"hollowing" a goblet

Re: "hollowing" a goblet

Rob Ceraso

>Hi Andy,

One of the first projects I ever attempted was a pair of rosewood goblets. I did the rough hollowing with a half inch spindle gouge and left a lot of extra thickness before switching to a heavy 1 inch round nose scraper to finish. I took a while but I was more than happy with the results.

And the little nub in the center comes off pretty easy with the scraper if you take light cuts and hold the tool down on the rest with your thumb.

Good Luck (next time?),

Rob

Re: "hollowing" a goblet

Brad Vietje

>Andy,

Hollowing a goblet, or end-grain bowl, is fundamentally different than hollowing a side-grain bowl, due to the different orientation of the wood fibers. A few ideas that I hope will help:

1. End grain hollowing is a LOT like making boxes, and a very good source is the Richard Raffan book and video: Turning Boxes with Richard Raffan. He works pretty fast, but the techniques shown will be very helpful (and the speed is pretty inspirational).

2. In the meanwhile, using a spindle gouge and scraper combination to hollow end grain will work best if you measure first, then drill a depth hole (w/drill in tailstock, if possible). Leave a very thick stem until the inside hollowing is complete, for added support. Then take cuts from the center hole outward towards the edge -- I have better results with the gouge almost on its side, flute facing outward, and handle lowered as much as possible to get a more shrearing cut. Try not to cut any deeper than the bottom of the drilled hole. If needed, the inside can be cleaned up with a scraper (sharp !). On the inside of a concave surface keep the scraper above center, with handle up a few degrees, and take very light passes, just skimming the wood. (On the outside of a convex surface, you'd want the cutting edge below center.)

3. Practice, practice, practice. Working with a local turning mentor is also a very good plan.

Good luck & safe spinning,

Brad Vietje

Thetford, VT

Re: "hollowing" a goblet

John Crissman

>I love doing goblets!

This is my method:

1. Round the cylinder.

2. Form top 2/3 of the outside of the bowl. (the portion that tapers back to the center)

3. Determine the depth of the bowl. Take a drill bit and drill a hole close to the bottom the bowl.

4. Work your tool in sweeping motions - Center outward. Do not take to large of a bite. (I have used many tools to hollow and most are pretty good.)

5. Scrape the pip out of the bottom. (I do have a preference here - get some heavy HSS flat stock and make your own scraper that has a U shaped tip and a LH side grind. Weigh the handle so it doesn't want to pop up.)

6. Finish the outside 2/3 of the bowl, then bring your tailstock back in to work the stem and base.

My two cents... hope it works for you.

John

Re: "hollowing" a goblet

John Lucas

>I do similar to Brad and John. To get rid of the nub in the bottom I turn the gouge so the flute is about 10 oclock and the start slightly below the nub and lower the handle so the gouge cuts up through the nub. Now that I think about it I probably go from about 5 oclock toward 10 oclock. When I use a scraper to clean up a goblet I start right below the nub and move the scraper up toward 12 oclock.

I have been making my stems thinner latelly so I started using a steady rest when doing the final hollowing of the goblet.

some more info...

Andy in Raleigh

>The great responses so far made me think of a few more comments...

I was running at 1500 RPM.

I did not drill. I used a "plunge" technique I picked up from a box making video, pushing the gouge in just off center with the flute toward the center. If I got too close to center, it got a little wild, which is why I ended up with a nib at the bottom.

After getting the depth at center, I was working from the outside in. It seemed easier to control, most of the time. But the times it became more difficult is when I wrecked the bowl. I will try the inside out next time.

I did only a little outside shaping before going inside. I did not shape the stem. I was concerned about retaining strength and I had a suspicion that I might be starting over shooting for a shorter piece.

-Andy

Re: some more info...

John Lucas

>Andy

Sounds like most of your problem is cutting from the outside in. On certain shapes this is good but most of the time on Goblets it works better from the inside out. Remeber that you should always cut downhill on the grain. If you think of your wood as being a stack of straws it is easier to visualize which direction of cut will be downhill on the grain.

John

Re: "hollowing" a goblet

Keith Tompkins

>Andy, I use a detail gouge to drill the hole, and to hollow the goblet. Form a small cone in the center,then push the tool straight in, bevel towards the center. Then take "scooping" cuts from the inside to the outside.

A freshly sharpened tool can be used to make the final cut (very light cut) from the rim to the center.

Re: "hollowing" a goblet

Andy in Raleigh

>Your non drilling method is a pretty good description of what I did, but I then made the mistake of starting at the outside and coming in. At first that worked pretty well becaue i was just making wider shorter cones, but once I started adding the curve the trouble started. My next blank is on the face plate and the epoxy is curing today, so either tonight or tommorow night I will take another crack at this.

Thanks!

Andy

Re: "hollowing" a goblet

Keith Tompkins

>Hi Andy, good luck! When cutting from the outside, like you describe, make sure the tool is not flat on the rest, I roll the tool over on its side, no catches that way.