While replacing the carpet and underlayment I found out that my rear floor pans need replaced. I already have them waiting in my garage. The drivers floor pan was repaired. I want to do it right and replace the whole pan. I bought a welder to learn while welding my 300zx exhaust. I did pretty good for a first time welder. Anyways, should I leave a little lip and set the pan in and tack it first or should I have no lip at all and tack it every 2 to three inches. After tacking it I would finish the weld. Am I on the right track or even close?

You are on the right track. I like to butt weld because it doesn't give dirt and eventually rust a place to hide between the layers.

Do I leave any kind of gap in between the panels? I have an article in Hot Rod that I will have as a reference. It looks fairly easy.

Like Daral says, butt weld it.:thumbsup:

Try and keep your panels as close as you can get them before you start welding. You will have less distortion that way.

Now, save yourself a lot of work and headaches, just spot weld here and there so you don't over heat the metal, its hard not to just give it a little more, but patience is the key, just a little bit here and there.

Rob

I'm going to spot weld in place first. . I don't want to over heat the metal and warp it. I'm going to take my time with this. Like you said a little here and there. Is there any tricks for holding it in place. Like welding magnets to hold the metal parts in place?

Get two sizes of hex head sheet metal screws, because you will strip some out and need a larger one.

If you can work it from one side to the other, this well help you be able to pull the pans down tighter to the supports, but make sure your outside edges stay lined up. Don't be afraid to put a few screws in, then have to take them out and put some more holes right next to the ones you just took out.

On my trunk pans, the first one I put a couple screws in each end, then it was really hard to draw down the center, and I thought I had it tight.

You could start screwing from the middle and work both ways, but watch your outside edge alignment.

I used some clecko fasteners for my toe boards, but sheet metal screws will hold them tighter

Rob

what we did was drill holes in new floor pan. with a 1/8 inch drill bit. than used 2 part opozy to put together and in drill holes pinched together and welded as in pushed up from bottom and put weights on top to push together welded. took some time but now welded together and epoxy got seam together with no chance of water getting into car.

Bill, I'm a little confused on what you did, could you run that by me again, thanks.

Rob

I will do the sheet metal thing. Thanks guys.

David - I used sheet metal screws like Rob suggested on my trunk pan. It works great. If you have a place with a gap that is a little too wide, put a piece of copper under it. You can hold it in place with a magnet or the sheet metal screws. The weld will not stick to the copper and it will let you weld the gap closed without burn-through.

Okay, I'm going to butt weld. This may be a stupid question. What is going to hold the sheet metal screws. The new pan is going to be screwed to what. Is it the support?

Are there any pics of this.

To butt weld it you will have to cut out old pan out ,, then fit new pan to fit ,,very tuff, overlaping is the easy way,, butt weld would be better if you have the time and skill,,good luck

I have nothing but time. I have some welding experience, not alot. I believe that I can do this. I have a backup plan. I'am one who enjoys working and learning. I see no problems. I measure twice and cut once.Thanks. I will post picks after I weld them in.

Okay, I'm going to butt weld. This may be a stupid question. What is going to hold the sheet metal screws. The new pan is going to be screwed to what. Is it the support?

Yes, you want to use the screws to hold it to the supports. If you are only replacing part of a pan and there are no supports under it, you can use magnets to hold it while you tack weld it in place. :thumbsup:

Thank you for the info. I appreciate all the knowledge that has been passed on by everyone. Thanks!

One trick that seems to work pretty well for getting a good butt joint is to cut out the old floor and leave a little extra metal on the new floor you are putting down so there is a slight overlap. Get everything lined up real good and then screw the two floors together w/sheet metal screws where they overlap every foot or so.

Now take a jig saw and saw through the area where the two floors overlap a couple of inches at a time. After you cut a few inches, push the new floor down so it is lined up and tack it to the part of the floor you are keeping. After you're gone around the whole floor, you should have a closer butt weld with about the ideal gap of .035". Then go back and add a little tack to each weld until you have a continuous bead all around. You can grind the bead down and almost never know that you had replaced the floor.

I assume you're using a Mig w/shielding gas.

Good luck!

Oakster, good idea, I'm going to use it:thumbsup:

Rob