rusty hood

[BruteForce]

The top side of my hood looks great - original black paint, perfect condition. The underside, though, is another story. It's rusted everywhere there was a "shadow" when the factory paint was applied.

Is there any way I can deal with this, get the rust out between the layers, without wrecking the top paint?

Also, what's that piano wire for that's towards the nose? Is it supposed to be there, or is it some kludge the previous owner stuck on?

[73Barracuda340]

I usually just use a 90 degree mini angle grinder with the roloc scotchbrite (red) discs and have at it.  I take off what I can and then follow up with phosphoric acid jelly (naval jell) for 20 min., deactive with baking soda water, dry and repeat with the roloc wheel until it is clean.  I use this process on areas when/where blasting is not an option or I just don't feel like messing with all that sand/soda mess.

Once clean I prime with SEM etching primer and the prime/seal/paint after the SEM primer has dried real well.  You have to let etching primers dry good or they will mess up your topcoats.

[dodj]

Is there any way I can deal with this, get the rust out between the layers, without wrecking the top paint?

Also, what's that piano wire for that's towards the nose? Is it supposed to be there, or is it some kludge the previous owner stuck on?

My hood used to look somewhat like yours. A combination of 3m wheels, da sanding and careful sandblasting eventually cleaned it up.
I haven't a clue what that piano wire is doing there. Real long overshoot with a MIG?

[BruteForce]

Thanks guys, I'll get the grinder and the pads. I have some rust converter stuff, too. But I still don't see any way to get between the frame and the top skin, and although you can't see it in the picture, that's where the most significant rust is.

Probably redi-strip is the only way, but that'll require repainting the top, and it'll never match the rest of the car  I suppose in a few years I'll be ready to strip the entire car down, dip it, and repaint it from the ground up. In the meantime, no more driving in the rain!

[73Barracuda340]

Ideally it should be soda blasted in there.

The only other feasible way to really get between the outer hood skin panel and the underbracing would be to remove the glue points that the factory puts between the outer panel and the bracing, and carefully slip some sandpaper in there then hit with rust converter.

The only problem with this would be that sometimes you can damage the top side of the hood while trying to break these spots loose.  I have done it in the past but it is a royal PIA to do.

[burdar]

Just use a Rolok disc on an angle grinder like was said above.  Spend most of your time out at the edges.  The center will be covered up by the hood pad. 

[72rtchallenger]

if you plan later on to repaint everything,,then seal the rusty areas with por-15

[RUSTY Cuda]

Got a little cautionary tale about redi strip, had a few parts done there & thought I was home free, You must get all the water out of the crevices used low fame torch for this, then i flooded it with por15 (really messy task & you really have no idea if you coated everything) then did all my normal prep & paint stuff. everything semed fine, finished the top of the hood last .Flipped it over to do something before installing it & found rust bubbles in a couple of places that were two or three layers, granted my car was a rust bucket, ended up scrapping that hood & workin a backup, heres what I've learned since.
Without an ecoat dip after the stripping there is no protection for the now raw metal in there the only way to be sure is to skin the hood, a major undertaking & a chance of messin up a decent hood.
So if your not gonna ecoat I would not redistrip anything thats layered(which unfortunatly is most parts on our cars.
Clean what you can, use some kind of rust treatment & really flood it in there & you'll probably be better off the a acid dip without ecoat!
Not a pro but messed with a lot of rust(well still am on the 74 now) over the last few years. I would not dip another part without ecoat ever! Rich.

[dodj]

But I still don't see any way to get between the frame and the top skin, and although you can't see it in the picture, that's where the most significant rust is.

I think I would go with POR15 in those areas.

[vinb]

Underside of a hood is a real pain in the A*#..

I would spend a little money and have it media blasted..

The time spent on the underside is not worth all that aggravation...

You'll get it back nice and ready for prime and or work...

[BruteForce]

Eventually, the redi-strip followed by e-coat for the whole car looks like the best solution.

I watch those car overhaul shows on TV, and they usually media blast the whole car. On one show, after blasting, they were working on the sheet metal repair. They cut into the frame rail, and inside it was all rust and scale.

(The interesting thing is, my 89 truck has sat outside for nearly 20 years now, and it has no rust at all on the body or frame. Detroit obviously got a lot better at corrosion protection, I wonder what they are doing now, as it clearly works.)

[E-Body Products]

Redi-Strip is the best option followed by E-coat.  This would be are really long term fix.

POR-15 would be the best short term fix, especially if you wanted to save the top side paint job like you mentioned earlier in the post.