Uneven surface after edge glueing

I glued up four 3/4" thick, 2" wide, 3' long birch boards. I used a biscuit joiner with #10 biscuits. I think I got a pretty good hang of ensuring the slots were cut evenly.

After I finished glueing, I noticed that the resulting 8" wide board had uneven surface due to slight misalignment of the 2" boards from which it was made, maybe not more than 1/16" of an inch, but it was obvious that it wasn't due to the different thicknesses of the boards, since in that case one side would be perfectly flat and the other not.

Anyway, since this is my first edge joining, I would like to ask the experienced guys, do you find this normal? If not, how do I ensure it doesn't happen? I neither have a jointer, nor a thickness planer, so I am limited to an old orbital sander to fix this problem.

Reply to
tezaksam
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Well, you will find that you don't actually need biscuits for edge gluing for strength but for alignment they are very helpful. That being said here are a few pointers.

  1. When cutting the biscuit slots

Reply to
SonomaProducts.com

1/16" seems like a lot of slop for a tight-fitting, aligned biscuit. Half that or even less would be more what I'd expect if the stock was finished to the same thickness.

One trick to help is to use a batten across the boards (place a piece of wax paper between it and the surface to avoid gluing it to the finished piece) and clamp it to hold the alignment (this also aids in maintaining /establishing a flat piece by counteracting the tendency of the clamping pressure to cause bowing).

Here's where a scrub plane, sharp scraper, belt sander or similar will come in handy lacking the surface plane. It's a ready-made excuse, right? :)

Reply to
dpb
  1. When cutting the biscuit slots - Clamp the boards down to the table before cutting slots - Be very careful with technique to apply down pressure on tool when cutting slot - Be sure you mark the "up" side of the board so you use the same alignment when you put then together later

  1. Utilize "flattening" techniques when clamping up the panel - You can use "hand screw" clamps across the ends of the panel
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    - And\or you can use clamping cauls across the panel, lots of methods for this but here is a good description
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    You could buy a hand plane and start learning the old school method of flattening the panel after it's glued. Confession: I consider myself an accomplished woodworker and I really don't know the proper techniques of using hand planes. I'm signing up for my first class next month.

Reply to
SonomaProducts.com

That is one of my concerns. The biscuit seems to be loose in the slot. I bought another bag of #10 (Freud) - same thing. My technique? I don't wobble around with the joiner, I use one quick move to cut the slot and retract it, that's it. I don't think this is causing the slot to be wider than it should be. Change the cutter? I don't know. When you say tight-fitting, you mean, there should be slight resistance when inserting the biscuit, and it should not be easy to take it out?

Thanks, I'll try that.

Reply to
tezaksam

I think I mastered it pretty well. I have Ryobi JM82, well yeah, not deWalt or Porter Cable, but I still think it can cut good slots. I developed a technique to ensure that the fence is resting square on the workpiece, and if it is flat then the slot should be parallel.

All done.

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=A0 =A0 =A0 - And\or you can use clamping cauls across the panel, lots of

There must be something about them since people pay so much money for them despite all the other more modern tools.

Reply to
tezaksam

For what it's worth, I don't use biscuits or dowels for edge joining, as the glue provides more strength than the wood. Biscuits or dowells are there solely for allignment. And with 2-4 inch boards, I don't use anything but glue. That said, the above comments are very useful if you do use a biscuit cutter.

I have a 13" planer, and when I have a 16 inch board to make, I use glue, and a load of clamps. Some to squeeze the joint, smaller ones on the ends to keep the edges flush ( one per joint, each side ), and cauls if needed for the middle. After drying overnight, I use a plane to get the big chunks down, a belt sander if I get lazy, and then a ROS and finally hand sand paper to finish. I keep forgetting to use my scraper, but am usually impressed when I do use it.

I do use dowels when joining longer boards, just to make the assembly easier to handle. It's a race to get the joint glued, alligned and clamped within the open time of the glue, and the dowels seem to help there.

Hope this helps.

Rich.....

Reply to
rich

----- Original Message ----- From: "rich" Newsgroups: rec.woodworking Sent: Saturday, March 15, 2008 10:25 PM Subject: Re: Uneven surface after edge glueing

So then, you do find it normal to have an uneven board after the glue has dried? Even after clamping everything you can? More to my previous point: If all my slots are done right, and I clamp it the way you do, should I still expect an uneven board?

Sure...thanks.

Reply to
tezaksam

No, it should be snug, not loose in the slot.

Some less expensive biscuit cutters I've seen reviewed have problems w/ runout/wobble in spindles. Also possible the cutter isn't mounted perfectly flat against the spindle or there's a manufacturing defect there. Also the cutter itself could either not be quite flat/in line or just slightly oversized...

--

Reply to
dpb

If you set the biscuit in the centers the boards could be different thicknesses and both side wouldn't be flat. Make sure you're setting the biscuit offset from one side and keep this side down when gluing up. Maybe then you can get one good side.

I'm not that experienced, but I do glue-ups often. Yes, it's normal to not execute a new procedure perfectly the first time, at least for me.

Start with correct components. Tune your table saw. It sounds like it may not be cutting perfect 90deg. The problem could also be different thicknesses. Get a micrometer and angle, ensure parallel - consistent thickness and right angles on all edges.

Perhaps a jig with a hand plane for 90's, easier done on a well tuned tablesaw or chopsaw.

A jig with a router for a thickness planer. Like this. Plans and usage instructions available in many routing books.

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this happens to me it's because I rushed, didn't measure and check angles and started with material of different dimensions or angles. I do marquetry and the condition of the starting components, their dimensions, angles and moisture content, determine the success of the project.

Use a micrometer and hand pick your stock for critical sections of the project. You may find variances within your stock.

In the end some tasks are more difficult without tools available for that task. A jointer and a thickness planer would probably fix everything. Have someone else with the tools prepare this stock for you.

Reply to
Joe

I don't use biscuits but I would suspect unevenness to be a function of their spacing. Even using a spline I would suspect some.

One thing not mentioned is that you shouldn't be too quick to cut down the uneveneness on your glue up. A lot of moisture was added to the wood by the glue so let it dry thoroughly before you sand/plane it down else you'll be sanding/planing a second time.

Reply to
dadiOH

No, this is not the usual in gluing up panels. It is very important to make certain all the boards are flat, square, 90-degree edges, and the same thickness. Work on a well-lit flat surface to check the fit for any gaps. K-Body clamps work best for panel glue-ups. Over tightening clamps may cause misalignment. After the boards are in the clamps, check again for flatness with a long straightedge or winding sticks. Biscuits are optional.

Reply to
Phisherman

wrote

There are many ways, like cauls and good clamps, that will help with panel glue-up alignment. Most importantly, particularly when you're working with expensive wood, is a practice glue-up during which you take care to study and implement anything that will get the job done.

One of my methods to assist in alignment, along with a careful and practiced tecnique with a _quality_ biscuit jointer, is use of these little clamping assists across the glue joints as seen in the link below:

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(scroll down to "I-Beam Supports/Clamp Assists", second picture with description)

Another way is break the task into smaller and more managable sections, do those perfectly, then glue these already leveled sections together.

In the "Trestle Table" section of the below page is a description of what it took to get this 100 pound plus glue-up perfectly flat.

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(scroll to "3/20/04" section, where the table top is being glued up)

Look carefully and you can see the use of the clamp assists mentioned above, along with 'whatever it takes to get the job done' techniques that were worked out beforehand, like jointed flat "cauls" beneath the top, and use of a handy "paperweight".

IOW, the more practice, planning and thought you put behind it, the more sucessful the endeavor.

Reply to
Swingman

I had the same problem with the Ryobi JM80 biscuit joiner. The blade cuts a thicker slot than most other joiners. I contacted Ryobi to see if I had a defective blade. Their tech support told me they intentionally made the blade thicker to prevent the biscuit from telegraphing through to the surface.

I dumped the joiner.

Reply to
Nova

There you have it!

Anything to do with "alignment" is only as accurate as each of the tools/techniques with which you do it.

Reply to
Swingman

I don't use biscuits or dowels. Clamps and cauls work for me. I recently learned to plane both edges with a hand plane (#6 or #7), and it works great. My cs will make a glue line cut with a Forrest blade. Another tip I've used is that a few grains of sand in the glue line (4-5 grains, not much) will lock the edges up when applying clamp pressure.

Reply to
Lowell Holmes

I'm at the other end of that spectrum. I'm not sure that I"m an accomplished woodworker, but when I started ruining wood, I did the very thing that you mention in #3 above. I took a course at a local college and all they taught us was hand plane techniques. At the time, I felt we weren't getting anywhere because we weren't "making anything".

In the end, we never did. Ostensibly, we were supposed to make a small bookshelf out of pine, but in the end, that was secondary. As I recall, it never got completed.

But I could sharpen. I understood how a plane worked, and some of the reasons it wouldn't do as I wished. It started a love of planing that continues to this day. Once the technique is acquired, it stays with you, and classes like that are invaluable.

To the OP: What was mentioned above about planing is very good advice. Planing that 1/16" would take very little time and you'd end up with a nice flat smooth surface. However, as mentioned there is a learning curve associated with planing, and having a dull plane iron is worse than not having a plane at all. Inasmuch as I'd encourage anyone in the hobby to learn these skills, you probably don't want to take the time at this point in your project to buy the necessary tools. (The plane is only the start. Sharpening is key to the whole thing working.)

Maybe it's just as easy to take it into someone and have them belt sand it for you for this go-round. But keep in mind hand planing for the next one...

YMMV

Tanus

Reply to
Tanus

What a neat concept! I've never glued up a panel and had never heard of this tip, but it sounds like a touch of genius.

Reply to
Gerald Ross

I can't take credit for it. I don't remember where I ran across it. I kinda think that box maker from Arkansas might have put it in an article. :-)

Reply to
Lowell Holmes

I suspect the Ryoby, sorry. I just did a real slap-dash job making a pine w= ork- bench top - put bisquits in every 8" to help with alignment. I have a Makit= a=20 bisquit joiner, and I use Lamello bisquits. I didn't glue the bisquits this= =20 time, but I have to lightly tap them into place with a wooden hammer, or pr= ess=20 them in with my thumb - they don't fall into the slot even when dry. I glue= d up=20 without any further alignment procedures described by other posters and the= =20 biggest step on the surface would be around 1/5 of a mm -- um, not sure wha= t=20 that's in inch but I guess well below 1/32 in any event; mostly I can't see= any=20 stepping at all.=20

I made all the cuts with the 'native' setting of the joiner, in other words= I=20 lightly press the board to be joined face down on to one of my worktables a= nd=20 slide the joiner across the table top to make the cuts, not using any fence= for=20 height setting, which works well for 3/4" boards. Because it eliminates any= =20 accidental angling of the cuts, this makes it somewhat more accurate, in my= =20 experience, than using a fence for height adjustment, but not THAT much of = a=20 difference if one works carefully with a fence.

-Peter

--=20 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D firstname dot lastname at gmail fullstop com

Reply to
Peter Huebner

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