When building roll cages and frames I like to fishmouth the ends of the rods and tubes for a cleaner fit and a better glue joint. However I have a difficult time getting the fishmouths centered in the ends of the tube (.080 and .100 size). I also have a difficult time getting each end fishmouthed on the same plane, in other words they are quite often a few degrees off from being parallel with each other. I use a small round jewelers file for this work. Does anyone have any ideas on how to get better, more even fishmouths?
Rick, it may not help you much but I use a round file, maybe a chainsaw file, the same Dia. as the tube I am using. I lay them both flat on the work surface and move the tube along the file until I get the cut I need. I check the fit or angle often while doing so. I mark the tube much the same way you would if doing the real thing. I hope this makes sense, I don't have a pic.
I don't use tube for starters, I use rod instead. I cut it with a rotary leather ponch, and clean it up with a round needle file. I give the joint a coat of ProWeld liquid cement, let it sit a few minutes, give it another light coat, and push it together until the softened edges bulge a little to form the welding seam.
Olderndirt
These are some good tips. Will give them a try when I get back on the bench. I especially like the idea of the "double-glue" in order to get a weld seam. That will definitely come into play when I build the cage and other tubing on my no-fender convertible racer.
I to use rod and also had the issue with the fish mouths not being in the same plane! I tried taking a piece of wood and filed a grove into it, then file a V notch at the end of the grove and took a small nail and pushed it into the grove so the rod is a little above the edge of the wood into the V notch. I then fish mouth one end of the rod cut to length then put the rod in the grove , fish mouth against the nail with the cut end a little above the end in the V notch hold the wood with the rod and file the new fish mouth, both ends line up! You will have t6o move the nail for different length bars. Enjoy
Rich
I use .080 rod. I start by making a center cut on the end (by eye) with a fine blade razor saw. I take the blade out of the handle and use just the blade, so I can control it better. Next I use a very small triangle file to enlarge the saw cut. Then I use a round file, one size smaller than the tubing to finalize the fish mouth. To achieve the weld bead look, I apply Elmers white glue, sparingly around the joint.
Maybe not the best way but it works for me.........