Mr.Gearhead

Hi all,
Car is running.... GREAT. Well the motor and FRAME are running smooth. The body turned out to be more work than I expected. Pass. side w/s corner rotted. Welded in new sheet metal and it looks okay now. Firewall is completed and all new wiring harness in the garage waiting to be installed.

BUT... I have a big issue.. well BIG to me anyway. I cut #4 nut off with .... sawzallllllll. So how do I remove what is left up in the cage nut? I cant even see the damn thing from inside! Do I remove the convertible springs? I know what I will do when they are out... new bolts and thread downward! Anyone have any advice on how to remove the #4 cage nut?

Tom73

That mount is under the hatch support base. The rivits that hold the body reinforcement under the body also hold the base of the hatch support. You do have to remove it to replace the cage and nut sorry....

tom...

Mr.Gearhead

Hi Tom,
The metal reinforcement under the body has about 6 rivets... is this what I need to grind down? Once I grind the rivet outs, will the rear hatch spring try to take my fingers off? Do I need to remove the springs first? Also, it looks like the rear fender support (fiberglass piece) is covering the back of the metal reinforcement. Do I need to remove this also? Are there rivets in the back as well? This sound like a lot of work... Has anyone else done this?

LemansBlue68

I did this on my '68. It's a job, but there are worse.

1) Remove the rear hatch (hinge) supports. Here's a tip: with the hatch closed, stuff some wooden door shims into the hatch sping to fill the gaps between the coils. Then, open the hatch and the springs will stay extended because of the door wedges. At this point, the springs will almost fall off. Remove the springs and set them aside.

2) Remove the hatch from the hinges. Unbolt the hinges from car. There are two bolts up top that are hidden but can be removed from behind and one bolt that screws into the cage nut cover. This is the worst part because the two hidden bolts are installed from behind. Now with the hinges out of the way you have full access to the cover which is concealing the body nut and cage.

3) Grind off the rivet heads that hold the cover in place and it will come off to expose the nut and cage which are undoubtedly iron oxide dust at this point.

4) While you're replacing the nut and cage, also consider replacing the #4 mount reinforcments (the sheetmetal parts in the wheel well that support the fiberglass around the #4 body bolt). Those are almost always rusty.

5) When you go to put things back together, because you wedged the spring open before you took it off, it will be a piece of cake to put back on. Just slip the spring in place, push on the hinges a bit to extend the spring a bit more and remove the wedges.

Good Luck!!

Mr.Gearhead

AWESOME! THANKS! I will stop by Lowes and get some wood shims. I will do this tonight and take pictures. Thanks LeMans! Hey... do you have any pictures of your car? I am going to repaint and I would like to go with LeMans Blue. I have seen several different LeMans Blue... I want the lighter blue with metallic in it.... THANKS AGAIN!

Mr.Gearhead

Okay, finished removing all that stuff. Decklid and springs removed. I used the wood shim method (GREAT TIP). Drilled all the rivets and removed the reinforcement underneath. Then remove the reinforcement on the inside. When I went to remove the cage nut.... NOTHING THERE!... hee hee Just one rusted bolt and a pile of rust.

I will order the new piece tomorrow. Which leads me to another question. I bought a rivet gun from the hardware store. The rivets are too small and they do not look good. (Did some trial runs...) How can I reproduce the factory rivets? What tools are needed. The gun I have now needs to have the excess trimmed with cutters... LOOKS LIKE SCHIT. How did you do it? THANKS.

Oh yeah.. the bolts holding the upper deck lid hinge.... :mad :mad

and that is being nice. Who designed that crap? I DRILLED behind the rear compartment wall two holes each side. Slide the longggggg extension through and PRESTO... air gunned those crapping bolts right off.

LemansBlue68

HA HA!! You would not believe the amount of swearing I did with those damn bolts!!! I ended up doing the same thing you did. I didn't do the wood shim thing. A friend told me that trick AFTER I was done doing mine. I thought that with the springs out of the way you MIGHT have a chance to get those bolts out without having to drill. I guess not. I used rubber well nuts to plug the holes (in case I ever need to take those dern hinges off again--God forbid), but I guess you could go with a more permanent method to seal the holes closed if you want.

The rivets I used were the factory style aluminum ones available through many of the Corvette suppliers. Zip has them, but I bought mine from Paragon. I bought a 0.401 shank rivet setting tool from the Yard Store (http://www.yardstore.com). They are an aircraft tool supply place. With a .401 air chisel and a hammer to back up the rivet head, it is easy to mushroom the end of the rivet in place. A rule of thumb is to place the head of the rivet against the fiberglass and hold the head of the rivet in place with a hammer head (you're using the hammer as a support, aka "bucking bar", and NOT actually as a hammer) and set the shank portion of the rivet that is backed up against the steel you are attaching with the airchisel and setting tool. Never set a rivet shank against bare glass or you'll just crush the fiberglass and the rivet WILL pull through.

I've heard some people say they've set those aluminum rivets with a hammer and a wide headed punch but the airchisel makes it child's play.

The two holes on the #4 mounts that face the wheel wells are very difficult to get to with the air chisel, so for those I just had to resort to 3/16" stainless pop rivets.

If you want to see pics of my car, there are some on my website at:
http://www.corvetteforum.net/c3/lemansblue68

That is, before I destroyed it.

Currently my car is completely stripped of paint, but hopefully in the next month or so, it will be blue again!!

mrvette

When I replaced those two rusted out shells, and removed the bolts, a-la sawzall, I just ground off the rivits, vacuumed out the wells, and used solid stainless hardware to reinstall, nuts and bolts.....done deal....

GENE

Mr.Gearhead

LeMans... your car is AWESOME. GRRRRR.... big block!

Okay, I see the .401 shank rivet set, but which one? There are a ton of them. I am still trying to picture how this is done. The rivets are two piece? Or one piece? I am thinking one piece and I push the rivet through the hole and use the air hammer to mushroom the other side? I guess I just don't have much experience with these types of rivets.... I will fully document this procedure so everyone else can have an easy task next time....

Mr.Gearhead

I ordered the shank set from yardstore. 3/16" 3 1/2 offset and straight. I also ordered the bucking bar. I can't wait to start putting it back together! Thanks for all the help LeMans.

I started thinking of what the Covette was when I bought it in 1998. Huge progress and a huge learning curve thanks to this FORUM. Unfortunately, I also started thinking of the money I have POURED into the car....

I suppose it is cheaper to buy a Corvette that is finished... but then I would not have learned anything....

LemansBlue68

The Yardstore is very prompt with their deliveries. You'll get the stuff in no time. They have lots of unusual tools that I haven't seen anywhere else and pretty good prices. I bought a few different rivet tools. One is short and straight, one other short and offset, and one about 8" long and offset. The offset ones are good when you're next to something and the short one allows you to get in to tight spots.

The rivets are one piece. One end has a large diameter flat head and the other just the straight, round shank. I think Zip may have a picture of one on their website. Push the rivet through the hole with the head on the fiberglass side. Back up the head with the head of a sledehammer or piece of substantial steel stock. I found a 1/2" thick X 3" wide and 5" long piece of scrap that a machinist friend gave me to be very usefull. Use the air hammer/rivet setting tool to mushroom over the shank end that is sticking out through the sheet metal that you are riveting. I usually try to leave about 3/16" - 1/4" of the shank sticking out to mushroom over. Any more than that and the shank of the rivet tends to bend over rather than mushroom down.

Good luck!! It would be a good idea to document the process and add it to the tech section of the forum. I've been too busy to do this.

One other thing: when you buy the rivets, buy the long ones. You can trim the rivet length to anything you want with a pair of wire cutters. They cut very easily as the aluminum is soft. When the rivets are set, that work hardens the aluminum and is supposed to make them stronger.


[Modified by LemansBlue68, 8:59 PM 6/29/2004]

NHvette

I'm about to put mine in.
The rivet I have chosen are 3/16 stainless pop rivets.
You need a backer washer, if installing them from the outside.
In addition to the rivets, will be using a polyurethane adhesive between
the 'glass and the reinforcement.
Similar to the way I did my #1s here:
http://forums.corvetteforum.com/zerothread?id=510409

That was a fun day of ski jumping

ps- my server is slow - so right click on red Xs and show picture. They'll come up.


[Modified by NHvette, 10:44 PM 6/29/2004]

Mr.Gearhead

NHVette-
So if I mushroom over from the outside (fiberglass side) I will need washer for the mushroom to go over? Any 3/16" aluminum washer? I never thought of this. Come to think of it, I do remember the washer on the outside. I was wondering how I was going to rivet the deck hinge support outside rivets. They are UNDER the bracket and I will not be able to get to it...

LemansBlue68

If you're talking about where the mount is sandwiched between the splash panel and the fiberglass portion near the mount, I drilled a 1/2" hole into the splash panel so that I was setting the rivet against the steel mount reinforcement. Then I used panel adhesive to fill the holes. The way the factory slathered on the panel adhesive in the seams in that area, the holes were nearly indetectable after I filled them. It looks to me like the factory must have riveted the mount reinforcements in place before they glued in the splash panels.

Stainless pop rivets are definitely another way to go and are probably easier to use but don't have the factory look (as if anyone is going to look back there). I just wanted to reproduce the factory look. I did cheat and use them on the two rivets that face outwards because I couldn't get my air chisel between the quarter panel and the mount reinforcement.