First attempt at home anodizing

[John Hasler]

I finally got what I wanted a file hard dye able part. I found the problem is the dye, I got some Rit dry that did what I wanted a nice Gold color. By using battery acid at 16 quarts of water( I used tap water they say use distilled) to 1 quart of acid, a lead cathode, at 5 amps 19-20 volts for 120 mins. the part is a tube 1 1/2" OD x 9" long which comes out to about 85 sq inches of surface (it's anodizing both the inside and the outside). The dye has no salt I've shown a photo of the box you add salt or vinegar for cloth, I mixed it 2 quarts distilled water to 1 packet of dye I might be able to add more water but it did work this time. You can see if you look at the fifth line it said add salt or vinegar to the dye and the bare spot on the part is where I filed though the anodize.

Todd

• :victory:

How do you apply the dye? Do you put it in while you are anodizing? Dip the part in the dye-water mixture afterward?

 

[Walltoddj]

There are a number of steps before you dye it but after you anodize it, rinse it then put it in the dye. I had a wire to it and submerged it in the dye the bald spots you see are from me filing to test the hardness of the part. Now it's suppose to go right in the dye after anodizing but I couldn't get it to take so that part was on my bench for a couple of days but still took the dye so I feel it's a good sign it's going to work out fine.

Todd

 

[Walltoddj]

I recall reading that some Rit dyes contain salt.

I stand corrected if you get a magnified glass to read the very fine print ( after the Spanish!!) it does say it contains salt I don't see where it would be a problem because you rinse it then seal it.

• :think1:
  

Todd

 

[Alan Douglas]

I don't know that it is a problem but apparently people have variable results. I have done only alodining myself, and used dyes with that, and got variable results on different alloys, so the company I worked for decided not to pursue doing it in-house.

As I understand anodizing, the surface is porous while the hydroxide film is forming (it has to be, to allow current to flow). The dye penetrates this porous surface, and then is sealed in (by boiling in water, as I recall reading). If the dye is penetrating, chloride ions could penetrate as well.

 

[Walltoddj]

I was able to get some dry black Rit dye today and noticed something I didn't pay attention to before Rit dye is 1 1/8 oz, Rit liquid is 8 oz, and Caswell is 4 oz liquid. I'm wondering about the dilution of each dye, Caswell is 2 gals to 4 oz of dye, Rit is 1 packet or 1/2 cup(4 oz) to 2-3 gals water. I'm wondering if maybe I'm not diluting it enough and that is why black is not dark enough? The yellow I did was one packet to 32 oz of water and it looks good but it colored fast.
Any ideas?

Todd

 

[Bill Gruby]

I am probably late with this . It explained a lot.

http://www.youtube.com/watch?v=QBWpB80xxZI

"Billy G"

 

[Walltoddj]

I am probably late with this . It explained a lot.

http://www.youtube.com/watch?v=QBWpB80xxZI

"Billy G"

Interesting I still wonder what concentration the dye is at he had 32 oz containers but could have mixed it any way he wanted. From watching him I will dilute mine a little more to see what happens because my parts are a hard coat anodize that I'm told is harder to dye. I'm still using battery acid I find it works the best to give me a hard anodize coating the sodium is to soft for my liking.

Todd

 

[Walltoddj]

Ok found out a couple of things current to the part is a big factor just because the power supply said 10amps doesn't mean it's going to the parts if you have more than one on at a time. I need to know if anyone is having a problem with the anode wire that you hang the part from dissolving right at the acid bath top level they seem to be getting eaten away by the acid and at time you can hear a sizzle. I did get them to dye black with the Rit dyes in 1 gallon of distilled water they came out jet black but had to leave it in for about an hour.

Todd

 

[aeroHAWK]

Todd,

I'm glad to hear that you had success! I am in the process of setting up an anodizing line. I haven't yet dyed anything but I've had good success with clear anodizing. It was a steep learning curve though. The thing I found that had the most effect on the quality of the anodize is that the power supply needs to be a Constant Current power supply. As the process proceeds the voltage increases in order to keep the current constant. As the surface builds, it increases the "resistance" of the whole system. A Constant Current power supply will automatically handle this, which allows much better control of the surface thickness using the "Rule of 720".

I didn't notice if you had any agitation in your anodizing tank. It is common to use a manifold of PVC pipe with holes to provide bubbles (like water boiling) to keep the bath "stirred" up. This may be why more than one part at a time may not be consistent for you.

Also, you shouldn't have the anode wire dissolving in the acid. Are you using aluminum wire? If it is aluminum wire, it will get anodized with along with the part - not eaten away.

From what I understand, Rit dye is not colorfast so I ordered my dye from Caswell. Also, black is apparently not easy to get dark, and this could explain why Caswell's black dye is so expensive. It's a lot more that the other colors.

I read somewhere that for different color dyes, the anodize thickness can be critical. I don't recall the number, but there is a minimum thickness required, I think it is just under a half thou. Also, too thick can make it more difficult for the dye to penetrate the pores on the anodize surface. My recollection is that you want to keep the thickness from a half thou to a thou.

 

[itsme_Bernie]

I missed this last year! Awesome! I am very interested in trying this too!

Bernie