Est. 1998 — 27 years of woodworking knowledge
Lapping plane sole. What to use?
Alan Tolchinsky
>I'm trying to flatten a #4 Stanley plane and wondered what you use for this? I'm trying 80 grit wet/dry paper and it's going slowly. I can see where it's sanding but the sole doesn't look any flatter. Any other advise besides buying a new plane. BTW this plane works pretty well but the sole is so irregular(not flat) that I wonder how much better it will be with a flat sole. Thanks. Alan in Md.
Re: Lapping plane sole. What to use?
Thomas Williams - Columbus Ohio
>I have used wet/dry paper and emery cloth starting at 80 grit. My #4 took about 2 hours on the coarse paper to get to an even scratch pattern. I have a #5 that I am trying L-V's 90x lapping grit on glass. It too is going slowly.
Coarse Waterstones
Steve Elliott
>After trying a few methods, I've settles on using a 240x silicon carbide waterstone. It's still slow, but at least the grit remains sharp. With sandpaper I was always tempted to go to a fresh sheet, which gets pretty expensive.
In the past 6 months I've done a lot of lapping of plane blades, untempered steel blanks that will become blades, and plane soles. Just today I bought my third 240x stone. The first one lasted 15 years, the second one about 4 months. The old ones are both 1/4" or less in thickness, and they started out 2-1/8 thick. Frequent flattening of the stone is needed because they're fairly soft.
Re: Lapping plane sole. What to use?
Alan Tolchinsky
>Holy cr*p! Two hours! You are the man. That sounds like a good upper body work out. I think I may have a lot to remove also. Did you notice an appreciable performance difference after flattening? Alan in Md.
Re: Coarse Waterstones
Alan Tolchinsky
>Steve, Where did you buy the Si carbide stone? Thanks Alan
Source for Waterstones
Steve Elliott
>Woodcraft carries them, priced at $38.99. (I went to the store.) Highland Hardware has them for about $36, but with postage that would be more expensive.
The brand is Sun Tiger, made by the Matsunaga Stone Co.
I tried a Shapton 120x and liked it, but I used it up way too fast. The Sun Tiger is a better value, in my opinion.
For plane soles, I go from the 240x to an 800x King stone, which gives a much smoother surface pretty quickly. The steel is matte gray after the King, not shiny, but except for appearance there's no reason I can see to go to finer stones.
Another advantage of waterstones is that they don't dub the edges as much as sandpaper, which is important on a smoothing plane with a tight mouth. Maybe it was my technique, but all my attempts with sandpaper left edges that were slightly rounded.
Re: Lapping plane sole. What to use?
Tony Z.
>Alan, Try some ceramic abrasive. Last Saturday I posted my initial try at ceramics and "alumina zirconia" (Hope that's spelled correctly). To make a long story short, a 180 grit piece of 4" x 36" belt on my granite plate made very short work of a tough 605 bottom and a 5-1/4 bottom. The material cuts far more aggressively than SC paper or SC grit on mylar and so on. Look up the thread from 5/8/04.
Use Al-Zr Belts
Todd Stock
>Al-Zr 50 grit belts (I buy the blue-colored Norton brand at the Borg, but have not needed anything new in a few years)- split and fastened side-by-side with 3M 77 to a flat surface. From start to flat, an old WWII #3 took about 15 minutes of work, which included working the right side cheek to square.
Al-Zr is very durable stuff when working cast iron - just use a shop vac to clear the swarf every few minutes. I usually use a broad-tip marker to grid the bottom and cheeks, then go until the marks are gone. Switching to finer grits (80 or 100, etc.) will finish the surfaces, then complete the job by breaking the edges with a fine diamond hone.
This technique is '90s Old Tools stuff, as mentioned a few days ago, and works well.
Ok, so whataya do...
Scott in Douglassville, PA
>...after the 180 grit? Keep going on SiC, drywall screens, waterstones? What's the best bet?
Scott, planning a trip to dePot in a little bit...
Re: Lapping plane sole. What to use? *LINK*
Ted Shuck
>I have not had a good experience with lapping plane soles. The sandpaper wears unevenly and then abrades parts of the sole more than others. Usually this leads to a convex sole.
Have a look at Bugbear's webpage for a better method. This method uses the reference surface to mark the sole of the plane so the high spots can be identified, then your choice of method to file/sand/scrape away the bits you don't want.
I have found this method to be much faster and to give a more reliably flat plane sole.
It works for me!
Ted
Bugbear's page on flattening plane soles
My method *LINK*
Roger Nixon
>You'll find grinding on abrasive sheets, especially coarse ones, will get you close but not really flat. Not that the sole has to be dead flat all over. Minor low spots in the sole wont hurt anything as long as they are not near the mouth. Since you are flattening a #4, I'm assuming you want it for final smoothing and, yes, flattening will make a smoother work better.
Flat sole
Re: Lapping plane sole. What to use?
Dan Clermont in Burnaby
>Drywall Screen! I use it on a granite reference plate. First I take a pice of 400 grit sandpaper and stick it to the granite reference plate and then I place the drywall screen on top. The swarf from the abraded plane sole falls between the squares on the drywall screen.
A similar procedure won a Popular WOodworking Tips and Tricks about 6 months ago.
Dan Clermont
Re: Ok, so whataya do...
Todd Stock
>Belts run up to about 150 or 180 in the Al-Zr (CRS kicking in again)- after that, you're just polishing rather than flattening, so silicon carbide or aluminum oxide paper works fine to make everything pretty.
The cheap method is to flip the plate glass over, spritz some water on the back of the Si-C paper, and move through 220 and 320. A little more expensive method is to use adhesive-backed aluminum oxide roll paper (3M Stikit). Both will finish the job.
Lots of Choices
Todd Stock
>I think any of these methods work, and as long as time is not money, they are all affordable. A few additional comments:
1. I use a back and forth movement on abrasives - never in a circle or figure 8. I reverse the plane every 20 strokes or so to minimize the tendency to lean the plane to the right (I'm a righty), and check frequently on the hatch pattern (made using a marker) to see if I'm removing what needs to be removed.
2. Use a shop vac to clear the swarf - takes just a minute to do it, and keeps the plane from floating on areas of buildup. The Al-Zr paper has much less of a problem than standard stuff, as the abrasive does not crumble nearly as fast.
3. Scraping is really efficient, especially with carbide scrapers (aka Iron Eater), which work better than mod'ing old files. Keep in mind that scraping takes some art to do well, but there is no faster method if you have a big hump in the center of the plane.
4. I have not had any problem getting a flat surface off abrasives (plane soles, blades, etc.), so scrapers are a 'last resort' technique for me, but try it on that beater number 4 with the crack near the mouth to see if you like it.
Contrary opinion
WoodburnBob
>You may have missed a couple steps and may want to reconsider how you are going about this. You are doing what many people recommend. But I think it would be useful for you first to get some idea of the topography of the plane sole you wish to flatten? Where is it too high and too low...and by how much? Is it generally concave or convex? If it's convex with broad depression in front of the mouth and a mound behind the mouth, lapping alone wouldn't be my choice. I've had planes with a 0.015 high/low deviation. I could lap about 0.0004 in an hour if I eat my Wheaties.
The point is I think you may be flying blind and putting all your trust in "lapping", hoping that if only there were the right abrasive then things would work better. When I was doing what you're doing, the most valuable thing I did was get a cheap granite surface plate, a not so cheap Starrett straightedge and a set of automotive feeler gauges. I also read up on how machinists and tool makers go about getting metal surfaces flat. Using light (between the straightedge and plane sole), spotting compound (or blue oil paint applied with a brayer from the art store), and the surface plate I got pretty good at understanding what was needed. This isn't rocket science, but it's not widely displayed knowledge either.
Using abrasive to move relatively large amounts of metal is pretty inefficient. It's like using a smoother to flatten a severely cupped and twisted board --- which you might well choose to do out of penance or the sheer joy of planing (not unlike scubbing the driveway with a toothbrush if you are so inclined). But if pressed for time, one would best reach for a scrub, then a jack, then a jointer, then a smoother...or some such sequence. All the while one would keep track of how surface fatness is improving or worsening and make appropriate adjustments. One might rock the board on a known flat surface or use a straight edge on length, width and diagonals. Without a reference standard that I am continually consulting, I don't think I'd ever flatten out a bad board by simply crisscrossing even a jointer blindly.
How do manufacturers like LN do this task? Presumably they rough and then finish machine the casting to within 0.001 or so, then surface grind...probably as much for appearance as anything. Surface grinding isn't lapping. To my knowledge they don't lap, since I doubt they believe they need to get into the 0.0001 range of flatness. All this is different from surface finish. You and I could get a consistent scratch pattern or luminous shine on a bowling ball by "lapping" but it wouldn't be flat.
Anyway, just my thoughts, for what it's worth.
Great discussion and Bob
Alan Tolchinsky
>what you say here makes sense also. I'm using a couple of squares for my reference( not the best, but) and they all seem to agree. I have no contact with the straight edge at the tip of the plane and mouth. It's off by a lot but I haven't measured. I'd say it's at least a 1/32 and probably more. So your theory makes sense as far as finding where and how much you're off and start from there. Thanks all for this very infromative thread. Alan in Md.
Re: Dunbars fault!
paul womack
>I could lap about 0.0004 in an hour if I eat my Wheaties.
Dunbar used the term "lapping" for his process of rubbing planes (and blades) and abrasives, glued onto glass. This jargon has become standard in handtool circles.
Sadly, it is not the same as what metal workers have called "lapping" for over a hundred years. This can cause "difficulties" when metal heads talk to neadethals.
BugBear