[OP]
Member
What a mess Im in now!!!! I went from a 10 in lathe to a 1624 Nova to make me some bigger bowls. Well Ive got me a pile of what were about max capacity on the 16 inch Nova when I started to dry them ,that are now warped too bad to rechuck and finish turn.Any solutions?I never gave a thought to how much they were gonna warp!!
Contributor
Yep....that is the purpose of twice turned bowls. Turn thick, let dry & warp, then when dry put back on lathe and re-turn to round. You have to leave enough wood in the initial turn to allow for the second one. Usually about 1/10th..........a 10 inch bowl will need to be left 1 inch thick to accommodate this second turning.
Make yourself a jam chuck with a tenon that will fit your chuck jaws, and extend to the bottom of the bowl. Use some sort of rubber mouse pad, or shelf liner, or piece of inner tube, and cushion the inside of the bowl and give it some grip to drive the turning. Put the bowl onto the jam chuck with tailstock support, and play with getting it to run as true as you can......it won't be true, but get it the best you can.
Then when it is the best you can get it, tighten down your tailstock live center against the tenon, and use slow speeds.......maybe 300-400 rpm, and re-true the tenon. Once that is done, place it in your chuck jaws, then proceed to true up the outside of the bowl.......once true, go to the inside and try to match a parallel shape on the inside.
You can only do this if you have left the roughout thick enough, but if you turned to final thickness, what you have is what you have.......warped bowls.
Remember, in a moments time, everything can change!
Vision - not just seeing what is, but seeing what can be!
Member
Sounds like what happened with a couple of my daughters (they were almost 12"and warped to almost 12.5" in the oval.
What we did was mount them on the lathe (lathe off) and use an angle grinder with a sanding disc to get them where they could rotate the full 360*.
You will be taking wood off of the two oversized sides.
You can then retrue your recess or tenon.
"I became insane, with long intervals of horrible sanity." - Edgar Allan Poe
Member
Doesn't the head turn on that lathe? Turn it out 45degrees to clean up the outside.
Contributor
In my opinion, the tenon should be trued up before ever attempting the truing of the bowl itself.....totally can eliminate any use of an angle grinder.....which is pretty much outside of any normal process.Originally Posted by Michael Mills
Remember, in a moments time, everything can change!
Vision - not just seeing what is, but seeing what can be!
Member
Sonny,
I thought you were asking a question about how to remount a bowl that Roger answered correctly in his first reply about using a jam chuck. After reading your post again and seeing other replies I see that might not be the case. If the bowl is just too big for the swing of the lathe I'd probably consider marking a line at the appropriate spot that will clear and cut the rim off with a jig saw, hand saw or whatever like minded tool you have.
Just in case you were actually asking how to remount a bowl, here's a couple pictures that show what Roger was explaining. This was for a vase and not a bowl but the process is the same. I usually use a vacuum chuck for my bowls so I don't have any pics of a bowl but like I said, process is the same. Maybe Leo has some he could post.
cva.jpgcvb.jpgcvc.jpg
Now that the tenon has been trued-up and mounted in the chuck, I'm able to finish off the machining inside and out and do whatever other processes I want to the piece.
cve.jpgcvh.jpg
Member Turners Anonymous Pittsburgh, PA
Member
I'm guessing the bowls warped to where they were wider than what would spin inside the throw. I turned a 10" bowl from a hackberry crotch that is now over 11" OD one way and about 9" the other. I think it will make a nice platter when finishedIn my opinion, the tenon should be trued up before ever attempting the truing of the bowl itself.....totally can eliminate any use of an angle grinder.....which is pretty much outside of any normal process.If it had started closer to 12" I'd be grinding away the sides trying to get it mounted.
Member
I just rough turned a number of oak pieces that were close to what my lathe could handle... Now I'm wondering if I'll be able to re-mount them when the time comes... hurray for heartburn!
Member
Depending on how it's warped you might be able to tilt it one way or another between centers.
Contributor
I use a rasp intended for horses' hooves to make 'adjustments' like this.
Contributor
Sounds like a perfectly good opportunity to tell SWMBO THAT YOU REALLY DO NEED A NEW AND LARGER LATHE!I just rough turned a number of oak pieces that were close to what my lathe could handle... Now I'm wondering if I'll be able to re-mount them when the time comes... hurray for heartburn!
Good luck with that!
Remember, in a moments time, everything can change!
Vision - not just seeing what is, but seeing what can be!
Member
Haha! Think that'll work?Sounds like a perfectly good opportunity to tell SWMBO THAT YOU REALLY DO NEED A NEW AND LARGER LATHE!
Good luck with that!
Contributor
If your bowl shape follows a continuous curve from bottom to lip, you can cut the lip back on a bandsaw. This will result in a somewhat shallower bowl with a smaller diameter but will clear the ways of your lathe allowing re-turning.
If your bowl shape has straight sides, then the previous suggestions can work.
Member
Be careful on that bandsaw.
[OP]
Member
Sorry for the slow response fellas, Ive been at work.Yes the swing of the lathe is not big enough to let it turn over the ways,therefore I cant true up my recess to chuck it to return.My headstock does swivel but I cant bring up my tailstock then to hold it to true the tenon.Its about 17 1/2 in and my lathe is 16,Im not sure theres gonna be enough left to come round even if I do get it where I can turn it.Probably all I can do is try to cut the rim down and take whats left.They are contoured toward the bottom.
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