Philbert

iTrader: (2)

Hi guys - wasn't sure where to post this so if it's in the wrong spot, sorry.

I have a 1980 Datsun 280ZX and it has some bubbling rust around the windshield (common for Datsun Z cars). Recently, I got a crack in the windshield, and figured now was a good a time as any to address the rust while I replace the windshield.

I've since removed the windshield (thanks to a handy harbor freight tool), and used a wire wheel (again, harbor freight) to remove the caulk, and some of the heavy rust - I basically ran the wire wheel around the immediate area where there was rust, exposing the bare sheet metal below so I could expose the rust areas and address them 100%.

Here is where I am at:











This spot above the driver's side actually had a hole (I think the wire wheel did this, but the metal was pretty weakened by rust):




And here, in the same area, on the roof part, you can see where I used the wire wheel to isolate the rust and expose the bare metal (non rusted) around it:







And the other bad part, the cowl, has quite a bit of rust - I also used the wire wheel to expose it down the bare metal around the rusted area:







Here's a smaller area that wasn't so bad, but I used the wire wheel to expose the bare metal around the rusted part:




You can see the dash is in bad shape - I actually took it out a couple years back and refinished it...but it cracked a few weeks later - plan is to sand it and use fiberglass to cover it up, retexture, and paint, while the window is out:





This is my first time taking a window out, let alone dealing with rust and primer/sanding/body paint, so I'm looking for some advice. The plan is to have the new window professionally installed once I have it the way I want it.

Here's what I'm thinking:
1) Use wire wheel/sandpaper to get the rust areas completely down to bare metal
2) for the rust area with the hole, sand it down to bare metal and use JB weld to fill in the hole - sand smooth when dry
3) (wet?) sand edges of bare metal where it meets body paint to make it uniform and smooth
4) prime (can I use a small brush instead of spray?) the bare metal areas
5) paint with factory paint from dealer the areas I primed
6) Affix the OEM plastic snap strips along the top and bottom of the windshield for the chrome trim (after the window is in)
7) take it to the window guy and ask him to take care not to goo up the snap strips for hte chrome trim


Does that sound like the right approach?

Any tips on prep work, wet sanding, what primer to use, techniques for brush painting/sanding to get the smoothest transitions?

Thanks in advance!

Ghettofab88

I'm no body guy, but I've got a similar issue on my 88pickup. From what I've learned, the only way to fix rust issues is to cut it out and replace it. You can try rust converters and covering it up, but the issue is that the inside is still rusty and it'll just come through again, except now it'll be worse than it was.

Take that hole above the drivers seat. What's on the other side of that? Probably more rust. You can't just fix the outside visible side and expect it to last.

Kevo

Philbert

iTrader: (2)

Thanks Kevo - I've heard similar about cutting out, usually with floor boards and fenders.

I have a welder but have yet to use it, and would be hesitant to on body work honestly.

Another thing that's getting me is that there is a 33 year old plastic trim piece where the headliner meets the top of the windshield, and I can't seem to get it to slide/pop out - it's very brittle and I'm afraid of snapping it. If I could get it off I could see behind that area and possibly treat it...

snobdds

Sand down to bare metal and use PPG epoxy primer, then put a top color coat to match. Never will have to worry again...

64tbird

2 things first. Do not drive it with the windshield out. On your unibody z the windshield is a structural piece. Imagine removing the trans crossmember, ratchet straping the trans up and hitting the road. One good pothole and the frames bent enough to need a good frame shop to make some pulls. 2nd when you take out a windshield its best to not remove the silicone (caulking) and cut as close to the glass as possible. Silicone sticks far better to itself then metal. On the rusted parts you have to do exactly what you did but everywhere else try not to.

The best way will be to remove the headliner and anything else that will melt or catch fire. Then cut out the bad metal and enough do you can weld good to it. Then bend up a new piece and STITCH weld it in. So tack it in then let it cool. Then maby 4 more tacks and let it cool and so on. Then epoxy primer the bare steel and a lap on the painted area. Then a primer surfacer. Wet sand that then spray on the paint and clear if needed. Wet sand it and reinstall.

Next best. Get some naval jelly (available at autozone) and treat the rusted area till all the rust is black. Then clean it up with water. Spray the area off with air so no water is left in the pores. Then i would go with fiberglass and patch it up. Then epoxy primer....

The primers can be brushed on but on the base coat of epoxy primer get it as even as you can. It dosent like to be as thick as the surfacer.

I have the same issue with 96 taco and had it on my 510. On the 510 i did it like i first said. On the truck i will do the same but luckily i dont have to worry about the windshield being structure.

64tbird

I should of waited for the the pics to load. I would do all that on the hole. On just the rusty spots i would navel jelly them then paint. Dont use body filler on the windshield surround because in the case of a accident it will pop off and you will lose the structural support. Same goes for fiberglass to a point. So do weld! But a decent welder will be able to weld up the hole and not have to make a panel. Or take a risk of the silicone filling the hole forever and just treat it and paint with the hole still there.

HighLux

hit the bare metal with a rust converter, metal ready is a good one. por15 the window channel. Paint.

last forever.

Philbert

iTrader: (2)

Thanks guys for chiming in - that all happened at once

Update since I posted (I posted a similar thread on my Z forum and got some great ideas):
- Used Naval Jelly on the rust spots (twice) and attacked with wire wheel and sanding in between.
- Have POR15 in the mail from Amazon right now and will treat the entire windshield area where I used the wire wheel.
- Bought some "Belzona" which is basically a super high end metal patch kit

Plan is to:
1) POR 15 the entire surround
2) Sand
3) Apply Belzona to hole and maybe a THIN layer on the pitter areas
4) Sand
5) POR 15
6) Sand
7) Prime
8) Sand
9) Prime
10) Sand
11) Paint
12) wet sand
13) install trim adhesive from dealer
14) have window installer do window
15) install trim

If anyone has tips on the priming/painting part, I'd love to hear them - I imagine I'll get the paint from the dealer with a small brush so I'll need to do some kind of sanding/belnding......

Thanks!