Biscuits?

[JBark]

I am thinking of making a cabinet to sell on craigslist or the like. I want it to be quick and easy...literally. Something I can make in a couple of hours and mass produce easily (I have delusions of making my first million with this piece.) I can make a cabinet easily with good strength a number of different ways but I keep coming back to the door. My thoughts came to a frame and flat panel door with biscuit joinery. How strong are biscuits? I have not paid attention to discussions/articles because I wasn't sure I would ever use them.

Do they hold up well?

[Beamer]

Now that's one of them long-held debates, eh?

I have only used biscuits a few times in panels, so I don't have a lot to contribute in their use for doors. The magazines have all run these sensational strength tests on 'em and whatnot, i dunno who to believe.

If it were me, lookin' to make my first million, I wonder a few things...

Is a simple frame and panel door style more of the shaker type? I mean without any decorative edge applied to the frame's inside?

Then again ... as I think through this ... what about just stub tenons? You already have to cut the groove for the panel anyway, don't you?

Do you have (or might you acquire) a couple of routers so you can just set these joints up once and mass-produce 'em? Even a Cope and Stick joint would be real strong - i've done some of those. Personally, I have had better luck with these style joints coming out flush, too.

I guess there's the idea that with biscuits or pocket-holes or dowels or floating tenons you don't have to account for the joinery involved. Then again, if you're mass producing something, you only have to do that math once for that style of joinery and have at it.

Since you're in the furniture industry already, I have to ask ... What does the company you work for use for their door joinery?

I know i veered a bit off your original question, but that's how it goes I guess

[dcarter636]

I rarely use bisquits now, and never in a stressed joint. They have some value as an alignment device, but that is all they are good for and are rarely the best solution there either.

They were over hyped initially with unreproducible test results and advertorials; like many other amateur joiners I went whole hog with biscuits in place of refining my M&T or T&G joinery. They reliably failed in butt joints with moderate stress and have completely lost their appeal to me as a time saving joinery device.

A door that maybe slammed on occasion sounds like a sure bet for biscuit failure to me. A half lap, T&G, or partial bridle joint are usually more durable and not much more time consuming.

Wouldn't a door, stick and cope, router bit set do the job economically?

[TDHofstetter]

I was just gonna' suggest half-laps for quick-and-dirty. They don't even need to be complete half-laps; they can be secret half-laps. Routed stick-and-cope is nearly as quick and not quite as dirty. They don't hold up as well as half-laps, though.

[fredbelknap]

I was looking at some Amish made cupboards in a store recently and the rails and styles were put together with pocket hole screws. Now thats dirty.

[Joe Lyddon]

Apr 11, 2010 15:27:39 GMT -6 fredbelknap said:

I was looking at some Amish made cupboards in a store recently and the rails and styles were put together with pocket hole screws. Now thats dirty.

... and it's Quick!

The main technique to be learned is how to Clamp the pieces properly so they don't wander around while you're screwing the parts together.. An EASY Quicklearning experience.

Kreg has very good videos on it to get you started...

I'm sure glad I got into it... It's amazing how FAST it can be!

Cut all parts to exact Finished dimensions, drill holes, clamp & screw... DONE!
... no waiting for glue to dry, huge clamp-ups, etc.

[Beamer]

Apr 11, 2010 15:36:37 GMT -6 Joe Lyddon said:

The main technique to be learned is how to Clamp the pieces properly so they don't wander around while you're screwing the parts together.. An EASY Quicklearning experience.

Boy you ain't kiddin, there! They do like to move when ya drive the screw. Once ya learn to clamp 'em, tho, all works well

[Ruffnek]

John,

I reckon I'll be a dissenting voice here. Depending on the size of the door, I wouldn't have any problem using biscuits if they were doubled...ie, two biscuits per joint.

Biscuits used in an end grain to side grain joint are stronger than both cope and stick and stub tenon and groove joints. In fact, cope and stick is probably the weakest.

So, IMHO, if a cope & stick joint will work for the size door you are building, then biscuits will work better. If you use plywood for the panel and glue it in place the door will be almost indestructible.

If you are still not sold on biscuits, then you could invest the $1000 or so for a Festool Domino. The Domino loose tenon is a bit stronger than dual biscuits and what's a thousand dollar investment with a million dollar return? ;D

[Stretch]

I have no problem using biscuits for doors in some instances, but they're not an end all joinery method by any means. A quick and easy flat panel door can be done with biscuits. Just make a frame with biscuit joints, rabbit the back side and glue in a plywood panel. I've heard people talk about biscuit joints failing, but I've never had it happen. The thing is that you have to use plenty of glue. That is coat the biscuit and fill the slot. Then you need to just plenty of clamp pressure to get a good butt joint. Too many people are worried about glue starvation from over clamping a joint. The only way you're going to get glue starvation is to not use enough glue in the first place. Short of using hydrolics, you're not going to be able to get enough pressure to squeeze all the glue out of a joint.

[brburns]

Apr 11, 2010 15:27:39 GMT -6 fredbelknap said:

I was looking at some Amish made cupboards in a store recently and the rails and styles were put together with pocket hole screws. Now thats dirty.

Them Amish LOVE poket hole jointery. I couldn't believe all of it when I went to Ohio Amish Country last summer.

[Ruffnek]

Apr 11, 2010 16:28:14 GMT -6 Stretch said:

Short of using hydrolics, you're not going to be able to get enough pressure to squeeze all the glue out of a joint.

I've read that a good glue joint only requires the glue be one molecule thick. That's a pretty thin layer of glue.

[Leo Voisine]

From what I have read bisquits do not have a high level of strength as compared to other joints. They are on par with dowels plus or minus a few points.

So how strong do they NEED to be?

They are likely strong enough.

I have used bisquits on a number of occasions - no problem.

I would also venture to say Pocket screws might do the trick also.

Lots of quick knock it together stuff is made both ways. Seems to be a proven process.

[JBark]

I should have been a little clearer on this. I have a shop with a Unisaw, shaper, bandsaw, 12" jointer and a 12" planer. I have a floor standing drill and a dedicated hollow chisel mortiser as well as two routers. I was raised trained in mortise and tenon and hand cut dovetail construction. I want to deviate from this because my family/work situation does not permit me to spend a tremendous amount of time in my shop and I would like to see if I can't squeeze something out for a nice quick and easy profit. I don't want it to fall apart in two days but ten would be okay. In other words I'm not going to use the best joinery but I want to use something that will hold up. What I see on my job selling "factory" made furniture is mostly pocket screwed stuff but I have no interest in sinking that low.

I wanted to determine if the biscuit would give me an adequate joint. Cody reminded me that by gluing in a solid plywood panel I can make an indestructible door.

[Joe Lyddon]

Biscuits are only good for alignment... that's all.

The Domino, with larger tenons, would be stronger.

Plywood glued & screwed with pocket screws is VERY strong; that is if a good grade of plywood is used... an edge is 1/2 long grain & 1/2 end grain evenly distributed... glued to a 100% long grained side is very strong. So, PKT screws are NOT "quick & dirty"... they're "quick & good". ;D

[dicklaxt]

You got it Joe,,,,,, allignment only,very convenient but little strength.They were used only as a thought for strengthening before space age adhesives existed,beside mass produced for sale on Craig's list are not supposed to last to long anyway.

I have had butt joints used in segmented turnings hang on for years on very thin material,in fact its had to break them in most cases.

dick

[deepsplinter]

"Biscuits are only good for alignment... that's all."


Sorry guys, but I don't think biscuits are all that great for alignment. In theory maybe, but not in the real world.

I'll use 'em now & then on complex glue-ups, to keep "that end" close, while I'm working on "this end". In my experience, the biscuits just aren't that precise. I've soaked 'em in water to tighten 'em up before, but IMO, they're still "iffy" at best.


If I was wanting to whip something out real quick, I'd go with pocket holes.

[art3427]

I only use biscuits for alignment of long glue joints. I think they are substandard for your intended purpose. If you have cope/sticking cutters for a shaper that would be a much faster and stronger joint IMO. I have literally made thousands of raised panel doors using the stub tenon on the C/S cutters and have never had a joint failure.

art

[TDHofstetter]

I'll even chip in here, although I've been staying out of it so far. I own a biscuit joiner, and I've used it twice - when no other suitable method was available. In my experience, biscuits are neither strong nor precise... but they can occasionally make joints possible when nothing else is very plausible. I won't use 'em unless I need to.

Same goes for pocket screws, 'cept I don't own any pocket-screw stuff.

[Ruffnek]

I base my joint strength remarks on the test done by Fine Woodworking last year. They tested most of the popular joinery methods for breaking strength and ranked them accordingly...not subjectively but based on actual pressure requjjired to break apart the joint.

Even for those who question the test, I'll venture that it's more objective testing than anyone on these boards have done, if they've done any at all.

Remember "Where facts are few, opinions are many." Well, here are some facts acording to Fine Woodworking Magazine.

HALF LAP 1,603 lb.
BRIDLE 1,560 lb.
SPLINED MITER 1,498 lb.
3⁄8-IN. MORTISE & TENON 1,444 lb.
3⁄8-IN. FLOATING M&T 1,396 lb.
MITER 1,374 lb.
3⁄8-IN. WEDGED M&T 1,210 lb.
3⁄8-IN. PINNED M&T 1,162 lb.
5⁄16-IN. M&T 988 lb.
BEADLOCK 836 lb.
DOWELMAX 759 lb.
¼ -IN. M&T 717 lb.
POCKET SCREW 698 lb.
DOMINO 597 lb.
BISCUIT 545 lb.
BUTT 473 lb.
COPE & STICK 313 lb.
STUB TENON 200 lb.

I was wrong about the cope & stick joint being the weakest. It was the stub tenon and groove. "Weak" is a relative term, though. I've used both those joints a lot and while they are not the strongest (actually the weakest of the ones tested) they are strong enough.

I think, based on my own experience and even more so on the test results above, that the biscuit joint is plenty strong enough for medium size cabinet doors.

A dislike of biscuit joinery does not necessarily make it a poor choice, just a different one.

[Joe Lyddon]

I remember that report...

Was surprised to see the simple Half Lap to be that strong!

The Half Lap has it... by far!

(Tim's right again! )