Having trouble with your scraper?

[Roger]

 Thought this might help some of the aspiring bowyers...

One of the most important tools in my kit is the “scraper”. I have a variety of shapes to include a convex, concave, gooseneck & rectangular. Each one has come into play at some point in time while making bows. A scraper has a variety of uses in bow making as well. It is a great finesse tool for bringing in tillers because of the small and precise wood removal. It can be used to remove tool marks, which saves a lot of sanding time and paper. It can also be used as a “gauge” along the bows limbs to detect flat spots while tillering.
 All that being said…a scraper is no good to anyone if it doesn’t have the edges dressed properly. This is certainly not the only way to dress one, but it is how I do it. Don’t let the name fool you into thinking your “scraping” wood off a bows limb. Properly dressed it “cuts” instead of scrapes (yeah I guess it scrapes it off). It can remove fine ribbons of material or it can hog off substantial material as well. The cutting action comes from a “burr” that is rolled onto the edge of the scraper.



To obtain the “burr” we desire you will need the following:
1) A vise, clamps or some other means to hold the scraper while allowing you access to the edge.
2) A 10” or 12” Mill Bastard  file
3) A hardened steel punch or drill rod

Begin by laying the scraper on a flat object on its side. Take the file and lay it flat on the scraper and remove any existing “burr” that may be present. Be sure and do both sides.



Now…place the scraper edge up in your vise or whatever device you have chosen. Take the file and lay it flat across the edge to as close to 90 deg to the sides as you can get. Use your fingers as guides and to help steady the file. Begin pushing and pulling (draw filing) the edge of the scraper from end to end. You can feel when the file starts to cut or bite. The edge of the scraper will become shiny. Note: The closer you get the edge to 90 deg the better the burr you can roll…so pay attention to the file angles and keep it steady. Also if you hone the edge with a stone you will get even better results, but I usually just use a file. Do all four edges the same way. Now, you need to repeat this whole process again…trust me on this you need to do it.



Once everything is all filed and nice and square, Take your hardened rod of choice (I use a steel drift) and wipe the edge lightly a few times holding a little lower than 90 deg to the sides.
 


Now, wipe the edge a little harder and a little lesser angle as you begin to roll the hook. Test it with your fingernail…you can feel it.



Do all eight edges the same way until you have all the edges rolled. Now you ready to “roll”…:>)



Hope this helps….

R

[mullet]

   thanks Sparky,That was very informative.

[Coo-wah-chobee]

 Good thread rog-uh-wash your hands-bob

[duffontap]

Cool Roger--Thanks!

I was thinking of doing a similar thread, but it wouldn't have been as good!  Ha, ha.  Well I'll just say that a scraper is as important as a rasp, or bandsaw or anything in bowyery.  If you can learn to sharpen it, you will love it.  I was taught by a luthier how to sharpen mine, and I now sharpen it all the time for improved performance. 

I've started to do very aggressive burrs on my scraper and cutting with it at a steeper angle (sometimes laying almost flat).  All I do for this is quickly square an edge with a file and then make three progressively steeper passes with increasing pressure (lots of pressure) to form a single large burr.  I only do one edge most of the time and keep it very sharp while I'm tillering.  I mark my cutting edge with a 'X'.  I only do one edge when I'm using an aggressive cut because I could slice myself pretty badly with the edges I put on it. 

I'm going to try sharpening a scraper exactly how you do it.  That looks very precise.  Thanks for the info.


         J. D. Duff

Here's a couple pictures I took a while back while I was thinking about doing a sharpening thread:

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[Badger]

I normally do it the same way you do JD, but I also roll the edge on some of mine, I like the rolled edge burr better for my finish work before sanding and the hard burr done with only my file for more aggressive tillering, I used to do mine at 90 degrees but now push only one side at about 70 degrees, using pretty heavy pressure on my file, just until I feel the file dragging smooth across and cutting evenly. You cant miss the feel once you hyave done it. Steve

[Roger]

Thanks Eddie...hope someone can get some use from it...

Bob, LOL that saying brings back a lot of memories from my childhood (the Lava soap commerical).

 JD, that is some curl there dude! That right there shows just how effective and versitile a scraper can be. Very nice!

R

[Tom B]

thanks for posting that roger. sometimes you can add a lot of life to a burnished edge by using a utility knife to re-raise the hook.it can save a lot of down time by not having to go back to square one and is very simple. tom

[Roger]

Interesting thought Tom...can you explain how you do this please?

Thanks,

R

[Justin Snyder]

You guys make my bow making skills look silly, now you make my scraper sharpening look bad to. LOL  I usually just file mine square and go to work, I'm going to have to try this.  Thanks guys and keep up the teaching.  By the way, were do I send my tuition for this school of bow making?  Justin

[Tom B]

justin, if it was about building bows i would be the student.
roger,use a new blade and keep it as flat as you can against the body of the scraper. scrapers get dull when the burr folds over too much, so you give it a lift.i have cut myself this way be carefu . tom

[Roger]

Thanks Tom...i'll give it a try.

R

[huntersim]

Nice Roger. They should archive this in the how to section.

[lowell]

Thanks for great post. Can't wait to try it. 

Hands are recoverying from carpal tunnel surgery but will be trying as soon as able!!

[Roger]

Thanks guys...just trying to pass it along as it was done so for me   

R

[D. Tiller]

Can anyone tell me how to go about making a scraper from mettle laying arround the shop and home? On a budget these days so I'm looking for ways to stretch the dollar.