Well, I worked on the potmetal parts today experimenting with the fuel bowl coloring. Here's my set of potmetal parts for this 67 3810:
I'm trying to replicate a gold iridescent finish on these parts. On original carbs, there is probably a great variance in finish on all of the potmetal parts, it is very understandable as all the different parts were finished and colored in different baths, in different locations and by different vendors. There has to be a variance in the finish on the potmetal parts.
In this post, I'm going to concentrate on the fuel bowl finish, the results of a lot of trial and error to get that gold irridescent finish, somewhat greenish, as some remember. Here is how I found, it is done. This post may take a few posts because of the number of pictures.
Here is what I started with:
This is a bowl from a replacement 3810 which I think I recolored some years before, but it always seemed to come out too dark. As you will note in the picture, in disassembling I always use a little plastic compartment box so that I don't get confused when I reassemble. I also take photos of every part prior to disassembly, so I have a reference to where the parts go and their orientation when I reassemble. I think this is a good practice for amateurs like me.
First step is to strip the existing dichromate finish. I just dip it in a solution of muriatic acid (pool acid) cut 3 to 1 with distilled water:
You have to be careful with muriatic acid as it will eat zinc, potmetal (which is mainly zinc), cadmium as well as chrome. The dip here is no more than 30 seconds and just enough to take the dichromate finish off the fuel bowl:
This is just coming out of the acid dip. Then you would immediately neutralize in hot SP degreaser and or a baking soda solution. I use both to be sure the acid is neutralized on the zinc and in the little crannys.
Since I ran out of picture allowance for one post, I'll continue in the next.
I'm trying to replicate a gold iridescent finish on these parts. On original carbs, there is probably a great variance in finish on all of the potmetal parts, it is very understandable as all the different parts were finished and colored in different baths, in different locations and by different vendors. There has to be a variance in the finish on the potmetal parts.
In this post, I'm going to concentrate on the fuel bowl finish, the results of a lot of trial and error to get that gold irridescent finish, somewhat greenish, as some remember. Here is how I found, it is done. This post may take a few posts because of the number of pictures.
Here is what I started with:
This is a bowl from a replacement 3810 which I think I recolored some years before, but it always seemed to come out too dark. As you will note in the picture, in disassembling I always use a little plastic compartment box so that I don't get confused when I reassemble. I also take photos of every part prior to disassembly, so I have a reference to where the parts go and their orientation when I reassemble. I think this is a good practice for amateurs like me.
First step is to strip the existing dichromate finish. I just dip it in a solution of muriatic acid (pool acid) cut 3 to 1 with distilled water:
You have to be careful with muriatic acid as it will eat zinc, potmetal (which is mainly zinc), cadmium as well as chrome. The dip here is no more than 30 seconds and just enough to take the dichromate finish off the fuel bowl:
This is just coming out of the acid dip. Then you would immediately neutralize in hot SP degreaser and or a baking soda solution. I use both to be sure the acid is neutralized on the zinc and in the little crannys.
Since I ran out of picture allowance for one post, I'll continue in the next.
)
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