Lapping question

[David Beeler]

Most of the info I have read about lapping the sole of a plane with sand paper (sharpening the blade as well) recommends using glass or a granite surface (such as that sold by WC) as the flat surface underneath the sandpaper. Has anyone thought of or used Corian for the flat surface? It appears to me to be very flat and should be readlily available from a cabinet shop scrap pile. Any Thoughts?

Thanks,
David

[Brian Hale]

Hey David....

Corian would work perfect! Other options include the 12" x 12" smooth floor tiles from Home Depot and such, Lexan, Aluminum or any flat waterproof surface. The idea is to be able to get the surface wet and have capillary action hold the paper in place.

For lapping the soles of planes i prefer 4" wide rolls of adhesive backed sandpaper, starting with 100 (if needed) and working through 120/150/180/220. For this a jointer bed or tablesaw top work fine, just be sure to clean up real good.

Brian :)

[David Weaver]

If cost or size is an issue, check with your local glass shop and ask them if they make glass for cabinet shelves.

My first try, I got a 1/2 inch piece of tempered glass custom made and edged and it was $90. I didn't like that, and it was too short to lap larger planes, though it is a good piece of glass.

Second time around, I called a different shop and they said they could make me a piece of glass, or just give me an 8x42 inch glass shelf for $20.

With glass, unless it's really thick, it needs to be on something flat and solid. It helps to have a straight edge and feelers to make sure the glass is flat.

With either piece of glass, if the workbench is clean, I can't get a .0012 feeler under a starrett edge. If I even have one piece of 60 grit silicon carbide grit floating around under an end of a plate, I can easily get the feeler under the thing.

for lapping planes, long glass is nice because you can really get long strokes when lapping, and it's overall a lot less taxing on you. If you want to shorten up the strokes when you get to finish levels, you can do that, too.

[David Beeler]

Thanks for the feedback. I sometimes use corian to make pens on the lathe and got to thinking it might make as good a lapping surface as thick glass without being as prone to breakage.