Replies

1. 
   UncleDunc | Oct 08, 2002 07:19pm | #1

   Splines add little or nothing to the strength of that kind of assembly, if the faces to be joined are clean and closely fit. They are mostly for alignment.

   WRT the threaded rods, suppose you could find, and afford, a single plank of whatever wood you are using, big enough for the top. If you think the single board might fail, go ahead and put the rods in. The laminated top won't be much stronger. If you think a single plank would do the job, leave them out. The laminated top won't be much weaker.

2. 
   HowardAcheson | Oct 08, 2002 07:24pm | #2

   A spline is not not necessary. If you need something for alignment, uses a few biscuits. They're much faster. The surfaces of the boards will provide enough strength.

   Glue up no more than three boards at a time. You can use white PVA glue which will give you about twice as much open time as yellow PVA. Get a small trim paint roller (about 2-3" wide) to apply the glue faster. Just roll it on and clamp it tight about every 4" inches unless you you have some wider clamping boards. Clamp it as tight as you can get it.

   After gluing up your sub-assemblies, then glue the sub-assemblies together again, no more than three at a time.

   Do not use any type of cross grain device like a threaded rod. The glued up panel must be free to expand and contract as humidity changes. Restricting movement with a solid rod will either cause the wood to deform or the bolt ends will be drawn into the wood as it expands and then be loose when it contracts.

   Be sure that all your boards have the end grain either all running up and down or side to side or you will have later problems.

3. 
   BG | Oct 08, 2002 08:56pm | #3

   Doc,

   I'm almost to the same place in my workbench as you are...my planer is busted and i'm waiting for parts.  Have you done a dry run yet?  I plan to use biscuits for allignment.  I have the boards sitting in he clamps now getting used to the 'to-be' environment and figuring out any issues i'll need to confront.  I'm still deciding on which vises ..and where..Good luck 

1. 
   AlanTurner | Oct 08, 2002 09:13pm | #4

   Keep the information coming, guys.  I just picked up the boards for my bench, but haven't started it yet.  12/4 maple, 10.5" wide, 12' (will do two 6'ers).  The plank was cut from very near the center of the tree, and so when it dried, it has a funny angle in it, splaying away from the tree center.  Plan to rip it on this line, then joint, plane, etc., and will end up with very nearly quartersawn maple.  Any comments on this idea?

1. 
   BG | Oct 09, 2002 01:00am | #5

   S4S,

   The advise I got from here was to keep the cutting to a minimun.  Orginally I was going for the quater sawn thing by cutting up my 7" wide boards...many on here told me not to cut up boards if i didn't have to..that glue up would be a bear...

   I'm going to end up with three 6ish wide boards with 3" wide on the front and back (dog holes will be in there...on the front). I'm debating about a 2" wide strip with more holes (scratch!) in between the 6ish boards. 

1. 
   KraigY | Oct 09, 2002 01:31am | #6

   Thanks to all for the great comments and discussion.  The threaded rods option did seem a little counterintuitive but there was an article in Wood mag (blasphemy, I know) recommending it so I did not want to ignore the possibility. 

   I hadn't given just using a single plank as the top much consideration to be honest.  Two of the planks I have not milled at all yet are wonderfully flat and straight too...ahh the dilemma.  I think the idea of laminating a few subsections and then bringing these together with the aid of a spline or biscuit is the way I will go.  Although that could change before I even get home!

   thanks again-

1. 
   mike4244 | Oct 09, 2002 01:58am | #7

   Doc, use 3/8" threaded rods. If you have a drill press set up a straight edge and a stop block. Bore 1/2" holes 8" in from each end on every piece. On the out side pieces bore a 1 1/4" hole 5/8" deep for a counterbore.You need this size hole for the ratchet . Then set the stop block for two more sets of holes, you will have four sets of holes in the length of the top.Glue up three boards at a time with 1/2" bolts for alignment  and also takes the place of 4 clamps.After your 3 board sections are glued up , glue 3 of these sections together using your 3/8" allthread for alignment and clamping.Continue until width is reached.Make sure your allthread is at least 1" to long, cut the excess afterwords.Grease up the allthread and put a nut and washer on it. Drive each allthread 3" at a time until it enters the countered bored holes on the other side.I have built a number of benches for freinds and myself, mine is 35 years old and still tight as a drum.

2. 
   KraigY | Oct 09, 2002 05:17pm | #8

   MIKEK4244

   Thanks very much for the advice and detailed how-to.  One question - do you tighten down the nuts and rod pretty securely or leave some breathing room for the wood?  Also, since we are on the subject, if you laminate strips "side up" to give essentially a quarter sawn top, is lateral movement (particularly with respects to the threaded rods) in the wood that big of a concern anyway?  I am still mulling this over but will definitely share the results and what I learn with interested readers.

   Cheers,

   Doc

3. 
   HowardAcheson | Oct 09, 2002 07:54pm | #10

   What wood are you using and what is the width of your bench?

4. 
   KraigY | Oct 09, 2002 11:00pm | #12

   Hi -

   I am shooting for about 16-18" by 60".  I am using birch.

   Thanks

5. 
   HowardAcheson | Oct 10, 2002 01:44am | #14

   Plan for your tabletop to expand/contract between 0.3 - 0.4" for a relative humidity change from 25 to 75%. Go to http://www.woodbin.com and click on the "Shrinkulator" to find out how much expansion/contraction to plan for if you have differing parameters.

6. 
   mike4244 | Oct 09, 2002 10:40pm | #11

   Doc, I tighten the rods as tight as I can without stripping the threads. I think you might have to be King Kong to that though. I forgot to mention when you cut the excess rod off, loosen the nut about 2 or 3 turns on the side you tapped the rods in, Tap on the nut , snug up the opposite nut and cut off. Then slack off the last nut a bit , tighten other side of rod.This way when you tighten up the rod will be slightly short of the surface on each side.

    As far as wood movement is concerned, the rods are centered in the laminations, plus they are quartersawn so I see no problems at all.

   Doc, if you want square dog holes in your bench you can do this by inserting a spacer block in between strips as you glue up.My own bench is 3/4"x3" maple, so I used 3/4" spacers for home made 3/4" dogs.I made one bench out of 8/4" beech for a relative, I dadoed one strip every 4" for dog holes.If you buy dogs have one on hand so you can check the fit.I finished the top with left over varnish from another job. It's about time for another coat.

   Good luck with your bench

7. 
   KraigY | Oct 09, 2002 11:06pm | #13

   MIKEK4244-

   Thanks again for all the advice.  I was qoing to make some square dogs and approach making the holes like you mentioned in your last post - basically a series of dadoes in one of the strips prior to glue up.

   Doc

2. 
   HowardAcheson | Oct 09, 2002 07:52pm | #9

   Let me suggest not to cut up your wide boards. If they are flat after you finish acclimating them, they will basically stay flat. My bench is made up of two 7" wide x 3" thick maple boards, two 2 1/2" wide boards and two 1 1/2" boards that contain the dog holes. I flattened it when I finished and it still is flat.

   Edited 10/9/2002 12:53:11 PM ET by Howie

   
4. 
   JOEJOHNY | Oct 10, 2002 09:08am | #15

   C'mon Doc,

   Show some spline!

   You're not splineless are you?

   It just sends chills down my spline!