Saturday, October 5, 2013

Turning Soft Woods-Sushi Platter out of Western Red Cedar

Hi Everyone,

Let's talk a bit about turning soft woods.

What are soft woods anyway? Soft woods come from gymnosperms which is a fancy way of saying conifers, gingkos, and cedar trees. Here in the US we are lucky to have a lot of these types of trees. They are used extensively in construction and if we didn't have these types of trees, well, we'd probably be living in mud huts.

This type of lumber is often over looked by woodturners and that's a shame because it can be successfully turned on a lathe. It is softer than harder woods but that can be a plus as it turns and sands much more quickly than hardwoods. And softwoods can be a really good way for beginners and folks without a lot of cash to lay out for harder woods, which tend to be more expensive. And softwoods can exhibit the same lovely grain patterns that hardwoods do.

Most softwoods are available as dressed lumber here in the US. At better lumber yards, its easy to find clear, straight grained lumber that works well for turning. At the d-i-y types of lumber yards, you'll find less choice wood that tends to have a lot of knots. Both can be used for turning if yourr careful (see below).

The same principles apply to softwoods that apply to hardwoods as far as turning goes:


  • Careful wood selection
  • Careful set up on the lathe
  • Sharp turning chisels
  • High turning speeds and
  • And careful, thoughtful design


Wood Selection

If you are lucky enough to have a good lumber yard nearby, looking for clear, kiln dried lumber. Fir, pine, and cedar are common here and it's possible to make really interesting pieces out of all of these.  If you find yourself at a d-i-y lumberyard, look for lumber that has the fewest defects.

Knots can be turned if they are very tight and there are no gaps between the knot and the wood that surrounds it. Caution is advised here: knots can come flying our at you or shatter while they're being turning, causing injury to you and a big hole in your turning blank where the knot used to be. So be careful here.  Take your time and look for lumber that is straight and not coarse as coarse wood is just not turnable.

Lathe setup

The same steps apply to softwoods that apply to harder woods. Always be careful when attaching any block of wood to a lathe. Make absolutely certain that it is tightly and securely fixed to whatever device you use, be it a chuck or a faceplate. If you use a faceplate, make sure the screws are tight in the wood. And if possible, turn between centers. It's safer and it tends to dampen vibration, especially in wide, platter blanks. Remember, turning wood is fundamentally a dangerous thing to do-think about it: it's a big piece of wood spinning hundreds of time a minute a few inches away from your head.

Sharp turning chisels

Your equipment must be very sharp and it needs to be sharp all through the turn so stop and touch up the edges frequently on your grinding wheel. Softwoods tend to tear, especially across the end grain. Cut lightly and don't try to gouge out wood when you're hollowing out something.

Turning speeds

Softwoods require higher turning speeds. I usually start at about 700rpm. The higher the speed, the smoother the cut (I don't turn over 900 rpm).

Design

As softwoods are not as dense as hard woods are, items turned from them-and I'm speaking of platters, plates, and bowls here-need to have slightly thicker walls. This may or may not impact the design of your item. I make primarily kitchen ware and so I wouldn't use softwoods for spoons, rolling pins, kitchen mallets, etc, because they are not as durable as a harder wood is. So be careful about this.

Ok, enough said. Here are a couple of photos from a sushi platter that I just finished:

I bought a 2x12 piece of western red cedar today to use in a yarn bowl I'm planning for a friend. This is  a blank from the same plank of wood the sushi plate came from:


Since this is soft wood, this is the time to make a real big sweeping curve on it as this type of shape will work well with this type of wood. You can also see the knots in the underside of the platter. These are firmly apart of the wood and they turned very well. You can also see there is no detail to the underside as a really soft wood won't hold detail very well and often tends to produce tearing. So avoid that:


Here is a closeup. You can see how the mortise I've created for the wood chuck is kind of ragged and rough:


This is the top of the platter. It came out very smooth and the knots are just fine here. I think it needs a little more hollowing out:


And this is a photo of the large knot underneath. It's really pretty:



Now tomorrow, I'll probably hollow it out a little bit more and then sand and finish it. I'll be applying a food safe varnish to it so it can be used for serving food. I'll post finish photos then.

More later,

VW




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