PDA

View Full Version : engraving a powder coated stainless steel panel



Graham Taylor
10-12-2015, 12:53 PM
I have been asked to engrave some text and a logo etc on what would be a powder coated stainless steel control panel that will form part of a automated mailing machine.


Scenario A is to use CerMark on on a bare piece of stainless steel - not tried this before so could be interesting :-)
Scenario B (customer prefered scenario) is to engrave on a powder coated stainless steel for a better overall look and finish tor the machine.

So I guess my questions (after a search here) are:


I understand that it is possible to engrave the powder coating although it may need a couple of passes to get a clean finish but if the panel is a dark grey would the engraved text (which I assume would be the stainless steel colour) stand out and look good?
If the customer wants a better contrast/different colour, can it be paint filled and then sprayed over with some sort of varnish to give a hard waring finish?
I was thinking of starting with the same settings as I use for anodised aluminium. Does that sound reasonable? The customer has only given me a small test piece so cant try too many different settings (I have asked for some more test pieces).
As CerMark is not a product I currently stock or use use much, any suggestions of the best (cheapest) place to buy some in the UK? I only need a small amount to do some testing on a piece of SS so I dont really need a big spray can although I have read that it doesnt really have a shelf life so I could get away with using it now and again.

Thanks for any help offered.

Bryan Jater
10-12-2015, 1:25 PM
Hi Graham,

It depends on the thickness of the power coating but generally I would expect to have to hit it pretty hard (50% sp, 100% p) with a couple of passes to get it cleaned out. You will need to see if the contrast if sufficient to please the customer!

Cermark doesn't come in small pots but you can always pop into one of the Trotec showrooms to try it out or failing that send us the artwork and we can run you a sample if you want to get a customer agreement before purchasing. The product really is very easy to use.

PM me if you want any help.

Best regards

Bryan

Kev Williams
10-12-2015, 3:18 PM
I've been lasering a ton of powdercoated flasks lately, in every color imaginable. Regardless of the color, there's a 90% chance you WILL have to engrave it twice. I've been doing one particular brand of flask that does work out in one pass, but the coating is extremely thin, very consistent (I'd love to know who did it). All others, twice is the norm. Slow and hot on the first pass, faster and hot second pass usually works.

BUT- some colors suck, plain & simple. White, pink some greens, purple are bad, white being the worst, just can't seem to get it all out. And if you try a polish, it can affect the powdercoating. DNA usually gets off what WILL come off. The one positive I've found is that after giving up trying on some colors, I run lower power second pass which seems to even-out the leftovers. So far my customers think those look fine. (but, they're happy they can be done at ALL!)

BUT the final caveat is, no matter how well the laser removes the PC, the best end result possible is whatever the stainless looked like before it was coated. If they just coated raw, maybe sanded a bit, maybe scratched up mill-finish 304, that's as good as you'll get. If they coated #4 finish stainless (like all the flasks I've done so far, thankfully), they can turn out great!

Joe Hillmann
10-12-2015, 4:40 PM
Often times when engraving through powder coat to metal below there will be a very light trace of color left behind. Sometimes a second or third pass will clean it up but often using a Mr. Clean magic eraser does the trick but may scratch the powder coat if it is highly polished.

Bruce Clumpner
10-12-2015, 6:28 PM
The cermark will give you a smooth finish, cutting through the powder coating will leave an edge in the material and as said above, may not remove all the color. If the customer is going to match the panel you're lasering to the rest of the machine, you have no choice but cut through the powder coating. Another option might be to use your laser to vector cut laser mask and have someone sandblast the artwork to finish. May even be able to re-coat the clear area in another power coat color and re-bake.

Mike Troncalli
10-12-2015, 6:50 PM
I'm not responding with a lot of experience so please correct me if I am wrong. BUT... I had to engrave a few samples for a customer as a test. It was found that after engraving the powder coat would start chipping away where it was broken by the engraving.. No expert on this but thought since you were asking for advice, I would throw my 2c in...

Chris J Anderson
10-12-2015, 9:30 PM
Suggestion:
If you are going to laser thru the powder coat, ask your client to also have a small piece of plate powder coated so that you can do some testing on that, rather than testing on the final product.
It won't cost much extra to have another small piece coated, and you will be able to work out your favoured method.

Your laser should work extremely well on cermark, and its easy to find some stainless to test cermark on.

There's plenty of info on this forum about using cermark correctly.

Then you might have another line of work :)

Graham Taylor
10-13-2015, 2:36 AM
Thanks for the help guys.

If I get chance I am going to some tests later today and see how it goes. I am going to get some new substrates to engrave so I can build up my engraved sample portfolio so I can start to advertise my engraving services which is something that I have not yet done.

P.S. If anyone has a formula to fit 35 hrs into a day then I would be interested because I have loads of other work to do that does not involve my laser which is really frustrating me.

Dan Hintz
10-13-2015, 6:49 AM
I had to engrave a few samples for a customer as a test. It was found that after engraving the powder coat would start chipping away where it was broken by the engraving.

Bad powdercoat job...

John Stevenson
10-13-2015, 1:58 PM
In the UK 908ltd. do a starter pack for Marksolid which is one of the Thermark brands for £35 plus postage etc.
This get you a range of samples and a small 70ml aerosol of the Marksolid.

http://www.908ltd.co.uk/webshop?page=shop.product_details&flypage=flypage.tpl&product_id=1139&category_id=41

I did a few panels and purposely kept the power down as I didn't want to hit base metal as it was plain steel and might have rusted.
This was the result.

http://www.stevenson-engineers.co.uk/files/P1010927.jpg

Paul hardy
10-13-2015, 2:20 PM
I've had god luck in testing this on control panel enclosures. The powder coat is pretty thick, so a 2nd pass does make a better finish. I mask w/ a medium tack paper based mask, then laser w/ whatever settings work for you. Then I use rattle can appliance epoxy (only black or white available). After a couple of thin coats of the epoxy paint, the level of the paint is nearly the same as the powder coat. It does take a little playing w/ settings, so if you can get a sample piece to test it would be much easier.

Graham Taylor
10-13-2015, 2:48 PM
In the UK 908ltd. do a starter pack for Marksolid which is one of the Thermark brands for £35 plus postage etc.
This get you a range of samples and a small 70ml aerosol of the Marksolid.

http://www.908ltd.co.uk/webshop?page=shop.product_details&flypage=flypage.tpl&product_id=1139&category_id=41




hmmm, I will have a better look at that tomorrow but it may be worth a punt.

thanks guys

Graham Taylor
10-14-2015, 12:58 PM
I did a quick test - see pic below. The customer was very happy with the detail achieved (it's better in the flesh) and is now asjking if there is anything that can be rubbed over the text to give a good contrast? The powder coat is a dark grey and he was thinking black.

I was going to mask it up and engrave again a few more timnes with a couple of different settings and then try some acrylic paint to see how it comes out but if anyone has any other suggestiuons then I am all ears

Keith Winter
10-14-2015, 2:18 PM
Ehh I would be hesitant to rub anything in there. It may not take well and be temporary (read flake off over time), at worst you will discolor the surface surrounding the area you are trying to color. That surrounding texture might hold the color in. Be sure to mask before you cut if you are going to color just to be safe.


I did a quick test - see pic below. The customer was very happy with the detail achieved (it's better in the flesh) and is now asjking if there is anything that can be rubbed over the text to give a good contrast? The powder coat is a dark grey and he was thinking black.

I was going to mask it up and engrave again a few more timnes with a couple of different settings and then try some acrylic paint to see how it comes out but if anyone has any other suggestiuons then I am all ears

Bert Kemp
10-14-2015, 2:25 PM
You might try an enamel paint , like something made for appliances, get a good contrasting color like white. It shouldn't chip or flake over time.:)

Joe Hillmann
10-14-2015, 3:08 PM
Apple barrel brand paint in white or black is what I would use. It is an acrylic paint that walmart sells in their craft department. In my experience black and white are the only two colors that hold up over time.

Paul hardy
10-14-2015, 3:39 PM
If you want a rub in color, you might try Gilders Paste. It supposed to be pretty well permanent, but I've never used it on something like that. Definately need to mask your panel if you are going to try coloring it.

Dan Hintz
10-14-2015, 5:27 PM
If you want a rub in color, you might try Gilders Paste. It supposed to be pretty well permanent, but I've never used it on something like that. Definately need to mask your panel if you are going to try coloring it.

Not permanent, by a long shot, and definitely not in an industrial setting... alcohol-like solvents will wash it away in a heartbeat.

Kev Williams
10-14-2015, 7:04 PM
Painting over powdercoating is just inviting trouble, because the PC absorbs the paint, which effectively stains it. If you can get it off, you'll likely shine up (or dull up) the PC which is almost as bad as the stain. And based on the picture you posted, that mottled coating will trap paint like little ketchup cups...

I was going to suggest masking the panel with transfer tape, laser thru to the metal, then spray paint the engraving- But again, not with that mottled coating! The paint would bleed badly...

This may not apply here, but one of my customers had a novel idea: Their customer wanted aluminum boxes powdercoated,engraved, then painted white. My customer had trouble painting the powdercoating (wouldn't come off) so what they did was black anodized the boxes first. (they do it in-house so not much extra expense) -- the result, the laser removes the powdercoating and turns the anodizing white... :)

Graham Taylor
10-15-2015, 2:30 AM
OK, I am guessing that painting is not the best way to go so I will do some more plain engraving tests and then advise the customer so he can make the decision. If he wants to try some different methods after I have handed over the engraved only sheets thats up to him.

Thanks again for the advice and help.

Chuck Stone
10-15-2015, 1:35 PM
Woah .. just realized that I've been reading without logging in. Oops.

If anyone is so inclined, powder coat powders will melt if mixed with MEK in an old
blender. (glass recommended) and sprayed with an airbrush or Preval. Then bake away
in a toaster oven (provided you can control the temp well enough)

Since you don't have to worry about holding the electrostatic charge and the MEK will
evaporate leaving a semi-hardened surface, this leaves all sorts of options open for
cutting masks with the laser and doing multiple colors. But be SURE you let all of the
solvent evaporate, or it will just boil and ruin your finish.

After engraving down to the base metal, I'd use a lacquer meant for metal. (brass lacquer for
brass, for example)

.. just a thought..