I attached the glue block with carpenter's glue. What is the best way to part off the glue block?
-
We just finished moving the forums to a new hosting server. It looks like everything is functioning correctly but if you find a problem please report it in the Forum Technical Support Forum (click here) or email us at forum_moderator AT aawforum.org. Thanks! -
Beware of Counterfeit Woodturning Tools (click here for details) -
Johnathan Silwones is starting a new AAW chapter, Southern Alleghenies Woodturners, in Johnstown, PA. (click here for details) -
Congratulations to Dave Roberts for "2 Hats" being selected as Turning of the Week for April 22, 2024 (click here for details) -
Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.
parting off the glue block
- Thread starter Christa Schlegel
- Start date
- Joined
- Aug 31, 2006
- Messages
- 317
- Likes
- 115
- Location
- Montgomery, TX
- Website
- www.gulfcoastwoodturners.org
Use thin (1/16") parting tool to reduce glue block diameter adjacent to bowl bottom to +/- 1/2". Remove glue block from chuck. Finish parting glue block from bowl with thin saw (Stanley Fat Max Flush Cut Pull Saw, 20-331, https://www.stanleytools.com/product/20-331/stanley-fatmax-flush-cut-pull-saw). Sand/carve bottom of bowl to remove remaining glue block nub. - John
You may want to consider the paper glue joint technique as alternative work holding strategy.
Many will use a piece of brown grocery bag paper between the waste block and the bowl. If you have one of the painter's helper tools, it is simple to tap that into that joint and get it to separate on the glue line, Then just sand the bottom of the bowl. You can use a thin parting tool, and open up a double wide kerf. Or a wider parting tool, but you will probably still need a wide kerf.
robo hippy
robo hippy
- Joined
- Apr 27, 2004
- Messages
- 8,642
- Likes
- 4,985
- Location
- Lakeland, Florida
- Website
- www.hockenberywoodturning.com
You can part in a little with a thin tool then use a saw.
Lot easier to catch a stationary bowl than one that’s spinning.
Also be sure you don’t have a sharp edge on the rim. It can cut you while stationary so you know it can do damage spinning.
I use thick CA glue. Only works if you don’t get catches.
Will hold a wet blank too
To remove a flat chisel tapped against the glue joint will fracture the glue.
You’ll turn the glue of the piece finishing the bottom
The turn the glue off the glue block to reuse it.
Lyle Jamieson showed me this around 2000. He has a nice video on YouTube
Lot easier to catch a stationary bowl than one that’s spinning.
Also be sure you don’t have a sharp edge on the rim. It can cut you while stationary so you know it can do damage spinning.
I use thick CA glue. Only works if you don’t get catches.
Will hold a wet blank too
To remove a flat chisel tapped against the glue joint will fracture the glue.
You’ll turn the glue of the piece finishing the bottom
The turn the glue off the glue block to reuse it.
Lyle Jamieson showed me this around 2000. He has a nice video on YouTube
Last edited:
When making a paper joint use Elmers white glue.
Split the paper and clean up with a wet rag.
Split the paper and clean up with a wet rag.
Dave Landers
Beta Tester
I'll add to what others have said...
Use a parting tool to get down to a fairly thin nub. Doesn't have to be a thin parting tool if you don't have one - whatever ya got. You have plenty of glue block to work with, so you could even turn it away with a bowl gouge (but there won't be much left of the glue block for another bowl).
You might be tempted to part it all the way off, but there are two risks 1) it'll break as it skids across the shop floor - or, 2) the nub will twist at the very end of the cut and pull fibers out the bottom of the bowl. Neither is very rewarding. So the safe thing is to cut it off.
There's no magic saw necessary - I use a hacksaw with a regular hacksaw blade. Because I've got one and never wanted to spend money on anything else. (If you expect that saw cut to be a finishing cut, then you need more magic than a hacksaw can provide).
Once its off the lathe, you'll want to clean up the bottom. That can be as basic as attacking it with a sander. Or you can reverse-mount the bowl in cole jaws or a vacuum chuck or a jam chuck or etc and turn the bottom foot.
Use a parting tool to get down to a fairly thin nub. Doesn't have to be a thin parting tool if you don't have one - whatever ya got. You have plenty of glue block to work with, so you could even turn it away with a bowl gouge (but there won't be much left of the glue block for another bowl).
You might be tempted to part it all the way off, but there are two risks 1) it'll break as it skids across the shop floor - or, 2) the nub will twist at the very end of the cut and pull fibers out the bottom of the bowl. Neither is very rewarding. So the safe thing is to cut it off.
There's no magic saw necessary - I use a hacksaw with a regular hacksaw blade. Because I've got one and never wanted to spend money on anything else. (If you expect that saw cut to be a finishing cut, then you need more magic than a hacksaw can provide).
Once its off the lathe, you'll want to clean up the bottom. That can be as basic as attacking it with a sander. Or you can reverse-mount the bowl in cole jaws or a vacuum chuck or a jam chuck or etc and turn the bottom foot.
I'm assuming your bowl has a flat bottom and you glued the whole surface? Using wood glue, wood to wood, (with nothing in between) they are now one with each other.
I'm thinking the best way to remove it is to put it back between centers and turn away the bottom. Put a scrap of wood (similar in size or a bit smaller than your glue block) with a tenon in your chuck. Turn it flat and give the edges a nice, radiused edge where it touches the inside of the bowl. You need something to protect the inside, but also with enough friction to "drive" the bowl. (a patch of leather works well, but you could probalby put a couple layers of masking tape, towels/cloth, etc.) Then you bring up the tailsock and pinch lightly until you get it centered. Then you want to tighten it enough to allow some cutting action, but not so tight that you crush the bowl. (as you cut away the glue block, the remaining structure will be just your bowl, however thin you've made it.
Take some good measurements to find how much thickness there is at the bottom of your bowl. (how far above the glue joint) Your glue jount will be the bottom of the foot, (I doubt you want to take away any more than that) and hopefully you can cut beyond the glue just a little more in the center. Your glue joint will help show you how much you can/need to take off. When you get to the point that it's just a small nub, (about finger size diameter) remove the bowl and chisel/grind/sand away the last of it. It sounds complicated, but you got this.
Last edited:
odie
TOTW Team
- Joined
- Dec 22, 2006
- Messages
- 7,117
- Likes
- 9,856
I have used newspaper between the waste block and bowl.
(Back in the days when we all still had a stack of newspapers on hand!!!!)
I have used a saw to cut away the last bit in the center, after using a parting tool.
These methods will work, but after a couple thousand bowls, I have long since established a routine of using a parting tool to bring the center down to about the size of a quarter, or so.....(maybe a bit larger for the biggest/heaviest bowls.) Normally, I take several passes so the parted gap width is increased to about 3/16".....just large enough to slip in an old drum brake adjusting tool. (see photo) While still mounted to the lathe, and by holding the bowl in one hand, and the brake adjusting tool in the other, a small tweak of the brake tool breaks the bowl free. Very easy to do, but do make sure you slip the brake tool in perpendicular to the grain of the waste block, and not parallel to it. It breaks free much easier with this orientation.
The bowl is re-mounted, and the thin slice of the waste block still, attached to the bowl, is then removed with either a scraper, or gouge.....depending on how you intend to shape the foot of the bowl.
-o-
These drum brake adjusters are cheap, and work well for this purpose...
(Back in the days when we all still had a stack of newspapers on hand!!!!)
I have used a saw to cut away the last bit in the center, after using a parting tool.
These methods will work, but after a couple thousand bowls, I have long since established a routine of using a parting tool to bring the center down to about the size of a quarter, or so.....(maybe a bit larger for the biggest/heaviest bowls.) Normally, I take several passes so the parted gap width is increased to about 3/16".....just large enough to slip in an old drum brake adjusting tool. (see photo) While still mounted to the lathe, and by holding the bowl in one hand, and the brake adjusting tool in the other, a small tweak of the brake tool breaks the bowl free. Very easy to do, but do make sure you slip the brake tool in perpendicular to the grain of the waste block, and not parallel to it. It breaks free much easier with this orientation.
The bowl is re-mounted, and the thin slice of the waste block still, attached to the bowl, is then removed with either a scraper, or gouge.....depending on how you intend to shape the foot of the bowl.
-o-
These drum brake adjusters are cheap, and work well for this purpose...
Roger Wiegand
Beta Tester
Reverse the bowl in the lathe using one of the dozen methods available to do that, turn the block away, shape the foot and bowl bottom to complement the bowl, both on the inside and outside of the foot (assuming your design has one) and perhaps add a decoration on the bottom of the bowl. Many turners never use anything else.
Holding methods vary with the shape of the bowl. A friction drive works with every shape I can think of and is extensively documented here and elsewhere. It will leave you with a small nub in the center that has to get pared off (off the lathe) and frequently interferes with the ability to get the profile you want on the inside of the foot because it limits tool angles. Methods that leave the bottom free to work on include a jam chuck, where you turn a recess in a piece of scrap that gives a snap fit to the rim of the bowl and will hold it without tailstock support (though you should keep the tailstock in place as long as you can), cole jaws and their variants (expensive),and a donut chuck (easy to make from scrap). These all want a uniform rim to work well. Finally, a vacuum chuck will hold a bowl independent of rim shape and gives full access to the bottom, with the downside of usually involving a several hundred dollar investment (home made variants on vacuum adapters, chucks, and using a venturi pump rather than a mechanical one can reduce that by a lot).
Holding methods vary with the shape of the bowl. A friction drive works with every shape I can think of and is extensively documented here and elsewhere. It will leave you with a small nub in the center that has to get pared off (off the lathe) and frequently interferes with the ability to get the profile you want on the inside of the foot because it limits tool angles. Methods that leave the bottom free to work on include a jam chuck, where you turn a recess in a piece of scrap that gives a snap fit to the rim of the bowl and will hold it without tailstock support (though you should keep the tailstock in place as long as you can), cole jaws and their variants (expensive),and a donut chuck (easy to make from scrap). These all want a uniform rim to work well. Finally, a vacuum chuck will hold a bowl independent of rim shape and gives full access to the bottom, with the downside of usually involving a several hundred dollar investment (home made variants on vacuum adapters, chucks, and using a venturi pump rather than a mechanical one can reduce that by a lot).