Replies

1. 
   Jamie_Buxton | Feb 13, 2004 01:26am | #1

   Mesquite is a generally a small tree. Finding 8/4 is difficult enough. Finding 16/4 may be impossible.

   You might consider gluing up your leg stock so that the seam runs diagonally in the cross-section. On the surface, the seam is at a corner, and is far less obvious.

   As for the worry that glued-up 4x4 legs are stronger or weaker than solid 4x4 legs, don't worry about it. A 4x4 piece of hardwood is far stronger than any stresses you could put on it. You'll be able to park a truck on your table without fazing it.

2. 
   BenM | Feb 13, 2004 03:53pm | #2

   If you glue it up with 2 8/4 pieces orient them so the side that was the inside of the tree (I am assuming the pieces are flatsawn) are facing outwards.  Like this:  )(.   If any shrinkage occurs after glueup the joint won't open up.  Also, select your pieces for good color AND grain match to minimize seeing the joint.  Not to mention good jointing technique.

   Having the joint along the diagonal is also a good idea but you need at least 12/4 stock to do that.

1. 
   dumfounder | Feb 13, 2004 05:22pm | #3

   thanks to you both for the good information. 

   One other thing I was wondering about.  What's the 'best glue' for this kind of indoor project?  I've heard everything from yellow woodworkers glue (non-waterproof type) to epoxy, or even the gorilla glue urethane stuff.  Is there any consensus on this question?  Other than cost, I don't know of any downside to using epoxy (which will be used to fill voids in the top surface anyways).

   thanks again

   -Gus

2. 
   JohnWW | Feb 14, 2004 03:15am | #4

   Ben,

   I'm going to dispute your suggestion for the grain orientation, at least as it applies to most furniture woods, which have enough difference between their radial and tangential shrinkage to cause them to cup as they gain and lose moisture.  Mesquite is one of the rare woods that have very similar values for radial and tangential shrinkage which makes the wood less likely to cup.  That said, the following information applies to virtually all other woods. 

   When a flat sawn board gains moisture it will cup toward the heart side of the board.  If that happened to a leg glued up as you suggested,)(, the stress would try to open up the joint line on the outside of the leg, which might show a separation along the seam if the stress rises high enough. 

   If the leg were glued up in the opposite growth ring orientation, (), the same problem would occur any time the leg lost moisture, because a flat sawn board cups away from the heart when it loses moisture.

   The simple solution is to orient the rings in the same direction,((, then the boards don't fight each other as the leg gains and loses moisture.  An even better alternative is to use quarter sawn wood for the legs, then there won't be cupping of the glued faces.

   Your suggestion works only if you are gluing up fairly moist stock, say wood just brought in from an unheated storage building, that is likely to lose additional moisture before it settles down into the moisture range of wood kept indoors as furniture. 

   John W.

    

1. 
   BenM | Feb 17, 2004 04:28pm | #6

   Since wood usually loses moisture as it is milled into furniture pieces, rather than gains moisture I still believe )( is sound.  I will consider (( some more before passing judgment, but since the heartside moves more than the outside the possibility of getting a gap still exists.  As far as using QS wood for legs, if the legs are approximately square in cross section and 2 faces are QS then the other two faces are flatsawn.  Depending on species the QS and flatsawn sides may have very different grain pattterns and that should also be considered in your design.  My preference is to use a single piece without laminating and also for it to be riftsawn (grain on a diagonal) so all four faces have a similar grain pattern. 

3. 
   johnhardy | Feb 15, 2004 09:03am | #5

   Another option for gluing up the legs, and one which I developed while building Arts & Crafts furniture, is the following. It uses four pieces of wood for each leg, but each face is "full", and the glue joints are at the corners.

   What is involved seems complicated, but it's really very easy. Start with some pieces that are over twice as long as the finished leg (say, 12 inches longer). If you are making four legs, you'll need 8 pieces. Each piece needs to be at least 1/4 inch wider than the finished leg. Wider is a little better as it gives you "breathing room".

   Start by cutting a 45 degree rip in each piece. Take pairs of pieces and glue them together using biscuits every 6 inches (for alignment). You'll need to make a jig to help with the clamping. What I did was use some 1/4 inch MDF, glue a backer strip on it so that it would hang on the uncut side, and I glued the cutoff piece onto the other side at the other end. This created a short shelf that is parallel to the piece of MDF on the mating piece, and I could use clamps here to get even pressure on the joint.

   When the four pieces have dried (24 hours), you're ready for the next stage. Take a piece of 3/4 inch plywood and create a 3 inch thick piece (sled) that is 12 inches wide by 8 feet long. Run this sled through your table saw, with the blade at a 45 degree angle, and cut a deep "V" groove in the sled. If the legs are to have 2 inch sides, cut the groove so the sides are about 1.75 inches long.

   Next you want to run the sled through your planer, with the legs in tghe "V" groove. Run each leg through the planer at each setting, lowering the knives when you're done with a complete pass. When you're done planing the pieces will have uniform width of the sides and each piece will be identical.

   Next, cut each of the four long pieces in half. Then, glue the halves, again using biscuits every 6 inches for alignment. You'll have to make another gluing jig for this. You want even clamping pressure here so that the glue line is "invisible".

   When done you'll have legs that can pretty much pass for solid.

   If you desire, you can place "waste" wood in the original glueup (before planing), so that there is not a hollow in the center of the leg. If you're going to use leg levelers, for instance, this is a good idea.

   If you want to get fancier, you can resaw your lumber (it's 8/4), so that opposing faces are bookmatched. If you have lumber that is wide enough, you can do this and get the four faces bookmatched.

   My quarter sawn white oak legs worked out extremely well. I worked with a professional cabinet maker, who is now retired, and I showed him a cutoff of one of my legs, with the ends covered with blue tape. He said "nice legs, quarter sawn". Then he realized that quarter sawn legs wouldn't be QS on all four faces. I then showed him the legs, with the blue tape off, and he was mightily impressed.

   John

   
   

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   Edited 2/15/2004 1:05:20 AM ET by johnhardy