Beginner Steam Bending and Lamination
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- Опубликовано: 20 сен 2024
- I'm learning a new skill and trying to make bentwood hoops of wood for a future barstool project. All I learned building a steam chamber, bending, and laminating. Quite a bit of a learning curve on this one.
I have bent hundreds of rings now for drum frames. Your set up is awesome and what would do the job is cutting the end pieces of the wood list in such a way so it overlaps after being bent, creating a seamless joint. After you glued it you got a perfect, smooth circle and you can bend another ring just around it.
I'm no expert at steam bending, but I've been researching this for years to hopefully make steam bend drum shells and wood hoops once I've mastered the process. A few things you should look into:
1 - Check out the videos by Engels Coach shop, he has tons of helpful info on steam bending.
2 - Material you want to bend, has to be free from knots and as straight grain as possible. You want the grain on the edges of each strip to run straight / parallel to the edge. Wavy / diagonal grain is more likely to fail. If using kiln dried wood, you want to soak it for a few days, then steam it for 2 hours per inch of thickness. 1 hour per inch is the rule of thumb for air dried wood, but for kiln dried you should double this cook time!
3 - Compression strap! For bending anything over 1/4" you really need to use a compression strap. Not just a piece of metal or nylon webbing to go around the outside, the wood needs to be restrained somehow at the ends to stop it sliding along the strap as you bend it around the form. This stops the outside wood fibers from stretching as you bend, forcing the inside of the strip into compression. Wood can't stretch very much before it breaks, but it can be compressed a lot. The compression strap takes all the tension, forcing the wood into compression. You might get away with just clamping the strip of wood to the strap, but for thicker bends, you will probably need end stops on the strap. Have a look at the Veritas steam bending straps from Lee Valley. Galvanised steel banding / fixing straps work well to make your own strap clamp.
4 - For bending complete circles, like in your first design, you really need to cut scarf joints on the strips, so the ends of each strip of wood are tapered to a point. The tapered section should be at least 2" long, but ideally nearer 3 to 4". Then the ends need to overlap each other and the two tapered surfaces are glued together to give you a good strong glue joint. Butt joints will never work well, because you can never get the strip to bend evenly all the way to the end, so you always end up with a bit of a flat spot. The scarf joints help with this issue as the ends are tapered away to a point making it easier to bend towards the ends!
Hope this helps!
I'm thinking of heading down this road to make banjo shells so thank you for sharing your entire process!!
Working out the details for a project where I need to bend and laminate. Thanks for going through the trial and error and sharing!
Awesome work, man! And beautiful cat!!! 😊
Looking forward to the build!
Stay safe there with your family! 🖖😊
And happy holidays!
awesome work sir, it was very informative for me
You got so close with the full hoop. I really thought you were going to get one eventually. I am building a steam box to try some small wood bending work, nothing as daring as a full hoop. But now I am considering more.
How about cutting out flat circles from 1/4 plywood and glue them together instead of bending? It will be just as strong. After all-it is just a brace…
I learned a lot from this, and I admire your determination and ingenuity. For the gluing ring, could you cut a circle of the outside diameter out of a square piece of plywood and cut it in half, and then clamp the halves around the outside of the ring?
Yes, if it was precise enough, that would probably work, except the friction between the rings as I tried to pull them together was the real problem. Having a split mold to clamp with wouldn’t have changed that. Using a glue that is slipperier than PVA might change that though.
@@catspawcustoms Thanks for your reply. I am just starting my first steaming project, and I've been reading and watching videos. Yours gave me lots of ideas. I am also considering things like pressure and adding ammonia to the process (which I am hesitant about-it's toxic).
That cargo strap sure looks familiar 😂…love your videos and projects…keep it up!
I always wonder why people bother bending such thick strips. I am an engineer and during school we competed in a bridge design competition from popsicle sticks. We used two popsicle stick width glue laminated arches over a 1 m (3ft) gap. It held 1200 lbs! Glue laminated strips of wood are crazy strong. Just cut veneer thick wood, and build up as many layers as you feel comfortable with. I guarantee you can make a structure as strong as you need and is easy to work with. Just look at plywood. Supper strong. The strength is not a function of the strip thickness. It is only dependant on the overall thickness of the piece.
You are better of working out the circumference and cutting ends at 45 degrees so when to squeeze the timber together one end will push down and the other end will push up unless you work out the exact length. Do one laminate at a time and one glueing at a time, the first glueing is for the ends only, do not remove it, the next timber the circumference will change and you have to work this out. The jig should be perfectly round with no cut outs except if you want to use clamps, I used a very long stainless steel hose clamp which gave perfect and equal contact all the way around, you may have to use two/three hose clamps at the edges because your timber is wide. If you can't find hose clamps that are long enough for the circumference, then unscrew two hose clamps and attach together to extend the length.
Next step is to cut the high end where the two 45 degrees come together, you can do this with the table saw as you did but add some guides to the vertical timber you used as a fence so the it is not rocking back and forward, eg two pieces of wood in a V
shape so you can rotate the circle in the one spot. Use some plastic around your jig so that the laminated piece doesn't stick to your jig, I used packing tape.
Good luck and and post another video.
👍
Why not cut the strip to the exact length before bending.
here because i am trying to make banjo rims
If you want to try rings again you should check out home snare drum builds. The guy in the video below has a custom made steel mold, but i made one myself out of layers of MDF. The rings will want try to open outwards, so by placing the rings into a mold rather than wrapping them around one you can take advantage of this force. I dont know if the yoga ball will provide enough pressure for wood that thick, but definitely worth trying it out i'd say!
ruclips.net/video/OVDzcm4QJIo/видео.html
How hot does your steam get?
@@kevincinnamontoast3669 around 210. I think you’d need to be able to pressurize the vessel to get hotter.