Cermark question

[Andy Joe]

So i heard a rumor that amonia would remove cermark. Does anyone know if this is true. I ran a part last night and there must of been some chemical that the acholo didnt remove cause the cermark didnt stick in certian areas that looked like watter marks on glass. I was hoping i could remover the cermark without messing up the polished chrome and not have to buy a new 180$ part.

[Dan Hintz]

Chrome is possibly one of the most frustrating materials to mark with Cermark. Once properly marked, ammonia will not remove Cermark... if it is, you're initial marking was not done correctly.

[Richard Rumancik]

I highly doubt that it can be removed with ammonia.

There may be a possibility of polishing out the mark but you should probably get some advice from someone local who has the materials and expertise. I have removed marks on brushed stainless, using 2000 grit and 1000 grit wet/dry paper. But that will leave some sanding marks which was okay on brushed stainless. To get it back to polished condition will require polishing steps. (3M abrasives? tripoli, rouge? not sure) I can't say if it is feasible or not. You don't want to break through the chrome.

Even then, it may leave a ghost of a mark. That means good alignment between the old and new is best. If you used a holding fixture the first time, that gives you the best chance or re-alignment. If you placed it by eye the first time you won't hit it bang-on the second time and may see a witness of the prior version.

Cermark on chrome is harder to apply than on stainless. If I recall it needs to be run a lot slower.

[Andy Joe]

Well i have been running lots of test with chrome and i found swithing to a taller focal height and running really slow works well for me. This peice was in a batch of parts i ran the rest ok. The one i had problem i had i realigned by eye and it turned out perfectly. No ghost image or anything. I was just hoping not to have to test my luck with it again. I have a kern laser so i have a hex able top that is really weak so im not real sure how i would make a jig for realignment but thats a good idea. I should work some up cause these parts are motorcycle parts and i will be doing alot of them now. Thanks again

[Dan Hintz]

Are you talking about a longer focal length lens? If so, that would probably be worse as the heat is spread out over a larger area (the focal point of a 4" compared to a 2" is about twice the area, so half of the heat), which is why you need to slow down.

[Andy Joe]

Yeah a longer focal height lense. Before when i was using 2" barle the cermark was turning brown, i swaped after an idea i had while working with metal cutting lasers and the customer i have now. The laser beam is like and x and my theroy is when i switch tubes i bring the lines of the x closer together so my focal point stays better the farther away from the material i get. Most of these parts arent flat. Its worked great so far. I adjusted my speed and my laser curve and ramp and i seem to be getting a fairly good result so far. Thanks for all you help

[Dan Hintz]

Okay, sure, if the parts aren't flat then a longer FL will help give you a more consistent burn across the entire part.

[Ronnie Matthews]

I need to know more about lasering Harley Davidson chrome that isn't flat I have a vytek 35 watt I can't seem to get it right

[Dan Hintz]

Being more specific as to what problems you're encountering will greatly aid us in helping you...