How much rust is too much

[Martin]

Working on some trunk rust issues on the Cuda. Got the whole floor and extensions out. Wheel wells can be patched. Question I have is on the tail panel. The bottom section is rough. There is some good metal under the rust, but back side around the taillight brackets is bad too. I hate to replace the whole panel, since 90 percent is good. But the bad part is what the trunk welds to. Hate to put time money and new metal to leave rust that reforms and destroys my work.

Options:
- sand blast the whole area, cut and weld patch metal in the worse areas, coat in rust inhibitor
- replace the whole panel which is $400

This is not a show car, but I do want it to be done as good as possible.

Thoughts and opinions?

 

[rklein71]

I had a similar situation with my speaker tray, would have had to spend 400 bucks for a new one. I choose to repair. The patch is not visible once installed and turned out nice. I think you could do the same thing with your tail panel. The crease above it adds considerable strength to the panel, so it won't easily warp. Once installed, the bumper will cover up the outside of the repair and you will be undercoating the inside. You can do it, spend 400 bucks elsewhere. Rod

 

[Adam]

Go for it, you can’t hurt it at this point.
I would carefully cut out the rusty strip and use it to make a pattern, allowing for the thickness of the blade (pneumatic body saw would be great). Carefully tack in the patch and stitch it in back and forth to avoid too much heat/ warping.

 

[KATSAAR]

if you do decide to replace the taillight panel.
the good of doing that is you will be able to use a 1 piece trunk floor.

 

[rklein71]

if you do decide to replace the taillight panel.
the good of doing that is you will be able to use a 1 piece trunk floor.

I reused my old tail panel and had to do about half the rust repair you will need to do, maybe a 18 inch section along the bottom. KATSAAR is right, removing the tail panel will make putting in a one piece trunk floor possible.

Rod

 

[Martin]

I am doing a one piece truck floor. I have not tried to test fit it yet. I had read another post of someone installing the one piece without removing the tail panel. I’ll have to try that today. Luckily the frame rails are in pretty good shape. Plan on cleaning them up good and coating the inside before putting the floor back in.

Good point on worst case is I have to buy the new one anyway.

Now just need the weather to corporate a little so I can get my blasting done.

 

[jeff968]

I would fix it. As noted, you don't see it so go for a good clean repair, don't worry so much about the aesthetics, fully prime and cover with seam sealer and paint and you should be good for life!

 

[Adam]

You will have a tough time getting a one piece trunk pan to fit, been there, done that... I had to cut off the upper left corner and weld it back on. You could remove and repair the original tail panel, not too many spot welds, and it would give you easy access to everything.

 

[340challconvert]

View attachment 46215 You will have a tough time getting a one piece trunk pan to fit, been there, done that... I had to cut off the upper left corner and weld it back on. You could remove and repair the original tail panel, not too many spot welds, and it would give you easy access to everything.

Nice job with the trunk floor repair!

 

[73Machine]

View attachment 46215 You will have a tough time getting a one piece trunk pan to fit, been there, done that... I had to cut off the upper left corner and weld it back on. You could remove and repair the original tail panel, not too many spot welds, and it would give you easy access to everything.

Looks great! Could you happen to tell me the measurements on the Fuel tank support to attach it to the trunk. I'm going in blind on mine. Thanks!!!

 

[Adam]

Yes, I will get the measurements late tomorrow; my car is in storage... but the support straps line up with the grooves in the gas tank. If you do not have a gas tank, you might want to get one to ensure it will fit before welding.

 

[Adam]

Here is the bottom of my original trunk floor, looking forward. (In the upper left corner) you can just see at the rear of the trunk pan where the braces line up with the sides of a ramp in the trunk floor. The grooves in my tank were wider than the support straps, so there was a small amount of side to side tank adjustment possible (maybe 1/2 inch). If you mock up your support braces in this location, and verify your tank fits, and the filler neck is centered in your gasshole you can’t go wrong.

 

[Adam]

Here is a better view of the ramp.. a Cuda has a similar, but different ramp. Any Cuda guys have the measurements?

Btw, I used an AMD trunk pan, fit was excellent.

 

[Adam]

Looks great! Could you happen to tell me the measurements on the Fuel tank support to attach it to the trunk. I'm going in blind on mine. Thanks!!!

My trunk braces are 9 & 1/8 inches apart, measured from the center of one to the center of the other.

 

[73Machine]

Thank you so much Adam!!! Just waiting on mine to show from yearone to install on the pan.

 

[shakercuda]

A thread about one piece trunk floor installation on another Mopar site years ago, showed that it is possible to install the pan with only cutting a section of the bumper panel out, install the trunk pan, then reweld the bumper panel. I hope this helps, I'll be doing mine this way soon.

 

[Adam]

Cool. I didn’t think it possible..

It also looks like they welded on the gas tank supports before installing the pan.

 

[Martin]

I went ahead and took the whole back end out. I blasted the tail pan and I think it’s destiny is to become a cool wall light in my game room. The tail light circles are full of holes and there was a shitty repair from so old damage hidden under a lot of mud.

 

[Martin]

Yes the kitty likes the fishy.

 

[340challconvert]

I'm looking at doing the same thing. I am just about ready to cut out my trunk pan and am looking at my options; full pan, 1/2 pans welded at middle, and replacement of the trunk extensions. I think welding the gas tank braces in before would make the job easier, but I would need to weld in a full pan in order to do the repair that way.
My quarters are good except for small patches needed at the bottom. So my options are: cut out beneath the tail panel for a full pan install, possibly cut off he left corner of a full pan and re-weld after installing the full pan (like Adam did), or use the 1/2 trunk pans and weld the tank braces in later. These postings are helping me decide what to do.
Looking at what would work best for me?

Cool. I didn’t think it possible..

It also looks like they welded on the gas tank supports before installing the pan.