Coopered Lid and Strap Bending
Today I posted a finished keepsake trunk project: "Keepsake Trunk": http://lumberjocks.com/projects/107694
This blog is to provide more information and photos of the wood used for the project, the process of making the curved lid (coopering) and also the process of pipe bending the straps. In early 2011 I saw an ad on Craigslist for some VERY old chestnut boards. How old? How about 1799 old! To make this story as short as possible, I ended up buying 19 good sized boards that had been floorboards in a house built in 1799. The seller assured me it was chestnut when I commented that it looked a lot like oak. He was part of the crew that tore down the house. He showed me a picture of the house and also a marker reading 1799 that came from a corner of the house. I later learned that it was/is in fact red oak, but not before I had begun making the trunk. The boards I bought were all pretty long…some up to 16 feet. Here is a photo of the gem board. It is about 19inches wide:
Here's a narrower board I had cut into, showing both sides:
Most had finish and maybe some stain applied and a few were painted (perhaps for a closet?). The boards were filled with cut nails with smaller pieces of metal imbedded. I bought a metal detector to assure removal of all metal. Still, the finish took a toll on my planer knives. I resorted to using my belt sander with a 50 grit sanding belt to remove the majority of the finish and surface grit and then went to the planer. Some boards varied greatly in thickness from end to end. The board(s) used for the box sides ended up too narrow to yield Âľ" thickness so I went to 5/8".
The coopered lid is the featured part of this trunk and the most intriguing aspect to make. The trunk was designed by Garrett Glaser for American Woodworker magazine (Issue #149, Aug./Sept. 2010). Glaser provides the angles at which the individual staves are ripped. There are just two angles, 82.2 degrees and the sharper angle at the front and back of the lid which is 68.4 degrees. When all the staves are cut and set side to side, you apply tape across the top side to hold them together, flip them over to apply glue in the seams and then click, click, click the staves form an arc. You apply tape from one side to the other to hold the unit in place while the glue sets. Here are some photos of the process:
A few other processes take place next. You rout a lip for the lid end caps and cut the finger joints for the end caps. Then you use a block plane to gradually knock down the sharp edges until you have a relatively smooth curve. I followed that up with some sanding.
The only other tricky aspect of the project was bending the "straps" for the lid. The author recommended hot pipe bending but I decided to try steam bending. I had the majority of items needed to make a PVC steam "box". I purchased what I didn't have and made one. Long story short, I did not have any success and I am not certain why. I have my theories but I'm not sure. So, I went to Glaser's plan A and made the jig necessary to hold the propane burner inside the galvanized pipe.
You soak the wood in water overnight. You light the burner and let the pipe reach a good level of heat. It takes a certain touch and I ruined a few pieces before getting it right. Glaser used meranti (aka, Phillipine mahogany, aka luaun) for the straps. A friend gave me a piece for the project but I was unable to get it supple enough to bend; it kept cracking. I resawed some walnut, making extra pieces, and eventually got the hang of the bending technique. You bend a little test the fit, bend some more, test some more until it's just right.
I'll be happy to answer any questions. Thanks and be safe in the shop!
Today I posted a finished keepsake trunk project: "Keepsake Trunk": http://lumberjocks.com/projects/107694
This blog is to provide more information and photos of the wood used for the project, the process of making the curved lid (coopering) and also the process of pipe bending the straps. In early 2011 I saw an ad on Craigslist for some VERY old chestnut boards. How old? How about 1799 old! To make this story as short as possible, I ended up buying 19 good sized boards that had been floorboards in a house built in 1799. The seller assured me it was chestnut when I commented that it looked a lot like oak. He was part of the crew that tore down the house. He showed me a picture of the house and also a marker reading 1799 that came from a corner of the house. I later learned that it was/is in fact red oak, but not before I had begun making the trunk. The boards I bought were all pretty long…some up to 16 feet. Here is a photo of the gem board. It is about 19inches wide:
Here's a narrower board I had cut into, showing both sides:
Most had finish and maybe some stain applied and a few were painted (perhaps for a closet?). The boards were filled with cut nails with smaller pieces of metal imbedded. I bought a metal detector to assure removal of all metal. Still, the finish took a toll on my planer knives. I resorted to using my belt sander with a 50 grit sanding belt to remove the majority of the finish and surface grit and then went to the planer. Some boards varied greatly in thickness from end to end. The board(s) used for the box sides ended up too narrow to yield Âľ" thickness so I went to 5/8".
The coopered lid is the featured part of this trunk and the most intriguing aspect to make. The trunk was designed by Garrett Glaser for American Woodworker magazine (Issue #149, Aug./Sept. 2010). Glaser provides the angles at which the individual staves are ripped. There are just two angles, 82.2 degrees and the sharper angle at the front and back of the lid which is 68.4 degrees. When all the staves are cut and set side to side, you apply tape across the top side to hold them together, flip them over to apply glue in the seams and then click, click, click the staves form an arc. You apply tape from one side to the other to hold the unit in place while the glue sets. Here are some photos of the process:
A few other processes take place next. You rout a lip for the lid end caps and cut the finger joints for the end caps. Then you use a block plane to gradually knock down the sharp edges until you have a relatively smooth curve. I followed that up with some sanding.
The only other tricky aspect of the project was bending the "straps" for the lid. The author recommended hot pipe bending but I decided to try steam bending. I had the majority of items needed to make a PVC steam "box". I purchased what I didn't have and made one. Long story short, I did not have any success and I am not certain why. I have my theories but I'm not sure. So, I went to Glaser's plan A and made the jig necessary to hold the propane burner inside the galvanized pipe.
You soak the wood in water overnight. You light the burner and let the pipe reach a good level of heat. It takes a certain touch and I ruined a few pieces before getting it right. Glaser used meranti (aka, Phillipine mahogany, aka luaun) for the straps. A friend gave me a piece for the project but I was unable to get it supple enough to bend; it kept cracking. I resawed some walnut, making extra pieces, and eventually got the hang of the bending technique. You bend a little test the fit, bend some more, test some more until it's just right.
I'll be happy to answer any questions. Thanks and be safe in the shop!