"Glass out bonding strips"

[Les Veach]

Some bonding strips show through paint, some don't.

For a car to be Rally Red and for NCRS, would you advise "glassing out" ("V" grind, resin/mat, filler,etc) the bonding strips ?

Thanks
Les

[Harmon C.]

Re: "Glass out bonding strips"

Les
I would not want cracks in my new paint. I think as factory delivered you may have been able to see the bonding strips in a few areas but on unrestored cars they are easy to see as they shrunk up over the years. I would take the hit for over restoration or try to make it appear like it has the bonding strips in a few places.

Lyle

[Chuck S.]

Re: "Glass out bonding strips"

Technically, it's not the bonding strip that you see on the surface...the bonding strip is a flat piece of fiberglass that is bonded to the backside of the fender seam. The upper and lower fiberglass panels more-or-less come together in a "butt" joint, and the bonding strip is bonded to both pieces on the backside to strengthen the joint. Bonding adhesive filled any gap between the panels, and the adhesive was ground and finished to contour...it was not something the factory took a lot of time to make perfect.

I suspect the seam depression seen on the surface may have been due to poor finishing from Day 1. The popular theory is that it results from "shrinkage" of the bonding adhesive over time, but I'm skeptical that degree of shrinkage could have occured once the adhesive was fully cured. If the shrinkage theory is true, then our exterior judges are using the wrong criterion for judging...the sunken seams wouldn't have been there when the car was new, and to deduct for over-restoration if they're not there is BOGUS.

In my opinion, this "sunken seams for originality" issue is vaguely reminiscent of the ole broach mark debate. Both broach marks and sunken seams seem to have taken on obligitory status if a car is to be judged as a real car, which in my opinion is a mistake. The error here is faulty generalization based on too few observations; i.e. these cases had "it", therefore they ALL must have "it". I don't have that much experience judging, but I have seen enough original exceptions to know that neither characteristic is that "black and white"...the problem is that judging "gray" does not lend itself to an easy decision formula.

Having said all that, I would not set out to "'glass the seams" unless there was some signs of seam distress like cracking...even then I would probably only do it selectively by fender. In the first place, it's an incredible amount of work for no other reason than making the body non-originally smooth, and second, it's very likely IMO that what you see is the same as it looked when it was made...the seams on my 70 look much better than some I've seen; I may get deducts for over-restoration with my original seams.

Your decision: Want it perfect? It's a heckuva' lot of work, and judges won't like it. Got cracks?...It's a no-brainer IMO.

[Jack H.]

Re: "Glass out bonding strips"

Visible body panel seam lines + 'blow holes' in the thin, factory original, paint along those seams is, unfortunately, the 'badge' of factory originality. Some cars were worse than others, but fit and finish was a constant quality issue that original buyers simply dealed with. Whether to 'fix' by over-restoration or not is your personal decision and judgement call.

[Page C.]

Re: "Glass out bonding strips"

This subject came up at the advance judging school hosted by Terry McMannmon at the recent Carolina Chapter Regional at the Lowes Motor Speedway. His point was that the cars you see today with the deep sucken seams would not have been acceptable to the GM quality control group. They would not have let cars go out the door with every body seam showing like some cars we see today.
Regards
Page Campbell

[Jack H.]

Re: "Glass out bonding strips"

Well, that's obviously Terry's personal opinion and I RESPECT Terry! But, there's another current thread on the board where people cite actual experience with fit and finish quality from either being original owners or having researched their cars back to the original owner and there's more than a few complaint(s) cited...

While not a direct experience with GM/Chevy/Corvette, I grew up in Detroit and my stepdad was Director of Labor Relations at Chrysler. He was on the executive lease program perk (dirt cheap lease rate, but you were limited to 6-months or 6000 miles with a vehicle, which ever came first). We wound up having AT LEAST four new cars each year, sometimes 6-8.

Roughly 30% of those delivered from the factory were 'retouched' at the corporate garage. Now, Chrysler isn't GM, but I think we too soon forget what American production quality really was in the days following WW2 when we were about the only place on the planet with plant and equipment to churn out finished goods while Europe and Asia were rebuilding their war torn infra-structures....

[Terry M.]

[Chris Patrick]

Re: "Glass out bonding strips"

I remember a lot of new Corvettes that looked very good. There was the orange peel paint on many, usually on the sides, but the seams were not showing. That would have been a big rejection in quality and by the buyer at the dealer.

This was an era that Chevy owners glowed in the fit and finish of a Chevy compared to Fords where every panel looked like they had been painted a different shade.

I think in true bureaucratic form, people managed to get the thought behind the words backward. Most likely, the original intent was not to deduct for the seams showing as they could be original. Somehow people twisted that into only the seams showing are original and deduct if they don't.

I knew a '63 that has its original paint and the seams don't show on it. I also knew a '68 that had its original paint and the seems don't show on it, either. I knew a '69 that the seams showed on one rear fender and not on the other. And it was an all original 43,000 mile car at the time.

I saw a new dark blue C6 about a month ago. Beautiful car, but when you got up close, the shine on the sides wasn't like a mirror, it was fuzzy. And I realized that the paint had almost an orange peel look to it. The more things change, ...

[Chris E.]

Re: "Glass out bonding strips"

Ok guys, so I'm doing a complete nut and bolt, body off resto on my 67 roadster. Part of my work will be getting the car painted.

The body shop that works on a TON of Corvettes has said that they will grind down the body seams, fill them back in, and then gel-coat the whole car.

Given that I'm not doing laquer, does it make sense to leave the seams the way they are to get more points? How many points are talking about here for a deduction on "no visible body seams showing"?

[Chuck S.]

Re: "Glass out bonding strips"

Chris, my opinion is that grinding down the seams, and simply filling them back with body filler is a less than great idea.

In the first place, it's a lot of filler volume with the sole purpose of smoothing the contour, and in the second, it's only cosmetic and adds no strength to the seams. Fiberglassing the seams essentially eliminates the bonded joint...it's still there, but it's less relevant; the fender has been laminated into one piece with no likelihood of future seam cracks, seam sinking, etc. If originality is what you want, tell them to leave the seams alone unless they are really ugly IMO.

Rather than get my skinny behind out on the judging limb with unfounded ocmments, I will leave judging effects to others.

[Terry M.]

[Terry M.]

Re: "Glass out bonding strips"

Thinking about this some more leads me to think the body seams might more correctly be judged under body fiberglass, rather than paint. See, that is what happens when on doesn't judge exteriors much or at all.