: May 01, 2018, 01:36:15 am
content: I have an industrial strength ultrasonic cleaner in the garage- no semi-dry schmutz escapes me!

author: GerryBags
author_rank: Frequent Contributor
timestamp: May 01, 2018, 02:15:29 am
content: Careful cleaning your airbrushes with those, unless everything is fully disassembled any metal on metal contact can lead to one or both of the parts getting damaged. The nozzles are soft and I've seen them disintegrate following removal after ultrasonic cleaning. Not sure how the technical pens are constructed, but I'd be wary about a similar issue until you know it's safe.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: May 09, 2018, 03:31:15 am
content: Yes, have to be careful with tiny metal parts and the ultrasonic!The winning ink is the Daler-Rowney white ink. I did some sample lettering and it flows better than all the others, but gives well defined opaque letters. It's water resistant when dry and seem durable. Now I just need to get some spring clamps to hold the straightedge on the panel so I can position it for the various rows of lettering. Though I did this commercially long ago, I can't remember how we held the panels. Possibly on a drafting board with a drafting machine. It would make sense because those can usually be locked in position. I like antiques, but have no intention of finding and setting up a drafting machine!

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: May 16, 2018, 03:47:13 am
content: Here's the result on a new panel for an audio switch box. Not the equal of mass production silk screening, but not too shabby either.

author: Cerebus
author_rank: Super Contributor
timestamp: May 16, 2018, 02:30:56 pm
content: Hmm, better than I might have expected. Printing white over anything is always a big ask*but the opacity on that ink is excellent. Get yourself a bit more practice to get rid of the occasional odd letter spacing and baseline wobble and you'll be turning out stuff that's indistinguishable from good commercially produced lettering. By the way, nice kerning on the large type.*I spent a couple of years running a printing press and every time you saw an order with white or metallic ink specified your heart sank, you knew you were going to be spending the whole day getting the press set upjust rightand waste half a ream of stock before you got acceptable results.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: May 16, 2018, 05:18:23 pm
content: Yeah, my old eyes did better with the larger text. Getting the spacing to look just right takes more practice than I've had. Never run a press, but my first job was in a paper warehouse. Did everything from driving the forklift to cutting special orders on the big scary Seybold cutter. Pull up on the left, push down on the right? It's been a few years. Grain long or grain short? Oh man, I remember drilling hundreds of reams of 3-hole paper by hand on some obscure machine. Paper is darn heavy. More than a few times the rear wheels of the forklift came off the ground.