Carburetor Dye

I have a mid 30's Stromberg carburetor that has been recolored to gold. I would like to get the gold color off and return it to the original natural finish. I am not fond of bead or media blasting, as it surly would find it's way into a orifice and cause problems down the pike. Possibly some chemical solution???

Try gumout carburetor cleaner and a wire brush or steel wool. Bill

What makes you think that gold is incorrect? A year or so ago I went on line to see why some Carter WA1s were gold and some cadmium color. It turns out that the company Crown Plating that dyed the carbs for Carter was across the street. When Carter had enough parts to bring over for dying they were dyed with whatever Crown was running that day. See the Carburetor Shop web site for the story. Most Stombergs were zinc, but not exclusively.

Well, I base my opinion on the fact that I have been restoring 1934 - 1936 Auburns for 20+ years. I am the ACD club tech adviser and judge at the ACD Fall festival, and have never seen one. Additionally I have access to the factory specs. for these Stromberg carbs as supplied to Auburn and no such finish is specified except natural. I make every effort to do an accurate restoration, no better, no worse.

I would carefully try some muriatic or phosphoric acid.

I have both, I'll give the phosphoric acid a try first.

Actually muriatic or phosphoric acid are very good for cleaning but some times it will not work. its depend upon the carburetor. when same problem i was face i used some cleaners and brush. Please do it properly.

Zinc is the correct treatment for all of the 30's Strombergs I have seen. Many were then painted. We still zinc treat all the rebuilds we do. I would be carefull on a powerfull acid. The pot metal is just stable at best, unstable at worst. If you have a parts or junk carb try it on that one first. Here is a website of Stromberg parts if you need it. Good luck, Ed

www.piercepartsstore.com

I dipped a q-tip in the phosphoric acid and applied it to an inconspicuous place, rubbed a bit, no visible result. Did the same with the muriatic acid Viola, instant result !

Two seconds in 1/2 strength muritiac acid , a good rinse in baking soda & water, a bit of elbo grease with 000 steel wool and it looks almost as good as new.

And yes, all of the prescribed OSHA protection was employed.

thanks Fellas!

For zinc alloy castings, Stromberg used the following specifications for zinc alloy (as listed on the print):

None listed defaulted to class A (yellow iridescent)

Class B (bright)

Class C (black)

Class D (olive drab)

Class E (dyed to specified color)

Repeat, if no specification is listed on the print, the default color is Class A which is yellow iridescent. ALL of the castings were coated, NONE were left natural.

This information is from the Bendix Engineering Standards, metal standard BX-13.

Jon.

Good information Jon. I will pursue this. Is 'B' bright meaning silver? or Maybe dyed to specified color is silver.

This particular EX32 was rebuilt by a shop in Florida and dyed it at the owners request because he thought it looked cool. I know the guy.

Bright was for bright chromate (yellow, but not iridescent).

The chromate will fade over maybe a 20 year time frame to natural.

Jon.

What years do your specifications apply to?

What years do your specifications apply to?

The years of Auburns that I specialize in are 1934 - 1936 6 & 8 cylinder. The Stromberg EX22, EX32 ,EE1 color (IE. none ) specifications came to me from two old time restorers at different times. I put that in my book of facts and have judged at the ACD reunion accordingly. I am now on a fact finding mission. Just a couple of hours ago I was told by one of those old time restorers that I would never be able to convenience the powers that be. Well maybe not, but I just want the facts.

Curt - the finish for the main bodies for the Auburn EX-22, EX-32, and EE-1 are specified by Stromberg as "New Jersey zinc di-chromate".

It took several hours of searching 500 foot reels of 35mm microfilm to get this information.

I haven't found the exact spec for New Jersey zinc di-chromate, and I am finished looking; but would guess it would be a goldish green. Maybe you can find the specification on the internet.

Jon.

Jon,

Great info.

Yes it is good information indeed. Thank you very much Jon. I will make every effort to get to the bottom of this. The ACD Museum has library with some of this sort of info. In addition there is a well known historian in Orange California that I will be in contact with next week. This is very timely, as my wife and I are in the process of writing restoration guidelines for these cars.

This has been one of my pet peeves for years. As an AACA judge I am required to deduct points for incorrect cad plated spark plugs before a certain year yet no guidance on when "yellow cad" first came into general use.

What makes you think that gold is incorrect? A year or so ago I went on line to see why some Carter WA1s were gold and some cadmium color. It turns out that the company Crown Plating that dyed the carbs for Carter was across the street. When Carter had enough parts to bring over for dying they were dyed with whatever Crown was running that day. See the Carburetor Shop web site for the story. Most Stombergs were zinc, but not exclusively.

I should have paid closer attention to your post. This has been very informative for me.

Great info from Carbking / Jon as usual. I did not realize there were so many choices back in the day. It would be interesting to find out or make a listing of the correct finish for each car. On Pierce Arrow carbs they were painted black on all the V-12 Ex32's. as well as the UU-2 & UUR-2. But I know some cars had the EE-3 some were painted, some a natural finish. I have seen several NOS 30's Strombergs and they all looked different. Maybe the finish was different, or maybe the storage conditions. Some looked almost bronze / yellow, while others looked like bare pot metal. The finish on the hardware also varied from car to car. I think when judging I would deduct for a bare finished carb, but would let any tasteful zinc treatment pass. Anyone have any additional comments on the pre war Strombergs?

It is my belief that Jon is the last word in Stromberg carburetors. Years ago I had an EX32 1 3/8 venturi (Auburn Only) that was a yellowish greenish almost iridescent. At the time, I was told that someone had it recolored and natural was correct. I found it hard to believe because it was in excellent condition. Now, Ed says that a Pierce Arrow EX32 was black. So does that mean that the factory specified a specific finish to Stromberg? Or was it the other way around ? If we indeed get to the bottom of this, what will be difficult is convincing the judging committee's that was accepted as correct for 30 years in now wrong.

The more you know, the more you know that you don't know!

Curt, I have 2 NOS UUR-2's on the shelf. One came in the box when I purchased it. Both are black. If you look at the 1931 PA sales catalog it lists the finish on the UUR-2 and talks about how many pieces on the carb are plated / and or stainless. Factory photos of PA engines are common and show the carbs painted. I have seen photos of early UU-2 carbs in natural finish, but they soon were painted when they went to the cast iron upper in the early production. Some of the linkage on the PA EX-32 was made by Pierce as it has their part numbers on them. We zinc treat in OD green. It has a slight yellow hue to it. Over the years I have been amazed at how many different hardware finishes we have seen on assorted Stromberg's. We see brass, bronze, stainless, nickel, chrome, black paint, bare steel, the list is almost endless. At the PA meets, 29 to 35 carbs are taken as being painted. 1938 to 1938 it seems most were natural, but I have seen a few painted. Most people use the finish they find on the car when they get it. I am rather sure the auto show cars were painted, but production cars were left as treated from the factory. On PA's even the fuel fittings were PA were plated and not off the shelf brass. All the details can make your head spin. PA was also famous for using anything on the shelf as the year wound down. It's common to see other year parts on the last few cars made in a series. We are working on the last known 35 V-12 made right now and it has a 34 dash insert and trim. I am sure others did this also, even Cadillac did the same thing in the early 30's.

What kind of paint did they use? It certainly had to be fuel proof.

Wish you guys would play with Carter carbs, as finish questions on the Carters are quite easy!

With Stromberg, EACH individual item had a specified finish. And Ed is correct, there are MANY different finishes. To know for certain, the process is as follows:

(1) determine the original Stromberg assembly number in question (example - the 1935 Auburn 851 supercharged used A-17753)

(2) pull the 500 foot roll of microfilm containing that assembly number

(3) wade through the film until finding the 4 or 5 pages of bill-of-material

(4) make working copies of these pages

(5) sort the 200 or so part numbers into numeric order

(6) pull the various microfilm rolls (maybe 7 or 8)

(7) start wading through the rolls part number by part number.

Sorry, fellows, I simply do not have the time to do this project. At one time, I had a part-time employee working on digitizing these prints. In 3 years, maybe 5 percent are digitized. The cost to do the entire project would be enormous.

Jon.

Carbking:

I just have to ask: What are the finish options on Carters? I have one on a 1953 Special.

Thanks.

Joe, BCA 33493

Joe - this link should explain Carter finishes:

http://www.thecarburetorshop.com/Carburetorfinishes.htm

Jon.

Thanks for your rapid reply!

Joe, BCA 33493

Here is a batch of UU-2 and UUR-2 carbs getting ready to go out for Zinc treatment. We do them in batches of 6 or 12. These carbs are from no less than four different continents. One is being converted to a right had drive set up, another is a Stude carb that was on a super charged Bugatti. It didn't idle at all with all the incorrect parts. I'll post photos in the next few weeks showing the "green / yellow/ gold" shaded treatment.

Yes, please keep up posted. I have an interest !

Batch is finished at the Zinc treating company. I will pick them up today and try and post a photo by tomorrow.

Batch is finished at the Zinc treating company. I will pick them up today and try and post a photo by tomorrow.

Hey Ed, when are you going to post a few pix of those carbs?

Soon.... I left my phone at home when I picked up the parts. I'll try and get back to the shop tonight. Ed.

Here we go, I will post the photos then comment on them below.

Ok, 5 photos. Comments from top left to bottom right.

1 Newly treated air horn on left, as found air horn on right with no paint.

2 Close up of number one to get better idea of color.

3 Sideways photo. Lower is newly treated air horn, upper is a glass beaded air horn with no finish.

4 Same as 3 with better contrast showing zinc finish. In person in regular shop light it's hard to tell them apart.

The contrast in not as much as the photo implies. I would call the treated air horn as having a slightly green haze.

This photo is the best representation of what it looks like in hand.

5 Close up showing high contrast. I would say the contrast in this photo is ten times more than it is to the eye in regular light.

Now...... why olive drab green finish? Same as why when new. The company that does it for us is 300 feet from our shop. They can and did offer almost any color or dye we wanted. As All Pierce carbs and MOST other high end cars with UU-2, UUR-2, EX-32, and EE-3 are painted black; it doesn't matter to us on the color of the treatment. I am not aware of any other shop treating pre war carbs like this. I am sure there are lots of re builders doing it on post war stuff. The most difficult part of restoring these is the finish treatment on the hardware. Lots of time and money spent making, detailing, fitting, and tracking (time and transportation) all the small parts. Also it takes several hours to resurface ALL the gasket faces and jet seats to make sure they are square (done on a vertical milling machine). 100 percent of the time the good carbs have distortion on the gasket surface and they must be fixed to prevent leaks. Also where the main jet seats on the outside of the bowl will leak due to warping over time. Often people over tighten them causing the body to crack while they are trying to prevent a leak. We see lots of destroyed carbs from over tightening covers and jets.

Thank you Ed. This is informative. Does the shop next to you do one carburetor at a time? any idea what the approximate cost is? From the information supplied by Jon and the homework I have done, the finish I need is a very light yellow green almost iridescent finish. Do you cad plate the steel parts IE. choke hardware?

The company that treats our carbs is the research department of a large industrial coatings company. It is lab that tests all the batches of chemicals they make. They don't do production work, we trade off with them to service the owners collector cars. I would think that a rebuilder of later carbs would have access to treating your carb in the color you want. As far as hardware, it a big can of worms. We use nickel, chrome, and SIM-CAD with a few other finishes wen needed.

We have a local place that does "cad" plating for us, either what we call "yellow cad" or "silver cad", actually zinc. There is a minimum charge of $75. We recently had them do all the wheel bolts, Jaxon clamps and nuts for a 1920's car and the $75 covered it. Larger parts such as wheel rims run roughly $30 each since they have to be "racked" and plated individually rather than the "drum" plating used on smaller and less delicate parts. I think they rack carb parts.

Hemmings has many ad's for carburetor for carburetor rebuilds. can anyone suggest a shop that can do a very light yellow 'New Jersey zinc di-chromate' ?

If you are there Jon, possibly you have a recomendation?

From their work that I've seen, Daytona Parts does exterior finishes to match the OEM finish and they seem quite successful at that. Why not just give them a call?

I have a Carter BB1 that I rebuilt a few years ago. I was advised to boil it out, after removing parts, with plain water with a little detergent. A lot of gunk came out of the carb, but it changed the color to a light gold tint from the ? zink from before. Carb runs great, but why the color change?

Rick