C3 Resto Question

[Michael G.]

First like to thank those who responded to my stock speaker issue. Great info, very helpful. I'm new to the hobby so my question may seem elementary. looking to clean up half shafts and drive shaft. What is the acceptable form of protecting parts not coated from factory. Would it be wise to even blast them or leave them as Mother Nature has done to them?

[Kent K.]

Re: C3 Resto Question

Michael,

First, I presume you are planning to show the car instead of driving it daily. You could glass bead the drive and half shafts to clean them. Then coat them with a parifin based material like Coricone which may be wiped off with a laquer thinner dampened cloth. Or, you may leave it on until it turns a yellowish color (about 2 - 3 years). There are many other protectants for these shafts but you'll have to do a search through the archives.

Regards, Kent Keech

[Terry B.]

Re: C3 Resto Question

Michael,

If you want to have them restored to their correct look as they left the factory, contact Greg Gorniak at red65vette@hotmail.com . Greg restored mine and many others. No cast grey paint on these parts. He brings back the original finish even down to the heat marks on the weld joints. He does a great job at a reasonable price. He's an NCRS judge and has a '65 Duntov Award winner too.

[Eric F.]

Re: C3 Resto Question

Michael,

The answer to your question depends upon the existing condition of your parts. I recently completed a body off restoration of my wifes 75 convertible; and obtained a Top Flight at the NW Regional in Leavenworth, WA.

When it came to the driveshaft and half shafts I was able to restore them by using a combination of bead blasting and wire wheel. I used several diffent sizes and grades (fine to coarse. When it came time to use the wire wheel it took some practice so as not to overheat the metal and cause burn marks. Don't worry if you do because once you get the ahng of it you can redo the area and obtain the correct finish.

When all the rust was removed I wiped everything down with a protective oil. WD40 or something similar works well, but it does need to be reapplied as needed. You can also spray it with clear but you will have points deducted for the finish.

Good luck on your project.

Eric

[Harmon C.]

Re: C3 Resto Question

Michael

Driveshafts and halfshafts are not easy to get correct in the eyes of a judge. In my case their was about four points and if they were rusty or a finish the judge didn't like the deduction was about the same. I have seen them restored with marks like they were turned in a circular pattern. I have seen originals that I thought the tube had lines going lengthways of the shaft.
Lyle

[Chuck S.]

Re: C3 Resto Question

"I have seen originals that I thought the tube had lines going lengthways of the shaft."

Ideally, that would be the perfect goal for a restored finish...and virtually impossible to duplicate. The lines were faint tooling marks from the forming and welding process. Otherwise, I would expect the surface finish to be that of slick, raw, freshly rolled steel plate. Burnishing with a wire wheel gets you closer, but it's clearly not fresh rolled steel with forming marks. The blue heat affected zone marks are good if you can simulate them.

[Harmon C.]

Re: C3 Resto Question

I agree Chuck that even spending the big bucks to get them redone a deduction still may be in order. That's why I just took the small hit for the wrong finish and spent my time in other areas.
Lyle

[Terry M.]

Re: C3 Resto Question

I know some folks who have had new tubes installed in the drive shaft and half-shafts in order to get that finish, but my understanding is that tubing of the original wall thickness is difficult to impossible to get now days. This makes re-fitting the original ends a challenge. At least that was the story I heard a couple of years ago.

[Terry F.]

Re: C3 Resto Question

I am sure they would have used some type of "seamless" steel tubing. It would be expensive and you can order it through stock steel suppliers. If you can't get the correct fit on the ends, you can have a good machinest turn the inside of the tube to fit the yoke. Never done this but it sounds good to me. It would be difficult without proper equipment to measure wall thickness once assembled. I believe the big blocks 1/2 shafts did not have the heat markings because they were shot blasted to stress relieve them?? Small blocks had the heat markings (no shot blasting). I am not sure if this is a consistant finding for all years though. Blue heat markings were probably the result of electric welding. JMHO. Terry

[Terry F.]

Re: C3 Resto Question

I am sure they would have used some type of "seamless" steel tubing. It would be expensive and you can order it through stock steel suppliers. If you can't get the correct fit on the ends, you can have a good machinest turn the inside of the tube to fit the yoke. Never done this but it sounds good to me. It would be difficult without proper equipment to measure wall thickness once assembled. I believe the big blocks 1/2 shafts did not have the heat markings because they were shot blasted to stress relieve them?? Small blocks had the heat markings (no shot blasting). I am not sure if this is a consistant finding for all years though. Blue heat markings were probably the result of electric welding. JMHO. Terry

[Terry M.]

Re: C3 Resto Question

The marks on small block driveshaft and axle tubes are from the material being drawn through a mandrel. That is not the usual method used to produce "seamless" (which is really not seamless, but simply called that) tubing. If the only consideration for the tubing used in this application were size, that would be no issue and could be resolved as you suggest; but the reason to instal new tube is to achieve the "as original" surface finish. That is achieved by using material processed as the original was, and assembling the ends using the same techniques as the original.

[Terry M.]

Re: C3 Resto Question

The marks on small block driveshaft and axle tubes are from the material being drawn through a mandrel. That is not the usual method used to produce "seamless" (which is really not seamless, but simply called that) tubing. If the only consideration for the tubing used in this application were size, that would be no issue and could be resolved as you suggest; but the reason to instal new tube is to achieve the "as original" surface finish. That is achieved by using material processed as the original was, and assembling the ends using the same techniques as the original.

[Terry F.]

Re: C3 Resto Question

Can you buy tubing drawn through a mandrel? If not, I would use seamless tubing. I refer to seamless because of strength and consistancy of form. I suspect it would spin up and balance better when done. I would be curious what these driveline shops use for tubing? Terry

[Terry F.]

Re: C3 Resto Question

Can you buy tubing drawn through a mandrel? If not, I would use seamless tubing. I refer to seamless because of strength and consistancy of form. I suspect it would spin up and balance better when done. I would be curious what these driveline shops use for tubing? Terry