Hollowing

[Bigbud78]

Hey guys, Been really stacked at work so any free time I've been doing what I can. Made a Guiro for my daughter and a few pens and bowls but struggled a little with the hollowing on the Guiro

What does everyone use for hollowing Vase's and a like ? I would like to try turning some similar to George W, I was looking at the Munro but its a huge chuck of cash for something I'm not sure I'll use a lot. Any other suggestions ?

I have been using a 13mm spindle gouge flute up towards me and drawing back which works great for shallow openings but going deeper it likes to catch

Thanks

Jim

Also turned my first bowl from the timber I processed myself, still very wet and its bowed but I really like it.

 

[duncanh]

I have several tools I use for hollowing:

Munro tool - expensive but cuts well on wet wood and leaves a reasonable finish. Can get clogged sometimes (more so on dry wood) but easy to clear out.
Sorby sovereign hollower - similar to Munro but overly complex head, and wider than the Munro. The handle is good though.
Crown hollower - never got on with it and rarely use it.
Sorby RS200 - straight and swan neck. I like the straight version of this with the semi circular shaft as you either keep the bar flat on the rest and hack out material fast or have the rounded side on the rest, approach from more of an angle and get more of a shearing cut for a better finish. The scraper head is reasonable and I like the carbide tips which are held in place with a saddle.
Simon Hope carbide tips - small but very effective. I use them in bars I've made myself - buy a length of steel, drill a hole in the end and tap a hole in the top to hold the cutter in place.

Home made bars varying from 1/2 inch up to 3/4 inch - cut a flat on one end, drill and tap a hole for a machine screw or similar and you can fasten on no end of different cutter. These can be carbide cutter you buy onine (I think I got mine from http://azcarbide.com/), simple pieces of HSS cut from a planer blade.
My largest home made hollower is a length of scaffold tube in which I hold a length of 3/4 steel bar that has a cutter screwed onto it.

Most of my projects use a combination of these, depending on which cuts better on the day, how much vibration I'm getting and how good a finish is being left.

 

[woodpig]

Make yourself one of these from some 1/2" square steel bar and an 8mm carbide insert:

http://carbidewoodturningtools.com/cata ... ning-tools

You can get the inserts and Torx screws at reasonable cost from this company.

http://www.shop-apt.co.uk/carbide-tips- ... -tips.html

 

[finneyb]

Woodpig beat me to it.
I use 3/4 in round mild steel drilled to take a HHS insert that has been rounded for some of its length.
HHS is held in with superglue - heat will break the bond if you want to take it out.

Brian

 

[woodpig]

Yes, ones like that are commercially available Brian but easy to make at home. You can buy 4" lengths of HSS rod or square from the likes of Chronos or Warco etc.

 

[Castanea]

I don't have any purpose made hollowing tools so I use spindle gouges. There's a limit to how far you can hollow before the vibration becomes so severe that the finish suffers.

I did have problems with catches which I think I've got past. For me the trick was to avoid the wing - so get the handle back pretty quickly so the cutting is happening right up just to the left of the tip. I was being slow to turn the corner and the wing was catching.

The other thing I think I was doing was letting the handle come up a bit which let the tip drop and the wood seemed to try to pull it down and backwards (rather than just downwards) and then it would catch and travel across and into the vessel and make a big spiral gouge in the bottom. Keeping the handle very flat so I'm always cutting at 9 o'clock on the inside wall seems to have helped.

Also I'm turning my gouge to 30 to 40 degrees from horizontal rather than keeping the flute upright - so the flute is at 10 o'clock or so which I think makes the cut less aggressive.

I can't guarantee they will work for you but those are the things which I recently changed and which turned hollowing from a chore to a pleasure as long as you're not going too deep. If you are going deep a bowl gouge can help - the more solid the tool the less the chatter to a point.

Cheers

Ian

 

[nev]

A very light touch with a (sharp!) round nosed scraper works too.
Or if you like GW's stuff how about some of his own tools?
http://www.fromthetree.co.uk/hollowing-tools.html

 

[Phil Pascoe]

^^^^ - and don't forget that carbon steel tools can be sharper than HSS, and can be bought second hand cheaply as few people want them as they are conditioned to believe HSS = good, carbon steel = bad.

 

[duncanh]

I don't have any purpose made hollowing tools so I use spindle gouges. There's a limit to how far you can hollow before the vibration becomes so severe that the finish suffers.

I did have problems with catches which I think I've got past. For me the trick was to avoid the wing - so get the handle back pretty quickly so the cutting is happening right up just to the left of the tip. I was being slow to turn the corner and the wing was catching.

The other thing I think I was doing was letting the handle come up a bit which let the tip drop and the wood seemed to try to pull it down and backwards (rather than just downwards) and then it would catch and travel across and into the vessel and make a big spiral gouge in the bottom. Keeping the handle very flat so I'm always cutting at 9 o'clock on the inside wall seems to have helped.

Also I'm turning my gouge to 30 to 40 degrees from horizontal rather than keeping the flute upright - so the flute is at 10 o'clock or so which I think makes the cut less aggressive.

I can't guarantee they will work for you but those are the things which I recently changed and which turned hollowing from a chore to a pleasure as long as you're not going too deep. If you are going deep a bowl gouge can help - the more solid the tool the less the chatter to a point.

Cheers

Ian

Whilst you could use a bowl gouge I generally wouldn't recommend it, particularly for someone who has just started out hollowing. They usually have a lot of cutting edge and the potential for a catch is higher then with a spindle gouge. If avoiding the wing is the key to avoiding a catch then a bowl gouge has a lot more wing to avoid, unless you have an unusual grind. If you're going to have an unusually ground bowl gouge just for hollowing then it would probably be cheaper to make a purpose made bar hollower.

Even though I mentioned square bar hollowers (or the Sorby D profile ones) in my original post I usually suggest round bar hollowing tools as they let you start with the cutting edge pointing pointing down (for zero cut) and then rotating them slowly up to start cutting. I find that this gives you a lot more control than with square bar tools - like riding the bevel with a gouge and then raising the handle to start the cut.