What is this finish in your opinion?

[Curt R.]

I hope I'm not being too critical on my '59 restoration project, and this seems like a stupid question, but this bolt is one of the engine mount bolts and large washer for my early '59 and based on what I see I think it's either natural heat treated or black oxide and looks like a judged item in the JM, which shows it should be cad plated, I was about to just send it out for plating to meet judging guidelines but hate to ruin originality. What would you do??

[Gary B.]

Re: What is this finish in your opinion?

Curt,

Do you know the GM part number for each item?

Gary

[Curt R.]

Re: What is this finish in your opinion?

I don't, I just saw reference to these motor mount bolts in both the JM and the C1 restoration guidebook which both state that they should be cad plated, but I am sure these were not.

[Michael J.]

Re: What is this finish in your opinion?

Looks like black phosphate to me.

[Rod K.]

Re: What is this finish in your opinion?

Gary, IF they remained the same as '56-'57, the bolt is 100045, washer could be either 103343 (lower, under the bolt head) or 3700338 (upper, under the nut).

[Patrick H.]

Re: What is this finish in your opinion?

Note that the JGs haven't seen every Corvette and still have some errors.
Working on the 62 in the past year, I noticed some generator bracket fasteners explicitly called out as cadmium. The originals on this car were obviously black phosphate, so I redid them in black phosphate, and they judged fine.

If you think these are original to the car, don't be afraid to document that and restore it as you find it.

[Daniel J.]

Re: What is this finish in your opinion?

I would expect to see them cad plated for judging.

[Curt R.]

Re: What is this finish in your opinion?

Thanks for the feedback, Guy's! It is the original bolt and washer as well as the bushings which show some age, I think they are heat treated which give them the blueish/black color. It seems like there are two schools of thought on how I should refinish them, I guess I'll document them for prosperity and plate them for judging, I can always refinish them the way they came.

[Leif A.]

Re: What is this finish in your opinion?

Thanks for the feedback, Guy's! It is the original bolt and washer as well as the bushings which show some age, I think they are heat treated which give them the blueish/black color. It seems like there are two schools of thought on how I should refinish them, I guess I'll document them for prosperity and plate them for judging, I can always refinish them the way they came.

Carl,
Re-read Patrick's comments in post #6. If your bolts are known originals, I wouldn't be plating them just because the JG states otherwise. There are many cases of the JG being inaccurate, incomplete or incorrect. Don't change what you know to be original.

[Curt R.]

Re: What is this finish in your opinion?

Alright Leif, two out three wins! I'll refinish with the heat-treated look and add the pictures to my folder that I'll have at judging, this is a first day production car that have some left over 58 parts that were used in production such as the white corvette logo in the package tray, spiral shocks and left over engine block, it sure makes it challenging restoring the car for judging.
Curt

[Joe L.]

Re: What is this finish in your opinion?

I hope I'm not being too critical on my '59 restoration project, and this seems like a stupid question, but this bolt is one of the engine mount bolts and large washer for my early '59 and based on what I see I think it's either natural heat treated or black oxide and looks like a judged item in the JM, which shows it should be cad plated, I was about to just send it out for plating to meet judging guidelines but hate to ruin originality. What would you do??

Curt-----


I have no doubt these are the original bolts and I'm very confident that the finish is black phosphate.

[Curt R.]

Re: What is this finish in your opinion?

Thanks Joe! I agree with you since they were in the original motor mounts, and I can see the hardware has never been removed so I have no doubt that they came with the car when delivered and what's interesting is the headmarks are identical to the cad ones, and the car is a first day of production car. It is sure time-consuming cataloging all the fasteners and their finishes but keeps it interesting in a very laborious and time-consuming restoration! Curt