Biscuits

[Tom Winship]

Do most of you use biscuits when edge gluing boards for top a case sides? I have been, but seems as if it gets mis-aligned rather than helping align the boards. Even cut them on my table saw top to make sure everything is flat.

[Leo Graywacz]

I rarely use biscuits and almost never use them for aligning edge glued boards.

[Mike Henderson]

If you need something to align the boards of a panel while gluing up, use shop made cauls.

Mike

[Peter Pedisich]

Tom,

I fine tuned my DW biscuit joiner and now it will cut slots so well that with quality, uniform biscuits it aligns boards so well I feel like I traded it for a $700 Lamello. I never reference the cuts off the bottom/table - only on the face/fence side.
They take the stress out of some glue-ups, and add stress to some others!

You may be better off just letting the clamp bars align the boards.

Good Luck,

Pete

[Leo Graywacz]

How did you tune up your biscuit jointer? By DW I assume you mean DeWalt. I have the DW682K. Is this the one you tuned up. Mine doesn't align all that well.

[Steve Rowe]

I never use biscuits for edge glueing boards. For a properly prepared joint, there is no need as the glue is stronger than the wood. Mike made a good suggestion on the cauls. The method I use is to apply slight clamp pressure during glueup (just enough to start squeezing glue out) and align the boards by using a small deadblow hammer. Once aligned, tighten clamps fully.
Steve

[Peter Pedisich]

Originally Posted by Leo Graywacz

How did you tune up your biscuit jointer? By DW I assume you mean DeWalt. I have the DW682K. Is this the one you tuned up. Mine doesn't align all that well.

Leo,

Yes, the DeWalt DW682K. I loosened the two torx screws in the front face, either side of the blade, and you can move the base a little - just enough to check with a caliper against a tooth on the blade, and then re-tighten the screws. I saw the fix either in FWW magazine or on SMC.
Mine was off for a couple of years - I thought the thing was a piece of junk - and now I think it's a great budget Lamello!
I also stopped using Porter-Cable biscuits, and now use Virutex or Lamello brand, they are more consistent, and dont have chunks falling off them like the P-C.

Good Luck,

Pete

[Leo Graywacz]

Are you saying yours was tilted? Mine is straight. It just seems to have to much up and down slop.

[Rod Sheridan]

Originally Posted by Steve Rowe

I never use biscuits for edge glueing boards. For a properly prepared joint, there is no need as the glue is stronger than the wood. Mike made a good suggestion on the cauls. The method I use is to apply slight clamp pressure during glueup (just enough to start squeezing glue out) and align the boards by using a small deadblow hammer. Once aligned, tighten clamps fully.
Steve

That's what I do also, except I usually just use the side of my hand to tap the boards into alignment (not smart, I should use a deadblow hammer, that's what they're made for).

Regards, Rod.

[Chris Rosenberger]

I use biscuits when I glue up large panels. It helps with alignment. They also help align boards that may be bowed.

[scott spencer]

I used to use biscuits for almost everything because I thought the joints needed the strength, but now I rarely used them. Most tight fitting butt joints just don't need the help, and I use either M&T or pocket holes for those that do.

[Lee Schierer]

I prefer my biscuits with honey warm from the oven.

I don't use biscuits for joining lumber into panels or any other item. When I clamp up panels, I work from one side of the glue up to the other and tighten clamps one at a time and aligning the board surfaces by hand by lifting or pressing down on each board to get it aligned perfectly with its neighbor.

[Bill Arnold]

I use biscuits to aid in alignment of panel glue-ups but I quit using a wad of glue in the slot itself to eliminate telegraphing down the road. I also use them in some mitered joinery when I don't plan to add keys for decoration. I've had the DW682 for many years and it's still as it came from the box and alignment is perfect.

[Peter Pedisich]

Originally Posted by Leo Graywacz

Are you saying yours was tilted? Mine is straight. It just seems to have to much up and down slop.

Yes, mine was tilted, no slop.

[Cody Colston]

I use biscuits occassionally on panel glue-ups if I need help in alignment. Sometimes a bowed board does not want to stay in place long enough to tighten the clamps...and sometimes, that's the only board available.

Telegraphing can be prevented if you wait for the glue to cure and the wood to shrink before sanding the panel. PVA glue swells the biscuit(the wood also) and if you sand it right away, there will be a depression when the wet wood dries out.

I also somewhat disagree with the mantra that "the glue joint is stronger than the wood."

If you edge jointed a bunch of boards and let the glue cure, then tried to knock the joint apart with a hammer, it will often break at the glue line.

Sure, there is wood pulled loose and adhereing to the glue, but if the joint is stronger than the wood, it would always break somewhere other than the glue joint which I have not found to be the case.

If you use biscuits in the edge joint every 8 inches along with PVA glue, I pretty much guarantee that it will break somewhere (probably at the edge of the biscuit) other than the glue line.

I'm not necessarily promoting the use of biscuits because I don't use them that much myself, but just trying to clarify some of what I consider misinformation.