G-N-F Body fan

I have learnt a lot from TGO figured ide try logging in,anyway i have a 92 Firebird and here is a few images of what i had to cut out of the rear front inner fender/quarter I was just crushed after finding this mess.Ive worked on this car for several yrs.




Thanks and excuse my newbie status

kentuckyKITT

iTrader: (4)

Welcome to TGO! Might as well repair since you've gone this far. I suspect that just about every car has rust lurking in places that we cannot see. Metal likes to sweat and in the right conditions, condensation can form in places you can't even get to and over time, it rusts the metal. It's not until it's too late usually, that you discover it. For instance, when I replaced the air box on my 82 Trans Am, I found a rusted out hole in the firewall behind the box at he bottom of the firewall with a ton of rust forming around it. This area was completely invisible until the box was removed. Had I not changed the air box and repaired this area, it would have grown into a much bigger problem over time. The only thing you can do is just fix it when you find it or tear the whole car down to a shell and restore it. Guess what? It's going to do it again eventually, maybe not in your lifetime, but it will happen again.

All 3 of my cars probably have rust somewhere, I just haven't found it yet and frankly, I don't want to either!

DynoDave43

iTrader: (11)

Welcome aboard!



Forum member Drew found similar damage on a '91 Firebird he's bringing back to life. You can see his progress and methods at the link below.

https://www.thirdgen.org/forums/memb...d-project.html

Drew

iTrader: (58)

All those pinch welds and seams were sorta covered in seam sealer from the factory, and in key locations GM punched or left intentional gaps to let moisture drip out. Over time the intentional gaps and drain holes get plugged with dirt or debris, or they start to rust a bit and that corrodes the holes shut and water can't drain so it rusts away from the inside out. Also the seam sealer really only had a reasonable life expectancy of about 10 years. After that it started drying out, shrinking, pulling away from the seams, falling out and disappearing, etc. Without the sealer, or with the sealer not bonded to both sides of the seams, water gets in there, doesn't evaporate quickly because it's wicked between the panels, and you get rot.

No big deal. Neutralize the rust you can, cut away what's too far gone to neutralize and weld in new steel. Strip away failed seam sealer, reapply new sealer. Make sure all the intentional drainage points are open and CLEAN. Assuming you have enough panel left to weld to, the hardest part is fabbing the replacement panels. If you don't care how close they look like factory, it's even easier.... It only really gets interesting when you're making a replacement patch panel with compound bends, but if you don't mind the welds or the time to grind welds smooth, you can patchwork it back together.

I say fix it, it's not like any realistic driver thirdgen is rolling around completely rust free.

G-N-F Body fan

Thanks for all your replies/advice i was repairing some rot in the drivers side floor and i asked my gf to remove the sealer with my multi-tool and wow i was Surprised/disapointed,w/o her digging it up i would have never found it.i have a 1984 T/A HO manual around back thats not in near this condition.I know in 90-92 GM added extra sealer for squeaks and im thinking that is part of the problem,this stuff is much harder than whats on the 84,also have the rot on the firewall around the drain.I was wondering how structural is this area ?I have always owned G-bodys so the uni-body is new to me.I have had to replace two fuel pumps in this car as well,neither time was it fun,,no trap doors for me.i am not a welder but i do have one ,im sure to fix this the tank has to come out again, Yippee.I am currently getting ready to drop the frame for new body bushings and cleaning on my 86 Olds Cutlass.I have a lot on my plate.Thank you all

TransamGTA350

iTrader: (2)

Those are the common spots that these cars rust. Just as Drew said, the drain holes plug and the seam sealer only lasts about 10 years. It’s all fixable. Not that hard, just time consuming and tedious.

i repaired all of those same area on my 89’. Here is the restoration thread I have been updating with photos of repairs of some of those areas. I did the rear wheel wells too, just haven’t uploaded those photos yet.

https://www.thirdgen.org/forums/memb...ns-am-gta.html

G-N-F Body fan

I will look into your thread,it looks like you have put in a lot of work.I am going to fix the car,ive replaced 4 springs,shocks,struts n mounts,front brake and hoses rotors and every electric motor on the car except the mirrors they work,windshield,gas tank that (doesnt fit btw!!) fuel sending unit,battery tray,head gaskets on up and a gang of other stuff.So yes im going to repair it.It has been a journey for me.Im thinking what i had to cut out is structural.I think the patches i need would be best cut from a donor car,much easier to install im sure.Any ideas on where i can source these patch panels?My apologies to all who replied,im just winging it here not sure how to get around on TGO just yet.Thanks

G-N-F Body fan

Thanks for your advice/time and im going to fix it,ive came much to far with it to quit now.but finding the rot was a bit discouraging.Everything about the car is now fine EXCEPT for the rot.Thanks Again.

G-N-F Body fan

Thank you and i found Drews post a few months back and read for maybe two hours.That is dedication/attention to detail for sure,the 90-92 seems to have a harder sealer than my 84 it was a bear digging it from the firewall.Thanks again and any ideas on a donor car patch panels would be helpful.

G-N-F Body fan

I found your thread a few months back and it is very impressive imho,thanks for all the info and pics im sure there are many lurkers like myself that it is very beneficial too.

Drew

iTrader: (58)

For the most part, the bulk of the structural rigidity is in the thicker gauge stamped parts. The frame rail stubs at the front that extend from the front impact bar, all the way back to the sides of the trans tunnel, and the rear from the rear impact bar forward to the trailing arm mounts. That's your unibody subframe. If you look under the car, on either side just behind the wheel wells, you'll see a short heavier brace tying the front subframe into the rockers. The inner rocker and outer rocker forms a box structure that takes a bit of load, as do the floors and roof, and so on. But really, the structure is spread around, and it's nothing you need to be too worried about as long as you don't cut away the subframe, or the upper frame extensions from the doors forward to the rad support. Even then, anything you cut out and weld back together, as in fixing rust, shouldn't harm the integrity, assuming your welds are decent.

I wouldnt worry about the rust that's been cut away compromising the car or safety.

TransamGTA350

iTrader: (2)

There isn't much available for patch panels. The only piece I needed that I was able to find new was the passenger floorpan. I sourced a used radiator core support and battery tray. Everything else I cut, bent and welded pieces of sheet metal. It really wasn't all that bad to do and I used basic body-working tools. (Body hammers, mallet/sandbag, bench vise, air tools for cutting/grinding, etc.). For more complicated sections where you would need to be able to make compound bends, you can usually build it out of smaller pieces, weld it together and grind the welds away. Once it's painted and seam-sealed, you can't really tell.

You could try to source all of the metal from a good rust free donor car, but at that point, I would probably just keep the donor car intact and transfer all of your good parts over.

Drew

iTrader: (58)

Rust in the corners of the kick panels and in the wheel wells is so common, I'd expect any donor car worthy of providing rust free cut-outs, is probably worth building unless it's got a significant title issue.

I used a Mustang fender with some nice dents and rust spots as a source of metal. Made things that much more difficult because I had to clean off the old paint and in some cases work the cut-out flat before I could reshape it. If you can find a metal supply and work with new, clean steel, you'll save a lot of time. My project has always been right on the edge of being cast away at any point, so I've done my best to keep the investment under control.

Pretty sure the only repro patch panels out there are the Camaro battery tray, rad support pieces, floor pans, rocker and lower door segments, 1/4's, trunk pan, and frame rails. Suppose aftermarket fenders are also likely available. Sometimes you can get lucky and find NOS panels, but GM flushed them out of the system by 2002 in most cases, so anything you find is usually been sitting in Cletus' shed for 20 years getting run into every time he pulls the mower out.

TransamGTA350

iTrader: (2)

New sheet metal is easiest to work with. I bought a 4’x4’ sheet of 20 gauge steel from a local auto body parts supply house. I can’t remember the cost, but it wasn’t too bad. Maybe $50-75 or so. I used that for all of the custom made pieces and still have some left over. I also needed a little bit of 18 gauge for the inside bracing of the front rocket corners. I just bought a small piece of that from Home Depot.

G-N-F Body fan

Thanks for the info,im not very knowledgeable on the uni-body design and i am thankful that its still ok, but the rot had to go.The car has some substantial dents in the sub frame you speak of, ive wondered about.It looks like its been bottomed out on rocks etc.a jack didnt do this, i dont think.A (hydraulic) jack did fold up both front jacking points to break things loose and start the rust process there as well.I purchased the car about 5 yrs. back for $700 on CL and it looked pretty good and had a very nice black interior and a newer black paint job/nice wheels a blown head gasket but i fixed that and the only reason im not driving it is, the ROT.I have the 84 T/A that needs a left side front floor patch and the firewall shows some light rot but the rear wheel area has none of this.I bought UMI sub frame connectors for the 92 (hate that flex) and t-top seals,hatch seal, door sweeps,wonder bar etc.Over the last 5 yrs. from studying ive been buying what i could afford to put together a nice thirdgen..I found the 84 T/A last year for well,Cheap with newer struts shocks exhaust,headers it needs engine work and interior of which ill put the black from the 92 inside it along with all the other goodies ive purchased over the past 5 years.I am going to finish the 92 though and install the gray interior from the 84 in it.BTW how did you get the seam sealer from the firewall ends?I cant get anything on the left side,and even the gutter area sealer was no less than a bear to remove.I used a fence post sharpened and heating it to remove that crap.Thanks Again.

G-N-F Body fan

I purchased a piece from Summit that was from AMD Auto Metal Direct that i have bent for the patch on the left front floor patch.I also purchased a new right side battery tray,the 92 battery is on the left side.I read it will work on here,well i had no luck with it.I purchased one from E-bay cut from a donor and grinding and bending on it was several hours to make it fit as it should,but still easier/quicker than fabbing up a piece of metal that looks like crap.Upside i have a new tray for the T/A now,anyway i appreciate your response/advice.

Drew

iTrader: (58)

https://www.harborfreight.com/heavy-...-pc-69601.html

They come pretty dull. A belt sander puts an edge on them pretty easily. The shank extends through the handle so you can put some force behind them and not crack the handles. The handles themselves are uncomfortable, but they're HF tools, nothing wrong with grinding them to be more comfortable. Can grind the handles round instead of square, or scrape and sand away the mold edges, file and sand the sharp spots on the handle so they don't give you blisters. Heat helps too, heat gun softens some of the stuff. A wire wheel on a drill strips the stuff away too. Must have used a bit of everything I could think of while stripping the old sealer.

Yeah, the repro battery trays are intended for the more common market, ie the Camaro and TBI/Carb cars, they all have the battery on the other side. Funny part is, the left tray on my Camaro was rough, and the left tray on my Firebird was rough, but only right sides are reproduced. And inexplicably that trunk well stamping. A piece that never really rusts, and if it's damaged from a wreck the entire back of the car would be smashed, but that's what they offer.

G-N-F Body fan

Thanks for the info,i just purchased the set you posted here and i also bought a 1/2" belt sander Item # 62863.It looks to be handy and honestly i appreciate HF, most of my tools are from HF, i just spent over $300 on mainly chemicals/rust treatments etc.at Eastwood.To remove ALL the sealer as you have,it will take me some time and patience and i know it should be removed.Thanks Again

TransamGTA350

iTrader: (2)

I have used various techniques to remove existing seam sealer. There isn't a single technique that works for all. There are a few different types of seam sealers used on different areas of the car and some are dried out and some not.

For the dried out and cracked sealer, gasket scrapers like Drew suggested seemed to work pretty well.

For more stubborn sealer, warming up the sealer with a propane torch and scraping with a gasket scraper seemed to work. I used this technique for most of the sealer removal.

A wire wheel on a 4" electric angle grinder worked for some areas, but that also tends to sling molten seam sealer boogers everywhere that you will have to clean up later with lacquer thinner.

The leftover seam sealer residue around the seams can be cleaned up with lacquer thinner.

For new seam sealer, I used 3M Ultrapro Urethane seam sealer. It comes in a foil package and is used in a specific flexible package caulk gun. Urethane sealers are much better than what was used on these cars 30 years ago.

G-N-F Body fan

The propane heat seems like the only thing i have not tried,and possibly the most effective.I will give that a shot,the firewall/gutter is tough stuff and just scraping it away would take forever.I used propane on a sharp metal fence post down in the gutter/firewall area and it was somewhat helpful,but probably more of a waste of propane/time.There is no sealer on my 92 that seems soft like the G-bodies and the 84 T/A either,mind ya i have not got to all of it,but what ive found so far is a pain.Thanks for the info,and apologies for the delayed response.

G-N-F Body fan

I have some AC Delco seam sealer ive had for over a year ide assume,and i just got some from Eastwood, nearly every type i looked at seemed to stay flexible.Just my thinking, that these cars could use some with an adhesive in it,sure seems like whats on this 92 sure had some bite to it.Thanks again ill look into your recommendation.

G-N-F Body fan

Yes that is special isnt it,im guessing no one sells many of those large trunk area panels.Sure would be nice if you could purchase portions of the floor etc.If i needed a complete floor i would have surely passed on the car.I think a flea bay scrap yard may work though,i got the battery tray there,after telling them which side i needed and there IS another battery tray on the left side as well,to just remove the canister/bolts etc. its under there.I used the battery on the right side for a lil while,but knowing it just wasnt correct bugged me.Thanks Again.