I've trimmed the tail of my '36 Chevy coupe with a small air cutoff tool. The choices I can think of to smooth the sharp edge are 1) grind/sand 2) tack solid rod below the cut and 3) split steel brake line, slide it over the edge and tack. The first two choices are pretty straight forward but if I opt for #3 is there a good way to split the brake line? OR do you guys have other suggestions? Thanks for your input.
What about just bending the end at the cut line about a 1/4" back under itself to form a double panel? The next option would be to weld a 1/4" round stock to the back side of the cut. Gene
It would depend on what you are trying to achieve. Another, better way would be to make up swaged piece with a folded edge and tack it on, although that may resemble what you cut off.
Yeah, guys, thanks. I'm hoping to get a 'rounded' edge to the cut (it's a 'bobbed' tail) and round stock may be the way to go but I also wondered how a lenghwise split of brake line could be done and how it would look.
I'm not sure how small of a lip can be folded on a brake but fold an L shape and hammer and dolly it for an edge covering the ruff cut.
Hard to give advice on something unknown to us as to what you actually want in the end. If just smooth after a cut as the title says, a simple hand file would do but then you start talking about welding rod and split line and things get confusing (at least to me). To weld split brake line on the edge of sheet metal is a pretty big job. Not at all something I'd do with a Mig and to Tig those two items together takes a pretty good hand. Even when done welding your going to have finish work to do.
Weld on solid rod. Brake lines are often an alloy that won't like welding, and they are damned thin. Strike an arc, and you are likely to vaporize it.
Forming a wire edge is the best way But you need to plan for that before you cut it A solid wire 3/16 or a 1/4"'welded onto the edge would've been easier than brake line. Can you fold it over like a door skin? With a wire in the fold
Nothing to it. Start with brake tubing that is plated, not painted or plastic coated. Bend it to the shape of your panel edge first because you will screw up the split if you try to do it afterward. Bending after it's split will open or close the slot and cause the tube to not be round anymore. After you're happy with the shape, grind a slot through the inside face of the tube with a thin cutoff disc in a die grinder. Take your time and you'd probably better make a line to follow. Holding it still is the problem. I would make a little V block from a piece of scrap wood and a table saw (or Skilsaw) a foot or so long and clamp that to your bench, in a vise or on a saw horse. Whatever it takes to hold it solidly. Then an assistant with leather gloves and a face shield can hold the tube with his/her hands and move it along as needed while you grind the slot. Clean the body panel and the tubing to bright metal. Slip the slotted tube over the edge of the panel and solder it in place. A small propane torch or big assed electric soldering iron will work well. Your assistant can hold the tube in place with the tip of a big screwdriver. I would solder it continuously the entire length to keep water out. Maybe let the tube fill with solder. Acid core would probably work well because it cleans the metal very well. Like I said, nothing to it.
There is actually a tool for doing this with. Henry did it to the Model A fenders. Not sure what year he stopped doing it. It didn't work very well. Like 31 Vicky said, planning ahead is always good.
Rather than a V block, clamp 2 blocks together and drill a hole the diameter of the tube through the split line. Sand enough off the adjoining surfaces so they will hold the line firmly without deforming it.
Years (decades) back we cut the wheel openings on my friends car for large tires. His dad helped us form and then split copper tubing to fit the rough edge. I recall the tubing was soft and I think it was used in house A/C installs. Anyway, we soldered it in place using flux, flux core solder and a propane torch. It seems to me the tubing was 3/8 diameter. We split it on a tablesaw feeding it slowly so we could control it.
That's a great idea if your tube is straight. However, the slot has to go in after the tube is formed to fit the body. Large curves don't matter, but a small radius bend (10 inches or less) will change the slot and make the tube out of round if slotted first.
You could try this from McMaster-Carr. I've used it on a couple things, and it works great, especially if it's a temporary solution. https://www.mcmaster.com/#sheet-metal-edging/=a7013a0628f942c28d7f2f8c6cf4ed07jyvyjwbo Roger
I would make a new lower panel with a bead roller and use wire like Henry did on his fenders and leave about 2" on the top. After I was satisfied with the shape of the bottom roll, I would set it over the cut area and scribe a line with the new panel overlapping the old panel, trim to the line and weld in like you would a Lower door panel patch. Tack it in and slowly weld between the tacks while using a hammer and dolly to keep the warp age down.
What are you trying to achieve, if you want to just stiffen the edge; take a piece of 1/4" bar stock, saw a slot into the about 1/4" deep, work around the edge bending it under a little at a time, finish up with a hammer and dolly; if you want a decorative beaded edge like a bead roller would do, make some mini dies (kinda like pullmax dies) and weld them to a pair of vice grips, again go around the edge adjusting the grips tighter each time until your shape is place and finish with a hammer and dolly.
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