Having trouble getting long board edge jointed for glue-up

[coloradotrout]

I'm machining eight 2x6x8' (construction grade) for a tabletop. At least it's kiln dried. Individually I have the faces jointed, and the edges jointed. I glued pairs together so now I have four, 2x12 (actually 1.25" x 10.5") 8' long boards. I was surprised that they glued-up as flat as they did. But I sense I need to hurry up and get it all glued... and get my braces in-place before they cup. I'll hope to end up with a 42" x 94" board that is mostly flat.

In any event, I edge jointed the now 1.25" x 10.5" x 8' boards, but find I am getting some hollow in the center. When I glued one, I could not clamp the hollow out of it. So I have about a 1/64th or so gap in the middle 2 to 3 feet. I could live with that, but then on the next pair of boards it seems worse. I believe it has to be because the weight of this 1.25" x 10.5" board is causing me to take more off in the center as I joint it. From reading around, I may try some infeed and outfeed rollers to see if that will help. Or maybe I need to buy a hand plane and get an education.

Any help appreciated.

[Jerry Wright]

Use an 8 ft straight edge template (side cut from an 1/8" sheet of masonite), and a 2" straight trim cut router bit with a guide bearing. You can get a dead flat and straight glue edge without wrestling a heavy board on a jointer. I just used this approach to join two long book matched live edge slabs. Also dowel the joint and you will get a near perfect alignment, so you can sand instead of plane.

[Edward Dyas]

If it were me I would have jointed and dry fitted all of the boards and glued all of them together at once. The joint you had that had the gap I would cut it apart and do it over. You just need to joint and dry fit your double boards again. It's really important that you keep working them on the jointer until there is no gap when dry fitting it. When gluing boards together the pressure you use to force the boards together is how much pressure it's using to break the joint back apart later.

[HANK METZ]

If you've got a garage door, you may be able to use this tip (http://community.woodmagazine.com/t5/Top-Shop-Tips/Garage-Door-As-An-Inspection-Tool/td-p/245210).

- Beachside Hank
Improvise, adapt, overcome; the essence of true craftsmanship.

[Jeff Duncan]

Just an FYI.....kiln dried construction material is not the same as kiln dried furniture lumber. Those boards are probably pretty wet so be wary of some movement once the piece goes inside the home. Or in other words....leave plenty of room for things to move!

good luck,
JeffD

[scott vroom]

What type of clamps are you using? 1/64" over 8' isn't drastic.....3/4" pipe clamps should pull it closed.

What size jointer (table length) are you using? (Obviously) longer infeed/outfeed tables are better witth long stock.

Infeed/outfeed rollers are a good investment....here we're jointing/planning 14' 5/4 QSWO. Also helps if you have a helper to keep the stock flat, particularly on the jointer operation.

[coloradotrout]

Just an FYI.....kiln dried construction material is not the same as kiln dried furniture lumber. Those boards are probably pretty wet so be wary of some movement once the piece goes inside the home. Or in other words....leave plenty of room for things to move!

good luck,
JeffD

Yeah, I figured so. This "top" is just going to rest atop our existing table. I plan to screw on a couple of supports near both ends to help with keeping it flat(ter). With the movement, I know to oversize the holes on these support. The center hole will be right sized, and then I'll oversize towards the outside holes. So far I am amazed just how flat the pair of boards are, and more amazed on the 1 panel that now has 4 boards.

[coloradotrout]

Jet 6" closed stand -- 46" bed
3/4" pony pipe clamps

The 1/64" gap is in my glued-up panel. My 3/4" pipe clamps would not pull it together. Now, that said, it could have been some issue with depth of my biscuit slot. I don't think so, but for the life of me, I could not squeeze that gap out, and I do not generally overtighten clamps. I generally subscribe to the notion that clamps should never change the dimension of wood. The gap was probably larger before I clamped. In fact I could have sworn on dry fit, it was perfect. But I may have missed it.

On the 2 boards I'm jointing now, the before glue-up gap is more like 1/16". On the 4 pairs I have already glued, I have no gap -- those went together surprisingly well. I wanted to glue-up in stages so I could rework the faces and edges along the way. I glued the pair of 6" boards, and then planed the faces, so I now have 4 nicely machined planks to work with (other than I cannot seem to get the edges perfect -- or down to a 1/64" or so gap before glue-up ) But they are now pretty heavy to guide through a jointer. So next up I will try my roller stands. I have 3 cheap ones. My concern is getting them to be aligned with the jointer bed. This really seems like a case where 1/16" or so is really all that one can do. Sure, I can get out my Starret straight edge -- align as best I can, but those little stands are going to move when a load hits them. But I'll set them up flush and maybe be surprised.

I do need to replace/sharpen the jointer knives. I am alternating my edges on the jointer to ensure they match 90 degrees. That worked slick on the 4 pairs I have done. In essence, lay out the boards, then joint each without ever flipping end for end... in that way one edge will be the good face towards the fence, the next will be the good face away from the fence. So long as both faces are in the same plane (after running through planer), then it should work out. And if my jointer fence is even a bit off of 90, it all works out.

I'm just using biscuits to help with alignment. In fact, I'm not gluing the slots. I've never attempted to glue-up such a large panel - 42" x 96". Probably using construction grade lumber makes it even more challenging. I did try to select flat, straight boards. I started with 16' 2x6s and cut those in half. I'm down to about 1.25" thick by 5.25" wide, and for the most part they are decent. There is a bit of bow, some worse than others, but not horrible. In glue-up I had no problem getting the faces aligned to what "felt" good.

[coloradotrout]

AND WOW! What amazing replies here! I used to spend time are the rec.woodworking newsgroup, but that seems to have gone downhill over the past few years.

[John TenEyck]

As mentioned previously, a router and straight edge are your best friend for edge jointing really big stuff. If your straight edge really is straight, it's foolproof. And keep your boards and glueups sitting on edge or standing up in between operations. That will reduce their tendency to bend, etc.

John

[Joe Angrisani]

......

Is Coloradotrout a first name or last name? Yours has got to be the most unique "real name" I've seen on SMC (must be real since we have to use real names for our user name). ;)

[coloradotrout]

Is Coloradotrout a first name or last name? Yours has got to be the most unique "real name" I've seen on SMC (must be real since we have to use real names for our user name). ;)

It's neither -- sorry :-)

I don't ever use my real name on the internet.

[coloradotrout]

... And keep your boards and glueups sitting on edge or standing up in between operations. That will reduce their tendency to bend, etc.

John

Interesting point -- I don't know why, but I perceived I needed to store my boards on edge after I have face and edge jointed. Maybe it was to save space atop my TS, but I sorta figured the weight stress might be better managed with the boards on edge -- though I admit -- having that 21" board on a 1.25" edge makes me a bit nervous!

[scott vroom]

It's neither -- sorry :-)

I don't ever use my real name on the internet.

Add a space between Colorado and Trout then it becomes more plausible....you know, sort of like Space Cadet vs Spacecadet. Makes sense?

[Chris Fournier]

What type of clamps are you using? 1/64" over 8' isn't drastic.....3/4" pipe clamps should pull it closed.

What size jointer (table length) are you using? (Obviously) longer infeed/outfeed tables are better witth long stock.

Infeed/outfeed rollers are a good investment....here we're jointing/planning 14' 5/4 QSWO. Also helps if you have a helper to keep the stock flat, particularly on the jointer operation.

He has a 1/64" gap after clamping. This is a problem. I would make sure that my jointer tables were not drooping at each end. Concentrate your downward force on the out feed table and I'd bet that you'll be okay.

[Mel Fulks]

The fact that your knives are dull has made the out feed table too high. Do you seem to be removing more wood at the beginning of the cut than when you get to the end?

[Myk Rian]

Jointer knives are set too low. That produces a banana surface.

[Ronald Blue]

I agree you should check jointer setup. But if knives are dull before you get into that you should rectify that issue.

Interesting that you were allowed to use a "screen name". I had to request acceptance of mine because I think the moderators thought it was bogus.

[coloradotrout]

Apparently my screen name is generating about as much interest as my posted thread. The mod has asked me twice to message someone and change to my real name. I won't do that -- or at least give my full legal name -- and frankly, I'd caution every one of YOU to reconsider; especially folks with rather unique first and/or last names. I won't go into all the reasons why -- but quite simply there is no reason "to" use your real name. Ronald Blue or Ron White is quite frankly irrelevant on internet forums like this. The content of what you post is relevant -- and if you desire, sharing your personal information when and how you chose is entirely up to you. But your real name as the required and worldwide visible ID -- there is no reason.

I checked my knives with a dial indicator. They were a 2-5 thou. above the outfeed. Also the tables are pretty flat and mostly coplaner; again within 2-5 thou. It's still a mystery. I did glue-up another panel last eve -- and this time the clamps took at the 1/32" gap. I'm now thinking on that other panel, there must have been something in the gap.

Probably my last post -- I do sincerely appreciate all the constructive advice.

[Harry Hagan]

I WAS going to suggest an easy way that I join lumber on the job site; but since you refuse to give your real name . . .

[scott vroom]

It's a privilige not a right to post here. Terms of service require a real name. If you don't want to provide that info then no one will be offended if you abandon your membership. Your choice.




Apparently my screen name is generating about as much interest as my posted thread. The mod has asked me twice to message someone and change to my real name. I won't do that -- or at least give my full legal name -- and frankly, I'd caution every one of YOU to reconsider; especially folks with rather unique first and/or last names. I won't go into all the reasons why -- but quite simply there is no reason "to" use your real name. Ronald Blue or Ron White is quite frankly irrelevant on internet forums like this. The content of what you post is relevant -- and if you desire, sharing your personal information when and how you chose is entirely up to you. But your real name as the required and worldwide visible ID -- there is no reason.

I checked my knives with a dial indicator. They were a 2-5 thou. above the outfeed. Also the tables are pretty flat and mostly coplaner; again within 2-5 thou. It's still a mystery. I did glue-up another panel last eve -- and this time the clamps took at the 1/32" gap. I'm now thinking on that other panel, there must have been something in the gap.

Probably my last post -- I do sincerely appreciate all the constructive advice.

[johnny means]

Coloradotrout, I require guests to take off their shoes. Everyone has the right to refuse, and stay outside.

[Myk Rian]

Might as well lock this thread. He has left this site, and now resides on WN, according to a thread he's involved in, that is attempting to tear this forum apart.

[scott vroom]

myk do you have a link to substantiate your claim?



Might as well lock this thread. He has left this site, and now resides on WN, according to a thread he's involved in, that is attempting to tear this forum apart.

[Myk Rian]

http://www.forums.woodnet.net/ubbthreads/showflat.php?Cat=&Number=6156730&page=0&view=collapsed&sb=5&o=14&fpart=1&vc=1
I'll let you figure out who it is.