66 hood support mounting plate

[Dan M.]

Need some advice and couldn't find what I was looking for on any previous posts.
I have a broken bolt in the hood mounting plate that seems unlikely I'll be able to extract. Seems that someone years ago tried and broke the bit off in the broken bolt. I've attempted to drill through it with some carbide bits, but no luck. It keeps slipping off the side of what remains of the old broken bit. I think my only alternative is to drill out the rivets and open a hole in the fiberglass where I can slide out the old plate and install a new one. And I'd like to resecure a proper rivet with the head flush with the inner hood rather than a pop rivet.
Has anyone attempted this repair before I start to cut into my original hood!
Any advice appreciated.
Tks
Dan

[Joe R.]

Re: 66 hood support mounting plate

Dan,

Here are the suppliers and their part numbers!

Long Island; 20-26
Paragon: 1826
Auto Acessories: 33231

Top two no longer in business. All C-2 owners shed tears!

JR

[Dan M.]

Re: 66 hood support mounting plate

Tks Joe,
I see Zip also has a mounting plate they sell for $22 with a couple rivets. I guess I could also just make one as it's just some metal flat stock with some holes drilled in it. Frustrated though that I have to cut out a small sliver of the hood to remove it. I suppose I can use a dremel tool to cut out the fiberglass, use blind rivets on the replacement and then patch up the hole I made. I suppose it's all painted anyway so it won't be seen. But the sight of the pop rivets I know will bother me.
I'm not sure I could easily "buck" a proper headed rivet given the tight working space. Might cause more damage than it's worth.
Dan

[Alan D.]

Re: 66 hood support mounting plate

Dan,
Modify the other end. Use 1 bolt and fab a pin. Perhaps cut a bolt head and a little more to go into bad hole.
Hope one bolt holds! If that fails then back to cutting.

[Richard M.]

Re: 66 hood support mounting plate

Dan, Yes I'd acquire or fab a new plate. You'll have to cut a slice in the side of the fiberglass to remove it.

So what about the rivets to hold the new plate. Clearly they cannot be bucked. Pop rivet? I agree, not a visibly pleasing option.

You might try to find small "Elevator bolt". It has a wide flat head like the stock rivet, with a threaded shank. You'll have to search around. Even if they have a Allen hex in the head, after tighten-up, you could fill the hex hole with filler, sand flat, then after blackout it'll look TFP. Like these.

HTB1hBH5eUKF3KVjSZFEq6xExFXaJ.jpg_640x640Q90.jpg_-1.jpg

Or... Use the standard rivets and cut threads in the shanks for a appropriately sized nut, say #10. It's only securing the plate so there's no shear stress involved. I'd think this would work ok.

Rich

[Dan M.]

Re: 66 hood support mounting plate

Tks guys, some good thoughts here. One bolt to secure may work but it's all headed for paint next spring and I'd hate to have to tackle cutting it open if it doesn't. Might be more mess than I'd like.
There is still body work to do elsewhere on the car so cutting this open is probably a small repair by comparison. So it's the look of the rivet that is most troublesome.
Rich the elevator bolts idea is one I'll look at. See if I can find something similar in size to the proper rivet. I suppose it could be shaped to be the exact shape and as you suggest fill in the head once secure. I've also read about bucking rivets from the opposite side. Perhaps there's still a way to do it.
Tks for the feedback. It's given me a few ideas for sure.

[Joe R.]

Re: 66 hood support mounting plate

Dan,

You do not have to do any fiberglass work to replace the plate. Looks like it was not original to begin with. Just cut the aluminum rivets and place the new plate on the back.. You can secure it with bolts and that will work fine, just not as original.

JR

[Robert B.]

Re: 66 hood support mounting plate

First Spray with some kroil on and off for a couple days and then I would first try to flatten the area with a carbide flat end mill, hopefully you can get a nice new flat surface. then go with the proper size drill out.

[Dan M.]

Re: 66 hood support mounting plate

I suppose it could not be the original hood. How can you tell?

[Richard M.]

Re: 66 hood support mounting plate

Dan, Roberts idea should work, if you can get past the broken piece. Maybe get some reversing drill bits too. If not, maybe this.

I'm thinking of another idea.

Put a bolt in the threaded hole and snug it up. Drill out the 2 rivets. Rotate the plate a small amount, just enough to drill and tap the new 1/4-20 hole. Then drill the plate for the rivet. You'll have to use pop rivets but you can flatten and shape them, then fill the holes with filler, blackout, etc.

Zip shows wide rivets. Here
m-4335--1.jpg

[David B.]

Re: 66 hood support mounting plate

Spot weld another bolt or nut to the broken end and retry unscrewing.

[Dan M.]

Re: 66 hood support mounting plate

Alan,
I tightened one bolt and I don't think there is any problem with it holding tight. It's just a hood so there is little stress on it. I could easily cut a bolt head and epoxy it in place. Probably look ok. So that probably works.
First I'll give it another go at drilling out the old bolt. I do have time to mess with it.
Rich your suggestion of turning the plate slightly is interesting. I wonder how much room there is to slide it around though. Not sure how wide the plate is relative to the space to move it. But a great thought.
Tks for the responses. A couple or good suggestions.
Appreciate it.
Dan

[Leif A.]

Re: 66 hood support mounting plate

Spot weld another bolt or nut to the broken end and retry unscrewing.

David,
I initially had the same thought, thinking the broken drill bit was standing proud of the surrounding hood skin, and he could drop a nut around the shank and spot weld it on there. But upon closer observation, I think it is broken off below the skin of the hood. Could be my eyes but...shadows play funny tricks.

[Dan M.]

Re: 66 hood support mounting plate

Leif
It's broken off flush with the plate itself and below the hood skin. Tough place to spot weld anything on so I think that's out as an option. The drill bit that is broken off is dead center in the old bolt and looks to be about 1/8". It's the broken bit that makes it really tough as it is not receptive at all to boring through it. Just too damn hard.
The easiest solution might be to just use one bolt, crank it on, use some threadlocker and cut the head off another bolt and epoxy it in to fill the other hole. Less risky and leaves the rivets in place. The only risk is the one bolt comes loose.

[Richard M.]

Re: 66 hood support mounting plate

Dan how about a Dremel with pointed grinding stones to get at the broken drill piece. You'd go through a few but a stone grinder is the best way for hardened steel.