Replies

1. 
   joinerswork | Feb 06, 2008 09:11pm | #1

   Webby,

   If the ends of the aprons (tenon shoulders) are square, you should have no problems.  Try to make sure the clamps are parallel to the edges of the apron, it is possible to pull a square joint out of true if the apron is narrow, and the clamps are cocked so they are kitty-cornered to the apron.  If a square can't be used to check the glue-up, measuring diagonals is perfectly acceptable.  You can also measure between the ends of the legs, to make sure they are not splayed (diagonals would still be equal in that case). This measurement, if taken inside-to-outside (equals center-to-center) works for tapered or turned posts.

   Using pads between the clamp and the project prevents bruising the wood, and can also put the pressure in line with the tenon, if the apron is set back from the leg.

   Ray

1. 
   webby | Feb 07, 2008 12:40am | #2

   Thanks for the info. I think that the difficulty I had was that the aprons were narrow and it was hard to get a clamp on the apron in each direction. the k bodys are kind of large. Do you think that spanning both legs with a longer board and clamping in the middle would help?

   Thanks Webby 

    

1. 
   joinerswork | Feb 07, 2008 01:09am | #3

   Webby,

   Best to do the glue-up in two operations.  First the end aprons to the legs, then the front and back aprons to the end assemblies (or vice-versa, if you prefer).  It reduces the likelihood of getting things torqued out of square. 

   I prefer to put clamping pressure directly over/across the joint whenever I can.  I think that by putting cribbing between the legs at the other end, and clamping in the center of the legs, you will risk springing the joint itself.

   Ray

1. 
   webby | Feb 07, 2008 01:51am | #4

   Thanks I will try the seperate glue ups. Seems like a better way to do it.Webby 

    

2. 
   hammer1 | Feb 07, 2008 06:03am | #5

   Band clamps and surgical tubing can be a help when clamping up shaped objects. I'll set chairs, small tables and such on a known flat surface to check that all legs are touching down. You can measure inside diagonals easily with a couple of overlapping sticks. Without a bunch of metal clamps in the way, you can flip the work around as needed. A tourniquet clamp, twisted rope, from leg to leg can help pull things where they should be if out of alignment.

   Beat it to fit / Paint it to match

3. 
   BossCrunk | Feb 07, 2008 05:46pm | #6

   Glue up the ends first and lay them flat on your assembly table during glue up to make sure they don't somehow end up with a little twist in them.  If they are twisted during the dry fit then you have a problem in at least one of the mortise and tenon joints.  The problem is usually cutting the tenon too rich and the paring operation, done haphazardly and without extreme care, puts a little twist into the tenon.   In a joint that fits pretty snug, it doesn't take much error in the tenon to put the whole assembly into twist.  If you put a straightedge on the cheek of a tenon you can sight over the top of it like a winding stick to see if the tenon is twisted.  See Ian Kirby's article from the B&W days of the mag.  This should be SOP on every tenon you saw out.  Twist in the mortise calls for help from Jack Daniels.  My advice in that circumstance is to drink heavily.

   Gluing the long aprons - I glue them upside down on the bench.  You don't need much clamp pressure. You ought to be able to do a dry fit with a few light mallet taps and then evaluate for square per Ray's instruction.

   Don't wait until you've got glue in the joints to find out there is twist in one of the mortise and tenon joints.  It's a $hitty feeling I can assure you.

   Don't shower down on the clamps.  Your clamps are able to exert magnitudes more pressure than you'll ever need to bring a well executed mortise and tenon joint together.

   
   

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   Edited 2/7/2008 10:59 am ET by BossCrunk

1. 
   webby | Feb 07, 2008 07:30pm | #7

   Thanks ever so much to everyone. Good advice here.Webby