Cermark problem

[David John Evans]

Hi all. I have been playing with Cermark on stainless steal with no luck. I have used high power low speed, high power high speed, low power high speed and so on. With the high power it burns the cermark and it flakes when in low power it will wash of. I have tried metho, acetone, water, sanding it with no luck. After cleaning I only touch the sides and leave if from 10 minutes to over night. Is there a use by date on this stuff and yes I did shake the can. Any ideas. David

[Allen Rawley]

Hello,

I have tried the Cermark spray, tape, and liquid and had, by far, the best results with the spray. The spray coating cannot be too thick, and must be evenly applied. After applying an even coat on a stainless steel part (shaped like a hockey puck), used a 60 watt glass tube Chinese laser machine, relatively new, put on full power and had mixed results raster engraving a logo. Sometimes the logo stuck and was fine, and other times it would wash off. The success rate was more or less 60%, with 40% being washed and run again (or sanded/buffed). The Synrad 100 watt did a great job, every time, even while running the same power level. However, the Synrad was retrofitted on a Techno-isel CNC router so it does not raster engrave as quickly as the Chinese machines.

More recently, I ran tests on the Chinese laser machine power supplies (more than one, sixty watt power supply). A Fluke meter was put on the return line to measure current. The laser was powered on at 100%. Then, watched the current. Overtime, the current was level, then would reduce and level, then increase and level, then reduce. The percentage current reduction was less than 10%.

[David John Evans]

Hi Allen. My laser is a Epilog 35w to me if the Cermark is burning the laser is up to high. I will try this weekend to connect my air compressor to it and see what happens. I will be doing an order from JDS this week some time so in a few weeks I will have some new stuff to try. David

[Dan Hintz]

There are a lot of factors to consider... fast and weak is never going to work. Slow and powerful is what you need, just not too powerful. On my 60W, I'm at 100P/25S @ 500 dpi. I think my Cermark about 10:1, and spray so that the dried coating just blocks out the metal beneath.

How thick is the piece you're working on? Too thick and you'll need to put a little more heat into it.

[Mike Null]

I use settings comparable to Dan's on my 45 watt but I use 600dpi.

[Gary Hair]

With the high power it burns the cermark and it flakes when in low power it will wash of.

That tells me you are putting it on too thick. You need to have a coating that you can still see the metal through the cermark, any thicker than that and you have the problems you describe. After you get that issue resolved then you need to do a test grid to see the optimal power/speed settings. You should never use less than 100% power and will adjust your speed only. Spray a piece that you can laser a bunch of 1/4" squares and starting in the top left use 5% speed then 6 next to it, 7 next to that, etc., etc. After you have lasered the entire piece then scrub it with a gray scotchbrite pad and see what sticks best - that's your optimum setting for that type of stainless and anything else should be close.

[Bruce Volden]

Sounds to me like the Cermark is being applied too thickly.

What Dan said works the best!! Keep it so thin it dries in less than 20 seconds and I think you'll be just fine. Stainless steel is one on my favorites to work with as it always comes out great.

Bruce

[Dave Sheldrake]

Just for giggles David try washing up liquid, a thin covering on stainless then hit it with mid power mid speed. The liquid contains selenium, the action of the beam causes it to turn into selenium dioxide (basically gun blue) that can give some good results on stainless steel.
Takes a bit of fiddling but does work well once you get it right.

cheers

Dave

ps: I concur with the rest of the guys, your cermark is too thick either in consistency or application.

[Richard Rumancik]

That tells me you are putting it on too thick. You need to have a coating that you can still see the metal through the cermark, any thicker than that and you have the problems you describe. . . . .

Sorry but I can't quite agree with this - if you can see metal through the Cermark then it seems to me that you don't have 100% coverage. In my opinion, when you hold the workpiece up to the light at any angle you should not see any metallic reflections.

It might not make much difference on coarse graphics plotted at low resolution but missing Cermark has same effect as missing pixels in the graphic. No Cermark = no mark.

[Gary Hair]

I've been using Cermark for 7 years and have lasered 10's of thousands of parts, maybe I still don't know what I'm doing... Take my advice or not, you get what you paid for!


Sorry but I can't quite agree with this - if you can see metal through the Cermark then it seems to me that you don't have 100% coverage. In my opinion, when you hold the workpiece up to the light at any angle you should not see any metallic reflections.

It might not make much difference on coarse graphics plotted at low resolution but missing Cermark has same effect as missing pixels in the graphic. No Cermark = no mark.

[Dave Sheldrake]

Translucent seems to be the way to do it, like having a coating of milk on an object.Not missing bits but not like paint.

cheers

Dave

[David John Evans]

Thanks for that I will try less spray. Richard I see where you are coming from so I will try both ways. Dave you must be all over it with a name like yours I will do this to. David

[Chris J Anderson]

That tells me you are putting it on too thick. You need to have a coating that you can still see the metal through the cermark, any thicker than that and you have the problems you describe. After you get that issue resolved then you need to do a test grid to see the optimal power/speed settings. You should never use less than 100% power and will adjust your speed only. Spray a piece that you can laser a bunch of 1/4" squares and starting in the top left use 5% power then 6 next to it, 7 next to that, etc., etc. After you have lasered the entire piece then scrub it with a gray scotchbrite pad and see what sticks best - that's your optimum setting for that type of stainless and anything else should be close.

Gary,
thats a pretty obvious answer... I wish I had thought of it a while ago.
Been wondering what actually is the best setting for cermark, and will follow your suggestion tomorrow,

thanks for posting a quick and effective test procedure mate...


Cheers,
Chris

[Tim Bateson]

Sorry but I can't quite agree with this - if you can see metal through the Cermark then it seems to me that you don't have 100% coverage. In my opinion, when you hold the workpiece up to the light at any angle you should not see any metallic reflections...

I think what is meant here is the Cermark should be thin or translucent.

[Dave Sheldrake]

I think what is meant here is the Cermark should be thin or translucent.

yup :) indeed it is :)

cheers

Dave

[Richard Rumancik]

I think what is meant here is the Cermark should be thin or translucent.

Tim, Dave - I can agree with translucent - but I didn't agree with any missing Cermark. Not sure what Gary means though as he did not say translucent or clarify in his response - he just said that what he does works. But I don't know what exactly he means by "see the metal". Maybe we all do agree on this.

Having said that, I have found Cermark to be pretty tolerant of thickness. Maybe if you go to extremes it makes a difference. I have scratched the Cermark on some parts before lasering - then given it another small blast with the airbrush to repair the scratch - and never had a problem getting an even mark all over the lasered area, even though some areas would be twice as thick as others, and no longer translucent.

[David John Evans]

Well I used less spray and it worked well with 100p and 5s. Thank you all for your input. David