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3-19-05 Last week I left the test piece in my heat treat oven for 1 hour at 175F and there it sat all week. It’s warming up here in the spring so the garage has been in the 20’s and 30’s. I brought the piece in to whack it. The Devcon 5 minute epoxy half failed. You can see 1/2 of it broke off, the other half is still hanging in there. All the others took the beatings. Then I threw the whole thing in the dishwasher. This is where I had to explain what I was doing to my wife. Even with all the goofy things I tend to do, this one still forced her to ask why I was doing this. To see which one holds the best was my answer. After the dishwasher cycle, I took the piece down and whacked it some more. Keep in mind, this is all with a large framing hammer and I have long since stopped tappjng these things I am giving them 3 or 4 good thumps each time. Two more failures to report, the Permatex and T-88 epoxies both fail. The Permatex came loose in the dishwashwer, the T-88 got tired of getting beaten.
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The T-88 failed by 3/4ths. A quarter of the test piece is still attached and I’ll leave it that way just to see how long it goes. The leaders at this point are Acra Glass, Golfsmith Shafting epoxy and oddly metal superglue. The polyurethane glues, I believe will with stand all of the tests better than any of the others but it appears to be a dreadful product to work with on a knife - it’s fine for wood working.
I also tested 324 Loctite Speedbonder with two metal pieces with sandblasted surfaces like the previous tests with PC-7. The Loctite held 100lbs (!) until the metal stated to bend and I started moving things around to stop the metal from bending completely over. I was torn between running for my camera or stopping the metal from bending. I didn’t run for the camera, I should have. Once I moved it around the bond popped but it was amazing. I immediately glued up another test set and will try to get a picture of this time.
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3-21-05 Here is what the test piece looks after it has been cooked, frozen, dishwashed pounded and now boiled for an hour and half. The body count rises on glue failures. After boiled, we lost JB Weld, Super Glue Metal epoxy and the clinging partial pieces of T-88 and Devcon 2 ton 5 Minute epoxy. The two metal pieces you see were glued up with Loctite 324 at a 90 degree angle and then load tested. This little 1” square lap joint held 100lbs for 45 seconds before it bent over and the joint peeld to failure. I still couldn’t get a picture of it holding the load so you will have to settle for the broken pieces.
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3-21-05 We still make knives while we fool around testing epoxies. Here is the Singapore Dagger getting ready for some drilling. The pattern is 1/16” barely held up to the drilling. If you look closely at the holes in the pattern, you can see what is a hard lesson to learn at first, most holes are not round, they are a 3 clover leaf looking affair. The holes in the pattern clearly show that. To get around this, you have to drill a slightly smaller hole and then using a reamer, ream the hole to the proper size. I had several holes to drill and then slightly counter sink to keep stress risers down during heat treat so I had all three drill presses going on these tonight.
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Most of the time, the holes kind of go where the mood takes me for aesthetics, this knife is symmetrical so the holes had to be precise (in the handle, not in the bolster). After getting them close with the pattern, I measured from the top and the bottom to find dead center using the digital caliper, then auto punch and then center punch to drill exactly where the holes needed to go. Once one is done, I can use the first completed one for a pattern to drill the other three.l
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3-21-05 These are going off to Paul Bos for heat treat in the morning. There are 8 folder blades on top that are drilled and profiled. They will be ground in the hardened state. I’ll have to keep the temperature down below 400F when I grind so I don’t soften them up. Now looking at the daggers, these are all from the same pattern. There are two more almost like these in the trash that I wasn’t satisfied with on the grind.
Lets look at the what we get using different thickness stock and different size wheels.
From the bottom, .2” stock using an 8” wheel for the top and bottom grind. Second from the bottom, the Singapore commission blade using .185” stock using 8” wheel top and bottom - the bottom grind has been ‘stretched’ a bit. What this means is a typical 8” grind would be a little narrower. Basically, you stretch the grind a little by rolling the knife into the grinding wheel. The effect is very much like that of a 10” wheel. This grind is in keeping with the clients specs. Third from the bottom, a 10” wheel bottom grind, 8” wheel top grind. You can compare the 8” and 10” grinds and find they are very close in width but also notice how much deeper the grind looks on the .2” stock versus the .185” stock. Fourth from the bottom is 10” wheel grind.
The bottom blades edge and point are very thick and stout. When this one is completed, you could easily pound this one through car door with little, if any damage.
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