[Tempted (Banned)]

With a rough finish it seems that at 3 amps cook time is around an hour or so. The last few parts I've polished seem to take twice as long. The first one I polished I let cook for about an hour and a half and the dye still didn't take well. After over 2 hours in the bath it took the dye alright but did have some bleed and came out much lighter than I anticipated. Should it cook longer or should I up the amperage? Or is there something else I'm missing. After I strip the part in lye I polish it using a compound and then clean it thoroughly with a degreaser.

[xsvdynastypballa]

There is A LOT you are missing. For one if you are running by amps, amperage needs to be based on surface area. Google 720 rule calculator.

http://support.caswellplating.com/in...g-instructions

Read this.


Anything you don't understand feel free to ask.

[Tempted (Banned)]

I thought the amperage was based on the CI of the acid bath, not the part. Guess that could be one issue though I've had nice results lately. I just started trying to do this last week. I restore and rebuild markers and figured I should learn how to finish the cosmetics rather than stopping at the mechanics. I did learn how to do touch up ano on scratches and scars, I'm sure that will come in handy.

I'm using a lead cathode, 70/30 water to acid, high concentration(low dilution) dye at 120 degrees F in a 5 gallon fish tank. I will be ordering a few things from Caswell in the next few days. From what I've found it seems as though their black dye is the most stable and will always come out black. Mine has been coming out purple. My blues are coming out nice and my red is great. I also want to pick up some of their sealer and a zinc kit.

[Tempted (Banned)]

After going through that, I am missing a few steps. Mostly temperatures. I have been lightly warming the acid and not warming the cleaning solution. I've also been boiling for too long.

[Tempted (Banned)]

Chrome stripping sucks :|

[xsvdynastypballa]

You are still all wrong....

First, Your acid is wayyyy to high!

Your at %30 when commercial shops run %20 max and these guys have the current to overcome the dissolution rate, big chillers to overcome the heat created by the high current and very aggressive agitation.

For your setup you need to be at no more than %10 acid and running at 6asf.

This is what I still run and I have a chiller along with a 50a power-supply. It will produce a repeatable constant finish. That actually holds dye.

What you are forming is a very expanded very weak matrix.

The acid is constantly eating the oxide layer.

The applied current is their to overcome this dissolution and build the matrix. The more acid you have the higher the dissolution rate. The higher the dissolution rate the faster you need to grow the layer with higher current density. The higher current density the more heat you have that needs to be separated from the part by agitation and chilled.

Its like domino's in a circle.. everything effects everything



I bet when your polished part is dry it looks really milky huh?

I promise if you follow that manual to a T you will have a working setup for everything.

Also check this out

http://ndhsubmersiblescience.com/ano/720rule.html



OH!!! What is CI?

[Stepchild]

Originally Posted by xsvdynastypballa

OH!!! What is CI?

I think he is saying Cubic inches of his electrolyte bath. Which is completely wrong either way so it's not like it really matters. As for the Acid concentration, This is one subject where I wish people would be much more clear. He said he made a 70/30 mix. Mix of what? Are you using pre-made battery acid from a place like NAPA? Using these are fine but you need to remember it is already diluted with water at about 50/50 mix. If he is using pure sulfuric acid then his concentration is WAY to High. If he is using battery acid (50/50 mix) it's not quite as bad, closer to 15% which is still a little high.

On another note, make sure you have all of the polishing compound cleaned off of the parts before you run them. Clean them with Toluene or something similar. Goo Gone also works really well to take off polishing compound but you will need to wash the parts with soap and water and degrease them before running.

[xsvdynastypballa]

I assumed he was using pure sulfuric acid...If not that might be a problem to haha...then he would be wayyy to low.

zing!

[Tempted (Banned)]

Yes, it is 50/50 premixed at a 3/1 water-acid, about 15% total. No, the parts aren't coming out milky but most of the colors I've used are very dark. My power supply(the one I had from powering high amp battery chargers) is rated at 50a max. I've tried from 500ma to 5a and the difference hasn't been much. I've had no real heat build up except for one time that the part slid over and made contact with the cathode.

As far as the power supply, is there a preferred voltage? I've gone from 12-20v and not seen much of a difference there either. What I mean is should I go by volts/amps or watts?

[xsvdynastypballa]

Ok thats better...Your wicks would be tighter if you went even lower though.

Again I run 10% and its plenty especially when you get some aluminum dissolved in the tank.

If you choose to start running Constant current..(i hope you do).

Turn you volts all the way up.

Tune your amps based upon the surface area of the part.

I suggest you start at 6asf and move up from there if you determine our heat can be controlled.


In case you didn't know, asf is amps per square foot...If your running 6asf and your running a part that is 1sf your amperage is going to be 6amps for 2hrs for 1mil.


Use the 720 rule calc I posted. Very helpful.


What temp are you running at?

If you choose to stay with Constant voltage good luck to you

[Stepchild]

You want to go by amps. If you hold the amps constant the voltage will rise as the ano process takes place. You need to set the amperage you want based on how much surface area you are anodizing. This is because the anodizing layer is insulating so the power supply has to up the voltage to maintain your set amperage. Holding the amps constant allows a uniform buildup of aluminum oxide. If you hold the voltage constant the amps will vary as the ano layer is built and it will not turn out as uniform.

Back to your original question. Normally you will see the dissolution(white powdery look) if your bath gets to hot or you run to much amperage. Which I don't think is your problem. The reason the 720 rule is recommended so much is because it is a pretty universal method that works on all surface finishes and give you a pore size that accepts most dyes. In anodizing you not only have to worry about the thickness of the layer but also the pore size (think diameter of the pore that holds the dye). And pores grow differently on different surface finished. My guess, without seeing the parts in person is that because you are using such a low amperage the pores you are building on the gloss parts are very small and not holding dye.

[Tempted (Banned)]

Wow extremely helpful, thanks to both of you. I'll check the temp(I have a frame going now) in a few and report back.

By the way, I'm not even going to touch one of my decent markers until I either get better or quit anodizing. All I'm practicing on are old Spyder parts I have laying around.

[Tempted (Banned)]

.... Screwed that up pretty bad. In the back of the frame there was a copper plug that I didn't see. Now I'm assuming that my bath is ruined(its milky) so I'll have to mix another tomorrow.

[xsvdynastypballa]

Try it man. Is it a red milky? If so I bet it will work. And I bet it will clear up in a month or so.

How big was the copper plug?

[Tempted (Banned)]

Nah it was white and I couldn't see the bottom of the tank. The acid is insanely cheap($20 for 5 gallons) so I'm not worried about it. The plug was about the size of a half a dime and an inch long buried in the back of the handle of the frame. I found it when I went back out there and it had changed color from the rest of the metal.