C3 underbody brackets

[William Holder]

Hello, I am removing and blasting and repainting or replating or replacing the seatbelt and seat mounting brackets and reinforcements. I know the seat mount reinforcements were painted black but am unsure of the Seatbelt reinforcements/brackets. I have read in some books that they were plated zinc or cad. I ordered the corner outside seatbelt brackets from Paragon and they were black phosphate and also ordered from Caledonia classic cars and theirs were cad plated. Does anyone know what came originally? my car was built in early jan 1968. Thanks for any help
Bill

[Joe L.]

Re: C3 underbody brackets

William-----

I believe that all of the brackets which you mentioned were black phosphate-finished.

[William Holder]

Re: C3 underbody brackets

Joe I was wandering where you got the idea that these brackets were black? is this from personal observation of 68 vettes or from articles? Are you a member of the judging team? I just noticed you have a lot of posts on here. The only info I have is from a book "1969 Stingray Guide book" by Bizzoco. PG 46 ..."The finish on areas low to the ground was Zinc dichromate plating. Federal regulations stipulated the plating had to withstand 48 hour salt spray testing if the belt was low in the vehicle as was the anchor mounted to the underbody."
I am not sure if he is just talking about the belt end or the mounting brackets. I would really like to hear from someone with an original car that has removed these brackets and saw traces of th finish on them. I saw black paint on the seat mount brackets but the rear seatbelt brackets were all to rusty. Please let me know if you have anymore info. Thanks in advance Bill

[Joe L.]

Re: C3 underbody brackets

Bill-----

My description of the brackets is based upon personal observation of 68-72 Corvettes, including my own original-owner 69. The brackets are, basically, all the same. All that I have seen are black phosphate or similar. Now, that may be where the confusion arises. Black phosphate is not necessarily black. It varies from nearly black to a dark gray. It has a "chalkboard-like" feel and texture. Also, it tends to rust much more easily than a metallic electroplated finish.

It's also possible that the brackets were a zinc phosphate finish. In fact, the more I think about it, the more accurate that sounds. Zinc phosphate tends to be a lot "grayer" than black phosphate and the finish on these brackets may more accurately be described that way.

In any event, I've never seen a bracket that was zinc plated or zinc with a chromate conversion coating.

Also, I do not participate as a judge in any NCRS or other judged events, so my experience does not come from that quarter.

[William Holder]

Re: C3 underbody brackets

Thanks alot for your response. Look forward to hearing more from you in the future.
Bill

[Harmon C.]

Re: C3 underbody brackets

In 1973 and 1972 the pan under the retractor was painted black. The U-shaped bracket in the tunnel for the buckle mounts was galvanized or silver cad.