I have a little hand held Holmenkol sharpener with ceramic cutting surfaces which really puts a sharp edge on the scraper. But as others have pointed out, scraper becomes non-flat after a while. Damn spendy too!
Here's a couple of low tech solutions which seem to work very well for making a *flat*, *square* edge on a Plexiglas scraper.
"The DJ Clipboard Jig"
(my invention, at least I haven't seen it before):
|A normal clipboard, regular or legal size. The stouter the better.|
|Find a piece wood about as long as the clipboard and as thick as the clip will hold (maybe about 3/4 inch thick) - like a 10 - 12 inch piece of 1 X 1 or better yet, I now use a piece of 2 X 2 chiseled down at one end to about 3/4 inch thick so it will fit under the clip.|
|A full sheet of sandpaper - maybe 150 grit give or take (experiment, I can't remember off hand what I'm using).|
|1.||Put sandpaper on the clipboard and clip it in place with the stick of wood on top of it - in any position.|
|2.||The wood now serves (a) to hold the sandpaper in place and (b) as a perpendicular guide for the scraper as you rub it lengthwise on the sandpaper to sharpen it. Move the stick to another place on the sandpaper to get at fresh grit.|
|3.||The clipboard serves as an always ready-to-go flat space (see below).|
|4.||The trick, as in all scraper sharpening, is to make sure that the scraper is flat when rubbed along the sandpaper to avoid convexity.|
This jig holds all your materials (sandpaper, perpendicular guide and flat surface) at the ready and can be hung up on a hook or pegboard. It is kind of self cleaning in that the sandpaper grit loses a lot of the Plexiglas residue as it hangs.
I hope this makes sense. If it doesn't, here's an even simpler way:
"The Normal Old Sandpaper With 2X4 Method"
(taught to me by a friend, probably a common method)
|Clear, *smooth*, flat surface (this is my problem during ski season - no clear space without lumpy waxy residue! - and why I came up with the clipboard method)|
|Full sheet of sandpaper as above|
|Something to use as a perpendicular guide - the edge of a small carpenter's level laid flat is great if your clear space is that big or a 12 inch or so piece of 2X4 will work|
|1.||Put the sandpaper flat and place the "guide" over it.|
|2.||Rub the edge of the scraper lengthwise on the sandpaper, along the guide, to sand it sharp.|
|3.||Change position on sandpaper to expose clean grit.|
Both of these methods work very well for making a flat, square edge on the scraper.