I'm trying to build a ornamental lighthouse for outside on the lawn.  I'm joining my boards lengthwise by the coopering method used to build barrels. I'm cutting the boards with a 12 degree tilt of my table saw blade so they eventually result in a circle but my problem involves adding a taper from bottom to top of the lighthouse. I want the boards tapered a total of 1 1/2 inches from one end of the length (44inches long) of my boards to the other. To achieve this I need to taper each side of my boards 3/4 inch so the total is 1 1/2 inches from bottom to top. My problem is my table saw blade only tilts in one direction so I can cut one side of my board with a 12 degree bevel and a 3/4 inch taper, but I can't move my fence to the other side of the blade to make the opposite side cut because my blade won't lilt in the opposite direction to give me the 12 degree bevel I want. Anyone with a suggestion on what I'm missing would be greatly appreciated, Thanks, Bob   

Guys did this by hand and by eye, some still do.  I came up with an idea for a mechanical method that might work in the hobby shop. It requires the construction of a  very substantial (in mass) jig to bend the staves hold them bent and pass them across the jointer.  But any machine would serve. The is  bending the wood first to the arc required for the barrel.

 

However:::: You application is Slack Cooperage.   You don't need it to hold water.  So why not try your hand at shaving and jointing the staves?

 

I have searched and searched for material on the trade of the cooper.  There is tragically little.  I bought a couple of books that purported to investigate the trade, but they didn't. They had pictures of the tools and lots of discussion of the topic but as for instruction:   ZILCH.

I made some flower pots that when turned upside down would resemble a short lighthouse. I did it using a tapering jig. Lay the board on the jig, make one 12° cut lengthwise flip  the board end for end and make the cut on the other long edge.

Bob, you can rotate or spin your board 180 degrees, do not flip it, rotate it. And adjust your tapering jig accordingly. Unless I am missing something here.

12 hours ago, John Morris said:

rotate or spin your board 180 degrees

That's what I was seeing in my mind but not what came out of my fingers.

8 minutes ago, lew said:

That's what I was seeing in my mind but not what came out of my fingers.

I see your reply too now Lew, it makes sense, I just was not seeing your reply yesterday, I was too quick!

Thanks for the suggestions guys but I'm not home for a couple days to try and resolve my problem. The idea of rotating and adjusting the jig may be the way to go although it stills sounds like I would have a problem. Picture the board going through the blade and getting tapered. Now I don't have a straight 90 degree edge any longer to put in my tapering jig, I have a tapered edge so when I run the board through the blade I'm not going to get the same cut as I did when the board had a 90 degree edge.  Does this sound confusing to you guys or am I just confusing myself?

I was thinking about my tapering jig when I answered your question, so it may not work with your jig. I would layout the taper on both edges of the board-wide at one end and the narrow at the other. Then mount the board on the jig with the taper aligned with the straight edge of the jig (blade tilted) and make the cut. Then rotate the board- same side up- and align the other taper layout along the jig straight edge and make the second cut.

 

 

 

Hope this gives you some ideas.

Lew, I just got back from a couple days at the Jersey shore and saw your post. We definitely have different tapering jigs. The one I bought several years ago simply hinges at one end and opens similar to the way your index finger separates from your middle finger. The rotation suggestion from John and yourself finally let me see the light. At first try it didn't seem like it would work but rotation combined with opening my jig wider produced the correct result. Thank you very much, now I just hope the 12 degrees tilt I used on the table saw blade will bring me full circle before I run out of wood. Thanks again, Bob.

Hope you post the finished lighthouse!