# Need advice on tapering thickness of a board...



## Keen1 (Nov 14, 2007)

This little project seemed so simple at first but I'm having trouble finding a way to taper the thickness of a board at both ends. The Goncola Alves board is 10" W, 30"L and 1 1/8" H (or thick). A friend of my wife's asked me to build a seat for a swing in their backyard and showed me a picture of what she had in miind. The ends of the board are rounded off (I used a 10" plate as a template). Looking from the top down it looks a little like a surf board. The side profile of the board is similar to "boat" shape or the profile of a plate sitting on a table. Flat across the top and tapering (or bowing) up the bottom edges 10" on both sides. Middle 10" on bottom completely flat. I'm not sure I have tools or skills necessary to make this profile. Any ideas on how to create this shape?


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## davidpettinger (Aug 21, 2009)

Use a hand plane and a belt sander. Start at the ends and work in toward the flat area. You should be able to achieve the shape that way. Experiment with some scrap wood first to get your technique down first.


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## Keen1 (Nov 14, 2007)

Any recommendations on a hand plane? Not looking to go out and buy anything really expensive here.


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## Keen1 (Nov 14, 2007)

Any thoughts on a handheld power planer? Neighbor has a bosch that I tried to use once for smoothing but didn't know what I was doing. Maybe use that to remove most of the wood, followed by small belt sander I have? I have an old hand plane that I've never learned to how to use and I have no idea what shape the blade is in. I can sharpen the blade but I think I like the power planer idea


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## Gregn (Mar 26, 2010)

I had a project something like that a few years ago. Was glad to have my RAS, although a table saw or circular saw would work. What I did was to draw my profile along the edges of the thickness of my board on both edges. I then went to work and cut a series of step kerfs not quite to the profile line. Once this was done I used a chisel to break away all of the step kerfs to get my basic profile. I then took my belt sander and began sanding to my profile line. Then cut the rounded end I needed on the band saw, you could use a jig saw as well. Had to make 4 pieces that way.


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## rance (Sep 30, 2009)

RAS, jointer, thickness planer… all viable.

Hand plane? Boo Hiss.  As a power tool guy I'd run it through the planer on a sled with the trailing end blocked up. Quick, precise, and best of all… no sweating.  You never said which power tools you had available to you Keen.


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## Keen1 (Nov 14, 2007)

Rance - I like your thought process. As for available tools, No jointer, but do have RAS, TS, Thickness Planer, Band saw (but 10" wide board is too much for the little guy), Router (both handheld and table - Used handheld with straight bit to round the ends). 10" sliding compound miter saw I actually thought about some type of tapering sled for the thickness planer. I searched a few places but only found tapering jigs for a table saw. Maybe I was not using the right search terms.

Only other idea I had was building some sort of 10" sanding drum for my drill press but I like the thickness planer idea better. Any advice on the process or building a sled? Don't forget, I've got to keep the middle at 1 1/8


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## Keen1 (Nov 14, 2007)

AHA….I think I have found the solution after rances post inspired me to keep looking. I "think" this is the answer (at least with a few more shims).

http://resource.grafsnowboards.com/images/IMG_0131%5B2%5D.JPG


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## Kindlingmaker (Sep 29, 2008)

All I have to do is use a jointer to flatten a board and it always comes out tapered. : (


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## rance (Sep 30, 2009)

> "I actually thought about some type of tapering sled"

There ya go, stealing MY ideas.  Yes, like in your link. Determine the angle you need…

30" - 10"(center section) / 2 = hypotenuse. Subtract thickness at the ends from your 1 1/8" in the middle and Bob's yer uncle, you've got the angle. Use online calculators to plug numbers into for a right triangle.

Now block up the trailing end to achieve that shallow angle for the whole board. Cut shims to span across the 10" width and space them, say, every3-4 inches all along the length. I can draw a SketchUp and email it to you if need be, but will be out of pocket until Sat or Sun. I don't mind, just PM me. I would simply post it here but I don't have a PB account, and don't particularly want one either. 

EDIT: Actually 30 - 10 / 2 = the other side of the triangle, NOT the hypot. Shows you how much I know.


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## swirt (Apr 6, 2010)

If you had a sharpened hand plane, you could have it done before you got that sled built. Planing to a line is simple and quite fast. If you had 10 of these boards to do then the sled might make sense, but honestly a plane would really make short work of it. You really wouldn't need one of the ultra precise planes either, if you can get the blade sharp and in place, you'd do great. Most of your planing will be done diagonally across the board. As Unionlabel mentioned, start at the end (where you need to take the most off) planing toward that end diagonally, then work gradually back to the place where their is no incline.

Literally the hardest part would be drawing the reference lines on the sides of the board.


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## swirt (Apr 6, 2010)

Forgot to mention. You could do this with pretty much any bench plane from a #3 to a #8, though something toward the middle would probably be best. If your old handplane has a knob on the front and handle on the rear, it should work just fine if it is sharp.


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## rance (Sep 30, 2009)

Keen, I went ahead and built it in SU for you. I can email it to you or anyone else in the next 15-20 min. Then just print it out on really long piece of paper, lay your board on the paper, then run it through the planer.  I assumed 3/4" thickness on the ends. Adjust as necessary.

FWIW, you can use this sled for jointing boards that are too wide for your jointer. I like jigs to serve multiple purposes.

Note: I'm not against you trying the hand plane method either, its just not for me. YMMV.


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## Keen1 (Nov 14, 2007)

Rance I'm probably too late but I just sent you a PM with my email address


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## Keen1 (Nov 14, 2007)

And if it makes you feel better Rance. You were close - Hypotenuse = 10.05 (of course that is assuming I did my math correctly)


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## a1Jim (Aug 9, 2008)

It seems this could be done on a router table with the router bit with bearing.


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## jusfine (May 22, 2010)

Kindlingmaker beat me to it, we must have the same technique…


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