Replies

1. 
   Phil_Twiss | Aug 02, 2002 09:09pm | #1

   Sandpaper, various grits depends on how clean you want the base to look.  I usually stop at about 180, I get bored and any more is probably cosmetic.  Oh and don't forget a big flat surface (saw table, jointer bed etc).

   Also it can be usefull to leave the blade in but retracted to that if there is any flex in the casting you will lap it under tension so its flat when you use it.

   Cheers

   Phil

2. 
   RSRose | Aug 02, 2002 09:28pm | #2

   Plane lapping is a very "painful" subject for me.

   I spent an entire weekend once lapping an old cheap plane that I was determined to improve. (somehow advice about silk purses and sow's ears keeps repeating in the background).

   I sustained a rotator cuff injury to my right shoulder. The symptoms didn't come on for about 3 or 4 days. Rotator cuff tendonitis is about the hardest thing to clear up. It took a good 9-12 months! I couldn't reach in my back pocket, reach to the back seat of my car, wipe my (never mind!), let alone do any wood work. It finally completely went away. Bad deal! The most expensive new LN plane would have been a fraction of the cost that that old plane cost me.

   Rich

1. 
   squeaky_jeep | Aug 02, 2002 09:56pm | #3

   hmmm maybe I can get my brother to do it for me!  :)  so do I need a special type of sandpaper?   should I get some that you use wet, or should  I just do it dry?

1. 
   RSRose | Aug 02, 2002 10:15pm | #4

   No special sandpaper. Just tape aluminum oxide to a jointer table. I would go to 220, even 320 grit. But I am no expert on the necessary fineness of grit.

   Rich

2. 
   PlaneWood | Aug 02, 2002 11:00pm | #5

   Do you maybe have an overhead drum sander?  If so, do this -

   Set the plane on a flat surface (table saw top?).  Using boards with both edges jointed and parallel and at least 1/2" wider than the plane is tall, put a 1/4" board up to one side and carefully trace the profile of the top of the plane.  Use another board and do the same to the other side.  Now, carefully cut along the line with a band saw (cut on the bottom side of the line).  Discard the bottom piece.  Turn the top pieces just cut up side down and glue to another 3/4" board with jointed edges.  Make sure the bottom edges of the boards are alligned.  Glue or screw a spacer board between the ends of the two that is just slightly wider than the plane.  This will be a cradle to hold the plane bottom parallel to the bottom edge of the boards.

   Cradle the plane and start making passes under the drum sander.  Start with 80 grit and work up to 220 grit.  GO SLOW!  Be prepared to spend 30 minutes or more with each grit.  The drum sander should be well alligned, sturdy, and capable of making fine adjustments.

   PlaneWood by Mike_in_KatyPlaneWood

3. 
   BG | Aug 02, 2002 11:29pm | #6

   rich, "couldn't reach in your back pocket" ? I've got several friends with that same back pocket disease..at the bar.

   I spray glued wet dry sandpaper to a sheet glass(12x12)...actually, two sheets of glass...automotive supply has WD up to 2000.  Hope this helps 

1. 
   squeaky_jeep | Aug 02, 2002 11:35pm | #7

   glass?

   I am assuming it was like 1/2" thick right? otherwise it might break easy I would think.  I thought about doing it on the top of my jointer. Also I don't have an overhead drum sander, but thanks.

1. 
   BG | Aug 02, 2002 11:48pm | #8

   Nope, normal glass...of course I put the glass on somethig level...TS, etc.  It would probably be better to have a heavier sheet of glass...

3. 
   Andrew | Aug 03, 2002 12:04am | #9

   it's probably not the cheapest option but it is the easiest and the most accurate. take your plane to a machine shop and have them grind the sole flat on a surface grinder. ask them to use a 60 grit wheel and you'll have a reall nice surface that will need no further work. and it'll be dead straight and flat.

4. 
   squeaky_jeep | Aug 03, 2002 12:53am | #10

   Thanks for all the advice... I am heading home to try it.

1. 
   bill_1010 | Aug 03, 2002 01:58am | #11

   another tip, use MDF and some powdered grit. ITs basically alum oxide in powder form from 50 grit on up.  Sprinkle some powder on the MDF and drop a few drops of Kerosene or even VMP Naptha.  THe grit embeds in the MDF and then you can let the fettling begin.  Lee Valley sells the grit i know. 

   I was able to pick up a machinist granite plate 18X24X3 for 30 bucks, i attach my cheap ole sandpaper to sharpen and touch up fettle.

1. 
   LarryPile | Aug 03, 2002 06:38am | #12

   I've used what they call "float glass"...basically the molten glass is floated on a liquid versus poured on a not-perfectly flat purpose.  It cost me around 8 bucks for an 8 X 12 piece of 3/8 inch glass.  I used spray adhesive to glue several grits of sandpaper on and sharpened everything at once.

   Good luck

1. 
   PlaneWood | Aug 03, 2002 07:54am | #13

   Hmmm, that's odd, every time I tried to use spray adhesive, i got detectable lumps under the paper.  I now use the commercial PSA papers.  Bought a 20 year supply of real high priced stuff on Ebay for a song.  I stick it to the back of my diamond laps and to 1/4" plates of aircraft aluminum.

   PlaneWood by Mike_in_KatyPlaneWood