Damaged rear end - want to shave it clean - where to start?

[Hugh]

Here's what my car looks like now:

 

 

 

 

and here's what I want it to look like:

 

 

 

Now where should I start?

 

I know I can buy the replacement piece for the center, and/or get a corner off a junkyard body to have it welded on... but is this the best course of action to take?

 

Replacing with new parts will net me the same bumper holes, and I want all that gone.

 

How would you guys approach this?

[AK-Z]

I haven't done it myself but here are some suggestions. if it doesn't sound right then there is probably a better way.

 

You can get replacements for the center and corner from tabco, thats where pretty much most companies order replacement parts from fo the datsuns.

 

For the bumper indentations on the side I see 2 ways in "shaving" the area.

One would be to cut a piece of sheet that would cover the indent and tacking it grinding and then body filling.

Second would be to cut out the indent altogether and cutting a piece of sheet and doing the same thing.

 

Now this is for the indent for the bumper and not the damaged area.

[goldenchild7801]

I also plan on shaving my Z's backside, keep the info coming

[SSflyer]

When I did mine I made templates of the areas I wanted to fill out of a manilla folder (just hold it up to the indentation and rub the edges with a pencil or a piece of chalk), cut the filler pieces, and tacked them in. It seemed to work well to position the filler piece and start tacking from the center out. When it was firmly in place I skipped around with tacks (to keep the sheetmetal from getting too hot), and finished with tacks every 1/4" or so. Then bondo and sanding. One thing I found out about bondo-ing this repair was to thin the bondo out with some Plastik Honey and then cover the whole panel. When sheetmetal starts peeking out during sanding, it's time to quit. I also went to the gas tank side of the panel and put seam sealer anywhere there was a visible weld joint, just some insurance to keep water out of the backside of the patch panels...

[Globerunner513]

what about just filling it in with fiberglass/bondo? my plan for the bumper holes in the rear end is to put some fiberglass strips in the back then fill it in. does that sound reasonable?

[AK-Z]

I wouldn't recommend doing that. Reason being, bondo and f/g expand and contract at different rates than metal. Over time it will show the effects through the paint. If anything I would use f/g, then rough sand the f/g and then even it out using bondo.

 

Bondo should only be used to even the surface of the area(s) and not to fill gaps and holes. Application of the LEAST amount of bondo is best, by this I mean the amount used that is on the area AFTER sanding. I went through a small can of bondo just to even the surface on a STRAIGHT and UNDENTED non-vent hood. Metal distorts over time, thats the reason why I bondo'd the hood and the amount left on the hood after, I would guess to be about 1/8 of a can for the whole hood.

[Dudeboy]

Hugh,

 

I bought my Z with right rear tailight damage, and I knew I wanted to shave the bumpers. You, may want to replace your panel with a panel from a donor car so that you get the Z shape in the rear. I had steel welded in to patch the bumper holes and the tailight damage and then utilize a product from Eastwood that is a metal filler, the stuff mixes and it looks like molten metal, but once you begin sanding it turns primer gray. I epoxy primered over the metal filler, then I smooth over some Evercoat Z-grip lightweight filler and then another coat of primer. I have a 77 -280 so I do not have the bumper indentaions on the side, so you can go in several directions to smooth that out: complete cut and replace with sheet metal or fiberglass/bondo and fill in.

Some welding and alot of sanding and shaping will get your Z smoothed out.

Hope this helps.

[PapaCreech]

i removed valance bumpers and mounts absorbers and such and then filled in holes with tacked sheet then finall dime welded seems grinded it down and went over all that with about 3 layers of FG sanded with 60 grit bondoed sanded with 180 bondoed kept goin until ig ot it down to 360 then glazed and finished filler primered and 800gritted primered again and spent some time with a water house and 1000 grit painted and finished

 

[Hugh]

i removed valance bumpers and mounts absorbers and such and then filled in holes with tacked sheet then finall dime welded seems grinded it down and went over all that with about 3 layers of FG sanded with 60 grit bondoed sanded with 180 bondoed kept goin until ig ot it down to 360 then glazed and finished filler primered and 800gritted primered again and spent some time with a water house and 1000 grit painted and finished

 

Now say that 5 times fast!

 

 

I like the idea of cutting off what I can, and adding new sheet metal over it.

 

Has anyone ever replaced the rear valence with a flat piece of sheet metal? It would be sweet to eliminate all the holes on the back in one swoop.

 

One more question, do any of the fender flare kits, like the Subtle Z kit, cover the bumper indentations on the sides? (even partially?)

 

I contacted them once to ask, they couldn't send me a picture of the part laid up against the car unfinished. I wanted to see what I would be working with.

 

I feel like if I'm going to do all this work to the back end anyway... might want to add in the flares now.

 

 

Thanks for the replies. Please feel free to add more... tell me a different way to do it, or post any pics you might have taken of the process.

[Dragonfly]

With mine I laid up f/g across the bumper indentations and overlapped by several inches, after the glass hardened I filled the void from the backside with expandible foam. Once the foam was cured I cleaned the area were I filled the void and laid glass over the hole to seal it. I then sanded and blended the glass into the surounding metal and used a little bit of bondo to make sure everthing was smooth and even. With the back piece I used some body hammers and dollies to remove as much of the indentations as possible without causing warps and wrinkles in the metal then I glassed the back side of all the holes and put a few thin layers of bondo to even everything out.

 

Dragonfly

[SSflyer]

Ditto what AK-Z said. The hood on my car looked perfect except for some hail damage, but I bondoed the whole thing anyway. When it was sanded out with an idiot stick there were large spots of bondo left all over. Most are so thin that they are translucent, but there were obviously low spots. When you watch shows like American Hot Rod closely, you can see that they use stuff like Plastik Honey AND they cover the whole car. What they never show is the hours and hours of finish sanding...

[Hugh]

Here's another thought - If I have to replace the corner, what about using a 280z corner without the bumper indentation?

 

What about cutting the whole lower rear area off another car, and then putting it on mine in one piece? This sounds scary... as though it wouldn't line up or something.. but it would give the ability to modify the rear valence area while the thing is off the car. (easy access to everything from both sides)

 

Plus I could do a lot of the work while the car is still on the road.

[Hugh]

You can get replacements for the center and corner from tabco, thats where pretty much most companies order replacement parts from fo the datsuns.

 

 

Here's what I found on Tabco's site:

 

 

Thats for the corner... only goes below the bumper indent it looks like. That won't work on my damage... I need above that.

 

I don't see anything else that I could use on their page here:

 

http://www.tabcobodyparts.com/html/table_of_contents.htm

 

 

I can get the rear section right from MSA, but thats expensive, flat, and would require extensive modification to remove the holes and indents anyway (kinda asinine, really)

[Dragonfly]

Here's another thought - If I have to replace the corner' date=' what about using a 280z corner without the bumper indentation?

 

What about cutting the whole lower rear area off another car, and then putting it on mine in one piece? This sounds scary... as though it wouldn't line up or something.. but it would give the ability to modify the rear valence area while the thing is off the car. (easy access to everything from both sides)

 

Plus I could do a lot of the work while the car is still on the road.[/quote']

 

I think you will find it much easier to use a body hammer and dolly than to cut out and weld in that section, having done both with no experiance on eitherit is much more dificult to cut and weld body pirces than it is to straighten out and smooth over with bondo. you can also remove the entire rear valance without much dificulty and that would give you easy access to working on the dent in the side and make it much easier to work on the dents in the valance.

 

Dragonfly

[alexideways]

How about this, I used to be a welder and work in an agricultur machinery

plant, I remember that the sheet metal parts that were curved and had holes in it were manufacrued in many sreps, 1rst: it was put in a press to stamp out the holes, after in another to shape small areas indents and then in a final one to give it the actual shape of the part.

 

My idea here is to call Tabco and ask for a special order where the employee would take the part directly to the shaping press skipping the holes and indentation steps, ther you have a stock smooth pabel that will

fit perfectly.

[Hugh]

I understand what you're saying. I tried that with the guy who makes the rear valence part for MSA. He said the die used to stamp it out was super expensive, and couldn't be done any differently.

 

Tabco doesn't have that part listed at all.

 

Also, that piece for the rear valence is not bent when they ship it... you have to bend it to conform with the body.

 

This makes me think just cutting a piece of flat sheet to fit the space would save time/money

[Sparks280zt]

 

Flat piece of steel, welded over all the old stuff

[alexideways]

Hun!!! Nice and clean, good job, guess you could do that with stainless to keep it from rusting again.

So, no need to go trough all the trouble tiing to get a special order.

 

Here is a dumb idea, cut the old valance out, fill and smooth with BONDOOOOO!!! and then you have a mold.

 

Lay some carbon sheets over this, a little resin, a refrigirator compressor and bags, a big oven and there you have a carbon fiber rear valance that is both light and will never ever rust.

[Hugh]

I seriously considered making a carbon valence. That would be sweet.

 

I think I'd have to put some bumpers on to make the transition from top to bottom, though.

[Guest 1972_240z]

cut and weld, cut and weld.....

 

18 gauge all the way around