Help on Using Scraper

[Hilel Salomon]

A while back I started using a large half round scraper to Help get rid of scratches on the inside of my bowls. The first several times that I used them, I had great results. Lately, the results are disastrous. I'm guessing that I changed the angle of the bevel or something, but whenever I try to use the scrapers on the inside of the bowl, I get a catch and have already managed to make shallow platters out of bowls.
Any suggestions as to angle of bevel or how to use these correctly? Thanks, Hilel.

[Neal Addy]

Have you done any sharpening on it since the first time? The bevel angle may have changed. If so it more than likely has been reshaped at more of an angle (to make it more aggressive). I'd start by checking that.

Second, have you changed the angle at which you hold the tool? You don't need to "ride the bevel" with a scraper as you do most tools. It could be that you were simply holding it with the handle higher and therefore presenting more of the edge to the piece. I find that cutting with the burr makes them cut much sweeter.

Placement above or below center makes a difference too. Scrapers like to ride a tad above. Maybe the toolrest height is different now than your earlier tries.

[David Walser]

Here's my suggestion: Adjust the tool rest so the to edge of the scraper is at center when the tool is horizontal (while the lathe is off). Then, with the lathe on, bring the scraper in towards the surface of the bowl with the handle raised slightly (this will bring the cutting edge in just below center). When the cutting edge of the scraper just barely touches the wood, lower the handle (but no more than horizontal). Raising the handle will engage the scraper and start your cut. If you get a catch, the force of the turning wood will take the cutting edge down and out of the cut, raising the handle at the same time. This will prevent any catch from being too severe.

[Hilel Salomon]

As usual, when I get a tool that works, I buy several, so that I now have about 7 scrapers (4 here and three in VA) and yes I did sharpen them and probably made the angle too sharp. I'll try both of your suggestions since there is only a slight difference between them. I liked the results of the initial workings and found that it compensated for my lousy gouge work. Thanks to both of you, and I'll let you know the results. Hilel.

[Paul Engle]

Hilel,
Some of us know about a burr on a scraper, the link is to Highland site shows the basic of turning a burr on a flat rectangle scraper. To turn a burr on a turning scaper I use a flat piece of hardened cut off tooling to " roll" a burr against , I roll it several times to get a smooth burr and the cold rolling action work hardens the burr it self. instead of the scraper flat on the vise and burnisher worked against the scraper edge, I do it just the opposite with the " burnisher " in the vise and my scraper's edge rolled against the flat of the burnisher in continuous stroke from one side of the scraper to the other keeping it flat to the vise and perpendicular to the burnisher. Boy this is hard to explain , maybe someone else out there can help you with this better than I can , course I could show you in about 30 seconds but ......good luck my friend and if you can get there , the burr will really amaze you how smooth it is.
http://www.highlandwoodworking.com/index.asp?PageAction=Custom&ID=105

[Bernie Weishapl]

Hilel I quit using a scraper on my bowls. I do like Mike Mahoney does. I got a 3/8" and 1/2" conventional grind P & N bowl gouges. I use these on my final two or three passes. I haven't used a scraper since. He teaches this in his video From the Tree to the Table.

[Hilel Salomon]

I never cease to be amazed at how helpful and kind turners are. Is it because the lathe soothes or is it because it attracts the right kind of people? I know that in my case, turning does improve my personality although there's still much much room for further improvement. When I'm working on furniture and something goes wrong, I tend to curse like a drunken sailor, whereas when I make a bowl and the bottom caves in, the side cracks, or I do something else which is dumb, I tend to laugh it off. In any case, I greatly appreciate your responses. I'm stuck with all of these expensive scrapers so I will give them another chance, but I'll also look again at the Mahoney video and see if I can avoid them in most instances. Thanks again for all your kindness.
Hilel.

[Gordon Seto]

Don't throw away your scrapers yet. You can't ride the bevel on these Stuart Batty bowls alone.

http://i118.photobucket.com/albums/o83/gbseto/StuartBattyWorks.jpgHilel,
Gordon

[Hilel Salomon]

Those are unbelievably beautiful. Did you make them? There IS NO WAY I'll ever be that good!!!!!
Hilel.

[Bob Opsitos]

I made a parting tool into a hardwood scraper ala sorby. Makes the scraper much less likely to dig in. Check sorby's website, they've a nice video on it's use and a close up of the grind. Very easy to convert and existing scraper.

That said, Dave's response is right on, though I've heard that the rest should be above center.

Another thing to look into is on some long radius scrapers engaging the whole radius of the tool into the wood can cause a catch because your attempting to remove a fairly sizeable amount of wood all at once which creates a fair amount of force on the handle.

And another thing is to look at is rest distance to work, the further that distance is the harder the tool is to control. I've a few scrapers that are much sharper ground than stock and generally don't have trouble.

Can you take a picture of the scraper?

Hope that helps
Bob

[Gordon Seto]

Did you make them? There IS NO WAY I'll ever be that good!!!!!
Hilel. Only in dreams and also high on something too good to share.
Those are Stuart Batty's pieces. He is a third generation professional turner. Probably most of us started a little late, won't live long enough to be that good.
When he reversed turn a bowl on jam chuck in a demo, he just likely tapped the bottom of the bowl and took another cut, no peeping, no measuring and no funnel. The bowl was already aweful thin already. He will make you feel humble without bragging how good he is. So far he doesn't use carving to enhence his turning. He demonstrates pure turning techniques.

Gordon

[Ernie Kuhn]

Took a beginners class from Stuart Batty at our local woodturners club last July. He showed and taught putting a negative rake on the scraper. No catches. The theory is that the burr sits lower on the front of the scraper. If the burr is on the top edge, it tends to pull the scraper into the piece. With the negative rake and burr lower on the scraper, it doesn't pull the scraper in. Hope this helps.
Ernie