Assembling and Gluing Staved Columns
Here's a boatload of advice and ideas about how to put together and glue octagonal columns made with staves. October 23, 2007
Question
Although I have glued and clamped 8 piece octagon columns, I'd like to learn about other methods. I have a large project coming up and I need more of a production approach than the method I currently use.
Forum Responses
(Architectural Woodworking Forum)
From contributor G:
The cheapest and simplest method I have seen is stretch film. The kind you use for packaging. We have used it on small octagons and large column wraps. Wrap it and stand it up in the corner.
From the original questioner:
Neat idea. These particular columns will be about 60" long and 8-9" in diameter. I'm wondering about how you held them in place before wrapping?
From contributor J:
I made some staved drum shells once. We used bicycle innertubes and a kid's inflatable rubber ball a little bigger than the inside of the column and not too firm. The ball (or 2 balls, if the column is really long) is inserted in the middle to keep the column from imploding, then you wrap the whole thing with the inner tubes. It's a little awkward at first, but you get the hang of it pretty quick. I like the shrink wrap idea also.
From contributor G:
Lay them out inside up. Tape them together on the down side with blue masking tape, lining them up real good, of course. Glue them, roll them up and wrap them with stretchy. The pressure should be equal so there shouldn't be any implosion. Your mitres have to be dead on. It takes two people to wrap the center.
From the original questioner:
Has anyone tried to use a plywood form to hold the pieces after gluing and just prior to clamping? I have placed the pieces outside face up, long edge to long edge and taped the joints along the entire length. Turn the eight pieces over and then glue and clamp. But there has to be an easier way to set this up.
From the original questioner:
I guess I'm trying to picture one of these column shops that do this sort of thing day in and day out. I'd love to see how they do it.
From contributor G:
I agree... We don't do so many that it has become an issue. Still like to look for that work and be able to compete without killing ourselves.
From contributor D:
We fix two half circular, u-shaped pieces of ply to the bench, with a radius larger than that being glued up. We mill all the parts with an 1/8" kerf, about 7/16" deep on both edges of each stave, and make 1/8 x 3/4 splines for a loose fit. Spread out the glue and get about 4 hands on everything and start assembly. The first 180 degrees is easy. As each successive stave is added, it will get a little trickier, until the last stave goes in. Taping as you go helps with horizontal alignment. The splines are not as structural as they are there for alignment and holding it all together until the bands go on. The mills that make these mill the staves on the bevel with a tongue and groove on each stave, but I haven't seen how they manhandle it all together. I have used the above method on columns up to 14' and with 12-14 staves. Use a slow glue!
From the original questioner:
I've seen the shallow tongue milled into the staves mostly to line the pieces together. If I used splines I'd have to mill them close to the inside edge because of the profile I am turning. Can you recommend a slow cure glue? I'm currently using Titebond 2.
From contributor A:
Epoxy resin gives you the most time. It's also thick so it hangs around while you are looking for your tape measure to figure out why nothing lines up. Fiberglass packing tape gives you the most pull.
From contributor D:
Yes - we put the kerfs right on the inside corner of the staves, and actually only about 5/16" deep. And they are only for alignment. We don't worry too much about gluing them - in fact, the kerf can fill with glue and the hydraulics can prevent pulling up the joints.
From contributor Y:
I do them like contributor G suggested, laying them down next to each other and taping them. I use clear tape, not blue, so that I can see if the joint is tight or not.
From contributor G:
Adhesive transfer may be a problem with the clear. I guess you could wipe with alcohol.
From contributor K:
I have done some by cutting the arc for the ends, and some mid sections for gluing up half at a time. I used epoxy thickened to latex paint viscosity with colloidal silica, and rolled on with a small roller. I used a half-round cutter on one edge, and a matching radius flute cutter on the other which eliminates the bevel problem.
If you make your plywood forms with a tab sticking into one end, then have a hole for the clamp to be tangent to the opposite side, the clamp will push them into the form, capturing them.
When you have two halves, run them over the jointer, and glue them together. Although, you may be able to make full round forms to hold the parts that allow them to stand on end while you stand them on their ends. If it is tapered, you should be able to slide the final part in from the end tightening them all up. Epoxy is very slippery, so tightening wedge shaped parts can be tricky, because, if you don't capture the wide end, one or more will slip out and loosen things up.
From contributor S:
Build some plywood yokes. Basically plywood jigs that have a hole slightly larger than the outside of your rough column. Either split the yokes and re-screw them back together, overlapping the parts, or leave the yoke as a single piece and feed the staves in from the end as you glue and assemble. Wedges between the yoke and the column and band clamps to hold things together and a rubber hammer to beat to fit, I mean to properly align the staves.
I like the idea of using a rubber ball to hold the staves from falling in as you assemble. I always thought that I was clever just using a crumpled up cardboard box at each end of the jig.
Search for Hartmann Sanders and look at their joint. Years ago I did some construction at one of their shops and was impressed at the massive columns that they were turning. They put like 5' diameter columns on a lathe and trued them up. As I recall they would blow an air horn when they were about to turn on the lathe and unessential employees would step outside for a minute while the lath was started. But all of us construction workers would come running in to watch a five foot diameter and 30' long column explode. It never happened; the RPMs were real low. Having seen their methods helped me years later when I made some columns.
From the original questioner:
Great ideas. I will be working with 8 pieces per column. I would prefer to shape the 22 1/2 degree bevel on a shaper, but has anyone tried to work right off the table saw with good results?
From contributor O:
I have been making stave built hollow forms for years. Two weeks ago I built an eight inch diameter tube using 12 staves. The 15 degree angles were sawed on my table saw. The work was adequate, not great, but if properly set up, a table saw can do a fine job cutting the bevels. I make templates on my CNC for specific angles. Draw them in AutoCAD, mill them, and you are good to go.
Also, I use rubber bands for my clamps on the smaller pieces. For larger work I used band clamps. The largest diameter I have glued up is just under 30 inches, and I used a come-along to tension that one.
From the original questioner:
I think I'll try one set on my saw with epoxy and filler for gluing and shrink wrap for clamping. 30" - wow!
From contributor R:
Lee Valley has a router bit to make a Bird's Mouth joint. Might be an option for you.
From contributor I:
One little trick we use a lot when doing glue-ups is to use a pin nailer to keep the parts from sliding around. Glue two staves, line them up and pin the ends - go to the next one. Leave a couple of inches extra on each piece and cut off the ends before the next machining operation.
From contributor Q:
When I do something like that I use a bird mouth bit from Magnate and then use Jorgensen ratcheting nylon band clamps. They work great. Hold everything really tight.
From the original questioner:
My stock thickness will be 1 3/4" so the router bit will not work. If I shape I'll either order a 22 1/2 deg shaper cutter or use a tilting shaper to get he bevel. I have used the smaller web clamps but the ratchet tends to push the section it is resting against inward. Their large rweb clamp, which I don't own, has a different kind of crank that will not interfere with the section below it.
From contributor Q:
Magnate has a bit that I think can handle up to 2" stock. I just ordered one for a column in 6/4 wood I need to do. I haven't tried it yet.
From contributor B:
Last December I did a run of small staved box gifts. These were only about 4" across, but I figured column manufacturers probably did something similar.
I designed a moulder knife that cut an interlocking joint for the edges. I ran 4' lengths of straight stock through the moulder and then just cut them into 8" lengths. Glue up of the 8 staves for each box was simple. Alignment was automatic and a couple rubber bands held it until the glue was dry.
If I had wanted a round exterior as well as interior, I could have had a second set of knives made and run the interior cut first and then the outside cut. That would have resulted in a round column with no turning work involved. This could of course also be done with a couple of shaper knife sets for the edges since a column doesn't need a rounded interior.
From contributor A:
The birds-mouth can be done on the TS with a dado head. These are great for accurately controlling diameter. They can't be beat for doing tapered sections. Many mast makers use this method.
Do not use silica with epoxy. It is meant for fiberglass. The recommended fillers are filleting blend (aka wood dust), and milled cotton fibers. MAS epoxy sells a line of epoxies similar to the System 3 guys. Except they sell two viscosities of resin. The super thick one is called Flag resin. I rarely have to add thickener for most applications. I believe it is the best epoxy for wood made today. The West System is too runny for me.
From the original questioner:
I would like to know what you are talking about running a birds-mouth on a table saw. Can you draw the profile and post it?
From contributor A:
There's a pretty good description on the Lee Valley website. Better and faster than I could draw. Item #16J40.58. They sell a fancy router bit. You can also use a tilting shaper if you happen to own one. These cuts can also be made on a tablesaw with a little thought.
From the original questioner:
Thanks, but that won't work. I'm using 1 3/4" stock.
From contributor Q:
Why won't the bit from Magnate work for you? It is almost the size of a shaper cutter. If you look at the specs for the largest bit, you will see that it can handle up to 2" stock.
From contributor T:
CS Osborne is primarily a leather working tool company. One product they make that patternmakers have been using for over 100 years is pinch dogs. A Google search will yield many sellers. A pinch dog looks like a heavy metal staple. It is driven in the end grain of two boards being joined and provides a surprising amount of clamping force. They are reusable. For short glue-ups up to 24", no other clamp is necessary. I use them on long board glue-ups as well. I'll align the faces of the boards near the ends and drive in the pinch dogs. I then take a block of wood and hammer to align the faces across the remainder of the boards. The initial clamping force provided by the dogs keeps the boards in alignment. I then clamp the boards with the appropriate bar clamps. The same can be done with your columns. Use the pinch dogs to assemble the column and supply the initial clamping force and hold the shape while you apply your band clamps or stretch wrap.
From contributor N:
We use a tilt spindle shaper for this kind of joinery. For us it’s usually just a few columns or mitered corners, so I never bought the purpose-made cutters for the shaper or molder. Garniga.com has some nice dedicated cutters if you have the production volume. Page 13 – 14.
The picture shows a rebate cutter with 3mm slotting insert. I was convinced of the clear shipping tape method for most corners, so we don’t use the spline on L and U shaped columns. For your 8 side column the shipping tape might be worth a try, but some type of joinery might be easier.
We employ an outboard fence with power feed when milling. This makes for a clean, accurate miter. In a past woodturning life I made a few 8 side columns using a sliding saw with a parallel fence. The problem with sawing, especially with 8/4, is the stock wants to lift. A pressure beam clamp would help. Or possibly sawing with a power feed. I think it would be possible to use T&G or glue joint cutters on a tilt shaper to do this also.
Click here for higher quality, full size image
From the original questioner:
It may be time for me to invest in a tilting arbor shaper. The Garniga site has some interesting tooling, though, for these sorts of applications.
I'll probably use the taping method several have talked about unless I invest in similar tooling mentioned above.
From contributor P:
I would love to come to your shop and show you how to do coopered columns ready for the lathe. I just retired a year ago from doing just this. We had a very neat and quick method, using two men, and when put on the 12ft Hapfo lathe, they very well balanced also. Where are you located?
From contributor M:
In lieu of a tilting shaper, just build a tilted sled or bed. Also, nearly any glue joint or t&g cutter will work.
