Replies

1. 
   murphreejz | Mar 29, 2006 08:31pm | #1

   In my humble opinion, biscuits are as viable as splines for alignment purposes. Splines *may* add a nominal amount of strength and stability to the joint.

   Whatever method you decide upon, above all else just make sure your boards are well jointed and glued. Everything else is rather circumstantial.

   JM

2. 
   John500 | Mar 29, 2006 09:10pm | #2

   For my bench top I used clamps/cauls, this worked fine and had been in service now for about a year and all the glue joints are holding like new.

   John

3. 
   highfigh | Mar 29, 2006 09:24pm | #3

   They'll work, but with something that gets heavy use, I would put in a double row. Better yet, 1/2" or 3/4" plywood will resist shear better and add a little more stiffness.

   "I cut this piece four times and it's still too short."
1. 
   SteveSchoene | Mar 30, 2006 07:31am | #7

   In my mind, the more biscuits the weaker the joint since the biscuits reduce the glue area.  They all have to be very precisely placed for them to be pulling the joint out of alignment instead of into it.  I've only seen that precision accomplished with a Lamello Top 10.

   With most tops glued up to be 2 1/2" or more thick, the most important thing is getting the glue line sufficiently clamped.  Genuine bar clamps about every six to eight inches, fully tightened, should do it.  Less powerful clamps, like K-bodies, would require clamps every 4" at a maximum.  (PVA glue calls for 100-200 pounds per square inch of glue line surface for hardwoods.)  K-body or pipe clamps are only good for about 1,000 pounds.  I-bar bar clamps can reach 2,000 lbs.  (Data from Hoadley Understanding Wood and the Bessy website.) 

1. 
   rhagenstein | Mar 31, 2006 07:58pm | #8

   Thanks one and all for the advice.  The take away message for me is that the biscuits may help with alignment, though clamping with cauls is the best bet against cupping and bisquits will either be neutral or negative in terms of glue joint strength (and this has been batted around sufficiently elsewhere - no need to go down that rabbit hole here).  Again, thanks for all of the input.

   over and out.

4. 
   BruceS | Mar 29, 2006 10:19pm | #4

   Another old method is to use a "Lamp drill"  and run Allthread through the whole top,  countersink the ends and plug.  Can't get much more sturdy than that.

   Work Safe,  Count to 10 when your done for the day !!

   Bruce S.  Counter Sales, Tech Rep.  http://WWW.EAGLEAMERICA.COM

    

    

1. 
   John_D | Mar 29, 2006 11:18pm | #5

   Just remember where your Allthread is, when you drill out holes for dogs and holdfasts. :)My goal is for my work to outlast me.  Expect my joinery to get simpler as time goes by.

5. 
   Buster2000 | Mar 30, 2006 03:03am | #6

   If you have a biscuit joiner, or want to buy one, then go for it.  It will probably help with alignment.  I used splines to align an apron on my bench, and cauls on the majority of the rest.

   If you're hoping that this will keep everything flat so you don't have to plane... good luck.  The splines worked okay, but I still had a slight 'bump' at the join.  The Cauls worked great.  The real problem for me as a little bit of cupping.  A little bit over 30" kind of adds up.  So out cam the #7, then the #4, and then the scraper.  Honestly the most fun I've had with planes in one day.

   Buster

6. 
   Troy | Apr 01, 2006 04:55am | #9

   when I glued my top up (about 3" thick) I used biscuits to help line things up. I don't think they where necessary for strength as a face grain 3" wide by 6 feet long has a lot of glue area.

   Good luck

   Troy

7. 
   JeffHeath | Apr 01, 2006 10:31pm | #10

   rhagenstein

   Biscuits add no strength to a long grain to long grain glue up.  You can save yourself alot of time by just preparing your stock flat and square, and using cauls and clamps.  In over 20 years building furniture, I've never had a long grain/long grain glue up come apart.

   You can save your biscuits for when you need to glue up mitered corners with end grain v. end grain.

   Jeff

   
   

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   Edited 4/1/2006 3:33 pm ET by JeffHeath