Holley Carb. plating

[awdmh]

You rinse in distilled water after the nitric dip, then into the chromate, correct? Thanks again for the help!

[dfarning]

Originally Posted by awdmh

Sean,
I've done cast iron carb bases with homemade solutions. Doesn't look too bad. I have some commercial solution from ShooterSolutions.

I've talked to a couple of carb restores who work with vintage stuff who plate the cast iron bases with zinc and then black chromate. They feel that with todays gasoline the zinc + blackener gives a stronger finish. I haven't been doing carbs long enough too be able to rate the longevity of my work. I have a few carbs with crack in the casting sitting in a bucket of ethenal to test their theories.

Dave

[awdmh]

I did not know about possible durability problems. Post your findings!

[dfarning]

awdmh,
I haven't seen any durability problems with either coating after 4 weeks in the ethanal. After I get my 20 gallon zinc plating setup going, I am going to set up a gasoline sprayer that works like a salt spray tester.

Hope I don't blow up the workshop and house. I've been looking around for a inexpensive CO2 fire bottle that can used to replace the air above the container that hold the gasoline.

[fxstcguy98]

I don't know what you are doing, sounds dangerous. Could you use a CO2 tank off a paintgun?

[dfarning]

My first brainstorm has been to put a wire rack about two inches high in the bottom of a 5 gallon pail for the test part to sit on. The sprayer would be powered by a little aquarium pump. Two plastic hoses would be run through the sides of the bucket. The input would pull fuel from the bottom of the tank. The output would spray fuel onto the part to be tested. An inch or two of gas would be poured into the bucket.

There would be two holes in the lid. One would attach to a CO2 bottle. The other would be a vent hole. A squirt from the CO2 bottle would purge the air out by replacing it with CO2. The vent hole would be plugged, then the CO2 connector would be removed and replaced with a plug.

I was thinking of testing the sprayer by: Putting a spark generator in place of the part, Putting a very small amount of fuel in the bucket, Setting bucket in the backyard, Waiting a few hour, Then setting of the spark generator.

Dave

[fxstcguy98]

make sure you video tape it, the money from funniest home videos might help with the medical expenses. Just ribbing ya. Your doing all that just to test the longevity of the zinc plating? Good luck and don't kill yourself.

[awdmh]

I tried dipping a couple of carb airhorns in nitric acid, then chromate, and they came out kind of chalky looking. I'm thinking the acid may not be active anymore. It is from a school science lab, it is a few years old. Any ideas?

[PaulProe]

A couple posters have mentioned using Phosphoric acid dip for "livening" up a zinc casting prior to Chromating. But no one mentions the strength or time of the dip.

Can anyone help me before I ruin a couple Holley carb bodies.

What strength % is the phosphoric acid and how long was the dip?

thanks

Paul

[RAlll]

Here is what I have done and it works great. Get Eastwoods metal wash. boil your carb bodies in the metal wash for 30 minutes. then bead blast the exterior.I then boil it again in metal wash. after that I bake it it an oven for 30to 45 minutes at 225F to remove any moisture.Let the parts cool. Then I bead blast it one last time. I take one gallon of distilled water at between 80 degree F and 85 degree F(any hotter or any cooler the results were not as good).I add one tablespoon of teh yellow chromate to the gallon of distilled water and dip my parts in the solution(stirred well 1st) for 30-45 seconds.then hang and air dry. seems like a alot of steps but after many,many tries this is what has produced my best results..