Oxidized Issues

[Jeff Thorpe]

I'm running a New Hermes IS700, but that's not really where my issue lies. After engraving satin silver plates, I oxidize them. It looks just fine when I'm done, but I've had 3 come back now with a weird, spidery crackling radiating out from the lettering. Have any of you seen this before? Is it something I'm doing?

I appreciate any help I can get.


This is what I'm looking at...
295086

[David Somers]

Jeff,

This is an absolute guess on my part. But it looks like some sort of crystal is growing under the coating and lifting it or changing it? Perhaps some soft of contaminant in whatever you used to oxidize with? Or something left on the surface prior to oxidizing?

Again, a complete guess on my part.

Dave

[Mike Null]

Do you mean satin aluminum? If so, it may be the acid causing the lacquer to craze. I don't recall an occasion when I oxidized silver.

It looks like you used a rotating cutter to engrave it rather than a diamond.

[David Somers]

Mike,

Just curious. Would the use of a rotating cutter vs a diamond drag make a difference in this? Both would be physically scoring the surface unlike a laser attempting to do something similar. I am not familiar with this oxidation process and am very curious about it. (you know me...perpetually curious...<grin>)

Dave

[Mike Null]

It would be very unusual to use a rotating cutter on silver and for that matter to oxidize silver. You can oxidize lacquered aluminum but not all are meant for that and flaking is possible with every lacquer I've seen. If I am doing black lacquered brass I buy the laserable type as it is faster and looks better and it would not need oxidizing. FYI, many who do black coated brass use a rotating diamond and burnish the finish which looks better than using a rotating cutter. But anybody who has a laser will likely use it rather than the rotary machine.

[David Somers]

Thanks for the background Mike!!!

Dave

[Kev Williams]

I'm guessing the engraved plates have been 'wrapped' around a cylinder shaped something-or-other after the engraving and oxidizing.

My next guess is (a) the lacquer finish didn't like being stretched, (b) the acid worked its way under the edges of the engraving, which led to (c) the lacquer pulling itself off the silver...

... I guess.. ;)

[Scott Shepherd]

I agree with Kev, it's got a clear lacquer on it, the oxide process must be a solvent type product and it's wicked under the edges of the clear and caused that.

[Jason Hilton]

Are you using a electrical process for oxidizing? Those look suspiciously like current lines that occur when current finds it's own way through a surface, the heat causes the spidering...

[Mike Null]

Kev

I like your observation too but I've never seen anything quite like that.