Toothy Scraper

[John Tisdale]

You might find the following to be a new wrinkle:

Take a dremel tool with a cut-off wheel and make a set of light scores about 1/16" apart across the top of a scraper perpendicular to the edge - I make the scores maybe 1/32" deep - consistency is not an issue.

Each tooth acts as a shield to the next tooth preventing too heavy a scrape/cut. The corner of each tooth is a point that will remove stock. Kinda like 5-grit "sharpenable sandpaper".

I make mine out of M42 wire-stripper blades I get from a surplus shop for $.50 each. You can slot the back to mount on a Stewart hook tool or you can make a straight tool with 3/4" or larger drill rod with the end cut a 10 to 15-degrees. Presenting the edge at a 10 to 15-degree angle works good for me.

Some blades are 1/2" wide and only four or five teeth. Others are over 1" wide and maybe 8 or 9 teeth. The edge is always curved to keep the corners out of the cut.

You'll find it a very controllable and civilized tool. Comes in handy when removing bumps and tool-marks from the inside of hollow-forms. While I'm not a bowl guy, don't see why it wouldn't work to smooth the inside of large, or small, bowls.

I got the idea from the tooth-blade for bench planes used for fast stock removal.

To anyone trying this, let me know how it works for you. To quote Keynes: There is no harm in being sometimes wrong - especially if one is promptly found out.

John

 

[Odie]

Thanks for the suggestion, John..... I have no idea if the toothy blade has any application to bowl turning, but I'd certainly be interested to hear from those who have experience with it. Here is a YouTube video that will serve to understand the concept behind the blade.....

https://www.youtube.com/watch?v=Gl8Tj1lUha4

 

[Charlie Knighton]

would you need to turn in forward and reverse modes to similate the viedo?????????

 

[Hal Taylor]

John, I'd love to see a couple of photos of your toothy tools. They sound very interesting.

 

[hockenbery]

You might find the following to be a new wrinkle: Take a dremel tool with a cut-off wheel and make a set of light scores about 1/16" apart across the top of a scraper perpendicular to the edge - . John

John, I curve my scraper blades.
So the scribe makes would not be parallel sort of a star burst pattern so that each scribe line is perpendicular to the tangent to the curve?

I use my scrapers to leave a surface that is smooth visually and do not sand. Sort of a 120 - 180 surface.

I do want to try the scribes. It seems like a mini thread chaser.


Al

 

[John Tisdale]

Response to Odie, Hal, Al

Odie,
Thanks for posting the video. And regarding your comments:
- "I had no idea if the toothy blade has any application to bowl turning" - I don't know if it does - I think it does - I use it to sweep across the bottom and sides of large hollow-forms. Produces a lot more shavings than a regular scraper. Maybe some guys like you, Al, Bill and others will try it out and either improve or proclaim it doesn't make sense. Whatever the jury says is my gain.
- "I'd certainly be interested to hear from those who have experience with it" - I am most of the those - I showed it to James Johnson down in Kerrville and I think he started using it immediately. If you talk to James, get him to do you a tool-rest too - he does the best on the planet. I showed it to Trent Bosch and gave him one - haven't heard back. I gave out three of four to guys at the club - don't know if they're using them or not. So everyone that read this post can be early users.
It's a funny thing: Take away my toothy scraper, James Johnson tool-rest, Rolle Munro hollower and D-Way gouge and I'm stopped. Other guys doing far superior work wouldn't consider using the above in the first place. At some point in time, most of us tend to "settle in" with what works and get good at it. Whether or not "what works" is the best is not a consideration.

Hal,
There is a pic at the following address: www.dallaswoodturners.com - go to newsletters - go to 2012_3 - small picture on page-6. Take the time to read through - you'll see pics of some really cool guys

Al,
That's exactly why I did the post. Guys like you will think it through, question, and improve. No doubt scoring perpendicular to the tangent will improve - actually I have a 1.5" wide with a 2" radius with the scores sorta perpendicular to the tangent - works good. It takes me about 20-minutes to make one with a die-grinder and Dremel - these are redneck tools.

John

 

[Hal Taylor]

John, I checked out the newsletter, incidentally y'all put out a great one, and saw the picture you mention. The grind (cut) looks to about .5 in. into a very small scraper. I was envisioning more of a saw tooth as you described.

 

[Odie]

I also looked up that photo in the newsletter. Was there nothing written about it?

If I gather things right, and if the purpose of a toothed scraper for woodturning is basically the same as for flat work, then I'm not seeing where it will benefit a woodturner......or even possible to duplicate the method. Charlie, in post #3 hinted at the problem. It looks to me that the purpose was to remove wood quickly, without any tearout in a previously difficult spot left by a planer. The cuts should be alternating directions, in order to eliminate the tearout and avoiding a "bowed" surface. Looks to me that the direction of the sweep of a theoretical toothed scraper, used in a woodturning application, might need to be reversed with subsequent cuts......and, off hand, I foresee problematic issues with safety while doing that.

Possibly a toothed negative rake scraper could overcome the safety aspects, but now we're getting so complicated in producing/sharpening/using the tool, that it may be better to just concentrate on mastering plain old gouges and scrapers.......

Still.....everything I've said here is nothing more than mental evaluation, and I could be completely wrong in my analysis. There isn't enough positive evidence for me to cut slots in one of my scrapers to find out for sure......so, if someone else wants to give it a try, I'd sure be interested in hearing their findings........

ooc

 

[robo hippy]

This is one I have never heard of before. Not sure if I will try it or not, but if some one had one and wanted to let me use it, I would try it. The biggest problem for me with scrapers that are kind of grabby is more from trying to put too much steel into the wood at one time. My favorites are 1 1/4 inch wide by 3/8 thick.

robo hippy

 

[John Tisdale]

You guys are forcing me to put some thought into personal canon - not a bad thing.
- All my toothy scrapers are similar to a scraper that would come with a Stewart hook - they all attach to a hook or straight tool with a #10 screw to fasten down
- I always present at a 10 to 15-degree angle.
- The shallow score creates a sharp corner for each tooth - each tooth is maybe 3/32" wide
- I only use the scraper after the 2nd stage hollowing (after the rough has dried to around 6%MC)
- My toolrest for hollowing has a pivot pin - sweeping from the center to the shoulder is easy
- The toothy scraper, with its sharp corners, will remove more wood than a smooth scraper
- Zero (0) difference between sharpening the toothy vs. a smooth scraper - I put it flat on the Wolverine flat rest and sweep the edge on a 180-CBN.

As I only do large hollow-forms, perhaps my turning in general and tool-use in particular is much more narrow and confined to specific tasks. I don't do bowls and obviously never tried it on such. Likewise, I've never used this scraper on the outside - only on the inside. Used within the narrow confines of my tasks it's a great tool - used in a broader range of tasks is TBD. I think it a good thing to try with a small piece of planer or stripper blade - it it doesn't work for you your out less than $1. As far as scoring an expensive Thompson scraper, I don't know. My guess is that it would only improve and would not detract - then again, it's not my expensive scraper.

I'll try to take a few pics and post - my past efforts at posting pics have not been good - maybe I can get a grandkid to help.

BRAINFART: I'm going to score the wings on an old Elsworth grind M2 gouge and see what happens - will let you know the results from either the Turner Hall of Fame or the hospital.

John
ps. It's astonishing the folly one holds true when one thinks too long alone.