Does anyone know how to dull CAD plating?

[theknucklehead]

I am trying to color match my CAD plating. Some of the CAD is the correct "dull" finish. The more recent Cad plating that I have had done is comming back very shiny. During a recent judging I was docked points for the Cad not matching. The judges almost thought that my dipstick cap and speedo cable had been chromed, they were that shiny, compared to the shifter rod which is right next to it and dull grey in color. Of course I would rather not have everything re-done if I don't have to. Any home brew recipes would be greatly appreciated.

[exeric]

Wow, that is shiny cad. I wonder if walnut shell blasting would dull it up without removing material ?

[DaveSwanson]

Shell blasting is good, or a quick dip in muriatic acid would do it.

[T. Cotten]

Cadmium plating should NOT match over the entire machine;
Revisionism runs rampant in our hobby.

Meanwhile, just leave it out in the weather and Nature will take care of your concern!

...Cotten

[rousseau]

Cotton

I have found that using a "paste" made from cleansers such as comet,ajax or soft scrubb will knock off the "mirrow" finish on chrome. These items have very mild abrasivies. You might want to experiment with this.

[theknucklehead]

Eric,
The shell blasting worked so so. I went one step farther and tried a light bead blasting and that did the trick. It gave the parts a dull even look. The speedo cable will have to stay bright and age on it's own. I don't think I could ever get the glass beads out of it if I blasted it and I agree with Cotten, some of the CAD should be a little different since the parts came from different places on the original bikes.

[T. Cotten]

Let me begin by noting that I have no need to dull cad. Brighten, perhaps!
Beware of any abrasive, as the plating is quite thin and not nearly as hard as other metals.
And beware also of its toxic properties.

Cad appears differently on different metals; Cad-plated cast iron will look different than steel or bronze or brass.

Attached is a pic of several NOS float pivot pins soaked from cosmoline simultaneously from the same lot. Cad on brass can vary with itself.

It is absurd to claim that all cad plating on a machine should match, any more than parkerizing should.

...Cotten

[theknucklehead]

Cotten,
Just delivered a batch of parts to the CAD plater. He told me that when their tanks are freshly cleaned the CAD comes out very shiny as opposed to when the tanks have been used for a while, the CAD has the more "dull grey" appearance. He also agreed with you that different metals have a different a shine to them when they are plated. Most of the CAD that they do is for the airlines and industry and they want their CAD to be bright and shiny. Thats where the money is so thats what they get.





"Good parts aren't cheap and cheap parts aren't good"

[Lonnie]

My last batch also turned out quite shiny - we used the same vendor as always. It does seem to be slowly losing a bit of sheen once installed, since seeing road use.

Some of the judges get carried away - I would have gone to the head judge and b*tched about losing points for that, especially since I doubt anyone on this earth has color photos taken right after delivery of a new machine to verify the statement that the cad should all match!

Lonnie C. from SC

[exeric]

Lonnie makes a good point in that there is no Rosetta stone for judging the patina of a restored bike to original motor company products. The judges have a tough job and they have to be critical but I would venture to say that many of them have never worked in a factory and seen the industrial process. Our company had many of their parts cad plated back in the day. Of coarse that has been replaced by zink today. Cad comes in a rainbow of shades and hues based on the metal it's on and the finish of that metal. Cold rolled steel has a smooth finish compared to hot rolled steel and that will give it a shiny appearance. That speedo cable was die made and good dies genereally further polish metal. Most companies will tumble their production parts in a big drum full of ceramic stones or beads to remove burrs and sharp edges. Tumbling looks similar to glass beading but not quite.

I remember an extreamly well done '47 FL getting gigged at Oley for non-matching cad plating. I knew the restorer and he came from an industrial background and is a stickler for authenticity and correct finish. The judge, who I also have a lot of respect for did not come from a manufacturing environment but had spent his life working on bikes. His knowledge was empirical from years of hands on experience. Needless to say, it turned into a p*ssing contest.

Personally, I would go with the logical manufacturing finish and let the shades and hues fall where they may. Like Cotten said, time will give it's own patina to the parts.