A prototype

[Big Don]

So, I had half a sheet of diamond plate aluminum sitting in the back yard for the last few years. I decided to make a training knife out of it. I traced a training knife onto the flat side of the diamond plate and cut a number of blanks out. I matched two up and epoxied them together. I considered holding it together with pop rivets. I thought about giving it a really good polishing, then I noticed that if I took my time with the wire wheel, the aluminum got a nice satiny looking finish to it. Here is a pic I took of it by the simple expedient of laying it on my scanner:

What did I do wrong? How much would it cost to have someone heli-arc the seam? What do you think? Dumb idea? Brilliant? This is not the finished product, just a rough prototype.

 

[elder999]

What did I do wrong? How much would it cost to have someone heli-arc the seam? What do you think? Dumb idea? Brilliant? This is not the finished product, just a rough prototype.

Without handling it, I can't say what you did "wrong." I can think of a couple of things that I might have done differently. If the scan's actual size, it looks pretty good.

If you don't think your diamond plate is thick enough, you should probably just go and get thicker plate, rather than trying to join two pieces, but it is what it is.

You don't want to heli-arc or TIG the seam, you want MIG or wire welding. People carp about whatta ***** it is to weld aluminium, but it's not that hard with a MIG, really-just takes some practice-high wire speed and highest voltage setting, with a forehand push. Needless to say, I wouldn't have epoxied at all, but probably welded the whole thing....bwahaha haha, and all that. If you can't weld, then no, it probably isn't worth having someone weld it for you, unless you know someone who'll do it for free. There is an alumium brazing rod that you can use with a Prestolite (propane torch) but I've never used it-sounds like it might be perfect for your application, though.

Since you did epoxy it, you might try peening and lightly grinding the seam over-especially since this is an in-progress experiment, but that might just give your practice blade some sharpness, or bust the epoxy bond.

When I really got into making blanks, I started drawing and cutting "lasts",patterns on wood or leather that I can trace a blank out on with a scribe or marker. You might try this-you can cut a couple of those until you have a shape or variety of shapes that are satisfying.

How did you cut the aluminium? After you trace the patern from the last, you should drill starter holes along the traced lines, and maybe cut with a sawzall or hacksaw.

If you don't think your diamond plate is thick enough, you should probably just go and get thicker plate, rather than trying to join two pieces-or use the aluminium you have and fashion epoxy or wood handles for the blades-with diamond plate, I'd probably go with making some sort of mold and liquid epoxy that could be poured-or even some of that "dip-grip" stuff that they use on tools.

Not too bad, though, Don.

 

[Big Don]

Thanks Jeff.
One of these days I have got to learn to weld...
The scan is actual size, for some reason, the picture is not. Don't know how I managed that... The grip just fits my, fairly large, hand.The Plasti-dip stuff... I've used on tools, it isn't the greatest, imho. I may wrap the grip with 550 cord, I found a youtube video that shows how to do it. The plate was too thin to use one piece... I also wanted the diamond plate pattern on both sides. I cut it with a jigsaw, the first time I had used a jigsaw since the eighth grade, 25 years ago, and the first time I ever tried cutting metal with a jigsaw. Well, I went through a 10 pack of blades, but, they were cheap, and I did cut ten pairs of blanks to put together. Aside from the seam, which is more visible than I prefer, I'm not too unhappy with it. I thought about using pop rivets to join the pieces but there is always a small tit that is left and I'd rather not accidentally hurt someone. (doing it on purpose is fine)
I am going in search of the aluminum brazing rod tomorrow, locally.