Blue Chromate?

[Inferno]

I plated my first parts with the copy-cat kit this weekend. The plate went on nice and smooth, however I had an issue with the blue chromate. I added 1 quart distilled water to the solution. I dipped the part in solution and it came out shiny, but had no blue hue to it? I thought it was supposed to dye the part blue? It definately changed the appearance of the part by changing it from a dull gray to a shiny near silver. Anyone who has used this please chime in and let me know what you got. Thanks.

[seanc]

Re: Blue Chromate?

Inferno:

That's normal.

"Blue" chromates are really supposed to be clear. Some manufacturers describe them as "blue (clear)" or "clear (blue)".

The word "blue" is used to describe them because the majority of them all impart an unavoidable blue tint, to a lesser or greater degree, depending on which formula of chromate you're using.

Caswells blue is VERY subtle (I like it). Unless you can compare it to a part done w/bright zinc w/out blue chromate, you'd never know.

Here's a photo of some examples:

Bolt at far left is done in "brand X" - the blue is quite evident
Bolt at 2nd from left is Caswell blue - not nearly as noticeable
2 bolts at right are in a true clear

Notice how the Caswell bolt is slightly more blue that the last 2



Sean

[Inferno]

Re: Blue Chromate?

Thanks for the reply, at least I didn't mess something up. Is there a different chromate avaliable that will dye the parts blue? The factory bolts on my vw have a blusish coating. Is this some type of a chromate, or something else?

[seanc]

Re: Blue Chromate?

Your VW bolts might have been dyed after chromating. Do you have photos of them? are they really a full blue color?

Most "blue" chromates are really clear with only a very slight blue tint, like the one in my photo. The degree of "blueness" depends on the particular chromate formulation.

There are hundreds of different blue-clear chromate formulations from dozens of different manufacturers, but Caswells is the only one available in small quantities (as far as I know), for reasonable cost.

Sean

[Inferno]

Re: Blue Chromate?

On this page the 6th picture down shows some of the blue vw bolts:

http://www.passatworld.com/forums/showthread.php?t=104287

I did notice on some of my fasteners that the blue was splotchy as in there were areas with noticeably darker blue. This may help identify the coating.

I also have some yellow chromate. Are the yellow and blue chromate equal in corrosion resistance? Are there differences only cosmetic?

[seanc]

Re: Blue Chromate?

The pictures don't show the best detail, but from what I see, and your description of them being "blotchy", I'd say they have been dyed.

Generally (but not always), yellow chromate has greater corrosion resistance than blue. Again, it depends on the manufacturers particular formulation. I think Caswells blue is nearly as good as the yellow.

Sean

[Inferno]

Re: Blue Chromate?

Thanks for the help seanc. I think I will go with the blue chromate for now, as I like that the fasteners are real shiny almost like chrome.

[seanc]

Re: Blue Chromate?

You're welcome!

Post some pictures of your parts.

Sean