Carburetor Shaft Coatings, Sticky Linkage, Worn Needles, & Internals

A. Hi Bob, You should not do cadmium plating; it is a cumulative poison, forbidden in some countries and used only for indispensable life-critical applications in others. Use zinc plating instead.

But I don't think you need an electroless substitute--small quantities of small parts can simply be 'wired' (hung from a small plating rack, or tied in place with light gauge copper wire), or possibly barrel plated.

Plating is highly regulated if you are a business rather than a hobbyist. You might consider retaining the services of a plating jobshop ... but zinc plating is not beyond the reach of a dedicated hobbyist. Good luck.

A. Hi,

I owned and operated a 1965 Sunbeam Alpine, and a 1964 Triumph TR4, so I used to be an enthusiast who was constantly under these cars. But they were fun when they would run, I was seventeen, you know the drill. I think one had SU's and the other had Strombergs. What I really wanted was a Sunbeam Tiger, under whose bonnet some genius had stuffed a Ford 289.

Here is a way to add copper that might work.

Most platers should have a few of these homemade devices around, but in case they don't, here is a (very) rough sketch:

The squiggly thing is my rendition of a chain. The contraption is a plastic tube with holes drilled into it, capped on both ends with the chain running through the inside and outside. There are many variations of this cell, you can line the inside with fine screen for tiny parts, different ways to make the caps, electrical contact could be bolts through the body, etc.

Stick the pins inside, close it up, and take it to a barrel plater, Platers have these around to test plate a small amount of parts in their big barrels. They put the sample parts into it, and toss it into a barrel filled with the usual run, (see Mr. Frank R. Zemo's excellent Introduction to Barrel Plating, of Polaris Plating Co. for photos of a barrel plating operation).

Make sure that the diameter of the plating cell is not so big that the pins can get tangled. You may also need to put some media inside to help plate smoothly. I would suggest some samples before you try your metering pins.

I would say that a few dozen donuts should cover the plater's cost, but you would have to find out what they get in your area. Maybe a tuneup or a brake job?

A. Don't try to plate the needles they are tapered to cope with your fuel mixture; incorrect coating could cause damage costly damage contact Wilson Carburetors Queensberry st Carlton Vic Australia. Give them your vehicle details with c/o, h/c emission reading and they will be able to supply you with the metering needles you require.

A. I believe that the coating you seek is Acheson Colloids [Port Huron, MI] Emralon. I have an old brochure that shows carb parts, painted with the stuff. It is indeed a PTFE dry film lubricant in a phenolic or epoxy resin. Mike

A. If it were my part, I would machine it (undersize/oversize) and put 0.001 ± of electroless nickel. No post treatment is required if you spec out your machining tolerance and plating tolerance to a combined amount that you can live with.

Plate the easiest part to plate. This costs a little more, but is fantastic for your stated needs. It's hard, corrosion resistant and is naturally slippery.

A. You will not want to go with cadmium plating these days as it's a bio-accumulative poison similar to lead and mercury, and it's use has been drastically curtailed in the last decade. Tin plating is okay. And Eastwood offers a tin-zinc plating solution which might be ideal.

However, personally, I'd suggest you take them to a plating shop if you want the plating done right. Conceptually, zinc plating is dead easy-- see our "How Plating Works", complete with instructions for young schoolchildren to do it. But demonstrating a concept and doing robust plating are different things. According to Jack Dini, former metallurgy and metal finishing section head at Lawrence Livermore National Laboratories, writing in Electrodeposition--The Materials Science of Coatings & Substrates:.

Good luck.