Cermark problems on aluminium

[glenn schramm]

I am doing a job where i need to print onto 0.5mm sheet aluminium. I have tired with my Cermark lmm 6000 only find find that the whole of the ink washed off.
I was running my epilog 45w at 100 power and 25 speed. at 400dpi. They are the cermark recomendations for my machine. I would just like to know if there maybe something im doing wrong that someone may no about before i try again. As the job take about an hour to run through.would appreciate any advice, thanks.

[greg lindsey]

You need to slow it down to 15s and up it to min 600dpi.

[Tim Bateson]

I agree on the 600dpi, however I would say you need to speed up. The Cermark rule I believe is the machine wattage=speed, thus 45 watt machine = 45 speed. Also insure you have cleaned the metal and use a very, very thin coat of Cermark - you should be able to see through it - just.

Note: I have had a couple cases that the metal was coated with something I couldn't see and nothing I did would get Cermark to stick.

[Mike Null]

I have stopped trying to do aluminum with cermark--especially something that thin.

[Richard Rumancik]

I agree with Mike - the only thing you are doing "wrong" is trying to mark aluminum with Cermark. It is usually either a technical failure or a financial failure - meaning that if you can get a permanent mark on aluminum, you have to go so slow to achieve it that you will be unable to charge the appropriate amount (based on laser time.) The second problem is that with 0.5 mm aluminum the high heat required will actually cause distortion of the plate. So IF you can get a mark it is quite likely that your plate will be warped.

[Dan Hintz]

<chuckle> So many opinions, so I'll add another one...

The 600 dpi recommendation is a good one, but I also believe the speed is too fast... on my machine (producing 70W), I'm at your speed for SS sheets. Aluminum dissipates heat faster than SS, so you have to go even slower... figure on 15S being about right. If the sheet is thin, however, be prepared for some bowing.

[glenn schramm]

Cheers for your replies, i managed to get it to work on my own, i discovered the aluminium sheet had a coating on it. The client suplied the sheets and did not tell me. So i gave it a sand with fine grade paper, then i slowed it down to 10 speed. worked fine. But yes it took forever. The client will be paying for the time it took. Lucky for me the job he needed doing is unique and could only be done this way so he will have to pay for the luxury of laser engraving.

[Bill Cunningham]

When it comes to Cermark, and even Alumamark, I never refer it to a customer as laser 'engraving', but rather 'laser marking' when you say 'engraving' to the uninitiated, they think it's going to cut into the material. I use the term laser marking, laser etching, and laser engraving. Marking is marking, Etching is surface affected to maybe a few thou. If there is actual depth, it's Laser Engraving. This way your not giving the uninitiated customer any misleading or false expectations on what they may actually be getting..

[Tim Bateson]

I agree Bill. It takes a while to explain to some customers the difference and they are always shocked to learn this type of laser is incapable of etching or cutting metal.