Polishing a taper jig hole.I

[just bill]

I've made a burnt out 6 cavity mold into a tapered core mold/jig. I do not know the beset way to polish it. Thought about valve grinding compound and a tapered wood or plastic dowel rod. Any guidance?
Thanks
Bill

[WallyM3]

I have done similar jobs with 0000 steel wool slathered with progressively finer grit lapping compound. The steel wool gets snagged on an arbor (in my case in the tail stock) and introduced into the cavity to be polished. The wool conforms to the cavity. With a 6-cav mould, I'd probably rotate the arbor and hold the mould fixed.

[just bill]

Thanks, the arbor is the one thing that makes me scratch the bald spot. I've never really used them for metal finishing or actually done any metal surfacing except honing brake cylinders or things I could attach Emory cloth to and spin on the end of a drill. Would you use a ridged tapered Dowell or something slotted in about 3/16. The taper is .35 to .25 over 1" roughly.
Thanks
Bill

[WallyM3]

There are a couple of options that come to mind that might work well. The first might be the easiest to gather up. Dremel makes a shank (probably in more than one size) that has a tapered screw thread on the end to grab felt wheels and such. There's not a lot of force required in your job (as there work be in milling or drilling) so their 1/8" shank would probably suffice and give you plenty of clearance.

What I envision happening is packing the lagging compounded wool into the mould cavity, screwing the shank into this compacted mass and commencing to turn. I think with a couple of tries, you'd get a sense of how much more the wool would compact under powered rotation and could adjust the amount of wool and your technique accordingly. I suppose even a wooden dowel with some sort of "grabby" surface would work. Perhaps using a very coarse sand paper to taper the dowel would provide a rough enough surface.

One thing is sure...that wool would fetch up around a rotating shaft if you didn't want it to. And rags...and abrasive paper...even brush bristles.

[just bill]

I went to "THE BOX" and found some old brass brass cleaning brushes, they would grab the steel but good. There is a cleaning wad with wool or a cotton wad over a brush , used to be brass off to the gun shop gotta get a new toy.
Bill

[WallyM3]

Perfect!!!

[just bill]

I think the brass brush, green pad, chrome polish did the trick. No steel wool, don't know what happened to it.
I will try to mold some cores tomorrow, thanks to Deputy Dog 25.
Bill