rookie goes jammin'

[Walt Caza]

Good Day Turners,
I used a scrap from my Morris chair arms to make another bowl. (career bowl #2)
Since the 8/4" QSW oak was already thinner than I might prefer,
I added a 3/4" plywood glue block to the bottom.
The false tenon would prevent me losing oak to an integral tenon.
2-inch-QSW-oak-bowl-blank.jpg

Waaay back in highschool, I turned my only bowl with a faceplate screwed into a 3/4" plywood glueblock.
No reverse chucking - just chisel off the plywood and sand the bottom flat. That was maybe 27 yrs ago.

So, of course all these yrs later, I thought plywood would be the way to go. Wrong!
I now suspect the screws through the faceplate into the glue block help it stay together.
But a spigot gets no such help from any screws. darn
The ply seperated and my lil bowl rolled gently onto the floor. No drama... just thunk
plywood_tenon_seperation.jpg

So now I'm in a pickle... How am I gonna recover and hollow this thing?
Coming from flat-land, I tried to glue on a new solid oak tenon with clamps.
I mucked around with 4 Bessey K bodies, like wrestling an alligator.
No joy, gotta learn some new approaches.
In hindsite, I suspect the tailstock could have clamped this glue-up?
vice_second_tenon.jpg

So, my best idea to let me continue, was a stub of framing 2x8 spun into a jam chuck.(?!?)
faceplate_holds_jam.jpg

Unsure how to go about it, I made some kinda taper to catch my lil bowl.
Things are getting interesting for this rookie... (novelty is everything)
jam_taper.jpg

continued next post...

[Walt Caza]

On we roll...
(ya, right onto the floor)

So, after some tweaking, I jam my white oak missile,
along with it's new 1/2" thick red oak square spigot onto the jam chuck.
new_square_tenon.jpg

It stayed convincingly, but discretion being the better part of valour,
I bring up the tail for a little help.
One launch per bowl, yep... that's my new policy.
tail_help.jpg

So, not knowing anything, I used a parting tool to bring the new-improved
glueblock spigot into round, by working around the live tail.
new_round_spigot.jpg

The new tenon let me hollow the inside, but my struggles were not over.
My fresh Cole jaws did not show much interest in my outer form.
Too round and slippery, like the last pickle in a deep jar.

So, still finding myself a caveman... I used the tail to pin it to the jumbos, too.
I turned the red oak spigot as small as possible around the live center,
and then sanded the remainding stub flush, off the lathe.
Not a pretty bottom, but something new to drag home for show-n-tell.

I seem to have lost ground, as my second bowl is not as good as my first? hehe
Some tear-out, and I tried Shellawax liquid this time, but did not achieve full coverage. ack
Some tiny bare spots, most likely tear-out? eww
my_second_bowl_QSW_oak.jpg

I'm guessing QS white oak is not quite the ideal wood to turn bone dry?
Yep, I know this bottom is a hideous mess!
oak-bowl-bottom.jpg

Of course, my darling bride proclaimed it beautiful, and then claimed it. shrug
Well, at least I had fun and didn't lose any teeth...
Hope you get some shop time,
Walt

ps in the moment my bowl was rolling across the floor, a flash of memory...
I remembered, as I danced my first jig, Bernie W. somewhere mentioning
that plywood was no good for a tenon.
shucks

[Walt Caza]

Hi again,
quick question:
Should my spigot be deep enough to bottom out in the chuck jaws?
This seems to help square it to the axis.
My first spigot I went 3/4" long, my second just 1/2 and inch.
Would less hold enough? Such as 1/4" tenon?

Until I get some thicker turning stock, I just want to minimize wood loss
to a tenon that gets turned away anyway.
I imagine it is even worse when you are using some pretty stock...

Funny throw-in:
My father passed by the shop as I was spinning this second bowl and says quizzically: "another bowl?"

Jeepers, I guess he has no idea of much money I have spent so far,
nor how much more I intend to spend,
let alone that I aim to turn a dozen or two more bowls before Christmas!

Odd moment, was he thinking that the one lil bowl was gonna do it for me?
You can't write this stuff, you just gotta live it!
be well,
Walt

[Dick Strauss]

Walt,
You never want the tenon to bottom in a 4-jaw chuck. If the tenon is too long, it won't engage the shoulders of the chuck. The shoulders provide lots of additonal support that is lost if the tenon is too long. You also want to make sure that the tenon is perpendicular (or dovetailed as necessary) so that it matches the shoulder profile to get the strongest hold.

FYI-My stronghold chuck bottoms at about 7/16". I try to shoot for 1/4"-3/8" when possible and turn away the excess length when the form is complete...

Since you are dealing with dry wood, I'd suggest you glue a solid wood block (of the same material if possible) on the bottom for sacrificial tenons/feet.

Your first piece looks nice for a first effort!

[Alan Trout]

Walt you are doing great! You are using you head and figuring stuff out as you go. That is a great way to learn as long as you are safe.

I agree with Dick you never want you spigot to bottom out in the chuck.

I use a lot of glue blocks. But use spigot jaws or power grips. I like using the spigots with glue blocks because they are very deep and my spigot can be very deep.

I usually find some scrap hard wood and on the drill press take a hole saw without the drill bit and cut out a bunch of glue blocks all at once. 2" is what I use most with the spigot jaws that I have.

I never suggest that anyone does what I do but I have turned some pretty crazy heavy stuff with a 2" glue block but I always do it between centers. When ever you can always use the tailstock it is one of your best safety devices that you have.

Alan

[Dick Strauss]

One thing I forgot to mention...some chucks will hold a square tenon...don't trust them to hold much unless you have the tailstock engaged as well. square tenon + no tailstock = no holding power. A round tenon will be held much better by the chuck with or without the tailstock!

[Steve Schlumpf]

Walt - I see you are figuring things out! That's great and you have been given some pretty sound advice.

I have Oneway Talon chuck and try to make my tenons 1/4" to 3/8" but no longer. Also, as was already pointed out - the shoulder of the tenon - where it meets the bowl blank must match the profile of the jaws on your chuck for the strongest amount of 'grab'. In my case it needs to be a 90* angle but I know some chucks use a dovetail. Also, you want the diameter of the tenon to be fairly close to the closed inside diameter of the jaws on your chuck for max holding power. Example would be if your chuck jaws hold a minimum size of 2" - turning a diameter of 2 1/4" or 2 1/2" would work well. You only run into problems when trying to max out the jaw diameter. When that happens - stop - and replace the jaws with the next larger size.

Hope that makes sense. Anytime you have questions - ask - either here, PM, email, etc - especially if you have any safety concerns!

Happy turning!

[Bernie Weishapl]

Walt that is beauty for your first. You have already had some good advice on the tenon. I also make my tenon's no more than 1/4" to 3/8" long. I try to use scrap maple or some hard wood on my faceplates. Plywood not so good.

Oh and you had better build plenty of display space because if the LOYL is like mine everything is cute and pretty much ends up displayed somewhere in the house.