Scraper Question

[Harvey Ghesser]

For scraping the inside and outside of bowls, would a round nose scraper be the one to use? Anything better?

Thanks as always!

Harv

[ROY DICK]

Harvey,
I use a heavy round nose scrap on the inside of bowls, and a bowl gouge in shear scrape method for the outside. Both of these are sharp and very light cuts.
Just the way I do it, others have their own proven ideas.

Roy

[Bill Bulloch]

Harvey, they make several different kinds of bowl scrappers, the round nose scrapper is just one of them. Look at this link for another type: http://www.highlandwoodworking.com/bodger1-12hdbowlscraper.aspx I can't figure out why this bowl scrapper cost twice as much as a Bodger Round Nose Scrapper of the same size and thickness, but it does: $79.99 vs $39.99. I like this style scrapper (just not the price) so I made one like it and use it most of the time on larger bowls.

The secret to using a scrapper up the sides of a bowl is to present the scrapper to the bowl on about a 45 degree angle. Presenting it this way with very light cuts will eliminite tearout and result is a very smoother cut.

[Steve Jenkins]

There is an article on this very subject in the current Fine Woodworkling Mag.

[Greg Just]

The secret to using a scrapper up the sides of a bowl is to present the scrapper to the bowl on about a 45 degree angle. Presenting it this way with very light cuts will eliminite tearout and result is a very smoother cut.[/QUOTE]

I agree with Bill about the 45 degree cuts. Like he said, your cuts should be really light and you should be getting fine dust.

[curtis rosche]

the tilted scraper works well, but you should practice on a peice that isnt inportant first. if you get a catch like that, it can be worse than normal, atleast from my experience

[Steve Schlumpf]

Harvey - much like Roy, I use a bowl gouge for just about everything with the exception of the final passes inside a bowl. For that I use this: http://www.pennstateind.com/store/LX130.html There are a number of different scrapers available - all designed for different functions - but I have found the size of this scraper reduces vibration, the metal takes a great burr and with light cuts I get shavings off the bowl (face grain or end grain) just like a gouge.

Like any tool - the performance/results you get comes with practice.

[Harvey Ghesser]

To all,

Thanks for all of your thoughtful answers. I don't know what I'd do or how i'd do it if not for all the support available from the good people here at this forum. I will opt for a round nose scraper (Thompson 1 1/4). Since they come square, Doug asked me to let him know how I wanted it and he'll grind it for me to get me started.

Thank you all once again!:)

Harv

[Reed Gray]

I was wondering if any one else had caught Erine Conover's article on scrapers in Fine Woodworking. What he does is a little different from what I do.

First, a scraper makes an excellent bowl roughing tool. There are 4 basic profiles on scrapers.

A round nose which is good for inside and outside bowls, plus it can be used for pull cuts on the inside or outside of the bowl, and when the bowl is mounted for turning the outside and bottom (away from the headstock) or for turning the inside bottom mounted towards the headstock. The Oland tool is a smaller variation of the round nose scraper.

There are swept back grinds, commonly called inside and outside scrapers. This is similar to the swept back grinds on gouges. The inside one has a rounded nose, and is swept back on the left hand side like the one in Bill's link. This one will do great for roughing a bowl blank when you start with the bottom of the bowl facing away from the headstock. You can rough and shear cut with it. For me, I use the nose for roughing and the swept back part for shear/finish cuts. The nose will be too dull for a finish cut, but the swept back part is still fresh. This scraper will do an excellent job of roughing out the inside of a bowl when it is reversed, and if you want to use it for a finish shear cut on the inside of the bowl, you need to put a fresh edge on it as it will be dull from the roughing. It is not suitable for touching up the outside of a bowl (when the bowl is reversed) with shear cuts as the sweep is on the wrong side, and you will be working with the cutting edge being above the center line of the scraper, which can cause catches. This is where the outside scraper comes in. It is the mirror image, rounded on the left side, and swept back on the right side. For me, I turn to finish before reversing, so don't need to fine tune the outside of the bowl when it is reversed. I do find it handy for flattening the top face of the bowl while the blank is still in the rough. This is to help balance the blank. This can also be done with a round nose scraper.

The last type of a scraper is more of a square nose profile. The most common use of this one is on box bottoms, or to flatten out a platter bottom. The corners are usually eased or rounded back a bit so you don't get little tool lined across the bottom. I don't use one on my bowls or plates. I have found that I can get it really close with a gouge by feeling the bevel on my gouge. This is the same 'feel' you can get when rubbing the bevel of a skew on a straight cylinder, or even leveling with a hand plane. I then will lay a straight edge across the bottom to take out any problem spots, and use the gouge for any big humps or dips, and a shear cut with a scraper for fine tuning. Some times the 80 grit gouge will work as well.

There is another variation on scrapers and it is in the ground profile, rather than the shape. Most scrapers are ground with a steep bevel, in the 70 degree range. Then there is a negative rake scraper. Think of a skew chisel. There is a ground bevel on both top and bottom of the scraper. You grind only one side, and this produces a very fine burr on the edge. This burr is very delicate, and excellent for fine touch work, but lousy for roughing work. Also, since it is so fine, it will function better for a finish scraping cut (scraper flat on the tool rest, and handle raised above center). This is especially effective on really hard woods.

For me, I prefer a scraper with a burr fresh from the grinder. First, I remove the old burr with a flat diamond stone, then push it firmly into the grinding wheel. The finer the wheel is the better it works. I should try one of the Verital burnishers to see how that burr works. I have tried a round burnisher like used on card scrapers, and couldn't get a good burr, even though I supplied a lot of brute strength to it. The rounded burnisher just doesn't work. I did try one of the triangle burnishers, and could raise a good burr, but the performance wasn't any better than the one from my grinder. Some people will hone the burr off for the finish shear cuts. It never really worked any better for me than the one off the grinder. You can also hone off the burr and then bring up another very fine one by honing the bevel of the scraper. This is a very delicate burr like the one on the negative rake scraper, and good only for finish cuts.

Flat scraping is an excellent way to rough out bowls, and even spindlels. This type of cut does 'pull' more at the wood fibers, and will leave a fairly rough surface. If you try a flat scrape on the inside of a bowl, especially on the rim for the finish cut, you will get a lot of bowl vibration and some screaching and howling from your bowl, and explosions. This is just too rough of a cut to use. For a finish cut, you need to have the tool at a 45 degree angle on your tool rest. This puts the cutting edge at a shear angle, and you will get a better slicing of the wood, and cleaner cut. You can shear cut with a scraper or a gouge. On the outside of a bowl, it is simple. On the inside, it is more difficult to make a pull cut from the rim down to the center. Here, I will pull from the bottom up towards the rim. I know that this is backwards from what you are supposed to do, but it is a very fine cut where you take several passes to clean up tear out and tool marks, but because it is so fine, it works.

robo hippy

[Richard Jones]

Reed,

I tried one of the Veritas burnishers several years ago, and like your experience with the handheld burnisher, couldn't raise a burr on it to save me. Maybe something to do with the HSS? Maybe I was operating it incorrectly..........

Anyway, like you, I use the tool straight off the grinder, in my case, the Tormek. I use the toolrest so that the wheel is turning away from the edge, so that it polishes the face and pulls the burr at the same time. It is not very coarse done this way, but resharpening only takes a second or two.

I also shear scrape from center to rim, can't really tell any difference in the quality of the cut, only that it's easier for me to control a pull than a push. I wasn't aware that was wrong technique....:)

Rich

[Skip Spaulding]

I do the same as Roy & Steve, have a BB round nose 3/8x 1-1/2". Just finished a cherry bowl, will post pic if I get to it.