I brought this up over on rec.woodworking, and they recommended I take
it here. The gist of it is as follows...

(this was copied from a post over at rec.ww)
snip
The typical way we make large turning blanks is to glue
four pieces of thick stock into long square tubing using 45d miters.
So it's hollow in the middle. I don't know, he was pretty dismissive.
In any event, if I want to hop on the lathe at work (after I dig it out

from under two tons of crap), is this the process by which I should do
it.....

I need (4) three foot lengths of quarter round with a 3" radius. So I
take (4) 3 foot lengths of 3.125"x3.125" stock and glue them together
with a piece of grocery bag in between. Then I screw on a faceplate,
being sure that it's centered on the intersection of all four pieces.
Then I mount it on the lathe, and align the interesection at the other
end with the tailstock center. Then I turn it round to 6". Once done,

I simply take it off the lathe and split it apart - I'm assuming with a

chisel pounded into the glue joints?


Sounds very nifty. Have I missed anything?

TIA
JP

Jay:

Overall, the process is much as you've describe, however, If I were
doing it, I'd eithere a spur center (second choice) or a chuck to hold
the headstock end, and a rotating center on the tailstock end.

An ordinary brown paper bag is ok to put between the sections, but don't
go overboard with glue, and do not use thicker card stock (like a tablet
back. I recieved a nasty concussion in a wood shop class back in the
mid sixties when someone used a tablet back to glue up what was to be a
pair of bookends, and then turned the lathe up too fast. Unfortunately,
I was in the line of fire, so to speak, and woke up on the floor some
time later, then spent the majority of the next three days sleeping as
my system (hopefully) dealt with the concussion. Some 40+ years later,
I can't say there was any long term detrimental effect from the
concussion, but I wouldn't recommend it to anyone...

Given that you're working on something that is going to start at 6 1/2
or 7 inches diameter before you turn it, I'd start at low speed and keep
it under 1000 rpm or so through the entire process. I'd also look into
working with a hollow form, so you don't need so much wood to begin
with. If you've got access to a jointer, you could make an 8 sided
hollow tube to begin with that would make the actual turning process a
relatively minor finishing process.

Thanks
--Rick

wrote:

I brought this up over on rec.woodworking, and they recommended I take
it here. The gist of it is as follows...

(this was copied from a post over at rec.ww)
snip
The typical way we make large turning blanks is to glue
four pieces of thick stock into long square tubing using 45d miters.
So it's hollow in the middle. I don't know, he was pretty dismissive.
In any event, if I want to hop on the lathe at work (after I dig it out

from under two tons of crap), is this the process by which I should do
it.....

I need (4) three foot lengths of quarter round with a 3" radius. So I
take (4) 3 foot lengths of 3.125"x3.125" stock and glue them together
with a piece of grocery bag in between. Then I screw on a faceplate,
being sure that it's centered on the intersection of all four pieces.
Then I mount it on the lathe, and align the interesection at the other
end with the tailstock center. Then I turn it round to 6". Once done,

I simply take it off the lathe and split it apart - I'm assuming with a

chisel pounded into the glue joints?


Sounds very nifty. Have I missed anything?

TIA
JP

writes:
The typical way we make large turning blanks is to glue four pieces
of thick stock into long square tubing using 45d miters. So it's
hollow in the middle. I don't know, he was pretty dismissive.

Just FYI, this link will generate a PDF for you that illustrates what
he was talking about:

http://www.delorie.com/wood/segturn....pages =single

In this case, you'd turn away the outside, leaving a square hole down
the middle. You'd still need to do the paper bag glue trick, but
you'd need four 6" x 6/4 stock instead of four 3.25 square stock.

Here's one with eight staves, needing eight 2.5" by 4/4 stock
(i.e. standard 1x3s):

http://www.delorie.com/wood/segturn....pages =single

Thanks for the tips and links guys.
JP



DJ Delorie wrote:
writes:
The typical way we make large turning blanks is to glue four pieces
of thick stock into long square tubing using 45d miters. So it's
hollow in the middle. I don't know, he was pretty dismissive.

Just FYI, this link will generate a PDF for you that illustrates what
he was talking about:

http://www.delorie.com/wood/segturn....pages =single

In this case, you'd turn away the outside, leaving a square hole down
the middle. You'd still need to do the paper bag glue trick, but
you'd need four 6" x 6/4 stock instead of four 3.25 square stock.

Here's one with eight staves, needing eight 2.5" by 4/4 stock
(i.e. standard 1x3s):

http://www.delorie.com/wood/segturn....pages =single

Instead of using paper in the glue joint cut your stock 2" longer that
needed. To glue spread 1/2" on each end and 1 drop each 3: down center of
pieces being glued.. When you are tough turning cut 1" off each end ad
split the pieces apart,

--
Art Ransom
Lancaster , Texas

www.turningaround.org
wrote in message
ups.com...
I brought this up over on rec.woodworking, and they recommended I take
it here. The gist of it is as follows...

(this was copied from a post over at rec.ww)
snip
The typical way we make large turning blanks is to glue
four pieces of thick stock into long square tubing using 45d miters.
So it's hollow in the middle. I don't know, he was pretty dismissive.
In any event, if I want to hop on the lathe at work (after I dig it out

from under two tons of crap), is this the process by which I should do
it.....

I need (4) three foot lengths of quarter round with a 3" radius. So I
take (4) 3 foot lengths of 3.125"x3.125" stock and glue them together
with a piece of grocery bag in between. Then I screw on a faceplate,
being sure that it's centered on the intersection of all four pieces.
Then I mount it on the lathe, and align the interesection at the other
end with the tailstock center. Then I turn it round to 6". Once done,

I simply take it off the lathe and split it apart - I'm assuming with a

chisel pounded into the glue joints?


Sounds very nifty. Have I missed anything?

TIA
JP

Art Ransom wrote:
Instead of using paper in the glue joint cut your stock 2" longer that
needed. To glue spread 1/2" on each end and 1 drop each 3: down center of
pieces being glued.. When you are tough turning cut 1" off each end ad
split the pieces apart,

If it's particularly long, you could use a short strip of doublesided
tape in the middle too. That stuff is very tenacious but slow gentle
pressure will pull the wood apart...

....Kevin
--
Kevin Miller
http://www.alaska.net/~atftb
Juneau, Alaska
Registered Linux User No: 307357