Primitive Archer
Main Discussion Area => HowTo's and Build-a-longs => Topic started by: Roger on December 22, 2006, 10:51:45 pm
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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.
(http://i6.photobucket.com/albums/y215/Sparky59/scraper1.jpg)
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.
(http://i6.photobucket.com/albums/y215/Sparky59/scraper2.jpg)
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.
(http://i6.photobucket.com/albums/y215/Sparky59/scraper3.jpg)
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.
(http://i6.photobucket.com/albums/y215/Sparky59/scraper4.jpg)
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.
(http://i6.photobucket.com/albums/y215/Sparky59/scraper5.jpg)
Do all eight edges the same way until you have all the edges rolled. Now you ready to “roll”…:>)
(http://i6.photobucket.com/albums/y215/Sparky59/Scraper6.jpg)
Hope this helps….
R
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thanks Sparky,That was very informative.
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Good thread rog-uh-wash your hands-bob
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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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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
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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
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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
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Interesting thought Tom...can you explain how you do this please?
Thanks,
R
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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
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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
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Thanks Tom...i'll give it a try.
R
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Nice Roger. They should archive this in the how to section.
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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!!
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Thanks guys...just trying to pass it along as it was done so for me ;D
R
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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.
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Look for metal with a high carbon content-old circular blades are good- use a flat bastard or bastard file to get a straight edge -then follow whats said in this thread about getting a hook-bob
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Knives-karge and old machetes work well-just sharpen them to a razor edge-though you wont be able to give them a hook-look around for metal thats about 1/8 " thick or so. Betcha y'all can find something-bob
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if you need a scraper almost any cutting blade will work at 90 degrees. no not serrated lol.pocket knife etc. with a HOOK you can do more. ihave several scrapers,all with different hooks. some can be laid almost flat to the work to help remove washboard. at angles too.I LOVE SCRAPERS.tom
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addendum. dont neglect using a scraper at an angle because it helps.don't be scared of flexing the .... out of one either because sanding sucks. :)tom
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DT--the luthier I was talking about made his own scrapers out of old handsaws (you know, the ones you'd use to cut dimensional lumber with). A hand saw from a garage sale will provide enough material for quite a few scrapers. Cut them out with a good hacksaw. Cut slow so you don't lose the temper.
Badger--I do roll the burr when I sharpen mine. I just square the edge with about three passes with a file and then roll the burr with three passes with the steel (sp?) kitchen knife sharpener (while my wife isn't looking). The luthier who taught me how to sharpen these things insisted that they should be sharpened every 15 minutes or less. Now I don't get fancy but I sharpen my scraper more often. It takes me less than a minute to put a fresh edge on a straight scraper--if I can find my tools.... :)
Roger--Thanks again. This is a perfect archive thread. Did you ever read the Torges article in TBM about card scrapers?
J. D. Duff
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you betcha! tom
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Thanks guys...
JD, no I didn't see it. I dont subscribe to any magazines...however I think Santy is gettin' me a subscription to PA ;D
Is his method different, the man knows wood and tools....
R
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Here are a few scrapers I use. Machete (broken) and resharpened like a razor.Sheffield steel rectacular scraper. Pieces of 3/16" steel in different shapes.Carvers draw knife-razor sharp-good scraper-though dulls quickly. Dick Baugh's Bowscraper-2nd one-Ist one lasted 10 yrs or so-1095 steel/40 deg bevel-really good. And last "Gorgon"- 14"x6" piece of 3/16' steel-sharpen only one side-talk about to the bone-what I really like about it is you can work for a long time without resharpening and rolling-if you move down the edge. Coulndt find piece of obsidian that I use for real fine work-gawd I hope my barefoot dosent find it.-bob
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OOps posted same pic twice-here
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Roger, your method is the accepted tried and true method, some of us develop some tecniques or shortcuts on our own but yours is basicaly the correct procedure. I keep a little slot pocket on my shaving horse I can drop my scraper into and it will hold it for me to file. I sharpen several times over a few hour period. A good edge that is rolled as you describe can last for weeks. I should have mentioned that. Steve
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Hey Steve-Always wanted a shaving horse-never saw what I liked- do you like it ? Post a photo if you get a chance-I use a tool stand(heavy) and a big ole' swivel vise when I work outside which is most of the time-thx-bob
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You better clean that file up Sparky ! I like to oil my files and scrapers with PAM nonstick spray to keep them from rusting . Also helps keep the files and rasps from plugging up .
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Roger,
Torges' article is TBM was from about 12 years ago. I think it may be in Hunting the Osage Bow. I think his method is about the same as yours. If he heard how I sharpen mine I would probably be the butt of one of his anecdotes about sloppy bowyers! Take care.
J. D.
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Would cutting a 12" miter saw blade up with a torch produce usable scrapers?
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ATT -The heat would ruin the temper in the blade and what you made woundt stay sharp.-bob
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I've never been very good at sharpening scrappers. Appreciate the post, will give it a try.
Greg
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Thanks Bob. I'll continue to use it as a frisbee for vacuum cleaner sales people.
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Ha-ha-ha-ha- frisbee ! Actually if you want to do the work-heat it up- let it cool down-cut it-heat it to cherry red-dip quickly in oil or water-sometimes water will warp it-put in oven for about 45-1 hr -then sharpen-volia!-bob
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My neighbor across the road has a band saw for steel. Maybe I'll have him cut it into a couple shapes. Doable?
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Att_you have to keep the heat down so you dont lose the temper. Doable / I think so-just cut very slow and oil the steel or keep wet with water if he dosent mind-makes a mess though. you can do yourself with a good hacksaw-just cut very slow so you dont raise heat -some is ok-alot is not.-bob
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addendum-If his saw for steel is horizontal -it will have a cooling squirter-then no problem -wiil be easy-bob
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I picked up a set of 7 cabinet scrapers at the Timberline Tool store the other day for about $7. It has all kinds of shapes and a couple that are just 8x4 rectangles. I still like to finish with my free scraper. Justin
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The $7 solution may be the way to go.
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BTW, can I use a sawblade like that to make points, or would the steel be too thick?
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I have made points from sawblades(circular) and they came out ok-for me they weren't too thick.-bob
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I cut an old table saw blade with a cutting disk. I got lost from there. Should I sharpen it then flatten it and roll it? After I cut it I made it straight across with a file and could not get a burr. I think the blade may be too thick. Any thoughts, should I just break down and spend the 5.00? I'm cheap!!!
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Chessieboy, I like using scrapers cut from table saw blades, and my simple unorthodox method for getting an edge is to run it through the grinder @90deg. with a medium wheel. Depending on how you use it , and the thickness of the saw blade you can pull off thick shavings or fine hair-thickness ones. Use the opposite side of the curl. Often works best flat on surface to about 45 Deg.
Rich-
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Thanks alot, read how to do it in Deans book but didnt understand, now i got a good scraper(wide hacksaw blade) and it only took a few minutes
Thanks again.....Brian
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In their new catalog, Grizzly Products offers a 6 piece scraper set for $11. Also, An old pair of sissors with the rivet removed makes 2 excellant scrapers. Pat
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Pat, I thought I was the only poorboy who done the scisser thing- works pretty good... Brian
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For anyone interested, I went down to the local welding shop today to get some metal for trade points. While I was there I got a 24"X8" piece of stainless sheet metal and they used their shear to cut it to scraper sized pieces. I came out with 6 4"x8" stainless scrapers plus a piece for points for $3. I also asked about high carbon steel (like band saw blades) for more points and they gave me 3 old blades from their saw that are 1"x 8' long. It might be worth a trip to your local welding or metal shop. Justin
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ttt
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This is such a great How-to post I thought I would bring it back up to the top for the newer members to see.
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thanks for this info, I know what I am doing tomorrow 8)
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This is just what I was looking for! I'm glad that this was brought to the top, even as old as it is. The only thing I wish was that the images were still intact on the original post. Everywhere I was looking people kept showing that you needed a diamond/oil/water stone for the sharpening process -- I'm glad that isn't the case (less money that I have to spend getting one shipped, since nobody nearby has one that I know of).