Issues with cermark and a 3" logo

[Keith Downing]

This is my first shot at using cermark for something relatively large and solid. This was a test piece, so no worries. Couple problems showed up right off the bat though.

First, I realize that the surface of the metal (in this case a flask) is ever so slightly bowed; but I'm getting a weird change in "texture" about halfway through. What's the most common cause of this? I was thinking maybe residual heat buildup? The flask did warp badly towards the octupus head (see pics). But still, it's such a well defined line, almost makes me wonder if it's something else.

Second, I've noticed this with some of my smaller pieces before, but those are 2-3 pixel wide white spaces around the logo (what looks like the octopus's eye) that are showing up as just a slightly less black line. Again, is this too much heat? Or does a white "line" just need to be more than 2 or 3 pixels wide when working with cermark?

This is a 60 watt tube, set at 80 mm/s, 95% power, 1000 dpi, with an interval of .05.

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[Kev Williams]

I've never been able to get, in my opinion, 'great' results with Cermark using my 80w glass Triumph. I do some 1/4" wide outlines on SS panels which I do via vector with the lines drawn .004" apart. To get a decent burn I run at 200mm/sec, power settings 22-high 17-low, and this is with a 3" lens de-focused by .06"...

Any more power or tighter-focused than this and the Cermark seems to burn away rather than burn IN...

So my advice would be to get the speed up to 150 or 200mm/sec, and turn your power down to around 30 or 40%, see what happens, and go from there...

[Keith Downing]

Thanks for the reply Kev. I thought most people ran cermark at 100 power on a 60w tube, with varying speeds. I'll definitely try giving it a shot with significantly higher speed and see where that gets me.

I was (am) just so worried that I won't get a full, dark mark and the piece will be ruined if I turn it down too much. But it does look like there's too much heat at the current settings.

[Ali Kemp]

So far in my experience and my setup I have always run at 100 power and around 50 speed on my Trotec. This gets me very good results. Do you know exactly what kind of metal your trying to mark and does it have a protective coating on it already? If it does that doesnt usually play well with the cermark.

[Keith Downing]

So far in my experience and my setup I have always run at 100 power and around 50 speed on my Trotec. This gets me very good results. Do you know exactly what kind of metal your trying to mark and does it have a protective coating on it already? If it does that doesnt usually play well with the cermark.

It was just an old stainless flask. But the final product will be on a yeti (or similar) drink cooler. Thus the extreme fear that resulted from the below average first test with the logo.

[Keith Downing]

200 mm/s speed and 80% power yielded a MUCH nicer result. See below.

Oh and I did have to blow up the logo about 25% and add a 2 pixel stroke outside (on both sides) to get it to show up how I intended. But it does have a pretty cool effect now.

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[Mike Null]

Keith

My guess is that the focus issue was more of a problem than anything else and I would have run the job twice focusing on the highest point, then the lowest point. Since I can't see the curve that is obviously just a guess.

I use 600 dpi on my 45 watt Trotec. The warping is not a surprise as the flask metal is very thin and too much heat will warp it in a flash. I would experiment with 600 dpi on thinner items to see if that helps.

[Keith Downing]

Keith

My guess is that the focus issue was more of a problem than anything else and I would have run the job twice focusing on the highest point, then the lowest point. Since I can't see the curve that is obviously just a guess.

I use 600 dpi on my 45 watt Trotec. The warping is not a surprise as the flask metal is very thin and too much heat will warp it in a flash. I would experiment with 600 dpi on thinner items to see if that helps.


Mike, I could be wrong, but on the Chinese lasers, isn't it the interval NOT the graphic dpi that is actually the final determination on the quality/detail the laser lays down?

This was my understanding; that the dpi could be 1000, 2000, whatever, but if the interval is set at .05 it would still only do roughly 500 lines per inch.

Feel free to correct me if I'm wrong! I just don't see how, if the interval determines the number of lines in the grid the laser runs, that dpi could still matter (unless of course it's lower detail than the number of lines per inch, that would seem to matter a lot).

[Keith Winter]

Keith that turned out really nice! Question for the group. Can cermark coated parts be stored for weeks or months after coating prior to engraving? Like those tumblers if you coated a couple dozen at once then worked through them as need. Would they be ok or would the cermark degrade or be hard to remove after sitting on the tumbler for a few weeks or months?

[Dave Gates]

The last large order of Yeti cups we marked, I had some cups that had cermark on them for about 10 days with no issues. So these items may hold up ok for longer periods.

I marked a customer's knife 2 weeks ago and the cermark stained the metal after being on it for about 30 minutes. I got lucky when cleaning it up though, a jewelry polishing rag and 20 minutes removed the stain.

[Keith Downing]

Keith that turned out really nice! Question for the group. Can cermark coated parts be stored for weeks or months after coating prior to engraving? Like those tumblers if you coated a couple dozen at once then worked through them as need. Would they be ok or would the cermark degrade or be hard to remove after sitting on the tumbler for a few weeks or months?

Thanks Keith! I was happy with it as well.

According to the website, that's the difference between Cermark (which can be stored and handled) and Thermark which can't .

I will say though, just based on common sense, I would store them away safely in a cool dry place. Small nicks and dings will obviously show up. And, of course, since water washes away the excess I'm assuming extreme humidity would be detrimental to the coating bond.

[Keith Downing]

The last large order of Yeti cups we marked, I had some cups that had cermark on them for about 10 days with no issues. So these items may hold up ok for longer periods.

I marked a customer's knife 2 weeks ago and the cermark stained the metal after being on it for about 30 minutes. I got lucky when cleaning it up though, a jewelry polishing rag and 20 minutes removed the stain.

I have read that on stainless steel the cermark can leave a stain, and the longer it's on the worse it is. But I have yet to experience it in my limited use.

[Mike Null]

Keith

I have zero expertise on Chinese lasers so I can't address your dpi question. You can clean the Cermark stains with stainless polish or with automotive polishes.

[Kev Williams]

This of course is just my opinion based on my experience, but concerning power/speed settings and overall engraving results, metal RF lasers cannot be compared to glass DC lasers. They are as different as automatic and manual transmissions in cars; different ways to get the same results...

I've found with my metal lasers, it's nearly impossible to 'overburn' Cermark on stainless, while at the same time it's also nearly impossible to get them to reliably fuse Cermark to raw aluminum or the brass I laser- But with my glass laser, the exact opposite is true. So far (but still trying), I find it hard NOT to overburn Cermark on SS. When I get close to a nice black result, it tends not to be fused to the metal well, can be washed or brushed off... Adding a little more power helps, but the results aren't consistent, some sticks, some don't. But adding more power then fuses it like gangbusters and gives me very consistent results, IF I'm okay with a bronze-ish dark gray result-- But I'm NOT okay with bronze-ish, I want BLACK-ish. But on raw aluminum and brass, crank up the power and the glass laser works great. The results are very consistent, and while not as black as I'd like, the results are still much darker than I get on stainless.

*to the best of my knowledge* (<<disclaimer!), metal RF lasers always fire in pulses, while glass DC lasers are either ON or OFF. Because of this (partly), RF lasers don't suffer 'lag time'. Each pulse is an instantaneous on and off, at the power setting chosen, with each fired dot essentially identical to the next. The Synrad laser in my LS900 running 72" per second and 1200 dpi is firing over 86,000 times per second, and it's not breaking a sweat.

But a glass laser, since it's simply "on" like a light bulb, does suffer lag time, getting to full on AND off... In many cases it's not a big deal, like engraving plastics. But with Cermark and stainless, it does create problems-- for me at least...

What I've had trouble with is basic 1/2" or so tall text-- The letters T, and F for example, have long horizontal expanses in the X-plane (laser ON for a LONG time,), but very short vertical expanses (laser on for a very SHORT time)... So the issue I have is this: If I get nice black tops of T's the vertical shafts don't get enough heat from the laser to fuse, and they can be washed off. But if I add power to get the vertical shafts nice & black, then the horizontal tops get overburnt, and turn bronze. Frustrating! I sold 100-something 2" x 4" SS plates to a customer with 3/4" arial font lettering that was a checkered mishmash of bronze-ish and black-ish text. The customer didn't mind as they were strictly 'info' plates and looks didn't matter (his words), but I thought they sucked. And I've yet to be able to find a cure for the problem, aside from engraving VERY slow. And I still can't get it black, dark bronze-ish gray is the best I can muster.

But even running my Synrads at full power and glacial speed, they will not turn Cermark on SS bronze. I still haven't figured out exactly why!

[Neville Stewart]

Hi Keith, just noticed you're in Austin. Hey from the east side. I do a fair amount of stainless marking. If I can help out let me know. Neville

[Keith Downing]

Hi Keith, just noticed you're in Austin. Hey from the east side. I do a fair amount of stainless marking. If I can help out let me know. Neville

Thanks Neville, I was wondering how long it would be before I ran into a fellow creeker here in Austin. We are still in more of the learning phase on a lot of things, but the offer is much appreciated. Maybe we could stop by your shop sometime, it'd be worth the trip for me just to see the bigger trotec and the fiber laser in action!

[Neville Stewart]

Thanks Neville, I was wondering how long it would be before I ran into a fellow creeker here in Austin. We are still in more of the learning phase on a lot of things, but the offer is much appreciated. Maybe we could stop by your shop sometime, it'd be worth the trip for me just to see the bigger trotec and the fiber laser in action!
Any time, just give me a ring or a note. All my contact info is on my site. See you then.

[Michael Perrault]

The last large order of Yeti cups we marked, I had some cups that had cermark on them for about 10 days with no issues. So these items may hold up ok for longer periods.

I smarked a customer's knife 2 weeks ago and the cermark stained the metal after being on it for about 30 minutes. I got lucky when cleaning it up though, a jewelry polishing rag and 20 minutes removed the stain.

I always hated the staining that Thermark/Cermark leaves. They say it's the strong solvent that can effect the surface of metals. I think it's just alcohol, however. If you dry it and remix with water it's supposed to reduce the staining. Depending on the contaminants on the surface, it can still be a problem. I found that Noxon and metal polished can remove some of the marking. After years of this problem, I ran across Citrisurf, a passivation product. They don't give it away but Cermark isn't cheap either. It works so well, you can quickly and gently rub it across the surface of the metal with a soft cloth (aluminum is what I usually use it on) and the stains wipe right off. If you're really aggressive for a minute or more this can eventually remove some of the marking as well. As a bonus, you can use it before to prevent staining. Rinse well with water.
Now that I finally found an easy solution, I'll probably get a UV printer and not use the stuff any more.

[Kev Williams]

The new version of Cermark loves to hang on. While it seems like it stains stainless, as it can sometimes seem impossible to get off, the trick is simple: Magic eraser. I actually use the Home Depot brand because it's not quite as aggressive as the real ones, but even using the heavy duty real ones, they've never left a mark on the SS even wiping across the grain, (but I go with the grain whenever possible!) and conversely, the HD ones clean Cermark off just fine. I tried the HD version on a polished SS plate the other day, which can scratch if you breathe on in hard, but the eraser didn't scratch it...

That said, the new Cermark CAN and DOES stain brass as it really speeds up the oxidation process. ---beware if anyone brings you carbon steel tools to be lasered, like chisels, I did some once and the Cermark made them rust immediately, and that was the OLD formula! The new is worse-

As for Cermark longevity, I've had a brass cowbell kicking around here I Cermarked at least 3 years ago, I lasered it earlier this week, looks just fine. As it was the old formula, the brass beneath was okay too. The new formula on these bells is a race against time, sometimes-- they're plated with reclaimed ammo shell casings, and some batches won't tarnish hardly at all, while others will darken up within a couple of hours...

[Brian Leavitt]

Can cermark coated parts be stored for weeks or months after coating prior to engraving? Like those tumblers if you coated a couple dozen at once then worked through them as need. Would they be ok or would the cermark degrade or be hard to remove after sitting on the tumbler for a few weeks or months?
I had a bunch of samples I wanted to engrave for display, a while back. I coated them with the cermark (I use the spray can), but ran out of time to actually burn them. Then I forgot about them and they sat in a box under a work bench for a year. When I found them again, I decided to engrave them and everything worked as if I had just sprayed them that day. I was a bit surprised, but I had no issues whatsoever.