Panel glue-up... Again :)

[Maurice Arney]

Ok here is one for the experts... What would cause a panel glue-up to be out of square? For example, (and this has happened to me twice) seven pieces of 5/4 X6"X72" stock, presumably all pretty close to 5 1/2" each in width, glued up to make a 38 1/2 inch panel. But the end result is a panel that is 38 1/2" on one end and 37" on the other end. :confused: I didn't even notice it until I was measuring it up to trim off the ends.

[Rod Sheridan]

Hi Maurice, The only reason the panel could be tapered is because your stock is tapered.

Did you rip or plane the pieces to width, or did you just joint both edges?

If you rip on a tablesaw, you get parallel edges, same as if you plane them to width on the planer.

If you joint both edges on a jointer however you will wind up with tapered pieces as the jointer doesn't make sides parallel, just straight.

Regards, Rod.

P.S. You can salvage your panels by gluing another strip on, then ripping them on the tablesaw.

[Jeff Duncan]

Yup, that ones pretty simple. If you want proof, take your tape measure and measure the width of each of the boards you glued up at each end. I think you'll find the answer out pretty quickly;)

FWIW It's important to true up one edge and rip the glued up blank to width before you trim the ends! Even if you have the widths pretty close small discrepancies can add up over 7 boards. Then you have the situation your in where the board is not parallel and your trying to square it, which is obviously not going to happen:(

good luck,
JeffD

[Mel Fulks]

I hope your question mean that the jointer is now adjusted .

[Maurice Arney]

Again... I'm going to have to pay more attention the next time I glue up a panel. Most of the stock was fine the way it was so I only ran one piece through the jointer. I can't imagine why it would be 1 1/2 inches off though. The last time this happened was on a desktop about two years ago and, I could be wrong but I don't think I even used the jointer on that one. It was a pine top and there were some gaps but I just squeezed the heck out of it to close them up. If I recall, that one ended up as a rhombus shape... LOL Could it have anything to do with my clamping pressure, technique, inexperience?

You guys are right... I just looked at it more closely and there is one board right in the middle with a taper on it. Sneaker jointer :mad: Now I know what is going on... won't happen again. :)

[Jay Jolliffe]

Don't count on your store bought lumber to be even sized the whole length or square edged....I rip & joint all my glue up pieces so I know they will be the same size.

[Jeff Duncan]

Wait, wait, wait a minute now.....if you found a single board in the middle that's off it probably was not the fault of the jointer....at least not entirely! The board was likely off to begin with. For in order to get a single board with over an inch of taper either your jointer was WAYYYY off, (to the point of being unusable), or you would have run the same board over in the same way many many times. So that leaves me with the impression your board was off to begin with, and you skipped the very fundamental step of making your stock parallel after jointing the first edge!

Your description of the two glue-ups makes me thing your going astray somewhere along the way:( Next time you mill stock remember, joint one edge and one face, plane second face, rip second edge, glue up. Now if necessary you can take a shallow pass off the sawn edge, but it should be only a very light single pass on your hopefully well tuned jointer;) Also, any glue up that's going to be a finished surface, (ie not painted), should be arranged before clamping. Put your clamps down on the bench and put your boards in place on top of them. Arrange them for best look and also check for gaps. Take your pencil and draw a triangle across the boards, this helps you re-align them once the glue is going on. Anything significant gaps should be taken care of before glue up to prevent problems down the road. Now if you have say 1/32" of gap over 4'+ on edge joints you would be OK. If you have 3/16" over 4'.....bad mojo.

hope this helps your next glue up go a little easier:)
JeffD

[Maurice Arney]

This is all starting to come together now. I have another chance for a glue-up this week when I make a new desk for my son. I may need more practice with the jointer, but now I know what to look for and how to correct it.

Thanks!

[phil harold]

join the boards
rip the boards
run the group of them on edge thru the planer...

[Pat Barry]

I've never tried your planer idea with boards on edge phil. How do you control them?

[Peter Quinn]

Simple procedure for every board in every panel I ever glue up. Joint one edge, rip to parallel the other edge, joint to make a good glue surface. (Ok, very occasionally I'll use a glue line rip blade and glue up right off the saw, but its rare). You can't trust pre milled lumber to be anything but ballpark, and clamping the snot out of a pile of boards with gaps and rough edges is a bad long term strategy. It may last on occasion, it may fail in the short term, it may fail after a few years, why take the chance for so little effort to eliminate the problem?

[Mel Fulks]

Most clamp a fence of some sort with notches cut out of the bottom so it won't freeze up the bed rollers.You just clamp it on an angle and the pieces are kept against it . A good method for s4s and such.I don't like it for panel work and many boards are too wide to go through on edge anyway.

[phil harold]

I've never tried your planer idea with boards on edge phil. How do you control them?
They stand on edge
put 4 or more of them tight together since they are jointed on one side they stand up square
I like mel's idea of a fence
I have used a spring clamp to hold them together

I admit the most I can do is 6" on my planer

[Maurice Arney]

Simple procedure for every board in every panel I ever glue up. Joint one edge, rip to parallel the other edge, joint to make a good glue surface. (Ok, very occasionally I'll use a glue line rip blade and glue up right off the saw, but its rare). You can't trust pre milled lumber to be anything but ballpark, and clamping the snot out of a pile of boards with gaps and rough edges is a bad long term strategy. It may last on occasion, it may fail in the short term, it may fail after a few years, why take the chance for so little effort to eliminate the problem?

My problem is that if I, 1) joint one edge, 2) rip to parallel, then 3) joint the other edge, step 3) will cause it to be tapered again.

[Mel Fulks]

It's an old idea. Shops will sometimes keep several box type fences standing up against the wall. The fence can be an inch or more narrower than the stock,when doing wider material ,and still work well. Removing 3/32 at a time seems to work best. Machines with segmented feed rollers often do better than the solid.

[Jeff Duncan]

My problem is that if I, 1) joint one edge, 2) rip to parallel, then 3) joint the other edge, step 3) will cause it to be tapered again.

If you get the jointer tuned up that shouldn't be a problem. You'll only be making one or at most two passes on the single edge, so even if it tapers slightly it won't be an issue. And remember once your slab is glued up you want to re-establish that edges before squaring up;)

good luck,
JeffD

[Thomas love]

Maurice,

Sounds to me like your stock was tapered after you ran over jointer. I read your jointer thread before this one so I assume you know this now. When I lay out boards for a glued up panel I always rip my boards wider than I need as well as a little long on the length. I then joint my boards and dry fit until joints are correct. ( my boards are wider than necessary so no need to worry how much jointing it takes) I then glue up the panel over sized ... from there I will rip to final width and then crosscut to final length with panel sled in miter slot on table saw or straight edge and circular saw in your case with the panel 38"1/2 x 72". hope this helps

[Darius Ferlas]

My problem is that if I, 1) joint one edge, 2) rip to parallel, then 3) joint the other edge, step 3) will cause it to be tapered again.

#3 is also my concern at times so I will either run the boards vertically through the planer, or more frequently, rip them on my TS. To avoid the risk of blade chatter I may first rip to size + about 1/4 to 1/2 of the blade's kerf thickness, and then run it again shaving off just a hair or so. I do this with a Freud's T50 combo and the cut is glue ready.

[Erik Christensen]

man I must be missing something here - do you guys glueup a panel to final finished width & length? there is no way I am good enough for that to turn out well

I shoot for a panel at least 1/2" or more oversize in both dimensions - yah i waste some wood but less that if I end up with a panel 1/4" to short/wide and have to start all over.

my process - joint, rip, joint - glueup oversize - rip one edge & end on track saw so they are 90 to each other - table saw rip the other two sides to final width/length