Replies

1. 
   Danford_C_ | Jun 05, 2002 07:12am | #1

   John,

   I'm just a tad confused.  Flooring does not have dados for relief of cupping but, rather, grooves.  Cupping and twisting are two entirely different problems.  My suspicion is that the twist resulted from improper storage rather than any "natural" tendency of this board to twist.  Cutting relief grooves could compound the problem and doing so with a twisted board on the TS would not be advisable.

   Knowing exactly the amount of twist present would help a great deal in helping you solve your dilemma.  If the twist is not too great, there is every possibility that it can be steamed out, four squared by bench plane, or even splines might work.  I do believe there is a solution but, I don't think that relief grooves is one of them.  FWIW.

   Dano

   "Form and Function are One" - Frank L. Wright
1. 
   JohnKrist | Jun 05, 2002 03:54pm | #2

   Dan,

   Thanks for the thoughts.

   The twist is too much to be squared up by a plane or jointer without leaving something just a bit thicker than some veneer. Much of the wood I received had some defect, and only about 30% was really of the quality one would buy in a hardwood outlet. The main defect was shake, reportedly caused by Hurricane Hugo some years back as it whipped the larger cherry trees around, causing separation along grain lines in the heartwood of the tree.

   One board had so much shake that it easily bent up and down-I had to epoxy the cracks to provide some stability. Overall, the table top could support some weaker boards, so the flexibility that the shake gave to one board I thought I could use to my advantage by creating my own cracks. Twist is a combination of cupping and bowing both of which can be treated with vertical or horizontal (vs the board length) slots, grooves, or dados. The lengthwise slots on the bottom of flooring retard cupping, for example; with enough slots deep enough across the face of a 2x4, for example, one can almost make a circle out a 2x4x8.

   So, I am just wondering if anyone else has done something like this? with full 5/4 stock and the twist mostly in the one end of the board, steaming or pressure don't seem like options, especially since the stock is rather brittle (shake) on the whole. I would likely put the slots in with a skill saw if diagonal, or make repeated shallow runs over the TS until I go the depth needed to make the board flexible.

   Thanks for reading and any suggestions able to share.

   JK

1. 
   Danford_C_ | Jun 05, 2002 05:15pm | #3

   Well John,

   At this juncture, based on your description of the wood, I would go to plan B.  Unless your client is expecting a "rustic" table, I'd go with suitable stock, this stock, IMO, would make great fire wood but, lousy furniture.

   Dano"Form and Function are One" - Frank L. Wright

2. 
   GClancy | Jun 05, 2002 10:26pm | #4

   John,

   I have applied the technique you're considering in the past, for severely warped boards it's the only thing that will save them from becoming firewood.  If I read you correctly you may be contemplating way too many cuts per inch, I found about about 1.5 " spacing fine.  Anyways - snap a chalkline from high point to high point across the bottom of the board you wish to straighten, then draw lines perpendicular to that, spacing evenly, as I said, about 1.5"  The spacing amount is less important than keeping the lines consistently spaced.  (I use a framing square, and use the tongue as the spacer. Layout is the most lengthy process, I find)   For the 5/4 stock, I'd keep at least 1/4" remaining after surfacing, etc., adjust your circular saw to suit and make your cuts.  Afterward you should be able to fairly easily clamp the board flat on the workbench. Wedge the cuts now with shims and lots of glue, (cedar shingles work fine). DO NOT hammer them in !  It'll reverse the warp.  I've found pressing the shims in with firm hand pressure, or at most light tapping will work best.   After the glue has dried, you can joint and surface the plank as usual. 

   The techngue works very well, but as you're aware, the edges of the stock will need to be covered if for show.   Hope this helps, 

   Greg

1. 
   JohnKrist | Jun 06, 2002 06:07am | #5

   Greg,

   Thanks for the walk-through. Now I know what most of tomorrow's shop time will be.

   Much appreciated.

   JK