G'day Tom,
OK... I was just trying to get away from typing it all out, as I only have it as hard copy.
The following is a reply by Walt Galer regarding making your own chain loops.
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Howdy,
Looping your own chain is not as easy as it looks, and even a lot of dealers do not do it correctly. It is a fact, that most loop failures occur at the dealer or field made loop joint. This is why factories like to colorcode their loop joint tiestraps. Then they can be sure, and demonstrate if needed, that the failure occured where someone else fooled with the chain!
To avoid weakening the cahin at your joint you have to:
1. Be very careful when breaking the chain off the reel, or taking apart a pre-existing loop. With a hand breaker block, you must have the tiestrap on the bottom, pushed fully up against the top of the breaker block at all times. The block only gets hold of a very small area at the top of the drivelink, and this is easily cut or bent by the breaker block, grossly weakening the chain.
When punching the rivet, you use a punch with a blunt end about 1/16 inch dia. It should just penetrate into the rivet head a very little bit, so as not to slide off. You then firmly tap the punch, just dimpling and starting the rivet. You then go to the other rivet and do the same. You go back and forth ideally a couple of times taking the preset sidelink part out carefully, and keeping it from bending. You should follow this proceedure even if using a bench press and breaker setup. (Most people dont and just force the part out, which is one reason why the failures).
2. When riveting, the procedure is critical. If you just spin with the bench spinner, you form a beautiful head, but do not expand the rivet in the sidelink holes and so you are going to have loosening rivets, and cracked sidelinks eventually. If you just pound with the flat of the hammer, you do exactly the opposite and overexpand the rivet in the rivet hole, creating an extreme hoop [sic] stress, that will again lead to cracked sidelinks, and chain loop failure. Correct hammer riveting procedure is very difficult for most people. You have to strike the rivet with the flat of the hammer just enough to begin to expand the rivet enough that the sidelink wont fall off. The opposite side must rest on a good solid steel surface. (Very difficult if just on the side of the little breaker block on a stump!) Next step is to use the peen end of the hammer (yes, you HAVE to use a correct size ballpeen). You strike the center of the rivet first, then go slightly off center, running around the rivet circumference. This requires more co-ordination than most people have! The idea is to expand the rivet using the flat of the hammer and then form the head with the peen. The peen only expands the rivet when you strike on center.
With the bench spinner you get the expansion correct, by aggressive use of the take up handle. Take up 1/4 turn after bottom. Turn the spin/crank ONE TURN. Keep repeating this sequence until the spun head is almost flush with the sidelink. At the last, take a couple extra turns on the spin crank, just to make the head look nice. If you overdo it, you crack the spun edge, a defect called a "torn flange".
I would estimate that 75 to 80 percent of dealers do not do this correctly, and that is why about that percentage of cahins fail at the loop joint!
Regards
Walt Galer
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OK, there it is. Thanks Walt for the advice!
Cheers
Charlie.
