I have used my torch to weld sheet metal in the past and usualy used flux coated brazing rod. Now I am putting floors in my 52 Chevy and need to know what rod to use. Would the brazing rod be strong enough for floors? Thanks,
I always butt weld replacement panels in, not braze them. Use 1/16" filler rod, oxy and clamps. You could MIG if you wanted. You need to clean all the flux off. I wouldn't recommend overlapping as it will rust again.
Id butt weld it also. And on floors I'd probably mig weld it too. If you want to use your torch, Weld it with a steel filler rod. Available at any welding supply.
Welding and brazing are two distinctly different processes. A brazed joint is seldom, if ever, as strong as a welded joint. When you weld mild steel (automotive sheet metal) use a mild steel filler rod.
When I was a kid and broke , I learned to use coat hangers AKA 3/32" mild steel rods. Run them through the flame and burn off the coating then wipe off the residue with a piece of steel wool. Over the years I probably replaced a hundred or so patch panels and it works just fine.
I also butt weld with gas and if your patch fits with no gaps you won't need filler rod....but I keep a coat hanger close by just in case. Posted using the Full Custom H.A.M.B. App!
we use the steel rod from the welding shop buy about a tube of it as you will use it all up , we cut it into 18" sections to make it easier to work with and take the little parts and weld them to the new rod to use it all up with no scraps , and you can use mig wire ( non flux) in a pinch you just have to use 4 .035 wires wrapped up to make a rod. and the nice thing about gas welding is the weld is soft enough to hammer out and make a nice hidden joint , mig weld is hard and brittle .
I buy "welding rod" not "brass brazing rod" at the welding supply and usually do get about the same diameter as the wire in a coat hanger. that size seems to work pretty well for my needs. I'm another one that cuts the 36 inch pieces in half to make them easier to handle. The whole chop on my 48 was gas welded with that size of welding rod and it has held up well. I didn't have a mig or access to a mig when I chopped it that time. On the floors it won't hurt anything to overlap them but you want to make sure you seal the seams to keep moisture out. Butt welding eliminates that part.
What's a good "sealer" to keep the moisture out of an overlapped joint? I have thought about POR 15 liquid and letting gravity pull it down into the seam. Anybody done that?
There really isn't one which is why everyone says but weld them. The factory floor joints are lapped and they rust. The entire pan can be pristine and the lap joints rotted to dust. Seam sealer is about your best bet with some weld thru primer but its like sticking your finger in the dyke
It will ,however you will see a sort of "muddy" puddle with the gas torch because the extra de-oxidizers added for TIG welding will float on the surface of the puddle. The proper rod to use is an R45 designation, a mild steel fusion gas welding rod that will give a nice clean puddle with a neutral flame and a good strong weld. Butt welds are the way to go, lapped welds will always rust out with moisture between the layers that will form there through simple condensation from temperature changes even if the seams are sealed. Anyone who uses proper gas welding rod will never use coathangers again.
A brazed joint on mild steel can easily be stronger than mild steel = the steel fails before the joint. But that does require the correct type of joint, and that is not a butt joint on sheetmetal - too little area, a good lap joint would be stronger. For welding sheetmetal on the other hand, butt joints are perfect.
All English Formula 1 tube frame cars (and smaller classes like F2,F3, F JR, FF for that matter) were usually NickelSilver brazed together until TIG welding became available and affordable. I built tubular A frames using that approach and had no problems. NickelSilver rods are expensive these days but surprised anyone would consider any approach other than MIG for a floor pan. MSD example: ESAB All-State® 11FC is a high strength brazing alloy for joining ferrous and non-ferrous metals (except white metals), and carbon alloy steels. Higher strength than ordinary bronze rods, can replace many higher cost silver alloys.
X 2 on the copper coated mild steel gas welding rods , 1/16" should be fine with a good butt fitment . The key is a ductile weld that can be planished to take out the shrinkage .
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