Restoration of BringaTrailer 240z - HLS30-35883

[Patcon]

Are you self performing the sand blasting?

[inline6]

I am indeed.  I contacted a company at the start of the project to see about getting the entire car soda stripped, but they said they don't do cars.  I have had the sand blaster for years.  You don't want to read about how bad silica is for you.  

[grannyknot]

To really get the rust under the battery tray you have to drill out the spot welds on that large support that curves down to the rail, there is rust under it and it will spread right back after you paint it. You don't have to use sand, there is copper slag that is quite aggressive, also walnut shells.

[Patcon]

11 minutes ago, inline6 said:

I am indeed.  I contacted a company at the start of the project to see about getting the entire car soda stripped, but they said they don't do cars.  I have had the sand blaster for years.  You don't want to read about how bad silica is for you.  

Be sure and use a good respirator. I like these for dust

You don't want silicosis!! I use "black diamond" typically, which is coal slag

Also be very careful if you do any of the thin sheet metal. You can ruin it easily! Use as low of a pressure as possible and try not to blast straight on. Shoot it at an angle and remember you are work hardening the panel as you blast it

[inline6]

That is a nice design.  I will look at that one next time.  I have one, from 3M I believe, which is similar.  I may go with that one next time as field of vision looks like an improvement.  I have been using play sand because of it's light weight.  I haven't detected distortion using it.  Years ago, I learned that distortion could result when I used a heavier grain sand.  

How does the coal slag perform?  I assume that it is safer because it doesn't break into particles as small as silica does, and thus the respirator is more effective? 

[inline6]

21 hours ago, grannyknot said:

To really get the rust under the battery tray you have to drill out the spot welds on that large support that curves down to the rail, there is rust under it and it will spread right back after you paint it. You don't have to use sand, there is copper slag that is quite aggressive, also walnut shells.

Interesting.  What do you think of using a rust converter liquid and brushing it on and soaking that part of the battery tray?  I don't want to alter the cosmetic look - I want to keep the factory spot welds.

[grannyknot]

Eastwoods is just phosphoric acid and it works well for light or thin rust but not for the heavy rust you have under the battery tray.  Without removing the tray you will never stop that rust that is active between the layers. You could get access from inside the P/S wheel well and drill out the spot welds from there without affecting the look of the spot welds facing in to the engine bay then pull the tray up enough to get the sand blast nozzle in there.

 

[Patcon]

3 hours ago, inline6 said:

That is a nice design.  I will look at that one next time.  I have one, from 3M I believe, which is similar.  I may go with that one next time as field of vision looks like an improvement.  I have been using play sand because of it's light weight.  I haven't detected distortion using it.  Years ago, I learned that distortion could result when I used a heavier grain sand.  

How does the coal slag perform?  I assume that it is safer because it doesn't break into particles as small as silica does, and thus the respirator is more effective? 

the coal slag is probably a lot like sand in some ways. It feeds really well and doesn't clump like sand can do. It cuts quick and leaves a finish suitable for primer

I have 3m organic masks for painting. We use the Ellipse mask at work .

I would also remove the battery tray. You can replicate the factory welds if you want, but I would never trade hidden rust for factory spot welds

Edited November 7, 2019 by Patcon

[inline6]

One of the new tools I bought to utilize with this restoration is a stud welding gun:

I also got two sizes of pins, 2.0mm and 2.5mm:

I had never used one before and was looking forward to learning how to use it well.  It's important to me to improve skills and to become good at doing a thing because it becomes much more enjoyable when you can spend a 1/4 of the time (than you used to) to get results that are twice as good as your original efforts.  Here was the one of the first dents that I worked on at the rear edge of the right quarter panel.  Note that the metal is pushed in enough to bulge outwards on the left side into the tail trim panel opening area.  As I welded pins on and used a slide hammer to pull on them, I had to work that area back flat as well.

Here is after my efforts.  Three of the pins broke loose causing the small holes.  I think I could do it better, without making holes, now that I have more hours of experience behind me.  A touch up with the welder will fix these holes up.

If you look closely, you can see other areas that have been worked with the stud welder and pins:

This car was hit lightly in the rear, and the bumper caused some indentations in the tail panel and quarter panels:

A couple of in progress pics:

 

 

Edited November 8, 2019 by inline6

[Patcon]

You're doing good!

You picked 2 of the hardest areas on a z for a stud gun. The end of the quarter is paper thin, which is why the studs tore out and the area behind the bumper has an interal frame rail that can provide an amazing amount of stubbornness to dents. The quarter turned out nice

[inline6]

Here are some more pics showing work done with the stud welder.  The frame rails and floors typically take a fair amount of abuse on these cars.  To straighten the dents in the rails, I used the 2.5 mm pins a fair amount.  The 2.0 mm pins also got used in this application, but only for areas toward the center of the rails, away from the side walls.  Dented areas on or near the edges require more pulling force. 

 

Also, the floors often get bowed from the impacts to these rails over the years the car is on the road.  They should be flat.  So, when looking front to back and side to side at the lowest surface of the frame rail, they should be flat.  A section of 2 X 4 and a 5 lb hammer used judiciously will set things "straight".  ?  Placing the 2 X 4 strategically on the inside surface, I hammered hard against the wood to move the floor surface downward. 

There were also a few areas like this which received impacts. 

I spent two week ends shining a bright light at sharp angles onto both the inside and outside surfaces of the floor to find dents and imperfections.  Welding studs and pulling, hammer and dolly work, and using flat punches and hammers, I straightened every imperfection I could find.  Then did final clean-up with the sand blaster on the inside surface and sprayed epoxy primer.

 

Edited November 9, 2019 by inline6

[grannyknot]

@inline6, you must have some previous experience doing body work, if not then you're a natural. 

11 hours ago, inline6 said:

Placing the 2 X 4 strategically on the inside surface, I hammered hard against the wood to move the floor surface downward. 

So did you cut out the strip of floor pan from inside the cab that is just above the rail to get access to the rails?