Replies

1. 
   Kell | Jun 03, 2003 04:27pm | #1

   Richard,

   Depending on the radius, I've found several tools useful for outside curves.  A spokeshave, properly tuned is a joy to use for fairing some curves.  Rasps and files are useful, especially when the shapes change from one radius to another quickly and you don't want to keep changing tools (e.g. for cabriole legs).  I'm also starting to use micro-planes for some shaping and find them nice to use. 

   I've seen David Marks on Woodworks use a flexible piece of hardwood with sandpaper taped to it for fairing some radii but I haven't tried that yet.

   Kell

1. 
   rckendall | Jun 04, 2003 03:04am | #2

   Kell,

   Thanks for the response. I've tried all those you mentioned for outside radii. I also like the micro planes, especially with the offset handle. I've used pieces of plastic with sandpaper attached also. I guess what I'm looking for is a convex shaped cabinet scraper. It seems that something with a curve would suit much better than a flat cutting surface making a radius with many small cuts.

   Anyway, thanks again.

   Richard

1. 
   clampman2 | Jun 04, 2003 04:05am | #3

   A friend of mine and former neighbor restores antiques for a living. He has an extensive collection of metal scrapers in his shop. He also showed me one of his tricks for odd profiles - several boxes of broken glass. If he couldn't find the right profile - he'd just slam a box back down on the floor, and start looking again.

   Clamp;man

1. 
   Kevin | Jun 04, 2003 10:59pm | #4

   "If he couldn't find the right profile - he'd just slam a box back down on the floor, and start looking again."

   It was that kind of ingenuity that moved us from a relatively insignificant colonial backwater to the sole superpower on the planet. LOL

   Regards,

   Kevin

2. 
   Alan | Jun 05, 2003 02:34am | #5

   Richard,

   Don't overlook the possibility of making your own scrapers.  You can make them to any profile you want.

   I make a lot of scrapers (I suppose because I don't use a router) and I make many with the exact profile I want.  I make them out of other scrapers (I buy whenever I see a "sale" on cabinet scrapers; that keeps me pretty well supplied) and out of old saw blades that are good for nothing else.  They can be shaped with files or a Dremel-type rotary tool.  To reduce chattering I will often make a holder so the scraper blade is supported near its edge; but that usually isn't necessary, and if not I clamp them in a simple home-made handle.

   Alan

1. 
   rckendall | Jun 05, 2003 03:06am | #6

   Alan,

   Thanks for the help. I believe we are on the same page. I ordered an assortment of scrapers and had intended to make my own but was unsure how I was going to do it. I guess the filing and stoning stage will be a challenge with the small concave shape that I need.

   Regarding the chattering, are you saying that the scraper needs more support closer to the cutting edge?

   Thanks again for your help.

   Richard

1. 
   Alan | Jun 07, 2003 04:04am | #7

   Richard,

   When my scrapers are chattering I can usually get them to stop by either giving them some support out near the edge, or--if the scraper's shape allows--by flexing the scraper.  Flexing the scraper makes it cut more aggressively, and it somehow stiffens the edge and eliminates the chattering.

   If you have a tool like a Stanley #80 or Lee Valley's card scraper holder, for example, they both have a screw that flexes the blade; or if you're using a card scraper without a holder you can accomplish the same thing with your thumbs.  IME just flexing the scraper will almost always stop its chattering.

   (Whether the scraper is held in a tool, or is hand-held and flexed, for either measure to work presumes, of course, that there's a proper sized and turned hook, that the tool is held at the correct angle, and so forth.  Just holding the scraper at the wrong angle can cause it to chatter.)

   When I make a scraper to a particular profile of the sort that I cannot flex it in use, I make a holder for it that will support the it as close to the edge as possible.  IME flexing or support near the edge will eliminate most or all chattering.

   Wow...too long.  Sorry,

   Alan

2. 
   rckendall | Jun 07, 2003 05:33am | #8

   Alan,

   Thanks for the response. I had another pretty good session today on curly maple. Most of my work is in really small complex places where I need small tools. The scraper I used today is about 1" x 2" and thick enough that it won't flex. I did find that if I decrease the angle it helped but at times with the figured wood I just had to take what I got.

   I rough shaped with a 4" grinder or rasp and quickly followed with scraping. Then faired it with sandpaper on a plastic "block". Good results today but always interested in how others do it.

   Thanks again,

   Richard

3. 
   Clay | Jun 07, 2003 06:19am | #9

   There are several ways to minimize chatter.  The easiest method is to vary the speed of scraping.  slowing down will usually be most successful but occaisionally a faster speed is also helpful.  Since it is the easiest adjustment it should be your first attempt to control chatter.  Thicker scraper stock is stiffer and will tend to chatter less easily.  Wider scrapers also have a bit less chatter than narrow ones do as they can flex less easily and chatter is dependent upon flexing of the scraper.  Supporting the scraper closer to the work shortens the effective extension of the blade which also allows less flex and thus less chatter.  In some cases the scraper can be skewed to attack the wood surface at a slight diagonal compared to the prevailing attack angle.  This often allows the scraper to bridge the corrugates that were created by previous chatter and to cut them back to a smoother profile thus minimizing additional chatter tendencies.

4. 
   rckendall | Jun 07, 2003 05:22pm | #11

   Clay,

   Thanks for the input. You confirm all the thoughts I was beginning to form myself. I think at times I am just being too agressive on small areas. I am impatient with some of this, but the results so far are encouraging. At this point I think it is a matter of practice.

   Thanks to all,

   Richard

5. 
   HenryVIII | Jun 07, 2003 06:22am | #10

   An old tool may be your answer.  There used to be a thing called a "fid" in general use.  FW had an article a while ago about using these.  They amount to a tapered rod, kind of like a belaying pin (for the sailors among you) with a split lengthways in the tapered part.  You can make the rest into a handle that suits your hand.

   You put a piece of sandpaper in the split and wrap it around the tapered part.  This gives you an infinitely variable radius for sanding inside (concave) radii (radiuses ? ..whatever).

   Hope this helps

6. 
   JeffKurtz | Jun 07, 2003 07:46pm | #12

   But how do you form a nice edge and hook on curved profiles - especially if they're small?

   Jeff

7. 
   Clay | Jun 07, 2003 08:33pm | #13

   You use small tools to do the small profiles.  Jewelers files or small sets of variably shaped fine cut files will work well.  File at an angle so that your file creates the burr as you shape the profile.  Small profiled grinders such as are sold for sharpening chain saws are good too.  You can also make your own small burnisher.  Drill rod hardened and set in a handle is excellent.  Some commercial burnishers (especially the triangular ones) come with tapered tips that work well on small profiles.  Another source of good steel for burnishers is cut nails, which are sold for use in concrete.  They have pretty good quality steel and when heated to a bright orange red and then quenched in oil they will make a nice hard burnisher.  You want to shape them out on the grinder or belt sander before hardening (get them as smooth as you can by sanding here because after hardening you will work very hard to make much of a dent in them) and then polish them afterward on a buffing wheel (white diamond works well for me).

2. 
   MBL | Jun 09, 2003 09:53am | #14

   Dear Richard,

   You can make curve scrapers by cutting them with metal shears and fix with round or half-round files. Then hammer them flat and then sharpen them with files, probably the same ones you use to give it its final shape.

   Even straight scrapers get a curved edge the more one uses them, so for straigh flat surfaces, one has to check to make sure one is not using a curved edge scraper. A slight curve is ok, though.

   You can also get curves with a piece of a broken hack-saw blade, file the teeth away first.