plug weld

[Bilgamesh]

Here is a pretty good basic article about plug welding. I bought a Lincoln Weld-Pak HD as a first step toward replacing my driver's side floor pan. I was not aware that plug welding is the method of choice for this type of job until yesterday. I think that fact makes my job easier, as it looks like I won't have to practice much to do a plug weld. I do have a couple questions:

1. Is there any advantage to overlapping the floor pan over the existing or vice versa? (and which piece to drill)
2. How do you protect the mating surfaces from future rust?
3. What is the best/safest way to remove the old pans?

Thanks

 

[welndmn]

It really depends on what floor pan you buy, some are the full pans from the crossmembers, where others are a cut and replace what was bad pan.
But, go get some weld through primer from the welding store, clean and paint everything with it.
Anything with rust, you want to remove about 1-2inches from the last spot of rust IMO to make sure nothing is hiding.

 

[Dano 407]

Regarding the removal of your old pans, a plasma cutter will do the job the quickest and with the least amount of heat distortion. A 4" abrasive cutoff wheel on a small angle grinder will do the job very well also, but may be hard to get into some spots. A variety of tools is the best way to go.
Mark your lines, get out your equipment and take it slowly. It is easier to take more off than to add it back on.

Good luck,
D

 

[Bilgamesh]

I got a new DeWalt 4 1/2" Small Angle Grinder off craigslist for $30 yesterday. I am hoping I can cut it with that. It came with 3 wheels, two of which say they are for cutting metal. - Thanks

 

[wildbill]

If you over lap the floor pan make sure you use a very good weld typ primer or you will build a home for rust to start. I think the last rattle can was like 20.00 good luck and have fun. %) %) %) Bill %) ;D

 

[NicksTrix]

napa sells a good weld primer. easy to find if you aren't familiar with autobody supply sources.

i'd suggest you pick up a cheap flanging/ punch tool from northern or HF. it makes it a quick and easy deal to get your outlining holes in the panel. it's one of the tools you'l find more uses for once you own it.

 

[deltarat]

napa sells a good weld primer. easy to find if you aren't familiar with autobody supply sources.

i'd suggest you pick up a cheap flanging/ punch tool from northern or HF. it makes it a quick and easy deal to get your outlining holes in the panel. it's one of the tools you'l find more uses for once you own it.

I agree. I bought one from HF and the time saved was unreal.

 

[bushman]

Just my .02 here, but I bought a 15.00 air chisel and a set of attachments at home depot for another 15.00. I used this to pull out 90% of my floors. I used a sawzall for about 20 minutes and cut out all around the frame and crossmembers, then used the air tool to chisel the pans off of the crossmembers and split the spot-welds. In about 3 hours I had the pans off from one side to the other, including the transmission hump.
I saved an assload of time doing this, which I then spent drinking beer.

FYI: Those crossmembers are so thick, the chisel didn't deform them at all, just peeled up the floor remnants.

 

[widowmaker77]

im interested in this also as i will be doing floor pans and other body parts on my 77. what is this weld through primer iv heard of por 15 and miracle paint is this what you guys are talking about? does weld through actually mean the heat from the weld wont burn the primer off. also has anyone had their bodies media blasted and coated with line-x if so what does something like that cost.

 

[allenfahey]

You do overlap the old and new panels. Make sure there is no rust on the old panel. You don't weld around the whole seam. To do a proper weld on replacement panels you drill a 1/4" hole every 6-8". Look at the old panels you'll see the spot welds. As stated earlier Harbor Freight sells a pneumatic punch just for these holes. Grind the e-coat (black coating if it is even on there) off the face of the mating panel and around the holes. Spray a LIGHT coat of weld primer on the matting surface. Weld the hole and grind it smooth. Prime it, scuff it, seam seal it, reprime or use a sealer and then paint it.
A good seam sealer that is used in a regular caulking gun is Fusor 800 found at any autbody supply company.

Best way to remove panels is to use a spot weld bit found at the autobody store. Once the spot welds are gone you use an air chisel and peel it away.
Have fun and make sure you have your tetnis shot up to date