Coring, tolerances?

Someone asked, "what can we talk about next?"

How about grain fillers? What's your favorite finish?

That someone was me in a halfheartedly joking manner. Start a new thread and let the volunteers who are willing join the party.
This thread has probably over run its course so wide its like the Mississippi flooding Colorado mountain property. :wink:
 
Those of you who do tapered cores, could you post pictures of your setup?
A 12" boring bar sounds very strange, but they might exist I guess.
 
Since I'm an inexperience know nothing I was hesitant to post what I do but I haven't seen it mentioned in all the threads I've sifted through in the archives. I decided to do it like this through my own trials.

I core to a blind hole at the joint end of the forearm and use west systems. I am not using a stepped core. Stop the gun drill and leave around 1/4-1/2 inch closed at the end. Added benefit, you don't have to worry about blowing out the end because it's not popping through. Cut a spiral glue relief groove from end to end of the snug fitting core and a couple length wise ones. LIke DZ does in his coring video. Put a dab of silicone sealer into the center on the core to maintain it for later. Pour a bit of the thin epoxy into the bottom of the hole with it standing up. Put the core in and slowly just screw it to the bottom of the hole as the glue works it's way up the relief grooves and distributes around the core. It takes a few minutes to get it "screwed" to the bottom of the hole all the while the glue is rising up and distributing itself over the length of the hole with no dry spots. How fast it goes depends on the size of the relief grooves. Then just leave it standing up to dry. Then part off the end and find the center in the core at the joint end and clean the silicone out of it. If I'm alive in 20 years I'll report back on it's long term durability. I have cut up some mocks and the glue bond appears to be complete. The possibilities of dry spots doing it like this IMO is non existent as the glue level is rising up from a reservoir at the bottom and soaking the wood as it goes.

If someone smarter than me can point out the flaw in this technique I would not be offended in the least. I have a hard time distinguishing sheep shit from shinola on most days anyway.:smile:

JC
 
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Since I'm an inexperience know nothing I was hesitant to post what I do but I haven't seen it mentioned in all the threads I've sifted through in the archives. I decided to do it like this through my own trials.

I core to a blind hole at the joint end of the forearm and use west systems. I am not using a stepped core. Stop the gun drill and leave around 1/4-1/2 inch closed at the end. Added benefit, you don't have to worry about blowing out the end because it's not popping through. Cut a spiral glue relief groove from end to end of the snug fitting core and a couple length wise ones. LIke DZ does in his coring video. Put a dab of silicone sealer into the center on the core to maintain it for later. Pour a bit of the thin epoxy into the bottom of the hole with it standing up. Put the core in and slowly just screw it to the bottom of the hole as the glue works it's way up the relief grooves and distributes around the core. It takes a few minutes to get it "screwed" to the bottom of the hole all the while the glue is rising up and distributing itself over the length of the hole with no dry spots. How fast it goes depends on the size of the relief grooves. Then just leave it standing up to dry. Then part off the end and find the center in the core at the joint end and clean the silicone out of it. If I'm alive in 20 years I'll report back on it's long term durability. I have cut up some mocks and the glue bond appears to be complete. The possibilities of dry spots doing it like this IMO is non existent as the glue level is rising up from a reservoir at the bottom and soaking the wood as it goes.

If someone smarter than me can point out the flaw in this technique I would not be offended in the least. I have a hard time distinguishing sheep shit from shinola on most days anyway.:smile:

JC

I am not a very experienced cuemaker either but this technique sounds good to me. I will do a test using your technique on some poplar dowels. Poplar should suck up thin epoxy pretty good. If there are no dry spots on poplar, I would think it would work for all other hardwoods.
 
Ok, good luck with that.

Can you suggest to me a better material for that purpose?

Also I forgot to mention that as you're screwing in the core and the glue is rising up the inside any soft spots will fill up from the pressure. Sort of a stabilization if you will. I have cored some curly myrtle, birdseye maple and claro walnut that started sweating beads of epoxy on the outside in a few spots. Especially at the curls. It builds enough pressure to fill the voids and pores but not split the wood. Isn't this how wood is stabilized basically?

This can't be a bad thing can it?

I'm asking, not opining.

JC
 
Can you suggest to me a better material for that purpose?

Also I forgot to mention that as you're screwing in the core and the glue is rising up the inside any soft spots will fill up from the pressure. Sort of a stabilization if you will. I have cored some curly myrtle, birdseye maple and claro walnut that started sweating beads of epoxy on the outside in a few spots. Especially at the curls. It builds enough pressure to fill the voids and pores but not split the wood. Isn't this how wood is stabilized basically?

This can't be a bad thing can it?

I'm asking, not opining.

JC
Put a piece of masking tape over the end instead of the silicone.
Or just put nothing on it and poke a new center in it once you cut off the end would be the easiest way. A good dial indicator and decent technique will get that done for you.
Personally, I wouldn't want any silicone around any of my wood for any reason.
Dry or not dry.
 
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I'm pretty sure he means silicone sealer, not silicone spray. RTV would do the same thing. Masking tape? FAR to easy. :)

Silicone spray...EEEK!

Robin Snyder
 
I'm pretty sure he means silicone sealer, not silicone spray. RTV would do the same thing. Masking tape? FAR to easy. :)

Silicone spray...EEEK!

Robin Snyder

Masking tape will not stay put for the pushing and twisting required to work the glue up the core. Yes of course I mean RTV. Just a dab of gasket maker. How would silicone spray keep the center clean?

When you cut the end off the solid blob of it looks just about the same as last time you saw it. Just a tiny bit to pick out of the center hole. I know I could recenter the forearm but I just felt it's better for the core to remain the true center if possible in case the gun drill walks off center at all by the end. I'm just learning by trial and error.

JC
 
.....Yes of course I mean RTV. Just a dab of gasket maker. How would silicone spray keep the center clean?

jC

I get it, but I think others thought you were referring to a silicone lubricant, obviously a terrible idea.

Robin Snyder
 
Masking tape will not stay put for the pushing and twisting required to work the glue up the core. Yes of course I mean RTV. Just a dab of gasket maker. How would silicone spray keep the center clean?

When you cut the end off the solid blob of it looks just about the same as last time you saw it. Just a tiny bit to pick out of the center hole. I know I could recenter the forearm but I just felt it's better for the core to remain the true center if possible in case the gun drill walks off center at all by the end. I'm just learning by trial and error.

JC

Super glue a teflon or delrin disc them.
Make sure you have wax on the center hole.

Good luck.
Joey~Thinks Dave B. started a treasure hunt and he's laughing about it~
 
Super glue a teflon or delrin disc them.
Make sure you have wax on the center hole.

Good luck.
Joey~Thinks Dave B. started a treasure hunt and he's laughing about it~

Or just melt wax into the center. I like that even better. Thanks Joey

JC
 
Can you suggest to me a better material for that purpose?

Also I forgot to mention that as you're screwing in the core and the glue is rising up the inside any soft spots will fill up from the pressure. Sort of a stabilization if you will. I have cored some curly myrtle, birdseye maple and claro walnut that started sweating beads of epoxy on the outside in a few spots. Especially at the curls. It builds enough pressure to fill the voids and pores but not split the wood. Isn't this how wood is stabilized basically?

This can't be a bad thing can it?

I'm asking, not opining.

JC

I have not read all the posts on this. But my way of filling the center hole is to wad up a small piece of paper towel and stick it in the hole. I pull it out after the core is in. That keeps the hole nice and clean so my center is maintained.
 
Masking tape will not stay put for the pushing and twisting required to work the glue up the core.

JC

I disagree, but if you're worried, a couple drops of water thin cyno on the edge of the tape will take of that.
If you're worried about the tape caving in at the center hole, your center hole is too big.
A #0 60 degree center is more than enough.
 
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