Titanium etching

Howdy Folks, Has anyone else had any dark gray particles appear
on
items being etched with Multi-etch? The most recent Ti etching I did
left a coating, sometimes fairly broad, sometimes mottled looking,
on almost every piece I etched. I used the smae procedure as 2
previous batches. The only possible varialbes that come to mind are
the use of ‘roller printed’ sheet, shelf life of the Multi-etch, and
maybe a little higher (though not boiling) bath temp. I also didn’t
notice anything in the bath while etching. My process is pretty much
as follows; pieces are soaked in household ammonia, rinsed off with
tap water and spread on a paper towel on a cookie sheet, I prepare
some heated distilled water for both a rinse and to receive the
pieces after rinse. After the Multi-etch is brought to temp (over
140F-less than 200F, checked with candy thermometer) I drop usually
one ata time, 3 items (earrings of - say - 1-1 1/2 sq in.) in the
etch, then retrieve them one ata time so they get, maybe, 5-15
seconds each, sometimes more if I have trouble fishing ‘em out. Then
they get a swish in the rinse, then dropped in the recieving tub of
water. I didn’t notice the ‘scum’ till I was preparing to mask,
anodize, etc. It wipes off easily enough, but doesn’t seem to
’swish’ off and leaves a quit dark smudge on a paper towel/rag.
What am I doing wrong? Carl 1 Lucky Texan

Sounds to me like your bath is contaminated. Is it possible that
some other metal has come in contact with the bath? I never let
things sit in an etch, I either mount them in a holder or a basket
and swirl them around during the process. After your ammonia and
rinse do you dry the pieces? Spotting can occur if you do not. I
would hold them in a water bath until the next step.

Bill

Does anyone know if glass etching pastes will work on titanium?

Tony Konrath

Does anyone know if glass etching pastes will work on titanium? 

Yes it will strip the oxides if it contains potassium bifluoride or
other fluoride salts

James Binnion
James Binnion Metal Arts