04-25-2011 06:43 PM
I am getting ready to make a panel saw and the plans call for for the wooden parts to be either pine or fir. I would like to make it with a wood that is a little harder and more stable. I would prefer making with maple but for cost reasons am leaning now towards Poplar. I'd like other peoples opnions on whether the extra cost for the maple would be worth it. I'm planning on varnishing the entire project (except for the metal parts).
04-25-2011 08:25 PM
04-26-2011 01:38 AM
If it is just for stability, poplar would be fine. I often make my drawer carcasses out of poplar. It is an inexpensive reasonable wearing wood.
That being said - if it is going to take a lot of wear or is "structural", I would go for maple. As an example, I've made a couple of shaving "horses" over the years. I use hard maple for the sawtooth ratchets for the "anvil" which holds and supports the work piece. In that case, poplar would be too soft - the chock would probably cause the teeth to break and wear too fast.
04-26-2011 08:38 AM
It's a popular misconception that hard woods are more stable than soft woods. In fact, the least stable woods are hardwoods if you define the "stability" as the magnitude of wood movement as it loses or takes on water.
For example, hard maple and white oad or much less stable than lodgepole pine or douglas fir. Both the pine and the fir are considered stable woods. The hardwood poplar is more stable than maple or white oak but is still less stable than pine or fir.
So based stricly on the above, using pine or fir would be the best choice from a stability point of view.
The problem with pine and fir is that in most cases if you are purchasing from a big box you are getting construction grade lumber. Construction grade lumber is not dried to the same point as furniture grade lumber. Most construction grade lumber is dried to between 20% and 12% EMC. This means that the lumber is going to continue to dry quite a bit. This magniture of drying will mean that the lumber will have some rather large changes in dimensions until it reaches a point of stability with the relative humidity in area where it is stored or used. Once I gets to the equilibruim moisture content, it will expand/contract less than hardwood at its EMC.
The question you need to answer is whether you want to stack and sticker your construction lumber in a controlled environment until it reaches its EMC. For a panel cutter, high stability may not be high priority.
Another option would be to try some real lumber companies and see if they have fully dried pine and/or fir.
04-26-2011 12:00 PM
I like fir because it is durable.
It's used as brickmoldso it is exposed to elements yet it stay firm and it last a long time.