Quote:
Originally Posted by BLT
Some of my molds call for a #1 or a 1/0 hook. I like to use the larger hooks and they have a hard time filling around the hook shank, and the barb does not come out right at times. would/could this help with that? The smaller hooks pour great. I have the same issue with 2 of my Hilts bullet head molds not making a good barb on them.
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I suspect your fill-out problem probably would not be solved with this technique. But I think there is an easy solution.
I also like to use larger hooks in some of my molds. Two problems present themselves immediately when using a larger hook.
First, the larger hook draws more heat from the lead as it fills the collar/barb area. It's important that the larger-sized hooks be warmed up slightly (not
hot, but warm) before being placed in the mold. Seems like a small thing, but it can make a big difference.
And second, the smaller hook has a small gap (tolerance) between it and the hook channel. That gap allows air to vent from the mold. 1/1000" is equal to
fifty-thousand air molecules stacked side-by-side, so a tiny gap can be critical, and vent a lot more air than you might have imagined. When the larger hook is placed in the mold, you lose that very tiny vent (gap) and the lead cannot flow fully into the collar/barb area before it starts to freeze-up. That prevents the barb from filling-out.
The 1st remedy is to (if your mold design allows it) drill out the hook channel with a wire-guage drill 5 thousandths larger than the diam of your larger hook. This needs to be done carefully, but is fairly simple. If done properly, it should not preclude useing the smaller hook. I have done this to a few of my molds, and it works fine.
The 2nd remedy is to scratch a vent line on the surface of the mold (not in the cavity) from the tip of the barb to the nearest edge of the mold. That slight groove will vent the trapped air and allow the barb to fill before the lead freezes.
One of these solutions should make your molds pour great with the larger hooks. Smoking the collar area makes a noticeable difference too. Hope this helps, good luck!
