Replies

1. 
   Pippins | Oct 28, 2005 03:53pm | #1

   Cecil, keep in mind that you do not want try to roll the entire edge thickness into a burr. Your scrapers should be undercut slightly and the burr formed from just the very top layer of metal. 

   There are special burnishing tools that are made to roll burrs on turning tools but I have never used one.  

   You should be able to get a useable burr on the scrapers direct from the grinder. I use an 80 grit 6" white wheel on a slow speed grinder - 1725 RPM.

   Others will have their own technique. Try several to see what works for you.   

   I usually polish the top surface of the scraper. I am not after a mirror finish. Just a good smooth surface.  Set the grinder to under cut slightly and grind the normal profile with a light touch. At this point a useable burr will be formed. It will dull or dissappear with use.

   Once the profile is gound and the edge undercut, roll a burr on the top edge with a regular cabinet scraper burnisher. I frequently will polish off the top surface to eliminate an old burr and go back to the grinder.

   Steve Pippins

    

    

2. 
   papanick | Oct 28, 2005 04:25pm | #2

   Put two 1/2" Dia router bits in a vise upside down, about 2" apart.

   press the scraper against one, and lever the tip along the other (ideally a solid carbide bit).

   Turns a burr on anything.

   The older I get, the better I was....

3. 
   tailsorpins | Oct 28, 2005 07:59pm | #3

   The burr remaining after grinding a lathe scraping tool should be sufficient.  Actually, I'd suggest you move toward using the skews and gouges as slicing tools, as the work goes much quicker and the quality of finish is superior.

   I was taught that the primary teeth of a scroll saw blade should point toward the table or handle, be it motorized or manual (coping).  This provides the most support during the heaviest cutting stroke.  Naturally there will be situations with a motorized scroll saw where you want any splintering resulting from the cut to be on top, and you otherwise have means of holding it down to the table securely.

   John, back in Texas  

1. 
   cecil | Oct 28, 2005 08:43pm | #4

   Thanks to everybody It is so nice to belong to a Forum with such skilled members. I got good answer and I will conduct myself toward the advise.

   Thanks again, dearly

    

1. 
   jigsawjohn | Oct 29, 2005 12:49am | #5

   Cecil

   I put two 3/8' carbide blanks in an aluminum block and used the aformentioned method it works very well.

   As stated in another note I use about a 5 deg angle on my scrapers, but i only use scrapers on the inside, the skew is the most used tool I own.JigSawJohn

2. 
   Steinmetz | Oct 29, 2005 05:06am | #7

   tail, scrollsaw blades should cut on the down stroke ie: toward the table
   If you want your work to dance, try the reverse. By the way, for really smooth no splinter cutting, they make scroll blades that have upcut and downcut teeth in the same blade. Steinmetz.

1. 
   WillGeorge | Oct 29, 2005 09:52pm | #8

   I DO NOT do much scrolling but I have some olson? blades that cut UP/DOWN.. NICE..

4. 
   DennisS | Oct 29, 2005 02:13am | #6

   Cecil -

   Steve's given you the same advice I would have if I'd gotten here first (grin). What surprised me is that a very satisfactory bur will be raised with the wheel turning !into! the tool, that is into the top side of the scraper. It should be a slight, say 5 degree bevel is all.

   I used to agonize over trying to roll a burr as well until I saw this demonstrated at one of my turners' club meetings where the topic of discussion was sharpening. One of the members was grinding a scraper in this fashion, with the wheel turning into the top of the tool, and I asked the question, "How do you then raise the burr?" They passed the tool around and by golly, there was a very fine burr right there without bothering with any kind of burnishing tool.

   However, if you feel like you need to use a burniser, I picked up some old auto engine valves at my mechanic's shop which seem to be made of pretty hard stuff. I'm told Volvo valve stems are the hardest, though. My HSS scrapers don't seem to dig into the valve stems so I guess they're harder than the tool. In a pinch I've used the tang of one of my larger mill files.