Turning practice: laminated alder bowl

[sjk]

I'm a turning novice and haven't turned anything in over a decade.  I thought I'd try my hand at turning again and decided to attempt a bowl out of alder. 

I liked the idea Tommy Mac used on his "laminated bowl" (glue up the turning blank out of layers with the grain direction gradually rotating). (it's the project in Rough Cut season 3, episode 9 https://player.vimeo.com/video/98958543)

I'm aiming to make a taller, rounder bowl so that I get some experience hollowing.  I cut some 8" squares and then made the faces smooth.

I was surprised to find that figuring - no idea how that will translate into the finished bowl.

Then I glued up pairs of boards, rotating the top board by 20-ish degrees.

Once those were dry, I glued the whole thing together.  There's a chance I might have used enough glue.

Going to let that cure up and then it's on to turning.

 

 

 

[Brendon_t]

Sweet man. Ive never turned anything but love to watch it.

[wtnhighlander]

This sounds very interesting. I am looking forward to your next post!

[sjk]

Out of the clamps and to the bandsaw to make it roundish.

Screwed on a faceplate and mounted it on my little lathe.

Sharpened my never-before-used 1/2" bowl gouge.  I did a so-so job at sharpening it.  I matched the angle and got the sides looking right, but I got the tip of it a little pointier than it started and I failed to keep it symmetrical.

 

Then I turned the outside of the bowl.

I ran into two problems: lots of endgrain tearout and I kept getting catches as I tried to round the bottom of the bowl. 

For the tearout, I tried turning the speed up (I had started low, maybe 600 rpm, and it's about 8" in diameter) and that made a tiny difference.  I tried "closing" the gouge and opening it up, no difference.  I tried taking the barest hint of wood off, no change.  I wound up using a roughing gouge to round out the blank and then used a 1" round nosed scraper to shape it.  I got less tearout, but still a bunch, even with a very light pass at the end.  When I sharpened the scraper, I did it just on the grinder, I did not further hone the edge or burnish a burr.  Maybe I should have.

Afterwards I found an online guide to turning speeds (http://www.docgreenwoodturner.com/lathespeed.html), and it looks like I should have run it higher, like 750-1,100 rpm.  I tried one more light pass at 1,000 rpm and it was a tiny bit better.

For the catches, I was trying pull cuts going from the bottom of the bowl (on the right) to the side of the bowl so the fibers were supported.  I had the tool rest so that the cutting edge was slightly above center.  I kept getting catches.  I wound up using the round nosed scraper instead.  I used a square nosed scraper to create the tenon I'll use when I mount it in the chuck to hollow it.

After WAY TOO MUCH sanding, here's the shape of the outside:

Those odd lines are completely smooth - they're that figuring that I found earlier.  Here's a shot with some mineral spirits on it:

In this shot, the second layer from the left has the end grain right in front of the camera, the third has it a little above center, the fourth has it near the top.

 

Given my lack of success with the bowl gouge just shaping the outside, I'm nervous about the hollowing.

Does anyone have any advice?

I had ordered the usual three EasyWood tools from Amazon and they arrived a couple of days ago, so I may just use the round "finisher" tool to do the hollowing...

 

[Tpt life]

What is the purpose of the 20° spin? 

[sjk]

To give some visual interest.  With the right finish, the chatoyance will be very different between the end grain and edge grain.  That's the theory at least

[wtnhighlander]

looks pretty cool so far. Good luck with the hollowing. I have no advice to offer.

[-MattK-]

sjk, I'm new to turning, too, but I've been taking classes. Everything I've learned for turning bowls is "ellsworth-inspired."  BTW, the "ellsworth on woodturning" book is a great resource for bowls and hollow vessels.

Interior roughing cut:

• shaft is horizontal.
• Pitch ("twist" of the gouge) is ~45 degrees with open flute pointing towards the center of the bowl.  Bottom of the flute (where you'll be cutting) is aligned with the center line of the work piece.
• Cut from left-of-center towards the center of the bowl.  You want to cut in an arc.
• Start small.  Don't start out towards the edge, start from maybe 1 1/2" from the center.

and the bowl looks like a cool idea - I haven't done anything that's glued up yet.  Looks fun!

[sjk]

Thanks Matt!  I'll definitely give it a try when I get to the shop next.

[sjk]

I finally got some shop time this evening (solid week of rain every day + really big windstorms = tons of trees down + lots of power outages + screwing up my shop time).

 

I mounted the bowl in my chuck.  Still amazes me that the chuck only needs a 1/4” tenon to hold onto.

I reground my bowl gouge and followed MattK’s advice – much better results.  Lots less endgrain tearout (still some) and no catches.

Here you can see the endgrain tearout.

Once I got in an inch and a half or so, I started practicing making the walls the same thickness.

 

Hollowing the bottom was scary at first – even with a longer toolrest (the 10” from Rockler) and with it angled into the bowl, I still had the gouge hanging out a couple of inches.

The thickness practice on the first inch or so of hollowing paid off – I managed to get the walls pretty uniformly thick.  Here’s a shot after sanding.

 

Next time will be installing the jumbo jaws on the chuck, reverse mounting the bowl to clean the foot, and applying finish.

[sjk]

Took a while to wrap this one up - I lumped the finishing in with the projects I was making for Christmas.

I put the Mini Jumbo Jaws (nice name) on the lathe, mounted the bowl and cleaned up the foot.

Then there was the best part of all - sanding!  (sorry - no pics of that, I guess I was having too much fun working through the grits to run in and grab the camera)

Here's the first coat of finish:

And here's the finished piece: