N96 hood 69 RR question

[northerndave]

I've got my hood all taken apart, drilled all the rivets for the air grabber ductwork and removed it all so I'm dealing with just the metal hood.

I'm looking at the center section of the hood and I can see that it looks like the hood skin was sort of glued to the understructure in certain spots from the factory.

Mine has come loose from where it was "glued" , as in, the outer skin is floating free from the under structure in the center of the hood about where the main center portion of the air grabber and air cleaner boot fastens to the underside of the hood.

I'm wondering is I need to have that hood skin set back to what looks like an original height? as in, repair those glued spots?

I wonder if maybe at the factory they attached the air grabber pieces to the understructure with gobs of this factory adhesive between the outer hood skin and understructure, then pressed the hood skin firm to the air grabber unit and let it set up???

Anyone??

 

[dsd1967]

Air grabber ductwork was only riveted to the hood. The globs that you are talking about keep the sheet metal from rattling and adhere it to the underframe. Those globs are basically 3M seam sealer that was applied to various spots of the underframe at the factory before the outer shell and underframe were joined and welded. They got paint applied over them at the factory. What you have in place right now should set the factory spacing. If you want quick and dirty, just get a tube of 3M seam sealer and glob it next to the current globs and let the current globs maintain your spacing.

If you want the underside of the hood to look really good, you can break all the spot welds around the perimeter and separate the skin from the framework. Take pictures of where the globs are and then sandblast and prime the frame top and bottom. Then you can DA sand the underside of the hood skin and prime it and finish sand it. Put the globs of seam sealer back on the framework and rejoin the two halves.

It sounds like a lot of work, but you can typically break the spot welds in less than an hour. This allows you to rust proof the framework top and bottom, and get to the entire bottom of the hood. In reality it's probably quicker than trying to hand sand the the framework and hood while still joined because you can sandblast the framework without the fear of warping the skin. I did this to a 69 dart power bulge hood and was extremely satisfied with the results.

 

[northerndave]

wow, I just came back in from the garage and yes, what you say is exactly the conclusion I came to while I was out there investigating.

Generally speaking, I hate body work on any hood, roof or trunk lid, but this one takes the cake.

I can clearly see that these hoods are a real Pain In The ***!!

 

[northerndave]

Well, it looks like the hood skin wants to float free from the underframe.

I see the break and free air space gap in the original seam sealer between the under frame and the outer hood skin.

So, do I try to duplicate the factory height for the skin from the underframe with possibly a decent quality adhesive?

Or do I let it float where it wants to be in a natural state and bridge the natural relaxed skin to frame gap with seam sealer and use a thicker seal/gasket between the main air grabber center duct and the hood skin?

 

[dsd1967]

About the only other way to ensure they get really clean in all the nooks and crannies is to have them chemically dipped and then e coated. That's high dollar...and I'm a tightwad, so I took the option of separating them. I was a little tentative at first, but after doing it, I was amazed how easy it really was and would do it again in a heartbeat.

It really gives you confidence that there's no hidden corrosion, and you get the chance to seal it top and bottom.

If you've ever broken spot welds on a car...this is a walk in the park. There's only about 6 spot welds per side. Just take your time and use a Hyde putty knife with a hammer to help pursuade what you miss with the cutter. The hyde putty knifes are robust, but thin enough to not distort the surfaces you are separating. They'll take a good sharp edge and hold it through a lot of abuse.

 

[dsd1967]

If it looks good from the outside, I would recommend bridging it and going with a thicker gasket.

 

[northerndave]

I'm not afraid to split the spot welds, hell the rear welds were all loose already and I re-welded them on sunday before epoxy priming the underside of this hood.

I'm just getting burnt out on the project and every direction I look there is something that I COULD take to the next level. But Damn... I want to drive this thing again soon.

Hood skins are such a trampoline... I expirimented a bit tonight with the hood laying flat on the garage floor and pressed that center of the hood down tight to the original contact points at seam sealer areas. It looks to me like the hood skin surface would be forced out of ... well forced out of straightness.. if that makes sense?

I'll keep after it and make a descision along the way, but for right now I'm thinking that if I forced it back to factory placement I'm going to have a wavey hood.

There might be a happy medium here, I don't know.

I should go have another look I guess.

 

[northerndave]

If it looks good from the outside, I would recommend bridging it and going with a thicker gasket.

Looks like this is the way I'm going, the skin distorts too badly pressed back to factory placement. I'll bridge with seam sealer so the shin doesn't dance and I'll run a thicker foam gasket.

Thanks.

 

[dsd1967]

I know the feeling....you gotta eat the elephant one bite at a time.

I looked at it from the perspective that it would really piss me off if I put all that money and time into a paint job to have something pop up soon after.

When I was doing the dart, I would concentrate on one body panel at a time and each one completed was one more step to overall completion. I figured one per week was a success, and some took less time than that. A hood, a deck lid, two doors, two fenders and all of a sudden I was back at the body. Two quarters, a roof and a dutchman panel later it was ready for paint. Trying to jump all around the car made me feel like I wasn't making progress.

Stay with it...you will be happy you did.

On the hood, don't force it down...let it lay where it is. Did the spot welds line up where you rewelded it? You may want to reinstall it on the car and make sure the hood lines up with the cowl. You can get away with not installing the hinges and just sit it on and space it up at the back corners so it's flush with the cowl. Then make sure the center isn't heaved up too high.

Take you time and reinstall and align the panels before paint also....now's the time to make corrections...once in paint your options become a lot more limited.

 

[northerndave]

Yeah I hear you on the one bite at a time.

My main body shell is ready for my polyester surfacing primer, then the fine tuning of the foundation for my base coat begins (blocking)

My doors are ready for epoxy primer, the trunk lid will be ready very soon for epoxy (top side already is actually)

The hood.. Well, I pretty much expect the unexpected with hoods, but it's getting close as well.

Fenders... well both are off the car as well as all this other stuff. The drivers side is straight forward, patch at the usual spot down low ahead of the door, otherwise the fender is nice. Passenger side fender is a basket case.

Hammer rash from a 35 year old repair.

But the work that's behind me overshadows what remains by a great margin.

So I got that goin for me.

:grin:

 

[dsd1967]

You're well on your way....I've followed your thread but it's been a while since I visited it. You are going to have an awesome car when you are done.

 

[major50]

my hood has the same gobs on it from factory. some of them attach hood parts together others don't touch anything. the air grabber covers up all of mine. if you need to attach the hood parts together get some panel adhesive from 3m it should do the trick

 

[northerndave]

Someone out there is reading all of this and shaking there head knowingly....

Knowing plain well that I do need to get that hood skin sucked back down tight to that stamped frame.

Yep...

I looked at it more last night, I do need that hood skin pulled tight to the center window of that stamped hood frame because the gasket for the main "plenum" for the air grabber rides partly on the stamped hood frame edge and then steps down and seals against the hood skin itself.

So, for it to work correctly and look like it's supposed to I do need to get the skin pulled tight and adhered to the stamped frame.

Dammit.

 

[northerndave]

right through this area (red line) the air grabber plenum seals to the stamped hood frame ledge.

All the rest of the way around it seals to the underside of the outer skin. So, it does need to be drawn fairly tight to the stamped frame.