Cast aluminum= big pain

[rclint]

If anyone ever comes up with a sure fire way to anodize cast aluminum I would love to know. Here are some triggers off a Ruger 10/22, they anodize a dark gray color, will not take dye, and worthless unless you like the gray color. You can see where I tried to dye two of them and they come out a blue haze, but gray is dominate. Any ideas ? I done the etch, and de smut from Caswell, then I trie done after I anodized it in the de smut, polished, bead blasted, different times in the tank, different amps per square inch etc etc I can't find a way anodize this cast and get the results I want. I have anodized many other types of aluminum, and even some cast with zero problems and perfect dye.

Clint (not sure if I can post phots or not)

[rclint]

they are darker in real life

I scanned them and touched the photo up, but in real life they are a dark charcoal gray.

Clint

[mcaswell]

Re: Cast aluminum= big pain

Give us some specs on how you anodized this.

How did you attach the part?
Times, surface area, amps, temp LCD? Etc.

Have you checked through previous posts? I'm sure Fibergeek wrote numerous articles on this.

[rclint]

Re: Cast aluminum= big pain

Give us some specs on how you anodized this.

How did you attach the part?
Times, surface area, amps, temp LCD? Etc.

Have you checked through previous posts? I'm sure Fibergeek wrote numerous articles on this.

Yes I searched the post, I tried from 4.5 amps to 8amps, temp of bath was around 70*, attached via sput welder. I have the exact surface area somwhere it's around 2 square inches, I went with 6 triggers at one time on one test. I'm using the LCD method, Mastech lab power supply, in constant current mode. I tried a anodized thickness from .3mils to 1 mil,

Clint

[rclint]

Re: Cast aluminum= big pain

One note I forgot, this is the only aluminum I have come across that I can't get 100% perfect results on if I prepare the part correctly, anodizing is very easy, addictive, and rewarding ! Fibergeek really brought anodizing out of the dark ages and into the real world for us small time folks, I think we can compete with the big boys now on quality of work.

[sswee]

Re: Cast aluminum= big pain

I just tried a cast part I have had trouble with in the past. I get about the same results on turning gray. I did not even try to dye. What was your peak voltage? Just out curiosity, have you checked them with an ohmmeter to see if there is any coating at all? SS

[M_D]

Re: Cast aluminum= big pain

I have anodiized some parts machined from cast tooling plate with suprisingly good results, and will be doing another part soon. I'll try to take the time to get photos and post them. Of course, there are different alloys and I think you can't expect them to all anodize the same. From what I understand, some alloys are just about impossible to make look good.