I would like to make some decorative (non-load bearing) pillars/columns for a client. The total height of the pillars will be 3m(+/-9ft). Painted white, so I don't have to worry about what grade of wood to use.
I am aware of the fact that one cannot put that length of lumber in a lathe. The only idea I have is to laminate the timber to a PVC pipe, fill the gaps with resin, sand and paint. Does this sound feasible, or are there better alternatives?
(Architectural Woodworking Forum)
From contributor J:
I would stave build it, then turn it on a lathe. Barring that, I would find a company that builds columns and buy one. There are many companies which have experience in that area. Laminating around PVC is not a good idea - something is going to fail due to seasonal movement of the wood.
The classic columns all have the same fairly complicated formula to figure the taper to make them look right. A proper column not only looks right, but looks a whole heck of a lot better than some tube. You can easily approximate the taper on the lathe, without actually having to taper the staves. Study good photographs and you will see how the entasis lays out.
The columns wouldn't be load bearing and entasis could be worked in, should I get the shaping right. My biggest concern would be the lathe.
As for a lathe large enough to turn columns, I built my own. They, like the columns, can be purchased, too. It all depends upon which business you wish to be in and where you wish to spend your money.
If you have no lathe, are only going to build a few columns, are not concerned with the design issues of classical columns, perhaps buying the columns would be the shortest path to completion of this task.
So instead of PVC pipe, have you thought about using cardboard tube? This is made in a variety of standard sizes for manufacturing dry goods and food drums, etc. and the firms who make this seem to have fairly low minimum order quantities. These tubes are strong enough to stand up to shipping and being made from wood pulp, which is what paper is, will glue up using conventional wood glues without any worries about seasonal movement pulling the glue joints apart.
I actually did give a thought to cardboard. Also thin MDF and ply. The nice thing about PVC is its availability, and if I do it right, its re-usability... I know we in South Africa use the cardboard forms for concrete pillars and such, but I still need to find a supplier. I thank you for your input.
I missed the part about attaching wood to the PVC. Redundant in my opinion. Wood is the way it has been done (if not stone) for centuries, so it is achievable for you.