Since I'll have to install a new floor hump for the 833OD I plan to install, I'm wanting to weld it in and take the opportunity to get some experience welding sheet metal. From the little research I've done so far, it looks like I can do a pretty decent job if I keep a steady hand with an oxyacetylene torch (which I've used before for cutting but never for welding) after properly setting it up and using the correct tip. For those of you who've done sheet metal welding on your cars before, can you offer me any advice? I plan on doing much more reading up on the subject while I'm still piecing together parts, but any real world advice or tips I can get are welcome.

Also, the goggles and visors at the auto shop here on base are CRAP! Any recommendations on a good pair of goggles?

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

Though I do not have any experience with oxy torch welding , I would suggest some practice on spare sheet metal of the same thickness as the tranny hump before you start welding in your car.
If you can get access to a mig welder you might be better off .
Just my opinion.

Thanks Jeff

That's what I've always read--practice first. It's easy to warp with too much heat. Also: do the work in "stitches" -- that is, do an inch, then go over 6 inches and do another inch, etc. That way, the metal doesn't heat up too much in just on area.

I'm sure there is more info in some books out there; lacking that, every couple of years the rags (Hot Rod, Car Craft, etc) do an article on home metal work.

Although it is possiable to weld that way, you will wish you used a mig welder. The metal will warp and you will hate the job. A hammer will definenitly be needed to pound the warping back down. Also it will take forever. It could take 3 hours with gas and about 10 mins with the mig.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

I just got done welding patch panels in my quarters. I used a mig, but I've done lots of stuff with an oxA setup. It is true that back in the day a torch was the way to go, but the fellas are right, it is a lot of heat, especially for thin sheet metal. Wouldn't it be easier to braze the panel in? Truthfully I think that riviting it in would be plenty strong, but if you must have a hot connection brazing could be an easy and permanant solution, and not quite so warpy as trying to flow steel.

Also, be careful- even with a mig setup it is really easy to blow a hole through your metal and then spend even more time patching/filling with more metal!

radar

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madam im adam

The strength of what's holding the panel in isn't so much a concern as having it sealed well (and permanently) around the work. Something about riveting it and using sealer just rubs me the wrong way. It seems so half-assed

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

If there was ever an example of "learning it the hard way" it has to be welding sheet metal with a oxy torch. Back in the day it used to be the only way and it borders on being an art form when done right. You have to be able to quench but not cool the metal as you go.Some people use a wet rag and some a spray bottle,first you have to be able to bring the entire area "up" to temp,work it,hammer weld the bead as you go then let the whole thing cool down with out resembling the surface of the moon when your finished or done working for the time being.And believe it or not the coat hangers that were used on company uniform service for the pants was just about perfect as to workability and strength of the weld with out being brittle. Brazing is a lot more forgiving and when used in over lapping joints like your floor board and hump it will make a nice looking and strong repair.Use flux coated rods and practice practice practice. There is a certain amount of satisfaction when you get the hang of it. Plus brass will attach to rusty areas where welding with a mig will blow it out. Sorry didn't mean to ramble on.Good luck!

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Bill Jacobs

Here's a non-welding ALTERNATIVE. Instead of a sealer, it's a structural adhesive.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

I pulled a hump out of a 65 Dart that I parted out. The hump was overlapped over the crudely cut hole and was welded every 5 or 6 inches or so for about an inch. Then the whole seam was sealed with seam sealer. Seems the factory didn't take a lot of time in installing a 4 speed hump - I'd guess maybe no more 10 minutes start to finish.

Geez, you guys make gas welding sound hard. It is fairly simple to use. I use a Smiths setup with the 503 tip. You should use a nice copper coated steel rod about 3/32" in size.

Step 1. Trim your panel to match the hole. It should be with 1/8". If the gap is to far apart you will have some fun filling in holes. Filling in holes gives you a lot of practice in patiences. Use clamps, sheet metal screws, magnets, whatever to hold the panel in place.

Step 2. Tack the panel in. Start on one side and alternate sides. Go slowly and carefully. Allow the panel to cool off between tacks. Do this until there is about a 1" gap between the tacks.

Step 3. When there is about an 1" between tacks. You can start filing in between the tacks. Alternate between side and allow the panel to cool between fills. Go slowly and carefully.

When done right, there will be minimum warpage and a nice pretty bead. Much nicer then MIG, closer to TIG in appearance.

I'm with kesteb in this thing. Don't need for a MIG. Good hand on an oxy torch will give you better overall results than MIG.

However, I'll install my floor hump with screws and seam sealer because if I ever want to take it off (Say, for shifter rods or other adjustments) I don't have to cut it off again

I did (we did) all the welding in my restoration with oxy torches. The "secret" also lays in pointing the SMALL CONED BLUE FLAME not directly at the surface. It should be at any angle below 45° with the surface. Also when you're done mixing gasses it shouldn't wistle. If it whistles you have too much oxygen or too liitle acetylene. Too much oxygen will warp and chances are you'll put a hole in the sheet metal.

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

This is a really good point. I hadn't thought of that. Using Nutserts would be great too, since you'd be able to remove the screws/bolts several times without worry of enlarging the hole in the sheet metal...

I'm liking this idea better than welding...

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

You just nailed the fact that I didn't like about using screws for affixing the hump. I'll be using nutserts! Genius! I don't know why I don't ever think of nutserts... See what happens when we all put our heads together?

anyway, welding with oxy-acetylene ain't that hard. You can take a look at my work at www.infododge.com.ar/restauracion/page_01.htm there is 12 pages there.

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

The factory used seam sealer all over the body anyway. The welds are just spot welds.
If you decide to do any welding on the floor just keep in mind what might be underneath, like undercoating. Aside from a fire extinguisher, I usually keep a bucket of cold water handy when I am welding anything on or under a car. It's nice to have if you happen to burn yourself or start a fire.
Myself I would go the threaded insert or rivet-nut route and use a 3M or PPG body seam sealer.