Wow, I didn't realize that it had been so long since I updated this thread! For a quick update: the engine and transmission have been sold, along with the 4 row replacement radiator that was in the car. I'll update the cost area later, with the deductions for these parts. For various reasons, I haven't made nearly as much progress as I had hoped, but things are moving along pretty well right now. I stripped out the rest of the interior, including the complete dash, console, and all the interior trim, and started on the floorpan replacement. Both pans were badly rusted; there was one hole in the low spot under the passenger seat, and several pinholes throughout, along with some very thick scaley rust everywhere. I originally tried to clean the pans up with rust treatment, planning to patch the holes, but the rust was just too bad. The pans seemed very weak, and I didn't want to compromise such a major part of the car's structure. So far, I have cut out the passenger side pan, and I am almost finished welding in the replacement. I'll do a step by step on the process, with pics, for the driver's side. Unlike most, I am butt welding (my girlfriend laughs when I say that! ) the panel in rather than overlapping it on the tunnel side. A little tougher, but I think the results will be worth it. Overlapped seams give rust a place to take hold, and I didn't want anyone to be able to tell the panels were replaced on the underside. I'll detail all the techniques I used to do this, and some of the tricks to make it easier. More pics to come.

 

Cool, keep us posted.

I need to snap some pics and update my progress too...

 

Yes, please keep us posted, very interested.
At some point, hopefully in the next couple of months I'll strip the car and have it painted.

 

Ok, I'll start with the underhood area. The engine and trans were pulled as a unit, and sold, several months ago ($650). It still ran well, for a basically stock engine, but was far from what I want for this car. I have pics of the engine as it came out on my old cell phone, and I will upload them later. As you can see, its pretty grungy under the hood, but its in decent shape otherwise. The front clip will be coming off soon; its not damaged too badly (repairable), but there is some surface rust in the corners under the windshield frame area of the birdcage, and the only way to fix it right is to get the clip out of the way.

 

I got a bit ahead of myself while cutting out and replacing the passenger side floorpan, and didn't get any before or progress pics, but I will take plenty when I do the other side. Here is the driver's side, after rust treatment. I wasn't happy with it, so its being cut out next.

 

When doing any kind of sheetmetal work, one of the hardest parts is holding the panel in the correct position while you begin tacking it in place. The solution to this dilemma is a simple spring loaded, removable, rivet-like device called a Cleco. Originally developed for aircraft construction, they work great for any sheetmetal project. Just drill a hole through the overlapping panels (either 1/8 or 3/16, they are sold in both sizes), insert the Cleco into the Cleco pliers, and squeeze to extend the spring loaded tip. Insert the Cleco into the hole, and release the pliers, and the tip expands to hold the panels in place. Summit sells a kit, SUM-G1850, that includes the pliers and 10 1/8 and 15 3/16 pins, for $17.95. Extra pins in 1/8 are SUM-G1852; 3/16 are SUM-G1853. Each is $12.95 for a pack of 20.

 

Here are a few shots of the nearly-finished passenger side panel. Welding was done with a 115v MillerMatic mig welder, using straight Co2 as a shielding gas. The welder belongs to my dad, and has been used to put in countless body panels on probably a dozen different cars. He has had it for about 18 years, with no issues, ever.



If you haven't done a lot of welding, don't be intimidated...its fairly easy to get functional welds (pretty ones are a bit tougher, and aren't always "good" welds" ). For sheetmetal, on this particular welder, I set the voltage to 1 (the lowest setting), and the wire speed is on 10. This varies according to the thickness of the steel, and the welder itself, so don't be afraid to experiment. The main thing to consider when using a MIG welder (or any type of arc welder), is proper clothing and eye protection. It is very easy to burn your eyes with a welder, and its a painful experience. You don't necessarily feel it at first, but after a few hours your eyes hurt and you will be streaming tears for the next several hours. Ask me how I know, though it has been several years since this was an issue. I use an auto-darkening helmet to prevent this:



Always weld in a very well lit area (halogen floodlights work well), since even with the autodarkening helmet it can be tough to see what you are doing sometimes. You have probably seen people weld using the "look away" method, and while I am guilty of using it myself sometimes, its not advised. Keep in mind as well that you can easily get sunburned if you don't cover up adequately. Welding coats and gloves are the best way to avoid this, but most of the time long sleeves and gloves of some sort (I use a pair of old Mechanix Wear Extreme gloves for just about everything) are a mimimum requirement. Heavy gloves of some sort are needed when handling sheetmetal anyway, whether new or the old rusty stuff. Nothing can slice you open faster than a piece of sheetmetal.

Of course, you need eye protection when cutting or grinding as well. I have had metal cut from my eye twice, and both times I was wearing safety goggles. For best protectionl, I now use a full face shield.



The pan is overlapped at the rear and along the rocker, like factory. I drilled holes for the Clecos, and welded them up as I went along, to duplicate the factory spot welds. I am also welding the seam (not finished in these pics) for extra strength. I also used the Clecos to butt weld the pan to the tunnel. How, you say? I made a sheetmetal "bridge", just a steel scrap with 2 holes in it, to hold the panels close together so that they could be butted together.

 

nice work....only brings back memories....it'll be all worth it though!

 

Ditto on the memories.

Great work and the fact your son is helping makes it all the more better and memorable. Even the grunt work.

Doesn't look like you need it but there are pics of replacing the flor pans on my 81 at the link below. But you already have it under control!

FrankenSport Build-up

 

Thanks for the link Joe! You provided that one to me once before, and it was a big help. I have done floor pans on other cars, but never on a Vette. I hope to have this little project finished up by the end of the weekend.

 

Excellent tech thread, great to see the progress. It's going to be one fine ride. Let us know of any bumps or suggestions along the way, always trying to learn new things here.

 

Thanks. I'll try to explain some of the processes in as much detail as I can, so that somone who has never done it before won't be intimidated. Honestly, anyone could do this...all it requires are a few tools (which I will show in the next group of pics), some time, and a little patience.

 

Here are a few of the tools that I used to get the old floorpan out. There are many different ways to do this. The grinder at the top left is a 4" Makita. You can get grinding or cutting discs for it. At the top right is my Ryobi 18v corless drill; middle left is a Ingersoll Rand angled die grinder (equipped with a cut off wheel currently). The IR grinder is what I use for more detailed cutting, though an air powered body saw will do the same thing. To its right is a Campbell Hausfield air chisel. I use that to do the rough cuts, and to seperate panels at the seam.
Some people prefer a spot weld cutter for that (drill out the spot welds and the panel comes loose), but I didn't use mine because I was having difficulty seeing the spotwelds. A hammer and a pry bar or two are also handy. I have body hammers, but the weight of this hammer was better suited for the thicker sheetmetal of the floorpan.



Here are the tow most commonly used bits for the air chisel. The one on the left is for cutting panels...notice the upturned tip in the center. The one on the right is a flat blade, which is best for seperating panels.




I'll start with a pic of the new drivers' side floorpan. This one came from an Ebay vendor, and was about $250 plus shipping.



Notice the left side of the panel goes up, and welds directly to the rocker panel. While this is great if you have a lot of rust on that side, its not completely correct. The factory panel is flat on the left (outer) side, and overlaps a seperate piece that comes down from the rocker. If you are concerned about it looking 100% as the factory did it, you will have to cut the angled part off and overlap the piece coming off of the rocker. This is probably the easiest way to do it, but I chose not to, for a couple of reasons. One, I felt that the factory metal had been weakened substantially by all that flaky rust. Two, I suspected there may be rust on the rocker area of the birdcage (under the fiberglass skin).As far as the sheetmetal itself is concerned, welding in either way is about the same level of difficulty. If you do it the factory way, you don't have to remove any fiberglass. This would be preferable in a car that has good paint, but needs a floorpan. My way has the downside that the fiberglass rocker cover has to be removed, but since I am doing bodywork and repainting the car it isn't a concern. I just wanted to make sure I got all of the rust. I plan on keeping this car forever, for sentimental reasons, and don't want to have to do any of this kind of thing over again.

 

Here I am making the initial cuts on the drivers's side floorpan. Using the metal cutting blade for the air chisel, I started on one of the seat belt mounting holes and essentially cut until I had removed most of the horizontal surfaces. I always rough cut the panel out, much smaller than the new panel, to make sure I don't cut off too much.



Here you can see most of the panel cut out. At the front, it is riveted to the fiberglass toeboard so you don't want to get too crazy with the air chisel.



Here I am drilling out the rivets at the front. They are very soft, and come out easily.



The panel is rough cut out. Notice you can see the lip on the left side where the 2 panels are joined, as I mentioned above. The remainder there will be removed from the birdcage/rocker, but some fiberglass has to be removed first.



The rear of the panel, as I mentioned earlier, could be removed by drilling out the spot welds. I was having trouble seeing them, so I used the flat blade on the air chisel to seperate the panels. Be careful if you use this method, as its easy to tear up the flange. I thought I had a picture of this process, but I guess not.

To remove the rocker flange, you have to get the fiberglass rocker cover out of the way. In my case, the carpet was already removed by the previous owner. He left the sill plate, so I removed those first:



Next, I drilled out the rivets holding the rocker cover down.



The fiberglass piece at the front of the doorjamb needs to be removed as well, since it overlaps this panel. Start by drilling out the rivets, then cut at the seam where it joins the rocker piece. I did this with a small chisel, as there were tons of seam sealer or adhesive of some type holding it in place. It may take a little working back and forth with a small flat scraper to break the bonds, and get this piece loose. A little heat from a heat gun, or judcious use of a small propane torch will wrok wonders on the old adhesive.There will probably be some damage at the bottom, but this can be fixed easily enough later.Just be as careful as you can here.



Here I am using the cutoff wheel to cut the rocker panel cap loose from the rear doorjamb/quarter.



Once the rocker cover is loose, you can carefully pull it out. As I suspected, I found some fairly heavy surface rust underneath. The rocker itself was still very solid, thankfully, so other than cleaning and rustproofing it won't require any further repair.



The rocker/birdcage underneath...lots of flaky rust, as I suspected.



The front doorjamb area. There is some rust here, too. You'll have to remove quite a bit of seam sealer to really get this area clean. The door hinge shims will likely be stuck to the jamb, so this is a good time to carefully remove them and bag and tag them so you will know where they came from when you are putting the car back together. In this case, the whole front clip is coming off, because I suspect there may be more hidden rust that can only be properly repaired with the clip out of the way.



Speaking of seam sealer, there will be some on the front flange of the toeboard. If its dry and flaky, you may be able to get it off just using a scraper. I heated mine a bit, since it was still kind of tarlike.

 

Here I am seperating the remnant of the floorpan from the rocker/birdcage. I used the flat blade for this, and once the panel was removed I cleaned up the edge with the grinder. This will take care of any metal left by the spot welding. After this was done, I ground the top and outer side surfaces of the rocker with the 4"grinder, then used a wire brush on a die grinder to remove the rest of the rust. After a tip I heard recently, I wiped the rocker down with common household distilled white vinegar and it eliminated the rest of the rust. I noticed it smells just like Metalprep. Once all the metal work is done, everything will be coated with Rust Bullet (similar to POR-15), and all seams will be seam sealed.



After a little more trimming on the tunnel side with the cutoff wheel, I dropped the floorpan in place and carefully positioned it. It may need to be tweaked slightly here and there with a pry bar and hammer, especially at the rear. Once I was satisfied with the position, I started drilling holes and installing the Clecos to hold it in place.



Here are a few more installed. If you are doing a resto and want it to be exact, put the Clecos where the original spot welds were, so that when you spot the pan back in place it will be identical to the way it was originally. Since I am not concerned with this, I placed the Clecos where I thought they were needed to hold the panel best. Spacing isn't even, and I didn't intend for it to be.



Here is a view from above the rocker, with more Clecos in place. They will eventually be placed all along the back, as well as down the rocker. I bolt the floorpan to the toeboard as a temporary measure, since Clecos don't work well on fiberglass. I save the tunnel for last. Notice that the edge of the floorpan is higher than the rocker. Once the panel is spotted in (via the Cleco holes), I will use the 4" grinder to grind the panel flush to the rocker. After that, I will hammer the edge to get the gap as tight as possible, then start making short stitch welds to avoid warpage to the panel. Eventually it will be welded solid, both here and at the rear of the panel. I anticipate a little extra stiffness will be the result, though I don't know if it will make a measurable difference. Every little bit helps.

 

I'm doing my 81' i figure my 10 month olds hands will be perfect size by the time i get to the nitty gritty LOL