Comment on Benjamins Best scrapers

[Brian Kent]

I am wondering if the steel used in Benjamins Best scrapers is too springy. I was using the 1" x 3/8" scraper inside a small bowl (5.5" wide, 4.5" tall) and as has happened many times, the scraper bounced over and nicked the inside of the rim. This is some very hard, tough eucalyptus, which I had hollowed slowly and gently with a 3/4" x 1/16" round nose scraper that I got second hand at a club meeting. It was very controlled - no bouncing, no spring. I was using the big scraper to flatten the bottom but the tool rest was angled in until it almost touched the bottom. The tool was not hanging over too far. I was still trying for a light, controlled touch.

I remembered that this has happened many times with Both of Benjamins Best scrapers. I wonder if any others have experienced this.

My next thought is to get a medium size scraper from Thompson tools to see if the powdered steel has less spring.

Thanks in advance for your comments

[Fred Belknap]

Brian I'm no expert but I have noticed on a lot of things that scraping near the center and at close to 90° to the grain that they will chatter. I find that the scraper works better if it is pointed down, handle high, and the tool rest above center. I also put a negative grind on the top of my scrapers. The only BB tool that I have is a parting tool and it works fine except it seems to dull rather quickly.

[Roger Chandler]

Brian............I have the 1" x3/8" round nose scraper from BB. I agree with Fred...........the proper use of it is have your tool rest above center and your handle high and make your cuts just a hair above center line. I also tilt the scraper to about 35 degrees or more when transitioning from the bottom [center] to the rim to finish with a light shear scrape. I get very good surfaces this way and on a lot of bowls can begin my sanding at 220 grit.

Of course, I put a keen edge on the tool to begin with, but that scraper is my go to tool for doing final passes on a bowl.

[Thom Sturgill]

I have two Benjamin's Best scrapers (3/8" inside bowl set) , two Extra Heavy (1/2") Sorby's (Straight and inside bowl) and one of Doug Thompson's (custom grind) scrapers. Doug's seems most stable even though it is the thinnest of the lot. It's also the hardest to get a fine edge on. I 'roll' a burr rather than using the grinder burr and it is just too hard, so I made a negative rake scraper out of it. The BBs get the easiest burr, and cut well with a rolled burr, but I have to be careful not to roll the burr too far. The Sorby's are my work horses, while I use the BBs for finishing cuts, often held on their edge for a shear scrape.

[Jason Ritchie]

I also have the BB inside bowl scraper set and had tons of issues with chatter and catches until I re-did my sharpening setup and started using the 180 CBN wheel. I think my issues were due to the tools not being sharp enough. I did notice right off the bat that these scrapers were harder for me to get a sharp burr on than my other scraper. I find my best results using these on edge for a shear scrape with very light cuts. You have to really grind the bottom edge though so it doesn't dig into your tool rest as that bottom edge gets really sharp after grinding.

[Brian Kent]

Thanks for your info, everyone. Jason, what do you mean about grinding the bottom edge. Not sure what you mean.

I am working above center until that final point of the nib in the center. The angle is as high as I can get without touching the rim. Am I seeing correctly that when the tool rest is angled deep to the bottom and I use it for a final cut in the bottom center, that the geometry creates a sheer cut?

I am using a blue wheel for grinding and touch up frequently.

[Thom Sturgill]

Brian, the reason for cutting above center on the inside (below on the outside) is that a catch will force the tool away from the wood rather than making it dig in. The angle (or angled grind) creates a negative 'rake', that is it presents the tip of the burr (which is slightly rolled toward the handle) to the wood at the proper angle to cut.

I believe that you need to angle the scraper on its edge to get a shear cut where the wood fibers slide along the edge and are sliced off rather than chopped off. Some of us round over the left bottom edge to keep the scraper from digging into the tool rest when we angle the scraper.

[Jason Ritchie]

Sorry, I should have been clearer. When you bring the scraper up on its long edge for a shear scrape, that sharp long edge will dig into the tool rest as it become very sharp from sharpening. Its the long edge running from the handle all the way down to the tip. You have to grind it slightly to round it a little so it doesn't dig in to the tool rest when you bring it up on edge. Capt. Eddie talks about this in one of his videos. He also does this to his skew chisels to make them slide on the rest smoother without digging in. Does this help at all? I'm not the best at explaining things.

Here is a diagram. Yeah, my drawing skills aren't any better than my turning skills... lol
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[Reed Gray]

Well, if you have a 3/8 inch thick scraper, it should not flex under load. Possible reasons it seems to be moving could be because you are hanging out too far off the tool rest, and or your handle isn't long enough. This would make the tool more grabby. Another possibility would be the fit into the handle. My first scrapers came from Craft Supplies, and they are square tapered tangs pounded into a round hole. Not a good fit, and eventually they will work loose, especially if you use them a lot. Filling with an epoxy might help. With my Thompson scrapers, I make a 3 piece sandwich type handle. The center piece is the same thickness as the scraper, plus about 1/64th of an inch, so the fit will be tight. I mark out the tang size on the strip and hollow that out on the bandsaw, again, just a hair over size. Then the bread part goes on the outside of the center/meat (or pb and j). Glue it up, turn it out, use a 1/8 inch thick brass ferrule. Yea, I know, a bit of overkill, but strong and sturdy.

Rounded edges: I always grind away the bottom edge of the scrapers. I put a 1/4 round profile on them, and don't understand why they don't all come that way. Skews do, and a skew is a tool we know gets used up on its edge. A square corner will dig into your tool rest and not slide easily, even on the drill rod rests. I do need to get a belt sander to properly round over my edges, and smooth them out. Doing it on a grinder isn't easy, especially getting it smooth so there are no facets in it.

For scraping cuts, ALWAYS have the handle elevated on one side of the tool rest, and the cutting edge pointed down on the other side. This is standard scraper safety. You can hold it level, but never point it up into the spinning wood. When it digs in, it will always dig in much deeper. On the outside of the bowl, cut at center of slightly below, and on the inside, cut at center or slightly above.

For shear cuts/shear scrapes, you roll the tool on its side, and drop the handle, almost exactly like you do with a gouge. I prefer scrapers for this cut. Dropping the handle insures that you will cut with the lower part of the tool, just like you do with a skew. If you get onto the high side, the tool is unbalanced, and it will catch (I show a good example of that in the following video clip. The tool is 3/4 inch square stock, and is high centered to begin with, and I end up on the top side of the tool when the catch happens).

Scrapers need a good burr to cut with. The CBN wheels produce an excellent burr, and no burnishing/turning is necessary as far as I am concerned. I was told that you can not burnish/turn/ticket a burr on HSS by hand. Well, I found it not to be any problem at all. I have found that a triangle burnishing tool works better than a round one. If you stop to think how many psi you can generate with that tiny triangle edge, it is a lot. Those that I have watched using the Veritas scraper burnishing tool that screws down to your bench, seem to use huge amounts of pressure. You can over burnish to the point where the burr turns over like a breaking wave. A few light strokes with the burnisher at a very slight angle (bevel at 70 degrees, burnisher at 80 or so), a few light strokes and you are ready to go. However, with the CBN wheels, I just haven't found it necessary to burnish a burr, even on Doug's tools. I do generally relieve the bevel on the bottom of the tool also. Takes longer to raise a grinder burr on 3/8 inch stock than it does if you grind off/round over the bottom part.

Negative rake scrapers work best in very hard woods. I just don't use them except on boxes for the lids and bottoms. Probably should use them on the bottom inside. You do use them with the handle held high, and blade down.

https://www.youtube.com/watch?v=g92Ze9iMR4Y

robo hippy