Cermark THEN anodize???

[Bryan Schumacher]

All,

Thanks to the group we got the Universal 50 watt laser up and running over the past few weeks, and have started playing with different items. Everything is working wonderfully.

Here is my question - for one of the products, lasering anodized aluminum will not work since it leaves a rough surface (or at least semi-rough). Has anyone tried cermarking the polished aluminum, then having it anodized? I've read the specs on cermark, and it seems like it would be able to handle the ano process, but not sure. Seems to be extremely durable stuff.

I'm planning on trying a piece and having it ano'd as a test, but thought I'd check here first to see if it's already been done.

Thanks for the help!
Bryan

[Mike Null]

Bryan

Welcome to SMC. I haven't heard of the process you have in mind but that doesn't mean it won't work.

We have a Cermark rep or two as members so maybe they'll pitch in here.

[Hilton Lister]

I find that surprising. The only time I have lasered anodised aluminium and found the surface a little rough was when I had the power too high.

[Bryan Schumacher]

We would be doing the lasering on a watersports toy. The aluminum is highly polished, and even when it tarnishes, the rider can tell. So to have even a slighly rough texture would be too much. I know the cermark would have "raised" letters, but I'm hoping after the ano process, it would be more acceptable than the rough surface the laser leaves on ano.

[Gary Hair]

Part of the anodizing process is cleaning to remove any oxidation and grease/oils, etc. - this will eat the Cermark right off of the piece. I have tried a couple of different plating processes and none of them leave a mark afterward. The best result with anodized aluminum is lasering directly, too bad that won't work for you.

[Richard Rumancik]

. . . for one of the products, lasering anodized aluminum will not work since it leaves a rough surface (or at least semi-rough). Has anyone tried cermarking the polished aluminum, then having it anodized? I've read the specs on cermark, and it seems like it would be able to handle the ano process, but not sure.

Bryan, what you say is puzzling as lasering on anodize just changes the color of the dye from black to grey-white. I have never been able to detect any roughness after marking aluminum. So I don't quite understand the effect that you are seeing.

Cermark, on the other hand, may leave a minute amount of roughness. On stainless it raised on the order of only .0001". However, you may find it challenging to get Cermark on aluminum in the first place. Search on this and you will find some threads. Aluminum draws the heat very rapidly and you need to go very slow to get it to work at all, which will be expensive. Are you going to black anodize after Cermark? If so the contrast would not be that good.

Cermark creates an insulating deposit on stainless; I assume it would do the same on aluminum. It may resist the acid bath in the aluminum anodizing process but as to whether the end result will be acceptable you would have to try it.

[Mark Winlund]

Lasering aluminum with too much power will leave a rough surface. it is very distinct. Most of my customers like it this way because it leaves a tactile surface. It is like very fine sand paper.

The anodising process itself creates a porous surface, then dye is added to fill the pores. It is then sealed with boiling water or nickle sulfate, which closes the pores, trapping the dye.

Mark

[Rodne Gold]

Cermark is a very poor resist , we tried a multipart process of cermarking then etching with ferric chloride and the cermark mark itself is porous.
These compounds are basically glazes that get fired on the surface of the object by localised heat and they bond to the structure but arent "solid" enough to act as a perfect resist.
I have seen selective multicolour anodising done using various resists,.
We use lots of stuff as resists , like paint , mylar films , photosensitve laminations , vinyl, rub on letraset letters and even sharpies (permanent marker pens) An acid resist should also act as an electro resist when anodising