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David Griffiths
10-25-2010, 8:20 AM
I've just finished laser engraving a Nickle Plated award and I am unable to remove the tarnish marks the cermark has left.
When I carried out a test on the rear of the plate I encountered no problems.

I've tried using Silvo - Brasso - Lemon Juice to no avail.
Anyone have any tips for removing the tarnish and retaining the highly polished look?

Thanks

Frank Corker
10-25-2010, 5:06 PM
Therein lies the rub (pardon the pun). I have had similar problems in the past and the only way I was able to remove was by heavy buffing. Main issue is that sometimes if there hasn't been a good bond, you can lose the image you engraved. I'm not sure what is fully in cermark but it certainly seems to etch itself like some acids do.

Dan Hintz
10-25-2010, 8:36 PM
Frank,

In a nutshell, it's nothing more than a layer of glass with pigment mixed in... any chemical you pour on that will etch glass will remove Cermark. While lasering, there's always the possibility of there being a reaction between the substrate, the glass frit, the laser's heat, and the moisture in the air.

Rodne Gold
10-26-2010, 12:24 AM
Dan there is something else involved in Cermark, it stains some metals and the stains cant be removed
The stain is there whether you laser it or not , the longer you leave the cermark on the more probability of a stain , we apply , laser and wash off as quick as possible to minimise this.
Stainless is prone to this - so I dont think it's merely water or oxidation.

Dan Hintz
10-26-2010, 6:46 AM
Guess I misunderstood what Frank was saying... I thought he was talking about being able to remove Cermark with certain cleaning solutions (acids), but now that I reread it I realize he's talking about the Cermark itself doing the etching. My bad...

David Griffiths
10-26-2010, 6:53 AM
Therein lies the rub (pardon the pun). I have had similar problems in the past and the only way I was able to remove was by heavy buffing. Main issue is that sometimes if there hasn't been a good bond, you can lose the image you engraved. I'm not sure what is fully in cermark but it certainly seems to etch itself like some acids do.

The makeup of cermark must be every potent. We rubbed and buffed again and again to no avail. I don't think I'll do these anymore. The bond was very good. I'm led to believe the plate may have come from India or China. Perhaps something went wrong with the plating process !

Frank Corker
10-26-2010, 6:58 AM
David if you put it on, engrave and remove it by washing immediately, you will probably not have same problem. As Rodney confirmed, the longer you leave it on, the harder it is to remove. On the occasions when I have had this, I ended up coating only one at a time and engraving. Just a little more tedious.

David Griffiths
10-26-2010, 7:02 AM
Dan there is something else involved in Cermark, it stains some metals and the stains cant be removed
The stain is there whether you laser it or not , the longer you leave the cermark on the more probability of a stain , we apply , laser and wash off as quick as possible to minimise this.
Stainless is prone to this - so I dont think it's merely water or oxidation.

Rodne
We have come across this issue with certain types of SS also.
As soon as the Cermark was dry we lasered. Because the job took around 7 mins to engrave perhaps the extra time was a big factor. With other types of SS, we can leave cermark on for up to a month with no tarnish/damage to the SS pieces. (strange!) With our brass tags we have to use Brasso to get the tarnish off after its lasered so it is acceptable to present to our customers. We have left the cermark on for anywhere between 4 and 15mins with the same result. This all adds to the cost, and it's not a nice job to do.

David Griffiths
10-26-2010, 7:07 AM
Frank,
We're either going to have to get super qucik as you suggest or say a polite no!
I spent around 2 hrs trying to get the tarnish off. The plate was around 200mm (7" ?) in diameter and the design looked good but spoilt by the tarnish.
Live and learn (expensively) I guess :)

Bill Cunningham
10-26-2010, 8:36 PM
I almost thought I had a BIG problem with that..
I used Cermark to put a name on the blade of a 'Cold Steel' Bowie Knife (Cabelas Canada = $600.00) I used tape to hold the knife in position while lasering.. Afterward when I cleaned off the blade, there was a 'line' which looked like the secondary stain/etch you get from Cermark.. I buffed it with everything I had, including steel wool, and the mark stayed.. I was wondering how I was going to explain this to my customer, this was a gift for his best man. Then, I had a look at the case.. Inside the case right where the mark on the blade would contact, the leather had a gouge in it.. Something had been in the case that rub marked the blade.. I pointed this out to the customer and breathed a sigh of relief.. It turns out, that he had got a 'deal' on the knife because it had a mark on the blade..
He got a deal, I got 30 minutes of grief trying buff it off...:mad: