Zinc alloy turns pink

dave gibson

Elite Cafe Member
Joined
Aug 18, 2009
Messages
323
Location
Livermore,CA
I've been engraving some belt buckles that are cast from some Zinc alloy. I've noticed from sanding or sometimes stippling has brought out a pink hue in spots. It isn't a different color under the surface, I've dug down pretty deep on a broken sample.

Anyone know anything about this?
 

Diacutter

Member
Joined
Sep 12, 2007
Messages
85
Location
Kansas
Most likely you are seen a copper plating. Generally items like this contain several layers of plating. Copper is used for the best adhesion. Do you have a photo?

Dave
 

monk

Moderator
Staff member
::::Pledge Member::::
Joined
Feb 11, 2007
Messages
10,857
Location
washington, pa
IF IT'S very heavy, and soft may be an alloy of pewter. the cast pewter alloy buckles hold detail very well, but are not very good at remaining ding and scratch free. if of pewter, will melt rather quickly, and will be real shiney upon cutting.
 

Ron Spokovich

Elite Cafe Member
Joined
Dec 27, 2012
Messages
436
We used to cut large gears, in a machine shop, made of a zinc/aluminum alloy, and I don't recall any layering or color change in any of them!
 

Southern Custom

~ Elite 1000 Member ~
Joined
Mar 8, 2013
Messages
1,026
Location
Baton Rouge
Just a quick thought. Have you tried lightly sanding the throw away buckle? If plated, the plating will be so thin that you won't see layers if you drill through it or cut a section of one side. Sanding may show you a different story as you can slowly work the surface down. Plating is measured in microns, not mills so sanding is usually the only way to tell. Items like this typically are plated. Don't think Ive ever seen a zink costume piece that wasn't.
Layne
 

dave gibson

Elite Cafe Member
Joined
Aug 18, 2009
Messages
323
Location
Livermore,CA
Brian, I bought them from Eagle FeatherTrading Co. Their catalog says zinc alloy and that's all I know about it
Layne, I've tried light and heavy sanding, no change. I seem to remember light sanding produced it before on an edge, not exactly sure, I've just noticed it a few times.
It seems to be intermitant, it doesn't always happen, I don't think I could produce it if I wanted to. Not a major problem, just wondering if anyone knew anything like if there is copper in the alloy, what would make it show on the surface?
No big deal, just wondering, I'll try to get a picture.
Thanks all.
 

Brian Marshall

~ Elite 1000 Member ~
Joined
Nov 9, 2006
Messages
3,112
Location
Stockton, California & Taxco, Guerrero, Mexico
Dave,

There are literally hundreds of zinc alloys - as well as quite a few dealers who really don't know much about what they are flogging.

You may have any combination of the above? Only way to know for sure is to ask the manufacturer.

I have some pure zinc ingots lying around the shop that were used for plating (galvanizing) and they are not sumthin' I'd particularly want to engrave...


Check and see if the stuff is magnetic?


Brian
 

dave gibson

Elite Cafe Member
Joined
Aug 18, 2009
Messages
323
Location
Livermore,CA
pirateslounge.JPG
Brian, Not magnetic, checked that yesterday too. Look at the left edge.
 

Sponsors

Top