Seat Belt anchors

[David F.]

C2 Completing frame off restoration started by someone else. Body replace on frame leaving out the seat belt underbody mounting brackets. Frame has gussets welded to rear cross member and side rail with no room to install outer brackets. Any suggestion on how to install these brackets?

[Gary C.]

Re: Seat Belt anchors

David, moved your thread to the Technical Forum. Help Forum is for TDB use questions. Gary....

[Alan D.]

Re: Seat Belt anchors

What year car? If for your 63 then no gussets.

[Gene M.]

Re: Seat Belt anchors

David,
Are all 4 brackets missing? These are aluminum riveted to the fiberglass under body. The inner ones are easy to install. The outer ones will be next to impossible with body installed on the frame. I can't imagine anybody leaving such a major group of brackets out of the assembly process. But if the brackets were there the outer cabled mounts will also be impossible to assemble in out board positions with body on frame.

[Gary F.]

Re: Seat Belt anchors

Mine were totally rusted on my 63, so everything got re-done. I gotta believe you'll have to jack the body up a bit to get this done, since it is back on the frame.

[Tracy C.]

Re: Seat Belt anchors

You may be able to install the outer brackets with a #6 pop rivet. Use a flat washer under the head to simulate the head dia of the factory rivet. From memory I think that is about 1/2" dia.

Otherwise, You will need to lift the body about 6" so you can buck the factory style rivet.

tc

[Gene M.]

Re: Seat Belt anchors

You may be able to install the outer brackets with a #6 pop rivet. Use a flat washer under the head to simulate the head dia of the factory rivet. From memory I think that is about 1/2" dia.

Otherwise, You will need to lift the body about 6" so you can buck the factory style rivet.

tc

Aluminum rivets are peened on the bottom side. Unless you are super man lifting the body 6" is not sufficient room to buck the aluminum rivets. Keep in mind seat belts are a safety item and should be installed correctly using the correct fasteners.

[Tracy C.]

Re: Seat Belt anchors

Aluminum rivets are peened on the bottom side. Unless you are super man lifting the body 6" is not sufficient room to buck the aluminum rivets. Keep in mind seat belts are a safety item and should be installed correctly using the correct fasteners.

Six inches is more than enough to buck a rivet, but a 6 inch lift will allow for easier placement of the brackets. The rivet gun on the head side of the rivet does the work. Superman strength not required..

The crash load will pull the steel bracket (rivets and all) through the fiberglass floor before the rivet will shear....even if a pop rivet.

Sadly, there is very little protection provided to the occupants in a high speed impact for the early restraint designs having no tie to the car's frame.

tc

[Gene M.]

Re: Seat Belt anchors

Six inches is more than enough to buck a rivet, but a 6 inch lift will allow for easier placement of the brackets. The rivet gun on the head side of the rivet does the work. Superman strength not required..

The crash load will pull the steel bracket (rivets and all) through the fiberglass floor before the rivet will shear....even if a pop rivet.

Sadly, there is very little protection provided to the occupants in a high speed impact for the early restraint designs having no tie to the car's frame.
tc

Wrong, a solid aluminum rivet is bucked on the bottom side not the head. And there is no way lifting the body 6" will allow a hammer gun or any hammer to peen the solid aluminum rivet. The frame alone is 6" deep as the body sits down in there. Pop rivets are for gutters.

[Tracy C.]

Re: Seat Belt anchors

Wrong, a solid aluminum rivet is bucked on the bottom side not the head. And there is no way lifting the body 6" will allow a hammer gun or any hammer to peen the solid aluminum rivet. The frame alone is 6" deep as the body sits down in there. Pop rivets are for gutters.

Gene, I've been employed in the aircraft industry for 35 years. I know a wee bit about standard riveting practices. Typically rivets are "driven" from the head side with a rivet gun and "bucked" from the butt side with a bucking bar. The bucking bar is made from steel and can be shaped as needed to fit into tight spots. In the case we are discussing here the bucking bar could be shaped just like a 3 lb hammer. Anything solid to hold against the rivet butt and swell the shank as the rivet is driven from the head side with a rivet gun (or even a cheap air hammer). The key here is to use soft alluminun rivets and only about 20 psi to the air hammer. (Real rivet guns have a progressive trigger so air pressure is not a factor).

You are correct when you state that rivets are bucked from the bottom. You are just misinformed as to what that really means.

tc

[Gary F.]

Re: Seat Belt anchors

The in-board & out-board anchors from my 63 Coupe..............Soft rivets were used, and bucked with a bucking bar. The problem I had was that the heads of the original rivets were rusted away, and the anchors started pulling away from the body. I had the same thing happen on my No. 1 & 4 body mounts. MY $.02 cents worth of info.

[Jim S.]

Re: Seat Belt anchors

[Mike G.]

Re: Seat Belt anchors

Gene, I've been employed in the aircraft industry for 35 years. I know a wee bit about standard riveting practices. Typically rivets are "driven" from the head side with a rivet gun and "bucked" from the butt side with a bucking bar. The bucking bar is made from steel and can be shaped as needed to fit into tight spots. In the case we are discussing here the bucking bar could be shaped just like a 3 lb hammer. Anything solid to hold against the rivet butt and swell the shank as the rivet is driven from the head side with a rivet gun (or even a cheap air hammer). The key here is to use soft alluminun rivets and only about 20 psi to the air hammer. (Real rivet guns have a progressive trigger so air pressure is not a factor).

You are correct when you state that rivets are bucked from the bottom. You are just misinformed as to what that really means.

tc

Tracy: Certainly agree with the above as "standard practice". But take a look at a C2 spare tire compartment lid, specifically the "Y" brace rivets. The shanks are dome shaped. Suggests to me that the bucking bar was on the flat head side and a concave set was used on the shank. Actually, one of my cars has circular witness marks on the strap around the rivets.

And many other riveted-on items have domed shank ends, not flat from a bucking bar. What do we conclude? Maybe the engineers didn't like the idea of driving the flat rivet head against the fiberglass layer? Mike

[David F.]

Re: Seat Belt anchors

Vette is a 63 but person who did most of the restoration used a 65 frame with gussets.

[Gene M.]

Re: Seat Belt anchors

............................................You are correct when you state that rivets are bucked from the bottom. You are just misinformed as to what that really means.

tc

What ever terminology would be correct here is not the issue. The point is to peen the solid rivets while backing the heads against the fiberglass floor, sufficient access is required under the car. Weather one bucks the head or the shank is their choice. It would still require sufficient space. I think you will find most restorers peen the rivet shank. As this method allow for better seating of the head against the fiberglass floor while securing the brace on the opposite side against the fiberglass. thank you for sharing your background and information.