Cutting shim stock with electrolysis

G

geb

Plastic

Joined

May 6, 2007

Location

nebraska

• Apr 28, 2012

• #1

Hope I'm not being impatient here. I asked this in another related thread but activity seems to have dwindled there. Googling returns limited information on "electrolysis cutting shim reed valve etching" and related search terms. Maybe I need to refine the search terms?

I'd like to locate more specific information related to cutting thin metal shim stock via electrolysis. Can't seem to find a thorough source guide. This is close....
http://www.aardvark.co.nz/pjet/makevalves1.pdf
But still leaves room for questions regarding candidates for power sources, solutions, different shim material (brass, SS, carbon steel, alum) more details, etc.

Any links to share on this?

 

gbent

Diamond

Joined

Mar 14, 2005

Location

Kansas

• Apr 28, 2012

• #2

Back in the dark ages when mechanical drafting ruled the design room, there used to be thin templates of stainless called eraser shields. (that really revels a minimum age of old, doesn't it?) These were produced by electrochemical machining. There used to be a couple of jobber companies that would hand out samples at shows that also had their name cut in them.

But to help you out, I don't recall names or production data.

 

A

adama

Diamond

Joined

Dec 28, 2004

Location

uk

• Apr 28, 2012

• #3

There was a thread on here about it a couple of weeks back. Paint the shim, then scratch through paint outline of cut. Electrolysis was done in salty water. Bloke was making pulse jet valves, making a very nice job of them too!

 

Forrest Addy

Diamond

Joined

Dec 20, 2000

Location

Bremerton WA USA

• Apr 28, 2012

• #4

Should be abundant info out there. Printed circuits, detailed artwork on handsaws, theatrical lighting gobos (perforated light metal screens used at the primary fiocus of lighting unite to project black and white imagec and effects on stage sets from dappled light to prizon bars to comlicated cityscapes were once done with processes suitable for home at the kitchen table.

 

C

CBlair

Diamond

Joined

Sep 23, 2002

Location

Lawrenceville GA USA

• Apr 28, 2012

• #5

Look up Photoetching, you will find more information about it there. Particularly on Modeling sights.

Charles

 

oldbikerdude37

Titanium

Joined

Jun 29, 2010

Location

milton freewater oregon

• Apr 28, 2012

• #6

I have an old book that tells how to do it from 1937.

Polish and clean with benzine. coat with cereson wax or syncera wax, scribe the part through the wax.(crayons will work.)

then put in the acid made from, 3 Oz potassium bicromate in 32 OZ of water, and 3 OZ of sulfuric acid and a few drops of dish washing soap to make it stick. if you do aluminum add some hydrochloric acid.

I love the book where this come from, its called." Amateur craftsman's cyclopedia of things to make" It is way old school.

 

smalltime

Banned

Joined

Jan 10, 2010

Location

Kansas City

• Apr 28, 2012

• #7

CBlair said:

Look up Photoetching, you will find more information about it there. Particularly on Modeling sights.

Charles

Click to expand...

I work for a glass to metal seal house. We use photoetched parts every day. It is a very accurate way to get small stuff done. There is a thickness penalty though.

 

Z

Zonko

Stainless

Joined

Aug 20, 2011

Location

Northern Germany

• Apr 28, 2012

• #8

Potassium bichromate is "bad stuff" , its hexavalent chromium, bout as pure as you can get....

 

oldbikerdude37

Titanium

Joined

Jun 29, 2010

Location

milton freewater oregon

• Apr 28, 2012

• #9

Zonko said:

Potassium bichromate is "bad stuff" , its hexavalent chromium, bout as pure as you can get....

Click to expand...

In 1937 it was stuff you could find, im sure thier is an alternative that wont hurt you more then you grow a second penis and have 2 headed children.

 

LFLondon

Hot Rolled

Joined

Dec 1, 2007

Location

North Carolina

• Apr 28, 2012

• #10

Poor mans EDM that actually works 1 post from OP
http://www.practicalmachinist.com/vb/edm-machining/poor-mans-edm-actually-works-244565/

Thread: Poor mans EDM that actually works 17 posts
http://www.practicalmachinist.com/vb/edm-machining/poor-mans-edm-actually-works-244532/

 

SAG 180

Titanium

Joined

Sep 17, 2007

Location

Cairns, Qld, Australia

• Apr 28, 2012

• #11

There are stainless steel solder masks made by companies for the electronics industries that may accept your particular material ( I expect stainless would fatigue fast even if it's flexed minimally) and make the parts. Apart from that I'd suggest using ferric chloride with a DC current assist and a carbon rod out of a D cell for the other electrode. Straight hydrochloric acid is way too uneven for electrolytic etching , having a metal dissolved like ferric chloride in the solution seems to be finer and smoother.

 

Z

Zonko

Stainless

Joined

Aug 20, 2011

Location

Northern Germany

• Apr 29, 2012

• #12

oldbikerdude37 said:

In 1937 it was stuff you could find, im sure thier is an alternative that wont hurt you more then you grow a second penis and have 2 headed children.

Click to expand...

I have a container, from the photo and hobby lab owned by a late collegue of my father .
Never used it for anything, but i keep it, simply because i know very well that it is an incredibly useful chemical.

 

T

Toolbert

Stainless

Joined

Nov 29, 2003

Location

Vashon Island, WA

• Apr 29, 2012

• #13

At risk of answering a different question than the one you asked ... I routinely use abrasive waterjet to make intricate parts from shim stock down to .001", by stacking or sandwiching it between thicker layers of sacrificial material. Accuracy is ~+/- .002", may be on par with photo resist electrochemical, not as good as edm, just depends what you need.