C2:67 Holley Carb finish

[Gerard F.]

Been playing around with my 3810 and Yellow Dichromate. Is this the correct finish?


Jerry Fuccillo
#42179

[Warren F.]

Re: C2:67 Holley Carb finish

Jerry;

I have an original NOS '71 LS-6 carburetor, and that plating on yours looks to be pretty darn good. I'd say you got it right.

[Tom M.]

Re: C2:67 Holley Carb finish

Did you use the eastwood Kit, or what did you use to attain that color?

Tom McCabe

[Gerard F.]

Re: C2:67 Holley Carb finish

Tom,

The fuel bowls and metering block in the pic are a plated finish and I used the Caswell kit for Copy Cad and Zinc. For the pot metal bowls and metering block, I didn't even have to replate with zinc. I just buffed all the original dichromate off down to bright metal(blue fine buffing wheel on a drill), then dipped the parts in the Yellow Dichromate solution for 30 seconds, sprayed the excess off with distilled water, and hung to dry. That was it.

But it took me 3 times with each to get it right.

I have tried the eastwood kit in the past, It's kind of a phoney painted finish.
This is actually easier and is the original finish.

Jerry Fuccillo
#42179

[David N.]

Re: C2:67 Holley Carb finish

Jerry,

As a retired Ford Motor Co. quality control laboratory test engineer, l would say not only do you have it right but, it should last you much longer than a "simulated/painted" finish. Our Ford plant made the 2v and 4v carbs. for most Ford vehichles and I checked the chemical solution bath strengths used. You have an excellent appearance judging from your photo. Great job. I would also say that only 3 attempts to get the finish correct is not too bad for a "home garage mechanic" and worth the cost and effort.

David Nims member #19639

[Randy R.]

Re: C2:67 Holley Carb finish

I'm confused. Did you plate the bowls and block first or just buff them prior to the dichromate dip?

[Gerard F.]

Re: C2:67 Holley Carb finish

Randy,

I didn't replate the bowls and metering block in the picture, I "just" buffed them off with a Nylon brush wheel (fine) on a drill, but it was a little more then "just".

The bowls and metering block are pot metal which is die cast zinc. You have to bare fresh zinc for the dichromate to work on it. They say to bead blast them or blast them with baking soda. Not having the blasting setup, I thought I'd try the brush wheel and a small stainless steel wire brush for the crevices.
It was a trial and error procedure with the solution mix and dip time, verses the prep of the part. On the third try, it came out fairly well.

Here's how I did the last try: First, I wire and wheel brushed the previous dichromate off the part to a bright metal surface (not too shiny in flat areas, maybe leave some brushing marks in it). Then I dipped it in SP decreaser at about 180 degrees for five minutes, rinsed it off. Then wearing clean latex
gloves, I wheel brushed it again to a bright metal finish. And put screws or fittings in all the thread openings to protect the threads. (Screw in the float needles and power valve before in the metering block before you dip).

Then, only touching it with the gloves, I hooked a wire through one of the holes, and dipped it into the yellow dichromate solution heated to 80 degrees. I swished it around for about 30 seconds and pulled it out to check it, looking for consistency in the light yellow haze on the part. Don't worry if it looks too light, look for consistency. If you can see gaps in the finish dip, it again and swish it around.

Then I rinsed the part off with distilled water and let it air dry. Don't let drops accumulated on the part. I used a hair dryer for the final drying.

Pot metal is not the most consistent material. If you can see dark areas on the part when you buff it out, it's probably some other metal which won't take the dichromate. In that case, it would probably be better to plate with a fresh coat of zinc and then buff that to a bright finish.

But it's worth a try without replating.

Jerry Fuccillo
#42179

[Gerard F.]

Re: C2:67 Holley Carb finish

David,

Thanks for your comments! Did they use the same dip process at Ford on the carburetors, and did they apply the finish over bare pot metal?

I think a lot of us would be interested in how they did the carb finish on a mass production basis.

Now that I've got the fuel bowls and metering block done, I'm off to the air horn body. Probably another weekend project. It's fun.

Jerry Fuccillo
#42179

[Tim E.]

Re: C2:67 Holley Carb finish

Nice job! I just compared your photo to the 1966 Holley parts I recently got re-dichromated from Holley and you're right on the money.

I agonized over whether to go with the Caswell system or send parts to Holley and eventually went the Holley route. Like you, I like doing it myself if possible. My 1966 carb has been judged at a regional with no deduction.

For those of you not inclined to do it yourself, Holley offers the service for about $150 with a couple week turnaround. That includes all of the dichromated pieces. See the Holley website for details.

Now I'm agonizing over whether to try the Caswell chrome plating kit!