Subject: Good cheap anodizing wanted

From: [email-masked] (Chris D Paulse)
Date: 17 Feb 1994 22:42:15 GMT

Can someone recommend a cheap and quality outfit where I can send small
parts for anodizing?  Our department is also curious to know if this can
be done in house.  What exactly is anodizing?

---

From: [email-masked] (Angela Voll)
Date: 18 Feb 1994 05:26:46 GMT

Chris D Paulse ([email-masked]) wrote:
: Can someone recommend a cheap and quality outfit where I can send small
: parts for anodizing?  Our department is also curious to know if this can
: be done in house.  What exactly is anodizing?

  Good question.  I , myself am trying to find out
if it is possible to do "inhouse anodizing". Anyone
know what all is needed and about how much it would
cost to get set up? Up in Edmonton we don't have
ANYONE here who does it.

 Signed
Scott " Scooter" Freser

P.S. : anyone know if there is an FTP site to get
info on carbon-fibre???

Thanx again all.

---

From: [email-masked] (Malcolm Roe)
Date: Fri, 18 Feb 1994 14:24:52 GMT

>cost to get set up? Up in Edmonton we don't have

I assume you are talking about anodizing aluminium.  Titanium, magnesium
and zinc are also anodized commercially.  The commercial processes for
the anodic oxidation of Aluminium and its alloys are based upon the
use of sulphuric, chromic and oxalic acid as the electolyte.  Sulphuric
acid is the most widely used for general work.  Colours can be produced
by dyeing the oxide film.

My guess is that in house anodizing is possible although I've never tried
it on aluminium.  A trip to the library is probably in order.  The
general subject is called metal finishing and covers plating, anodizing,
polishing, painting etc.  What I have done is anodic oxidation of copper
using hot NaOH solution and a steel cathode.  I did this in the kitchen
at home without much difficulty.  You have to follow the usual rules when
handling nasty chemicals.  From memory, about one or two amps seemed to
be a good current.  Anodizing copper produces a strongly adherent smooth
black film.  It works well on copper plate.

-- 
Malcolm Roe                            Phone  :  +44 442 230000 ext 4104
Crosfield Electronics Ltd              Fax    :  +44 442 232301
Hemel Hempstead, Herts. HP2 7RH, UK    E-mail :  [email-masked] 
------------------------------------------------------------------------

---

From: [email-masked] (Michael Serafin)
Date: Fri, 18 Feb 1994 16:45:24 GMT

In article <[email-masked]>,
>cost to get set up? Up in Edmonton we don't have

Now this is all from memory of my experiences working with an anodize line
about 8 years ago.  We had 2 different anodize processes in house, one we
called "hard", the other "soft".  The hard process formed a much denser
oxide coating on the aluminum and stood up much better to abrasive and
environmental testing.  The process used a solution of sulfuric/oxalic
acid and current density was on the order of 25 amps/sq.ft, and I think we
ran at about 36 volts.  The soft anodize process used a sulfuric acid
solution and current densities were much lower, <10 amps/sq.ft.

---

From: [email-masked] (Andy Dingley)
Date: Fri, 18 Feb 1994 17:58:26 +0000

In-house anodizing is probably going to go the way of in-house
electroplating. Both of these processes involve some very noxious chemistry,
and the sewerage people *really* don't like them. Most of the river-borne
cadmium (bad news for rivers) in the UK can be traced to the electroplating
industry. If you want to do this on an industrial site, you're going to need
discharge permits for your effluent and a *lot* of paperwork. If you're doing
this on an industrial scale it's an unavoidable hassle, if you're only
looking to do one-offs it's not really worth it.

ObRedneck:

   Yes John, I *do* have the figures to back it up.

--
Andy Dingley   Codesmiths of Newcastle   [email-masked]

Klein bottle for sale.     Apply within.

From bigblue.oit.unc.edu!concert!xanth.cs.odu.edu!news.larc.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!cs.utexas.edu!swrinde!sgiblab!cs.uoregon.edu!news.uoregon.edu!netnews.nwnet.net!saturn.wwc.edu!krh_krhlab13.wwc.edu!johnric We

d Feb 23 21:26:39 EST 1994
Article: 3839 of rec.crafts.metalworking
Path: bigblue.oit.unc.edu!concert!xanth.cs.odu.edu!news.larc.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!cs.utexas.edu!swrinde!sgiblab!cs.uoregon.edu!news.uoregon.edu!netnews.nwnet.net!saturn.wwc.edu!krh_krhlab13.wwc.edu!johnric
From: [email-masked] (RICHARD ALLAN JOHNSON)
Newsgroups: rec.bicycles.tech,rec.crafts.metalworking
Subject: Re: Good cheap anodizing wanted
Date: Fri, 18 Feb 1994 18:50:36 GMT
Organization: Walla Walla College
Lines: 27
Message-ID: <[email-masked]>
References: <[email-masked]>
NNTP-Posting-Host: krh_krhlab13.wwc.edu
Xref: bigblue.oit.unc.edu rec.bicycles.tech:16654 rec.crafts.metalworking:3839

In article <[email-masked]> [email-masked] (Chris D Paulse) writes:
>From: [email-masked] (Chris D Paulse)
>Subject: Good cheap anodizing wanted
>Date: 17 Feb 1994 22:42:15 GMT
	Annodizing is the process where a oxide layer is built up on the 
base metal through the use of heat or electric current.  The type of process 
depend on the metal.  Titanium can be anodized with heat of electricity 
while aluminum (as far as I know) can only be done with electricity.  
	With aluminum, you build up the oxide layer (which is colorless on 
Al) and then dye it with some sort of dye and then seal it with a sealer or 
another electric process.
	I have heard that anodizing can be done with any power supply 
capable of putting out the required current and voltage.  In addition you 
need the correct wires and electrolyte to submerge the piece in.  
	The book on jewelry making by Oppi Untracht (the name escapes me) 
has a fairly complete section on anodizing although it is big (1000+ pages), 
expensive ($100 at the last sighting), and doesn't always have the easiest 
way of doing things although it is very scientific.
	So, after all that, yes you can do it in house and if you have many 
things over a period of time I would look into it, but if you just have a 
few I would send them out.

	Good Luck,
	Rick

---

From: [email-masked] (Bob Wooff)
Date: Sat, 19 Feb 94 01:18:42 GMT

Ask your local 'Hot Rodders' (as in cars) where they anodize their aluminum fittings.
( Scooter - I would be surprised if Edmonton didn't have one shop doing it.) We build astromical instrumentation here in Victoria and the structural pieces are all
aluminum - machined and anodized black or blue in our shop.  We built the anodizing 
tank ourselves about 10 years ago and from what I recall, it was mostly just a large
commercial power supply and a big tank. The tool and die guys don't seem to think
it's a health hazard.

Bob Wooff