Surface Rust on Engine Fuel and Vacuum Steel Lines.

[Pat Marshall]

My engine's steel and fuel and vacuum lines keep getting surface rust. I don't want to paint them and clear coating hasn't done the trick. Maybe I'm not using a good enough product. Does anyone have recommendations?

[Barry Wolk]

It’s very simple to replace the zinc plating. Or, simply have them duplicated in stainless as a forever fix.

[Pat Marshall]

Barry, have you tried doing the plating? I looked it up online and it does seem pretty doable.

[Barry Wolk]

I've been known to zinc plate every nut and bolt on a restoration. I zinc plated the inside of a Treadle-Vac booster canister. Steel hoses are easy if you have a container that will allow you to submerge the part. You need a DC power supply or batteries with an output of 3-volts at up to 5 amps.

It's very important to start with fresh metal. If I were doing a factory-plated part I would degrease the tubing and then reverse-plate the part, drawing the existing zinc off the part. I soak the bare metal in an acid prep until it turns black. If I can I use a 3-M abrasive pad to remove the blackened residue, but that's not always necessary. If you've handled the part with your bare hands degrease and a short bath in acid is in order.

Here's where you have to be quick. Everything has to be set up so that you take the part from the acid bath to a quick water rinse and directly into the plating solution. If you are slow flash rust happens and you have rust marks on the finished piece. On an important tube that shows I would make 2 or 3 passes with a light abrasive to remove a few atoms from the surface and plate again. If you build up enough zinc you can buff it up for a brighter finish, matching the original look.

If you want to get serious about it lay down a layer of copper and then zinc plate. My best results have come recently using a large Pyrex container on a magnetic spinner platform. Drop the covered magnet in the bottom and stir up the fluid as you plate.

Best results will come from using two strips of zinc as an anode. Plating leaves a dark gray coating on the anode that must be removed between each coat. Don't blow the parts dry as air from your compressor likely has water and oil in it.

This sounds like a lot of work, but you can really make some headway on nuts and bolts working with a prep helper. I find a supply of plastic tanks in various shapes used for storage baskets.

The Eastwood kit comes with prep, plating fluid, zinc strips and a 2 D-cell battery box. I just use copper wire from 14-gauge Romex to suspend the parts and the anode.

You can tell which Carhartt shirts I've worn while plating.

[lld]

Pat,

You could also try silver cadmium plating. In some states it can't be done but in most states it can. Silver cadmium was used on most gas lines in the fifties and sixties for British cars and perhaps some USA cars. Silver cadmium is still used in many places on aircraft. In most cases, plating shops will do silver cadmium much cheaper than any other type of plating. I have done restorations on a number of British cars where virtually every fastener was cadmium plated as well as all the air and fuel lines.

Note, do not put aluminum parts in with the parts to be cadmium plated; the process will severely damage the aluminum.

Larry

[Barry Wolk]

Good information, Larry.

I'm almost gonna bet that having stainless tubes bent is the most cost effective route.