C3 battery box repair
Thread Starter
Burning Brakes
Joined: Feb 2004
Posts: 958
Likes: 1
From: In the Beautiful Shenandoah Valley of VA
C3 battery box repair
I recently purchased a 1974 LS-4 coupe that has a rotted out battery box, from acid leaks and dropping batteries into it, I suppose. Try as I might, I can't seem to locate any reasonably simple repair procedure. You can see the ground through the box, and needless to say, it can't be driven until this problem is corrected. The only thought I can come up with is to cut a good one out of a junked C3 and come up with a way to graft it into the body. This forum seems to have people who have dealt with everything. Any one come up with a good fix for this?
Le Mans Master
Joined: May 2000
Posts: 6,493
Likes: 6
From: Bloomington MN
Cruise-In II Veteran
Re: C3 battery box repair (Steve's74)
I repaired some rather large cracks in mine last year. Pictures of your battery box would help with any recommendations for your repair. I think gtr1999 did a lower half box replacement on his. I just layered some chopped strand fiberglass over mine and sanded it smooth. It depends on the extent of your damage. It's not hard work, but it's a pain in the butt, and very itchy! It's a good practice area for us guys who are new to working with fiberglass, as not too many people will see the repair, so don't be afraid to do a little surgery. :cheers:
[Modified by A C, 8:57 PM 2/17/2004]
[Modified by A C, 8:57 PM 2/17/2004]
Thread Starter
Burning Brakes
Joined: Feb 2004
Posts: 958
Likes: 1
From: In the Beautiful Shenandoah Valley of VA
Re: C3 battery box repair (A C)
Thanks A C, I'll try to get in there with some light and pop a picture. The damage is pretty severe. The bottom of the box is completely broken away on three sides, with two large cracks running up the corners to the top. A battery won't sit in there without falling through. I've worked fiberglass before, but was hoping that this was a common enough failure that someone somewhere made a box that could replace this without building up the entire unit.
Burning Brakes
Joined: Jun 2000
Posts: 892
Likes: 0
From: GA
Re: C3 battery box repair (Steve's74)
My battery box was stolen. It was stolen by the driver side half shaft that broke while travelling at a high rate.... It didn't happen to me but a previous owner. The evidence is all over the rear diff. cross member. Then someone bent some aluminum and painted with undercoating... I missed this when I bought the car...
I have two solutions. 1. Like mentioned, cut a box from a junk Vette and then rivet it into the old box. Build up the seam with fiberglass and sand out. 2. Which I am considering... Summit sells a battery relocation kit with a sturdy box. Rivet this as well and build up then sand.
Both methods will meet your needs and will look good. The first method will provide a "stock look". Hope this helps! :seeya
I have two solutions. 1. Like mentioned, cut a box from a junk Vette and then rivet it into the old box. Build up the seam with fiberglass and sand out. 2. Which I am considering... Summit sells a battery relocation kit with a sturdy box. Rivet this as well and build up then sand.
Both methods will meet your needs and will look good. The first method will provide a "stock look". Hope this helps! :seeya
Pro
Joined: Oct 2002
Posts: 708
Likes: 0
From: somewhere south of normal
Re: C3 battery box repair (Steve's74)
I also have the same problem. Previous owner failed to tell me that the bottom of the battery box was almost gone. Shortly after purchasing the car I drove over some railroad tracks, and the battery fell to the ground. Luckily I kept the car running, so I could get home.
So I found my copy of Bubba's quick fixes, in hard cover, and this is what I did. I cut a piece of 3/8 ext. plywood to fit the openning and I secured it in place with L brackets. I bought a new battery and was back on the road.
Hopefully this summer I will find the time to actually glass the box back in, for a proper repair. I have no experience with fiberglass, so this is a good place for me to start.
:cool:
So I found my copy of Bubba's quick fixes, in hard cover, and this is what I did. I cut a piece of 3/8 ext. plywood to fit the openning and I secured it in place with L brackets. I bought a new battery and was back on the road.
Hopefully this summer I will find the time to actually glass the box back in, for a proper repair. I have no experience with fiberglass, so this is a good place for me to start.
:cool:
Tech Contributor
Joined: Aug 1999
Posts: 15,179
Likes: 3,999
From: Connecticut, USA
Re: C3 battery box repair (Steve's74)
I had the exact same problem the day I bought my 69 back in 1981. there was no bottom but heck I didn't care back then so I Bubba'd it up by using a piece of sheet metal to bent it up like a "U" and screwed it in. I figured I would fix it right once I got the other things done.
Well, I glassed in another box 2 years ago! THe sheet metal served me well all those years. I got a donor box form Gary Gruhala and cut it to fit the side walls of my compartment-there was no bottom left at all. I tapered the edges of both pieces and used resin/mat to build up 3-4 layers on both sides. After the first 2 layers I ground into the splice and walls to form a good bond.
It wasn't a hard job because I already had the rear suspension out and had clear access to it.
I have some pictures I can scan and send to you if you like.
Gary
Well, I glassed in another box 2 years ago! THe sheet metal served me well all those years. I got a donor box form Gary Gruhala and cut it to fit the side walls of my compartment-there was no bottom left at all. I tapered the edges of both pieces and used resin/mat to build up 3-4 layers on both sides. After the first 2 layers I ground into the splice and walls to form a good bond.
It wasn't a hard job because I already had the rear suspension out and had clear access to it.
I have some pictures I can scan and send to you if you like.
Gary
Drifting
Joined: Jun 2000
Posts: 1,955
Likes: 2
Re: C3 battery box repair (gtr1999)
Mine had just a little bit of the bottom left, mostly around the corners, so I took a flat board, covered it with saran wrap, the used a jack to support it under the bottom of the old box. Then I fiberglassed it over from inside the car. When that was cured, I removed the board and fiberglass it from the bottom, running up the sides a little for strength. I think I did two or three layers on each side, then sanded it to blend in. When it was done I sprayed undercoating on it and you can't even tell it was repaired. When I show the car I put it up on blocks with mirrors underneath, no problem.
Good luck with your repair.
Jeff
Good luck with your repair.
Jeff
Thread Starter
Burning Brakes
Joined: Feb 2004
Posts: 958
Likes: 1
From: In the Beautiful Shenandoah Valley of VA
Re: C3 battery box repair (no_radio)
OK A C, I've taken a picture. The damage that mine has doesn't sound too much worse than others. Thanks gtr1999 and no_radio, I'll give those techniques a try. I especially like no_radio's method with the board. I've just got to learn to think outside the box. Sorry about the pun. Now, if someone can tell how to add a picture to these posts, I'll try to throw a busted box up. Thanks again.
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Le Mans Master
Joined: May 2000
Posts: 6,493
Likes: 6
From: Bloomington MN
Cruise-In II Veteran
Re: C3 battery box repair (Steve's74)
Email them to me at ACinMN@hotmail.com and I will post them for you. Otherwise, just upload them to a photo hosting site, and link to them by bracketing the address with [IMG][/IMG] .
Thread Starter
Burning Brakes
Joined: Feb 2004
Posts: 958
Likes: 1
From: In the Beautiful Shenandoah Valley of VA
Re: C3 battery box repair (A C)
OK, let's give this a try and see if it works. Here's the photo that best illustrates the damage. 
Even this doesn't do a great job. The bottom of the box is hanging down about 3 inches below where it should be. I'll give some of your suggestions a try and see how it works!
Even this doesn't do a great job. The bottom of the box is hanging down about 3 inches below where it should be. I'll give some of your suggestions a try and see how it works!
Burning Brakes
Joined: Dec 2002
Posts: 1,205
Likes: 1
From: "Too Low, Too Fast, Too Loud" TX
Re: C3 battery box repair (1FUNVET)
I say screw the quick fix and fix it right once and for all and be done with it...do it right the first time and you wont have to do it again..from my dad-the Command Sargent Major-30+yrs Army Service! :flag
Advanced
Joined: Aug 2003
Posts: 85
Likes: 0
From: Portland OR
Re: C3 battery box repair (Steve's74)
I've got a little hole in the back of my box (that's what she said) that is on the wall so it's not too bad, but you can still see the ground. Is the fiberglass patching easy enough for a beginner? It's not nearly as dire as some of the stories on here, but I still would like to fix it.
Dave
Dave
Thread Starter
Burning Brakes
Joined: Feb 2004
Posts: 958
Likes: 1
From: In the Beautiful Shenandoah Valley of VA
Re: C3 battery box repair (gtr1999)
Thanks everyone. I think I'm going to try to find a reasonably good box in a salvage yard somewhere and cut out as much of it as I can. A close look suggests that someone in the past has already tried (very poorly) to glass the box back together. And the holddown pieces are either shot or fallen out. There is a bit of metal still there, but not much.
I agree with the idea of doing it right the first time. We never seem to have time to do it properly the first time, but seem to find the time the next time. Grafting the bottom of a good box in place seems to be the logical way to go. I'm really surprised that no one has offered up a replacement unit. So I'll give it a shot in a while.
Sure which I knew what I did wrong with the picture. Can't find much help here in the instructions. Thanks for posting the photo A C. :seeya
I agree with the idea of doing it right the first time. We never seem to have time to do it properly the first time, but seem to find the time the next time. Grafting the bottom of a good box in place seems to be the logical way to go. I'm really surprised that no one has offered up a replacement unit. So I'll give it a shot in a while.
Sure which I knew what I did wrong with the picture. Can't find much help here in the instructions. Thanks for posting the photo A C. :seeya
Drifting
Joined: Jun 2000
Posts: 1,955
Likes: 2
Re: C3 battery box repair (Steve's74)
Your box is in a little better shape than mine was. If you grind it down on the edges and use the "saran wrapped board" method it will come out nicely in about one day. You don't need to buy a cut out battery box from a wrecked car. You don't need the metal reinforcements. This was my concern before my repair. What I did was emulate the raised areas, then I used stainless steel hardware (washers, nuts, allthread, etc) to hold down my battery with the new 'glass I installed. I drive my car pretty hard, although I only have about 2000 miles since the repair.
Re-read the previous posts, I think this is a one day fix for you, without buying a box.
Jeff
Re-read the previous posts, I think this is a one day fix for you, without buying a box.
Jeff