Caswell Inc. Metal Finishing Forums - Anodizing Questions

Bead blasting for prep

shitthatkilledelvis — Tue, 07 Sep 2010 20:00:15 GMT

Hi everyone,

I am about to embark on an experiment with Oxalic Acid hard ano. My concern if that Oxalic Acid from what I have researched produces a smoother, less textured finish, than sulfuric acid. Would beat blasting be an acceptable pre-treatment due to the matte, more tactile finish I require.

thanks,

What is with 6asf

newanodize — Mon, 06 Sep 2010 16:18:44 GMT

Why is everybody attached to 6asf?

I can understand if you are trying to anodize WITHOUT a chiller so you don't see your tank temperature increase. BUT some of you guys with chillers still stand by 6asf?

What is the attachment?

new anod line setup

timhays — Mon, 06 Sep 2010 01:17:37 GMT

to whom it may concern,i am interested in setting up a new anodizing line.
my tank size will be 55 gallon for all solutions.

i will be using ti racks.

my parts have the following surface area 86 sq inches....93 sq inches....182 sq inches

the largest power supply i have found that will run on single phase is 150 amps 20volts lambda unit.

how many parts will i be able to run in a batch with this unit and at what time?

also is it possible to hardcoat type 111 the 182 sq inch parts and how many per batch with this unit?

thank in advance for your reply.

Newbie - Power supply good enough?

cpowellpumphrey — Sat, 04 Sep 2010 19:14:57 GMT

Okay, I have a line on this power supply but before I buy I want to make sure it's good enough. It is a used power supply though. I will be dying parts that equal 469 sq.in. sometimes a little more but sometimes less. I understand that you can go smaller without problems but can't always go bigger. I think this will handle everything I will want to do since it seems the capacity is large enough. Here are the specs, tell me what you think please. I'm looking at this as a retirement job and want to get on with it but do it right.

Two level of control for both current and voltage outputs: coarse and fine for ease of use

Outputs: 0-30 V and 0-30 A

Input voltage: 110V/60Hz

Line regulation: CV <= 0.02% + 3 mV, CC <= 0.5% + 3 mA

Load Regulation: CV <= 0.02% + 10mV, CC <= 0.5% + 10 mA

Ripple noise: CV <= 10 mV RMS, CC <= 10 mA RMS

Protection: constant current and short-circuit protection

LED reading accuracy: +/-1% for voltage and +/-2% for current

Environment: 0-40C, relative humidity < 90%

Size: 12" x 10" x 6"

Weight: 12 lbs

lots of amps

pyroracing85 — Fri, 03 Sep 2010 12:18:59 GMT

So who here with the larger tanks put 30 amps or so to their parts?

I just started ramping up production and I have a full rack of parts. From top to bottom I get color differences.

I have an idea on what it could be due to. That idea is because I have so many amps my solution isn't being mixed quick enough.

Has anybody else came across this problem?

Dark Discolouration on Aluminum sheets after Chromic Acid Anodizing.

Matthew_Patterson — Mon, 30 Aug 2010 18:39:15 GMT

Hello all,

My name is Matthew Patterson, a manufacturing planner in aerospace and a first time poster on this forum and so far I am impressed by the help of other people I've read on other posts. So I'm going to try my luck here.

I'll give you what I'm working with:

Material: Al 6013 sheet metal in T6 condition (received in T4) AMS4347 .040" Thick.

Process: Chromic Acid anodizing (Type I class 1) using 40 volt processing and hot DI water sealing.

Problem: randomly recieving parts in post-anodic condition with dark staining on the material which is transposed (mirrored) to the opposite side of the sheet.

Affected areas contain a slightly higher concentration of copper and slighly lower hardness value (both still well within AMS4347 specification).

Normal piece exhibited Cu. Content of .917/.927%.
Dark area exhibited Cu. Content of 1.04/1.05%.

I attached a few pictures but it is difficult to photograph the staining condition. The camera we use does not take well to anodic coatings. Please look carefully to find the random areas of dark discolouration as they are much more apparently in person.

As aluminum sheeting is not porus I cannot see any chemicals able to penetrate through the material and re-processing the parts does not eliminate the stains.

If anyone has any ideas as to what is causing this I would be most appreciative. If any clarification or if more information is needed please let me know.

I appreciate everyones time!

Matthew Patterson

Attachment 2548 Attachment 2549

Attached Thumbnails

anodize stripper leaving smut

newanodize — Fri, 27 Aug 2010 01:06:20 GMT

How does everybody get rid of the stubborn smut that stays on after putting it in the stripper?

I can wipe off a little but the rest stays.

I even ran it through the cleaner and deoxide and it gets a little better but still not enough.

Any thoughts?

Thinking about making a second attempt

91slicktop — Thu, 19 Aug 2010 03:20:30 GMT

My first few runs with my anodizing kit were nothing short of, nearly complete failue.

I just pulled my kit out again, which was never emtied out. All the buckets remained sealed for about the last 8 months.

I grabbed one of the aluminum test strips that came with the kit that I had attempted to anodize/dye several months back...and i put an OHM meter on it to see if i had even grown an anodize layer on the peice...and it showed nothing on the meter...which is a good sign.

I however, never was able to get any of the aluminum strips to take color. As far as prep work i never did anything to the aluminum besides clean it in the degreaser. I wasnt too worried about the finish, i just wanted to see if i could get it to take the dye.

I have a few questions going into my second attempt:

-Which chemical baths, if any of them, need to be replenished?
-I was just using one of the aluminum test strips as the tank bar, with a titanium wire wrapped around it suspending the part to be anodized...whats a better method?
-What is the best way to run power from my power supply to the cahode/anode? I was using normal 16gauge copper wire with aligator clips and attaching them to the cathode and titanium wire supporting the part being anodized.

I was attempting to dye using the Electric Blue.

Opinions on caswell power supply (5 Amp Constant Current Rectifier )

deere_x475guy — Wed, 18 Aug 2010 16:55:24 GMT

All,
I am looking into purchasing the 5 Amp Constant Current Rectifier from the link below.

Caswell Inc. - Plating Rectifiers

Do any of you have any experience with this unit. I called to ask about warrany and if this power supply would hold up to hours of use on weekends with the current set to 3.86 amps. I was told by the sales department that it would work fine. Not that I am doubting their response but sometimes real world experience helps.

Any input will be appreciated.

purple anodizing tank

newanodize — Tue, 17 Aug 2010 20:35:34 GMT

Anybody have any problems with the cleaner and glue in the PVC piping? I had my acid sit over the weekend and when I turned on the pump the acid had a purple dye color to it.

I am pretty sure chlorine and sulfuric acid make a purple color.

I am also afraid of the purple primer in the pvc glue.

Anybody have a problem with the purple primer bleeding through into the acid?

How Can these anodizing techniques be obtained? Pics inside

yomagic — Sat, 14 Aug 2010 17:26:43 GMT

Just like the title says im looking to see if anyone would know how to do these types of technique.

Swirl:

Maple Drip:

HELP stainless bushing in my aluminum

ka30270 — Thu, 12 Aug 2010 20:00:23 GMT

I have a stainless bushing pressed into a piece of machined aluminum that I am to anodize. Is there any way to cover or protect the stainless from the anodizing process so it doesn't get eaten away?

Thanks

Sput Welder

spankey666 — Wed, 11 Aug 2010 14:20:02 GMT

Has anyone got anywhere working out how to make one yet ? ie capacitor sizes etc ?
i found on another forum AcidRain has been enquiring any luck ?? 800,000 mf 50v caps are huge in size compared with the little box caswell used to sell :roll:

Will this work for a power supply?

yomagic — Tue, 10 Aug 2010 22:49:23 GMT

Schumacher/6/2 Amps manual battery charger | Battery Charger | AutoZone.com

will this work? I'm new to anodizing and plan on purchasing the necessary to start some home anodizing. I've never done it before, but im really excited to try it out. im only going to be running a small setup since im only going to be anodizing something that about 2-2.5 inches at the most.

thanks for an replies

Bad finish near the connection point

westsidemachine — Tue, 10 Aug 2010 22:32:26 GMT

Hi everybody
:mad: I'm having a problem, when I dye parts there are areas mostly around the connection point that the dye is not taking well if at all making an finish that is not uniform and splotchy. I'm sure my amperage is calculated right for the sq/in. Using a 720 calculator I found in one of the threads. Example: parts total 164.16 and the connecting wire in solution 27.72 = 176.88 sq/in 1.23sq/ft = 5.53amps for 112min to obtain a .7mil thick layer. The one thing that baffles me is, by the rule peak volts should be 11.25. Im always closer to 18 or so, max for my ps (cc/cv 18v20a). Is that where my problem lyes? I believe my acid ratio is ok. I have a chiller and I'm able to keep the temp (mostly) right around 70 degrees+/- 2. Occasionally the temp will rise a few, maybe 75 for a few seconds before cooling begins. Problem there? By the way, I'm using all Caswell dyes and my prep is 5 min in 140 degree degreaser - scrub lightly with Dawn to remove any trace left anywhere, rinse - 3 min lye bath, rinse, (desmut if needed) - rinse - ano. I don't think my prep is the problem. All freshly machined parts from 6061 aluminum.
I appreciate any help. I can post a pic or two if it might help to diagnose my problem. Thanks guys