So I know it has been a while since my last update, but before summer arrived in full swing and my other bikes started getting all of the attention, I spent a large portion of time trying to clean and replate some of the smaller specialty pieces I had taken off the bike with zinc.
This involved two steps, the first being trying to get all of the rust off of a part. My soda blaster had been doing well for light to medium rust, but the heavy rust on this rear brake brace was rather stubborn.
This is what I started with, heavy surface rust and pitting. What I did was use an old computer power supply tied to four pieces of iron rebar on one lead and a piece of wire suspended in the middle of the bucket. The part was attached to the wire and submerged in a salt and water type solution that would allow electric conductivity. Simply turn on the power supply and the rust process is essentially reversed and the rust cakes on the rebar. This doesn't fix bad rust pitting, which I had a lot of, but it is a start. Once the piece ran for a day or so you pull it out and scrub it with some steel wool and you get this.
You can still see some of the rust pitting, but it is a huge improvement. Once I had this I took a dremel and made sure I had all of the rust off (there were a few little spots that were still rusty from air bubbles being there etc) and dipped the whole piece in moderately concentrated HCl, this acts as a strip for the factory plating (in this case either Zinc or Cadmium) and makes sure your part is down to the bare metal.
Once this is finished you are ready for plating! The plating apparatus I made is similar to the rust removing bath with high purity Zinc roof strips in place of the rebar and the polarity of the power supply switched so our electron are moving in the opposite direction. the part is submerged and allowed to run for 10-15 minutes (you don't want all of you tolerances messed up by too much plating). This is the result.
OK, that doesn't look very nice, but here is the trick. If you take that and scrub it with a brass wire brush under some water you get this.
I then ran the part through the zinc plating process for a second time for a nicer finish. Notice there is still some pitting that kind of lets the piece down, but it is a huge improvement and is more then adequate for this non concours restoration.
I am going to do this process and every currently zinc plated fastener that is surface rusted, but here is an example of the factory finish in good shape and the replate for some exhaust bolts.
Factory plating is on the top and the replate is on the bottom. The black on the end of the replate nut is heavy pitting from rust, which is why I have the extra factory bolt.
This involved two steps, the first being trying to get all of the rust off of a part. My soda blaster had been doing well for light to medium rust, but the heavy rust on this rear brake brace was rather stubborn.
Once this is finished you are ready for plating! The plating apparatus I made is similar to the rust removing bath with high purity Zinc roof strips in place of the rebar and the polarity of the power supply switched so our electron are moving in the opposite direction. the part is submerged and allowed to run for 10-15 minutes (you don't want all of you tolerances messed up by too much plating). This is the result.
OK, that doesn't look very nice, but here is the trick. If you take that and scrub it with a brass wire brush under some water you get this.
I then ran the part through the zinc plating process for a second time for a nicer finish. Notice there is still some pitting that kind of lets the piece down, but it is a huge improvement and is more then adequate for this non concours restoration.
I am going to do this process and every currently zinc plated fastener that is surface rusted, but here is an example of the factory finish in good shape and the replate for some exhaust bolts.
Factory plating is on the top and the replate is on the bottom. The black on the end of the replate nut is heavy pitting from rust, which is why I have the extra factory bolt.
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