Replies

1. 
   MarkRoderick | Nov 30, 2004 03:48pm | #1

   Right now I am building a new top for my workbench because the first one I built was from construction 2x4 materials, which is full of knots. When I had joined everything together and was ready to plane it by hand with my wonderfully sharp tools, I had the horrible realization that you can't plane knots! I took it to a shop and had it surfaced with one of those huge abrasive surfacers, but now it's warped a little more (another downside of the 2x4 material) and I can't plane it flat because of the knots. All of which is to say that in my experience, avoid lumber with knots.

2. 
   AlbionWood | Nov 30, 2004 07:57pm | #2

   No, not good at all. Not only are they hell on hand planes, but even a power jointer probably won't get a smooth edge. Knots are often brittle and tend to chip or even shatter, rather than cut, so you get voids in your edge. And as Mark found out, any later movement results in warpage. Rip off the knots, or prepare to deal with the adverse effects.

   Having said that, some species of wood are not as bad as others in this regard. Fir and pine are probably the worst; walnut isn't nearly so bad. Even oak isn't too bad, as many of the knots are tightly intergrown with the trunk wood. But they invariably check.

   "Everything should be made as simple as possible, but no simpler."  A. Einstein

   http://www.albionworks.net

1. 
   budreaux | Nov 30, 2004 08:44pm | #3

   How do you deal with the knots on the surface of a board? 

1. 
   AlbionWood | Dec 01, 2004 09:51am | #4

   As far as possible, avoid them. If I can't cut around them, or if they aren't too bad, I'll plane/sand and fill them if necessary. I use CA glue for this quite often. But there's no getting around the fact that these are defects, and so I am settling for a slightly defective product. Rarely, I have cut out the knot and inserted a Dutchman.Usually I select boards so that I can cut around and leave the knots in the offcuts. Sometimes, though, they can become a feature in the face of a board, and I just have to deal with them. In the face, they always cause tearout when planing, because the grain reverses around the knot. So there is extra scraping/sanding to do; plus, because the knot is hard, scratches show up in it more persistently and are harder to sand out and you have to go to finer grits.On the face, it's just more work. On the edge, it can interfere with the joint itself."Everything should be made as simple as possible, but no simpler."  A. Einstein

   http://www.albionworks.net

3. 
   eddiefromAustralia | Dec 02, 2004 07:21am | #5

   Not a problem - just get the plane sharp and set it fine and you should be able to take a shaving.

   A plane with a bit of weight behind it also helps.

   Cheers,

   eddie