Need help on jointing/planing large subassembly

[Rod Sheridan]

And, to be clear, by that you mean face-joint, edge-joint, plane the other face, then run the other edge through the TS.

Actually I was thinking run 2 surfaces on the jointer, 2 on the planer.

If the last won't fit on the planer, then edge joint both edges and one surface...........Rod.

[Christopher Charles]

I built a bench with a 4" hard maple top as 2 12" wide sections this way without help. I glued all the sections together and flattened the bottom in the areas in contact with the base and then the top with hand planes. I probably ran the sub-assemblies over a 6" jointer and through a 12" lunchbox using roller stands. I did need help to flip the top once the two sections were glued together though!

Good luck!

[Tom Bender]

Collecting from Greg and Tom

Don't rush and use jointed cauls. Expend the extra material and effort on the cauls, the time will let you think thru the final steps.

[Patrick Walsh]

Million appropriate answers to this. Well at least a few.

But my opinion is as a few have suggested “and I have done what you are doing” a million times.

Joint two edges and plane two edges and laminate all the way up to the limits of the width of your machines. Then glue them together hopefully no more than one or two pieces.

If you do it this way as suggested a quick pass with a number seven followed by a number four and you will have a laser flat top.

There are other options but all are more work in the long run that will make getting a good result even harder.

[Sam Shankar]

Okay, got it - don't skimp on cleaning up all four subassemblies before the final glue-up. I will joint one face, plane the other parallel, and then, since I get a nice clean edge with my table saw (I think it's a Tenryu combination blade), I may use that to square up the edges before gluing rather than wrestling with the jointer (With heavy boards, I find that I have trouble keeping the face perfectly against the fence during the edge jointing. Why don't they make jointer fences much higher?)

[Sam Shankar]

workbench top glued up.jpgI followed everyone's instructions, and it came out GREAT. Thank you for all the help. First, I got a friend to help. Each subassembly weighs 40 pounds, which is pretty unwieldy for a small guy like me. I jointed the flattest face, then jointed both edges with the flat face as reference. (Even with a second set of hands I've been having trouble getting my edges perfectly square, but that's another thread.). Planed them all to the same thickness.

I used four dominoes over each 6' subassembly (so 12 in all) to guide the glue-up. This is the biggest edge-glueup I've ever done and I would have botched it without the dominos to help. (Plus, once you pay for one of these things you might as well use it.) The completed top (still in clamps as I write) is currently much more flat than I thought it would be. In fact, it's totally flat as far as my 48" level is concerned. I'm sure I'll have some work to do with a hand plane but not much. I cleaned the heck out of it with wet rags to make the planing even easier.

I'm very proud of myself. That is, until I see the awful mess of the bottom side, which I'm not even trying to clean now.

P.S. Why is there ALWAYS glueup drama?!? Drama #1 - the parchment paper I used to try to keep the glue off the pipe clamps got caught between the joints as I tightened the clamps. Oh, that was a scramble, tipping up the 200 pound top to try to pick the bits out before I fully tightened the clamps. I think there's still a few slivers in the joints. Drama #2 - spilled a half gallon of Titebond III all over my shop floor just as I was getting clamps on the thing. Had to dance around that awful puddle while clamping up. They are always stressful for me.

[Sam Shankar]

Ah well, spoke too soon. It's super flat along it's length. It is gently but steadily bowed across the width, to the tune of 1/32 high in the middle. I think it has to be due to the fact that I couldn't seem to get the subassembly edges square to the face no matter what...those edges were a hair under 90 degrees. So...glue several of those edges together and you get a little bow. I don't think I'll have much trouble flattening with a big toothed plane but it's a bummer. That's what I get for being proud of myself.

I really need to figure out why I can't get a perfectly square edge off my jointer easily. (Yes, I checked my fence for square!)

[Robert Hazelwood]

1/32" over 2'...I'd say you are doing pretty good. Doesn't take much angular error to get there. One way to take angular error of your fence setting out of the equation is to alternate the faces that you are registering against the fence.

If your fence is set dead square to the outfeed, and you are still getting an out of square edge then I'd double check the knives. If one or more knives is not parallel to the outfeed then you might get that sort of result.

[Frank Drackman]

Next time for each joint, try jointing one board toward the fence and the second board away from the fence. This will cancel out any error of the fence setting.

Another cause of bowing can be too much force applied by the clamps. If the joint doesn't easily come together during dry fitting take some time to fix the issue before glue-up.

[Sam Shankar]

I went over the jointer quickly and found that the fence wobbles a teeny bit in and out of square to the table along its length. I think it may be warped a teeny bit. (Either that or my tables are twisted relative to each other, right?) The fence is dead square to the table just above the (spiral) cutterhead, which is where I've always measured and set it. But it's tipped in to a hair under 90 about six inches further along.

[Sam Shankar]

The fence seems to wobble a teeny little bit in and out of square along its length. Either it is warped or the tables are. It is dead square just above and just after the cutter head though.

The joint came together really easily but I clamped the hell out of it with 3/4" pipe clamps.