smooth insides

[sue denim]

Which tool would be most appropriate to use for inside bowls (deep and wide) to obtain a smooth finish... most of mine have the corrugated roof effect
Just for info the one I started today .. sapele about 250mm dia 80mm deep... thanks in advance.

 

[CHJ]

A decent sharp bowl gouge, perhaps with a steeper front nose, say 45-50 deg.

If it's the bowl gouge you can't control to get the smooth sweep finishing cut then use a negative rake curved scraper to level out the surface.
The scraper works because the scraper is not using a rubbing bevel so does not bounce as a less than rigidly controlled gouge would and does not keep replicating and even enhancing any ridges due to grain direction/wood density changes.

Failing the above Rotary power sand with slow hand drill (battery) and lathe speed slowed down to 500-750 RPM max. with 80-120 grit abrasive.

 

[Bodrighy]

Is the bowl gouge big enough? The further the cutting edge is from the tool rest the more chance there is of chatter which is what you seem to be describing. Try turning the tool rest into the bowl as you cut so that you have less tool overhang. Also use the thickest bowl gouge you have.

Pete

 

[sue denim]

I have a 'long strong' bowl gouge but which is fine for flat bowls but when the sides start to curl over then the gouge will only do the bottom and not the sides or inside the top. I am not describing a hollow form, just a bowl with walls that curl over..... ...... ....I think !!

So I need something that gives a good flat finish up the sides and under the rim.

Thanks again

 

[CHJ]

.....So I need something that gives a good flat finish up the sides and under the rim.
..

Simplest and cheapest option is a stiff 1/2" Round Nosed Scraper.

The Alternate you can make yourself if you have a spare flat scraper (3/4") along the lines of this, adjust shaping to suit your needs.

 

[Sheptonphil]

Hi Chas

As a newbie, can you explain hot the scraper works in your picture, as I thought with the bowl turning anticlockwise the scraper would just lift off the rest. Or do you run the lathe in reverse?

Phil

 

[Richard Findley]

Hi Sue

Have you tried removing the heel from your bowl gouge? A common problem, especially on tight curves is that the heel rubs too much and produces a ribbed appearance. By removing the heel and so shortening the bevel, it allows you to easily make those tight curves with clean cuts. The only challenge then is to keep your movements smooth.

Hope this helps

Richard

 

[CHJ]

Lathe is in reverse Phil, I do a lot of my turning with scrapers, Orland tools and occasionally gouges in reverse so that I can see what I am doing without having to lean over the lathe bed or have the headstock turned too far out.

The Old back appreciates a 'higher than most' centre height on the lathe and a more upright stance, so leaning over is more of a problem.

 

[Sheptonphil]

Thanks for that Chas, I have never seen turning in reverse before, only sanding. I do like the idea of seeing easier what you are doing on the inside edges. Can bowl gouges be used in reverse turning as well, assuming the grub screws are in to stop the chuck unscrewing?

Phil

Had a think about it, and outside turning on a Graduate is in 'reverse' isn't it.

 

[CHJ]

Gouges are a bit trickier to get the hang of, its basically about scooping in the opposite direction and of course rolling the opposite way.
In all honesty I find an Orland cutter and scrapers do 90% of the undercutting and finish hollowing, they just need to be sharp to make sure you don't pull the fibres, just occasionally I get the brain into gear and concentrate on presenting a gouge 'in reverse' so to speak.

 

[Terry - Somerset]

I'm fairly new to woodturning but one of my better purchases has been a heavy duty (crown) scraper. This seems to give a good finish which sands easily starting with 120 grit and has the weight to avoid chatter and produce smooth curves to the inside of bowls.

 

[KimG]

I too often use reverse direction for bowl and indeed even hollow forms, you can often get a "better" angle and see clearer too. But one thing to watch for when using this technique, be sure that your chuck is securely tightened onto the spindle shaft as it can rapidly and disastrously come undone with the lathe in reverse if you should forget to check this.

For Sue, another aspect of turning the inside of a bowl that can have a dramatic effect on the finish is the tool rest itself, the closer you can get the rest to the work, the easier the tool will be to control and thus the better the finish off the tool. Look at the toolrest in Chas' image, it is nicely placed close to the work meaning a minimum of the tool is hanging over the end. If you don't have one, consider a purpose made bowl rest like the Sorby system, these can improve your work by making it easier.

 

[procell]

Phil mentions grub screws to lock the chuck when using the lathe in reverse. Is this a standard feature on most chucks now?. I have an old Craft Supplies chuck that only screws onto the spindle.
Its not a problem as my lathe only had reverse when the capacitor was on its last legs and needed help to get turning. I have now changed it and only have the normal turning direction. I am wondering how easy it would be to rig up a switch to make the lathe run in reverse?

 

[sue denim]

Thank you all for the advice. I need to invest in some scrapers I think as the only one I have is a small thing. As for the bowl rotation I work on the outboard side of an ML 8 therefore the rotation is clockwise for me. Hadn't really occurred to me that there was an alternative direction.

On that subject are all the side scraper ground for cutting counter clockwise or are they left square to grind to your requirements?

Any recommendations for a scraper set would be welcomed


Once again thank you all.