Sean Couch Posted June 2 Author Report Share Posted June 2 Reverted to working on the arching of the back. She is getting there. I think I might actually be close to switching from finger planes to scrapers. Quote Link to comment Share on other sites More sharing options...
MikeC Posted June 3 Report Share Posted June 3 That's looking good! I just did the scraping on mine last night. Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 3 Author Report Share Posted June 3 Thanks. I am going to do one more round with my templates and finger planes and then move onto scraping. After dozens of attempts, I still can’t turn a decent burr. I will get it though. I have a few things to try on the next attempt. Quote Link to comment Share on other sites More sharing options...
MikeC Posted June 3 Report Share Posted June 3 One important thing with scrapers is to make sure you start with a square edge. I made a small block of wood with square sides. Put it on the stone and hold the scraper flat against the square side of the block and then rub the edge of the scraper on the stone. I used cheap harbor freight diamond for the initial shaping. If the edge is not square but is slightly rounded, you'll have a hard time turning a burr. And when turning the burr, you only need the burnisher to be at a slight angle. Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 3 Author Report Share Posted June 3 I made a little jig to hold my scraper at a 90 to the diamond stone. I also honed the flat sides near the edge using the “ruler trick.” I think my issue is with the burnisher. I need to get the right amount of pressure and the angles correct. My burnisher is about 10mm in diameter. Does the size of the burnisher matter? Quote Link to comment Share on other sites More sharing options...
Mike Atkins Posted June 3 Report Share Posted June 3 26 minutes ago, Sean Couch said: I made a little jig to hold my scraper at a 90 to the diamond stone. I also honed the flat sides near the edge using the “ruler trick.” I think my issue is with the burnisher. I need to get the right amount of pressure and the angles correct. My burnisher is about 10mm in diameter. Does the size of the burnisher matter? I think the “ruler” trick is really meant for plane blades (though I wouldn’t use it) and on a scraper this would prevent you from getting a burr. because it essentially creates a sort of micro-bevel. if you’re referring to the ruler trick where you place a thin ruler under one edge while honing the other. Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 3 Author Report Share Posted June 3 Yup, that’s the trick I tried. I will try it without the ruler and see if that helps. Quote Link to comment Share on other sites More sharing options...
Mike Atkins Posted June 3 Report Share Posted June 3 Yeah, that will definitely make it almost impossible to get a burr on a scraper... that trick is from David Charlesworth and it's only meant for plane blades, not for chisels or definitely not scrapers... it would probably end up something like this: Quote Link to comment Share on other sites More sharing options...
MikeC Posted June 3 Report Share Posted June 3 I did this when I should be working... Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 3 Author Report Share Posted June 3 Hey Mike and Mike, thanks for the illustrations. I was able to get a little bit of a burr turned on my scrapers, but not very much. My scrapers are about 0.40 mm thick. How thick are your scrapers? On a whim, I went to my basement metal hoard and found some titanium that I used for liners in folding knives or to make mokume (don’t remember which). It is 1.25 mm thick. I ground a quick radius on it with the belt grinder and then polished it a bit. It is not super smooth as I didn’t spend much time on it. Then I applied the burnisher along the edge to try to create the burr. Bingo, I can make a burr! I can see the burr when I have my readers/cheaters on. Figured I would try it out on the violin and it worked. Not big shavings, but not dust either. I scraped for a few hours and the burr held up just fine. I even used it with my templates to refine my cross arching. Now I need to blend it all together again, but that is tomorrow’s job. The electrical tape is to reduce reflections from my light. I have plenty of high carbon steel that is about 1.6 mm thick. I may make some prototypes and see if various levels of hardness help or hinder creating the burr, its performance, and durability. Quote Link to comment Share on other sites More sharing options...
Mike Atkins Posted June 3 Report Share Posted June 3 35 minutes ago, Sean Couch said: Hey Mike and Mike, thanks for the illustrations. I was able to get a little bit of a burr turned on my scrapers, but not very much. My scrapers are about 0.40 mm thick. How thick are your scrapers? On a whim, I went to my basement metal hoard and found some titanium that I used for liners in folding knives or to make mokume (don’t remember which). It is 1.25 mm thick. I ground a quick radius on it with the belt grinder and then polished it a bit. It is not super smooth as I didn’t spend much time on it. Then I applied the burnisher along the edge to try to create the burr. Bingo, I can make a burr! I can see the burr when I have my readers/cheaters on. Figured I would try it out on the violin and it worked. Not big shavings, but not dust either. I scraped for a few hours and the burr held up just fine. I even used it with my templates to refine my cross arching. Now I need to blend it all together again, but that is tomorrow’s job. The electrical tape is to reduce reflections from my light. I have plenty of high carbon steel that is about 1.6 mm thick. I may make some prototypes and see if various levels of hardness help or hinder creating the burr, its performance, and durability. Nice! i’m glad you were able to figure it out. Maybe you just need to work on the other scraper until that micro bevel you created is gone and you have a nice square 90° edge. My scrapers I made from .55 mm thick, spring steel. The ones that you were talking about, may be too thick and definitely titanium is probably too hard, because you need to be able to flex it a bit in order to conform to the different curves. Titanium might also be too hard to get a good burr, the burnishing tool needs to be harder than the steel I think. Those would probably work fine for flat stuff though if you can get a good polish and burr. Quote Link to comment Share on other sites More sharing options...
MikeC Posted June 4 Report Share Posted June 4 I just use cheap cabinet scraper set from Amazon and cut to whatever size and shape I need. I don't know how thick they are but they seem to be good steel. I'm about to post a scraping video. At 11:55 minutes in you'll see me make a quick sharpening. Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 4 Author Report Share Posted June 4 Working on scraping and refining my contour lines. The lines are now fairly even, but I think they are the wrong shape. They need to be more oval and less like a peanut from what I understand. It looks like I need to remove some fullness out of the upper and lower bouts to get the contours more oval. Seems to be the story of my life. lol. I also modified the scraper and honed the edge. Every few hours I need to burnish again, but at least I have a functional scraper with a decent burr. Quote Link to comment Share on other sites More sharing options...
Mike Atkins Posted June 4 Report Share Posted June 4 32 minutes ago, Sean Couch said: I also modified the scraper and honed the edge. Every few hours I need to burnish again, but at least I have a functional scraper with a decent burr. Woohoo! you're getting a good burr, nice! Scrapers are a joy once you get used to sharpening them. Every few hours seems pretty normal I think, that's not too bad. I usually keep a strop close by and refresh all of my tools at least that often. Quote Link to comment Share on other sites More sharing options...
MikeC Posted June 4 Report Share Posted June 4 yeah, I'm glad you got the scraper working, they are fun to use making thin shavings. Your contour lines don't look too bad, they are very symmetrical, maybe a little pinched in the waist but not bad, Quote Link to comment Share on other sites More sharing options...
MikeC Posted June 4 Report Share Posted June 4 There's an old thread here that shows some Stradivari contour lines to compare with. Here's the images I saved from that old discussion. Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 5 Author Report Share Posted June 5 Hey Mike, awesome, thanks, those pictures help. I am pondering what my next move is. I can see the pinched C-bout area you mention, I will probably try to extend the shape in the C-bout into the adjacent areas more to take some of the pinch away, and I think I need to take out more material in the upper and lower bouts to get that 4.8mm line (the first contour line) further away from the edge. While I ponder away about the back, I will switch to working on the top. I have a bunch of material to remove from that plate. Almost looking like that upside down bowl again. lol. Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 5 Author Report Share Posted June 5 22 hours ago, Mike Atkins said: Woohoo! you're getting a good burr, nice! Scrapers are a joy once you get used to sharpening them. Every few hours seems pretty normal I think, that's not too bad. I usually keep a strop close by and refresh all of my tools at least that often. Aha, right on. Scraping is enjoyable when you can get a burr. Thanks for your help on that. I still need to find a way to get around my crutch of using thicker material. I feel compelled, for some reason, to get a good burr on my steel scrapers. I am going to try the accu-burr. Basically trade one crutch for another. Ahaha Quote Link to comment Share on other sites More sharing options...
Mike Atkins Posted June 5 Report Share Posted June 5 1 hour ago, Sean Couch said: Thanks for your help on that. You're welcome! I think really it's just a matter of getting that initial 90° edge on the thinner ones, and really if you don't even bother turning the burr but just leave it square, and use the burnisher lightly, it will work. Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 5 Author Report Share Posted June 5 I might spend some more time on the steel scrapers tonight while I have a few cocktails. I may buy some .5 or .6 mm stock and try that. My scraper works, but I’m still not getting those nice wispy curls so I have a ways to go. Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 7 Author Report Share Posted June 7 I worked on the belly a few days ago, not much to show picture wise. Took out a bunch of excess wood and started refining the purfling channel. For the past couple of days I have been pecking away at the back plate. Today I think I finally got the 6th set (yeah, I’m an idiot), the purfling fluting depth set, and two of the 5 cross arches set. After I set the other 5ths, I will blend and do the final scraping. It is coming along. Quote Link to comment Share on other sites More sharing options...
resonant Posted June 8 Report Share Posted June 8 (edited) Plates are looking great and I'm interested to hear the finished product! Gorgeous edges already by the way. Looking through this thread made me feel like making each component of the violin is its own separate project with its own set of challenges and goals but then again these separate components must form a cohesive whole. Also so great to see how forthcoming all the experts are with their advice in this thread! Free expert mentoring, who would've thunk it. Edited June 8 by resonant Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 8 Author Report Share Posted June 8 Thanks for the nice words Resonant. Yes, the feedback is great, I appreciate it all. The encouragement and the criticism from novices and from experts is wonderful. You really can’t ask for more. Its great when people are willing to share their knowledge. I spent some time today on the back getting another 5th set and the fourth one almost there. Right now, after spending so much time on arching, I am itching to move on to the next step. It is at this point in a project that I usually rush things. This time though, when I felt the urge to hurry up, I walked away from the bench for the day. Even old dogs can learn a new trick. Quote Link to comment Share on other sites More sharing options...
Sean Couch Posted June 10 Author Report Share Posted June 10 Getting there. Quote Link to comment Share on other sites More sharing options...
MikeC Posted June 10 Report Share Posted June 10 That's looking good! The second picture, side view can you take a picture with the camera a little bit lower, like halfway between that and horizontal? I would like to see what that looks like at a slightly lower angle. I think I got a bit too much recurve in mine in the upper and lower bouts. Quote Link to comment Share on other sites More sharing options...
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