1976 280Z Restoration Project

[Patcon]

Wheee!

The primer under you car looks pretty good. I wouldn't remove it unless I suspected it hid issues. I wouldn't POR over it either. I would treat any exposed metal with a phosphating product. Scuff it up good and shoot epoxy primer over that. Then color it or undercoat it. No need to POR 15 what isn't corroded. I had a patch panel on a car that was only covered with epoxy primer and sat outside for 2 years and didn't rust

[ksechler]

Your car looks a lot better than mine did.  I also encountered the yellow primer.  I guess they used that at the factory.  

 

I went to bare metal because I had some stupid notion of stripping the whole damn car.  I think I made a lot of extra work for myself but I know exactly what I sprayed over what and that there isn't any rust hiding there. My car was an east coast (USA) car and had a lot of rust hiding.  I feel pretty confident that I have an actual rust-free chassis now.  That should be an oddity around here :-).

 

You seem to be making good progress.  Keep up the good work.  I hope you don't finish before me since I had a pretty big head start.  

[wheee!]

, I am playing catch up all right... That will slow down once I finish the labour part and start having to shell out big bucks for parts. Paint and refinishing supplies too.... Arrrgh.

I am counting on your posts to help me with finishing mine for sure!

[wheee!]

Patcon, I thought the POR would help prevent future rust too. I know I don't really need it on good metal, but i thought it would be a good way to hide the rust protection under a finish top coat...

I don't want an under coated finish on the bottom of the car. I suppose I could get away with just a standard epoxy primer and body colour/ clearcoat. The car will not be a daily driver.

[Patcon]

The epoxy primer is very tough and sticks really well, plus if you stay with the same manufacturer you don't have compatibility issues. I wouldn't base coat clear the bottom of the car unless it's need to make your paint look correct. I would single stage the bottom and base/ clear what matters. When I jambed out my car, I sprayed the engine bay, interior, door jambs and inside of the hatch with single stage and will shoot base / clear on the exterior. Base clear costs more than single stage. 

[wheee!]

Yeesh...!

Passenger side sway bar and crossmember area. Not pretty...

[wheee!]

Battery compartment looks good though!

One old patch near the top and pretty solid elsewhere.

[Consigli]

Would someone be so kind as to explain the best way to clean a car body shell? Some acid dip. Some media blast, etc. I notice that on the show "Overhaulin" Chip Foose media blasts. While on the show "American Hotrod" Boyd Coddington acid dipped. Now both sand blast & powder coat frames. Not trying to hijack the thread so don't anyone get all butt hurt. I think its a relevant discussion that may help Mr. Wheee since he is just starting this phase of his restoration. 

[wheee!]

I'm always up for a good discussion..

[ksechler]

That rust looks bad.  It's pretty deep into the frame.  What is you plan for repairing it?

[wheee!]

Would someone be so kind as to explain the best way to clean a car body shell? Some acid dip. Some media blast, etc. I notice that on the show "Overhaulin" Chip Foose media blasts. While on the show "American Hotrod" Boyd Coddington acid dipped. Now both sand blast & powder coat frames. Not trying to hijack the thread so don't anyone get all butt hurt. I think its a relevant discussion that may help Mr. Wheee since he is just starting this phase of his restoration. 

 

I think my plan for now is to clean the bottom of the car like I'm doing, by hand, then wipe off most of the remaining undercoating with isopropyl alcohol, then tent the frame in the garage and sandblast the remaining rust and paint off. This is not ideal, I know as I don't have a proper blasting facility, but I can't justify the (local) cost of blasting at around $3000...

I guess my plan might change as I go. I am still unsure how to treat the metal after blasting and before painting. Do I coat it in Zinc Mate to prevent rust? Do I go straight to POR 15 and seal it right away? If I do that do I have to coat it in self etching primer within the tack window so it can be painted body colour later? Can I leave the exposed metal sit as is until the entire car is prepped and then go to Marine Clean, Metal Ready, then POR 15, then primer, then paint? A lot of questions and everywhere I go, someone has a different method as to what THEY would do...

 

That rust looks bad.  It's pretty deep into the frame.  What is you plan for repairing it?

 

My first thought was to call you.... 

[Mark Maras]

 Both acid dipping and media blasting work well but both have their negatives. I didn't see either show but I'm betting they weren't working on anything as thin as a Z. Both methods will remove rust as well as good metal if not done carefully. Media blasting can also warp thin sheet metal. I'm not a big fan of removing ALL the original paint and especially the primer on the sheet metal if it's still sound. Did it once and had to spend more time and money replacing what I had removed.. The seams & frame are usually the places that need the most attention. I would media blast those areas but only after attacking everything with a mean and nasty wire brush. It will show you what areas need extra attention and what doesn't. I don't have the answer for the the final prep. I coated the inside and outside of my new frame rails and floor pans with many layers of zinc rich primer before painting with equipment enamel. Spent a good share of my working life fabricating galvanized steel projects and have always used zinc rich coatings for protection on welds. great stuff.

 One other thought. While I had the front frame rail opened up where it welds to the floor board, I welded it on the inside and while the weld was hot I used a zinc stick (available at your welding supplier) to cover the hot surface with zinc. US Coast Guard approved method. 

 If I do this again I may have the new sheet metal galvanized before fabrication. No, It's not that hard to weld even if you don't remove it.

 Most of the horror stories about welding galvanized material are B.S. Fumes are a concern but easy to eliminate.

 Hmmm. I wonder how much it would cost to galvanize a whole Z body?