Creating a concave for a hand plane

PRCD

Michael Peterson status
Feb 25, 2020
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How do you create an even, symmetrical concave in a hand plane? I suppose you could shape some divinicel and then lay-up some okume or pawlonia veneers over the divinicel and vacuum bag it, but they you still have to shape the divinicel with an even convex shape. The other option is to hog-out some thicker wood with a surform. If you do that, do you use the the depth probe of a set of calipers to measure into the concave from a straight-edge laid across the hand plane at various points to see if the concave depth is the same on both sides of the center line? Are there other methods?

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kidfury

Kelly Slater status
Oct 14, 2017
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Massive concave is a game changer for handplanes. Check out Sole handplanes and the good ones that Slyde makes. Those things work.
 

sushipop

Gerry Lopez status
Feb 7, 2008
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The Dagobah System
I’ve never tried this so take it FWIW. I would first either trace on the bottom where you want the concave and it’s edges to be or tape it off. If you have access to an orbital sander or grinder start with coarse grit sand paper and you put it on edge at a slight angle with your passes. Start at the point closest to the nose that you want the concave to begin and as you remove material start your passes closer and closer to the tail until you get the depth you want. Use a straight edge (ie ruler or carpenter’s square, etc) to check your depth as you go. Keep the pad centered on the handplane and adjust the angle as necessary. Then, take a large cylinder like a coffee can and stick some adhesive backed sand paper to it. Use that to finish it off and clean up any bumps or divots, starting with a coarser grit and work your way up to at least 220 or finer. if you don’t have a sander or aren’t comfortable with it you could go straight to the cylinder/coffee can. The strength you build in your forearms and wrists will help you with other activities.
 
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Sep 27, 2009
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I've made a curved soled handplane ("handplane" the woodworking tool) for this exact purpose. I rough out the concave with a gouge first and then clean it up with my special built plane that matches the curve of my desired concave. Sometimes you have to make a handplane to make a handplane. I have also done the lamination method, where you build a mold and then vacuum press your veneers to the mold.

IMG_0995.jpg IMG_0993.jpg IMG_0990.jpg IMG_0991.jpg IMG_0998.jpg
 

PRCD

Michael Peterson status
Feb 25, 2020
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What type of wood are you using for the gauge and the hand plane? Seems like a spoke shave and a surform are the right tools for this.
 
Sep 27, 2009
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What type of wood are you using for the gauge and the hand plane? Seems like a spoke shave and a surform are the right tools for this.
The gouge is a U shaped chisel. The curved sole handplane I made from walnut but can be any wood that's hard. The wood I'm working with is Sycamore.

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The rough shaping done with a gouge

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After being smoothed out with the curved sole handplane.

The surform and spokeshave will work if they are curved, the normal flat spokeshave and surform won't be of any help on the bottom concave.

There is of course angle grinder attachments you can use if you want the fast/noisey/dusty approach. There is the arbortech turboplane or king arthur tools holey gallahad, finished up with with some sort of sanding wheel. I prefer using handtools, it requires a lot of patience but it is very satisfying work in the end.
 

PRCD

Michael Peterson status
Feb 25, 2020
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The gouge is a U shaped chisel. The curved sole handplane I made from walnut but can be any wood that's hard. The wood I'm working with is Sycamore.

View attachment 95688
View attachment 95689
The rough shaping done with a gouge

View attachment 95690
After being smoothed out with the curved sole handplane.

The surform and spokeshave will work if they are curved, the normal flat spokeshave and surform won't be of any help on the bottom concave.

There is of course angle grinder attachments you can use if you want the fast/noisey/dusty approach. There is the arbortech turboplane or king arthur tools holey gallahad, finished up with with some sort of sanding wheel. I prefer using handtools, it requires a lot of patience but it is very satisfying work in the end.
beautiful work man. In a lot of cases, power tools aren't that much faster after you get them out and set them up and deal with the sawdust. Also, it's too easy to take too much off. Do you have a calculator for dimensions vs. bodysurfer weight?

Did you make that chisel yourself? How do you sharpen it?
 
Sep 27, 2009
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beautiful work man. In a lot of cases, power tools aren't that much faster after you get them out and set them up and deal with the sawdust. Also, it's too easy to take too much off. Do you have a calculator for dimensions vs. bodysurfer weight?

Did you make that chisel yourself? How do you sharpen it?
The chisel is one that I bought, and I sharpen it on a diamond stone, you can youtube "how to sharpen a gouge". I think that handplane sizing has much more to do with personal preference than bodyweight, I size mine so that it is roughly the length of the forearm, this way you get maximum planing surface when on the wave but you can still bend your arm to swim comfortably with it.
 
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PLJ

Jul 10, 2020
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Shaping tools for handplanes are whatever gets the job done... It also is what you have available and are comfortable with... I prefer fast and efficient... The wood handplanes I make are roughed out with a 4" grinder spinning at 10,000 RPM with a 36 grit disc... The walnut handplane pictured above took me 20 minutes from the cutout blank to 80 grit hand sanding... There is heaps of concave on both the deck and the bottom... The thickness in the center is around 5/16"... Confidence with the tools is everything... I also shape the rails on my wood boards the same way... 36 grit at 10,000 RPM... Can rough out the rails on a HWS shortboard in seven minutes... Longboards ten... Cleanup takes just as long...!!!...
 

20W-50 and blood

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Feb 4, 2004
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i knocked a concave in mine...by drinking a 40...thena tall can...then taking the handplane perpendicularly across/into the lowest/most shallow setting of a table saw. sometimes.....god likes likes drunks...or feels bad...or protests...or who knows...but yeah!
 
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