Refinishing bolts

[Roger Legge]

Re: Thank You! *NM*

[Chris S.]

Re: Refinishing bolts

I have used Jerry McNeish at Camaro Hi Perf for my plating
I had some stuff gold zinc (cad) - It was perfect -
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I currently have some items at detail plating
I know another member who has used him with great success
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I tried Caswell's blackner this weekend - dont waste your time or money
The coating just flakes off
I am going to have to find another way to do my black bolts.
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my.02

[Chuck S.]

Re: Refinishing bolts

Chris, check the archives. I discovered and posted a source for black/gray phosphate solution a few months back. If you have enough fasteners to justify the trouble, you can have the real deal. There is also an article I wrote for The Corvette Restorer back around 1998 or so.

[Chris S.]

Re: Refinishing bolts

Not to start trouble
I was at an ISCA show about 5 years ago
Got to talking with this man - who had restored a Boss 302
and was talking about his fender bolts - etc...( perfect car by the way )
He told me - I took a torch or ?? - heated the bolt cherry red
then dropped it into a container of used motor oil ????
Now whether it is true or worked but his bolts were a nice black
and had a small amount of sparkle to them.
Just a story I had heard
Dont know if it is true of not ?
Maybe he was pulling my leg

[Chuck S.]

Re: Refinishing bolts

Yuk, yuk.

My opinion is: long hours displaying your perfect restoration can be made to pass much faster by blowing smoke up curious gogglers' skirts.

But, the cherry-red-fastener dipping in used motor oil technique DOES make the real phosphate process look easy and fast by comparison...not to mention cleaner. Heating fasteners to cherry red is a bad idea in my opinion...I sure wouldn't want to inadvertantly add some undesired and unexpected heat treatment.

[Donald Brunswick]

Re: Refinishing bolts

This is the place I think Chuck is talking about. I've used there product with great results. http://www.calvan.com/index.html

donald

[Terry M.]

Re: Refinishing bolts

Chuck,
The heat and dip technique does work, but it should be restricted to non-critical fasteners (like the afore mentioned fender bolts). NEVER ever use it on any fastener you would not want to fail. Now a F)*! fender..... D:
Blowing smoke can while away the time, as you mention, can also be rewarding.

[Chris S.]

Re: Refinishing bolts

I might try the above
I tried the Caswell - doesnt work
Did try my nuts and bolts black - but it was spotty and
the coating flaked right off - just touching it with my fingers or
and paper towel.
I just overnighted a package to Detail Plating for silver zinc
we will see how it turns out

[Terry M.]

Re: Refinishing bolts

Chris,
I have no direct experience with any of the systems mentioned, but forty years ago I operated a phosphating line for a research organization. When doing this kind of work cleanliness is vital. The parts must be surgically clean or the process will not work properly. We used near-boiling sulphuric acid - fiberglass tanks and lead pipes with steam flowing through them. Probably only one of the reasons plating companies are on the EPA hit list.
You may not be able to duplicate that process at home, and I don't suggest trying, but a strong degreaser, and bead blasting with clean media (no grease in it) should be a reasonable substitute. Be aware, however, that media blasting can alter the surface texture of the part and plating will not disguise that texture.

[John H.]

Re: Refinishing bolts

Trivia - The same process is used on (steel) car bodies in assembly plants; the raw body runs through a hot degreasing/cleaning/rinse process, then runs through a hot iron phosphate process, followed by a bake cycle. This provides the "teeth" for the subsequent prime coat.

The identical process was used as part of the black dip-prime/flow-coat system used for Corvette "small parts paint"; all the miscellaneous small parts, engine brackets, riveted-on body reinforcements, wheels, etc.

[Chuck S.]

Re: Refinishing bolts

Chris, the do-it-yourself article ("Black Phosphate - Do The 'Right Stuff' Yourself") is in The Corvette Restorer, Volume 26, Number Two, Fall 1999. If you don't have the hard copies that far back, then the article is probably also on the CD available at the NCRS store.

You probably don't need the article if you follow the instructions on the solution available from Calvan. The article does show tedious details on where/how to buy/build the equpipment you need, and things to look for during the process.

As Terry said, bead blasting will give parts/fasteners a matte finish that cannot be hidden by plating. This is particularly true on zinc or chrome plated parts, and less of a factor for phosphate; phosphate is by nature a flat, matte finish. For zinc or chrome plated parts that must have a smooth surface, I would strip the old plating using muriatic acid solution just before I did the plating. Neutralize the acidity on the parts well in baking soda solution, then rinse well in water. Hand dry immediately after the water rinse, otherwise they will rust like (...expletive your choice).

In the case of phosphate parts, bead blasting will probably cause you no appearance problems. After bead-blasting, solvent rinse the parts/fasteners in clean lacquer thinner to remove media dust and any oils present, then rinse the parts/fasteners in phosphoric acid solution as the first step in the plating process. Any handling of the clean parts/fasteners should be done with latex or vinyl gloves.