walleye warrior Posted November 3, 2012 Report Share Posted November 3, 2012 i need gto drill 1/16" hole through a 1oz. bell sinker, i have tried standard drill bits but they keep snapping. anyone have any sugestions? i need to due this 100's of times so buying hundreds of bits is not an option Quote Link to comment Share on other sites More sharing options...
Seeking 56 Posted November 3, 2012 Report Share Posted November 3, 2012 Try a cobalt bit, they're used to drill in stainless steel. s54 Quote Link to comment Share on other sites More sharing options...
Kasilofchrisn Posted November 3, 2012 Report Share Posted November 3, 2012 I drilled out a few dozen egg sinkers this year to Texas rig some duck decoys. I had to make the hole larger to accomodate the decoy line. I found I needed to add a drop of oil to each one to make it work. No cobalt bit needed. The lead easily gets hot and binds the bit up and it snaps. Buy an eye dropper and the cheapest motor oil you can find or have leftover in your garage. One drop per hole should solve your problem. Quote Link to comment Share on other sites More sharing options...
defish Posted November 3, 2012 Report Share Posted November 3, 2012 Lead is really "grabby" to drill as you found out, and it's going to be especially tough drilling it with such small bits. You can try grinding a "chisel point" edge on the cutting flutes of your bit (essentially flat spots instead of the usual cutting angle) so that the drill doesn't pull itself into the lead faster than you want. It works for brass, but I've never done it with lead. If these are sinkers that you cast yourself, it would be a LOT easier to modify your mold to use a 1/16 dia insert rod, than to drill the sinkers. Good luck. Dan Quote Link to comment Share on other sites More sharing options...
sdsaw Posted November 3, 2012 Report Share Posted November 3, 2012 The reason the drill bit is breaking is that the flutes are filling up with chips and the binding up and snapping off. A standard high speed drill should be fine. What you need to do is "pump" the bit in and out of the hole as you are drilling to clear the chips from the flute. A drill press would easier than a hand drill using this technique but a hand drill still works. Make sure that the chip is releasing from the flute before re-entering it back into the hole. WD-40 works good as a cutting lubricant. The trick defish mentioned (grinding the angle off the cutting face) works good on brass, PVC and acrylic plastic because it helps to prevent the drill from suddenly spiraling down as it is cutting Quote Link to comment Share on other sites More sharing options...
walleye warrior Posted November 4, 2012 Author Report Share Posted November 4, 2012 I drilled out a few dozen egg sinkers this year to Texas rig some duck decoys. I had to make the hole larger to accomodate the decoy line. I found I needed to add a drop of oil to each one to make it work. No cobalt bit needed. The lead easily gets hot and binds the bit up and it snaps. Buy an eye dropper and the cheapest motor oil you can find or have leftover in your garage. One drop per hole should solve your problem. thank you i am going to give it a shot today, i will update on how it works out Quote Link to comment Share on other sites More sharing options...
walleye warrior Posted November 4, 2012 Author Report Share Posted November 4, 2012 Lead is really "grabby" to drill as you found out, and it's going to be especially tough drilling it with such small bits. You can try grinding a "chisel point" edge on the cutting flutes of your bit (essentially flat spots instead of the usual cutting angle) so that the drill doesn't pull itself into the lead faster than you want. It works for brass, but I've never done it with lead. If these are sinkers that you cast yourself, it would be a LOT easier to modify your mold to use a 1/16 dia insert rod, than to drill the sinkers. Good luck. Dan an insert rod and modification was going to be one of my options, potential problem is i powder coat after i cast them and i believe i would either have to keep the insert rod in and having it stick or redrill through the hole to open it back up. both are options that i need to explore Quote Link to comment Share on other sites More sharing options...
walleye warrior Posted November 4, 2012 Author Report Share Posted November 4, 2012 The reason the drill bit is breaking is that the flutes are filling up with chips and the binding up and snapping off. A standard high speed drill should be fine. What you need to do is "pump" the bit in and out of the hole as you are drilling to clear the chips from the flute. A drill press would easier than a hand drill using this technique but a hand drill still works. Make sure that the chip is releasing from the flute before re-entering it back into the hole. WD-40 works good as a cutting lubricant. The trick defish mentioned (grinding the angle off the cutting face) works good on brass, PVC and acrylic plastic because it helps to prevent the drill from suddenly spiraling down as it is cutting thanks for the reminders, with my impatiance i forgot to go back to the basics and go through proper steps thanks to all for the input, got a lot of great ideas and some remiders of the basics from you all, thats what makes this site great!! Quote Link to comment Share on other sites More sharing options...
defish Posted November 4, 2012 Report Share Posted November 4, 2012 an insert rod and modification was going to be one of my options, potential problem is i powder coat after i cast them and i believe i would either have to keep the insert rod in and having it stick or redrill through the hole to open it back up. both are options that i need to explore There are a couple of easy ways to deal with powder paint getting into the sinker's hole. You can heat a nail, etc. that's a bit smaller than the hole and poke it through the hole to open it, and / or you can make an "eye buster" type tool to remove the paint if it's just around the outside of the openings. If you are going to make "hundreds" of these sinkers, a few minutes spent modifying the mold, etc. will save you a LOT of time in the long run instead of drilling them. Good luck. Dan Quote Link to comment Share on other sites More sharing options...
mark poulson Posted November 5, 2012 Report Share Posted November 5, 2012 How about just buying some 1oz. slip sinkers like we use for Texas rigging? Quote Link to comment Share on other sites More sharing options...
ING Posted November 5, 2012 Report Share Posted November 5, 2012 IMHO cutting tip of yours bit is too sharp. ( I mean the angle). The bit penetrating in the lead too fast and stack. If you could make it more obtuse on the soft grinding stone it should help: you will get less flutes especially in combination with oil and frequent flute cleaning. Quote Link to comment Share on other sites More sharing options...
