Thread: Biscuits or dowels for edge jointing?

Hi Derekcohen .

I have been using biscuits for about 10 years and have not had a single problem with them. My panel registration differences are no more than 0.5mm. The secret here is to buy a GOOD biscuit jointer eg; Lamello or what I bought was a DeWalt (it's grey in colour, that's how old it is). I regularly make panels up to 1200mm wide and have minimal hand plane finishing.

When I first started woodworking I tried dowels but there was so much time wasted I did some research and came up with biscuits. They are easy and very quick to cut the slots and help with alignment. Also biscuits are FAR stronger than dowels.

Now NO method will give you perfect registration of glued up panels except a commercial press even then the panels have to be with in 0.02mm difference in thickness of each other.
If you have a 2-3mm difference in registration of panels using a biscuit jointer you have either of 3 problems (1) Your jointer is crap or (2) the jointer has not been set up correctly (3) operator error while using the jointer.
Some further research into your biscuiting problem seems to be in order.

Major P

There are some things I agree with in your commentry. Such as the Lamello or DeWalt being a better biscuit joiner than the GMC (God, what an understatement!!). However my GMC is tuned and cuts accurately (measured by a digital micrometer). No, this is not the issue.

I also agree that the dowels are a Royal Pain in the butt to do (I thought I said so), and the biscuit joiner is MUCH more convenient (I think I said that as well).

Note, too, that neither biscuits nor dowels are needed for strength. This is a non-issue. If I started with perfectly flat boards I would not even bother to use dowels or biscuits.

When it comes to the issue of alignment, well I don't think that you read my description very accurately. I did not say that my registration was 2 - 3 mm out. Go back and read it again (I said the level was "good". You are confusing a later statement where I said that biscuits have a 2 - 3 mm margin of error -- for adjustment). Your estimation of your biscuited joints being about 0.5 mm out is about the same as I got (at most about 0.75 mm). But my dowelled joints were FLAT (zero difference).

Derek

If the boards to be edgejoined lay up flat, there is no reason to use any alignment aids...because they add zero strength to the glue joint.

They a waste of resources when not needed.

Dowels, biscuits, splines (a slotting cutter in the router and ripped 1/4" ply works dandy and fast...flip the board and make a second pass to insure the slot is dead center) are only needed where alignment of a large or odd-shaped piece is an issue.

Totally agree with Bob Smalser about dowels and biscuits both being a waste of time when butt joining panels. I have been making furniture for over 35 years and dont have problems with the panels I make. But it is important to work with dead straight edges and not rely on clamps to pull boards straight which can introduce very high stress in a joint.
MajorPanic
Have you done stress tests to determine that biscuits are stronger than dowels or is this just an observation?

I use biscuits for this job, because, like many amateurs, I don't have the requisite equipment to produce dead flat wide boards. I don't believe the quality of the biscuit jointer is what produces the minor misalignments that are liable to occur. I think these occur because some of the cheaper biscuit brands do not fit the slots accurately. You need to use higher quality brands, like Porter Cable, which are a tight fit in the biscuit slot. I also believe Derek's results would have been better if he had used the largest biscuit size, #20, instead of the smallest.

Rocker

Rocker, you dont need fancy tools for most woodwork.

With one exception I really dont have fancy tools. Many members of this forum have far better tools than I do. It amuses me somewhat about the fancy tools often used at home that are rarely seen in a pro woodshop.

I straighten all boards on my sawbench and sometimes use my old carbatec 12" thicknesser. And use a few sash clamps. I NEVER use my jointer, its just a dust collector.

It amuses me somewhat about the fancy tools often used at home that are rarely seen in a pro woodshop.

Using my fancy tools amuses me too!!

(Which is why I've got 'em... )

P

Originally posted by Rocker
I don't have the requisite equipment to produce dead flat wide boards.
Rocker

Tools? Edgejoining?

A cruddy old flea market Stanley 7 or 8 properly tuned is really the only tool you need if you are just doing the occasional one-off piece of furniture as a hobby.

http://media5.hypernet.com/ubb/ultim...c;f=1;t=008638

You don't even need a trysquare...clamp the board faces together in the vise two boards at a time...plane in any angle you like on the now side-by-side edges so long as it's straight and flat across both board edges....then remove from the vise intact and open the boards like they were pages of a book to mate the two planed edges. Bingo...perfection in just a couple of minutes with a sharp plane.

If the edges aren't true, ain't no biscuit or dowel gonna hole that glue joint together, given enuf time....and if the edges are true, you don't need alignment aids at all.

I've been doing something or another with wood almost every single day for the past 40 years...including furniture in juried shows during one phase of my career...and I don't own, never have owned, and probably never will own a biscuit joiner.

Nothing at all against them...I just don't see the need for me at least.

And PS...let's talk about using sized spacer blocks to align your clamping momentum dead square with the center of the edges sometime, eh? That's part of the problem for a lot of folks laying up squirrely panels...even those like me who should know better.

The easiest way to lay up perfect panels is with dead square and dead flat edges and dead square clamping pressure. Forget about fancy-schmancy clamps advertised to bring the pressure to bear square...all the ones I've seen that say that are lying...use spacer blocks with plain old Jorgensons or Records or your shop-made clamps and make sure.

I gave up on dowels VERY quickly - complete pain in the butt to get them aligned, and very slow.

I also gave up on the GMC biscuit joiner - the slot wasn't cut parallel to the fence, which kinda defeats the whole purpose. I bought a DeWalt and it does a nice job.

Most of the time when I use biscuits it's for aligning the joints in something that's cumbersome to handle, panels that aren't quite flat etc. Even with a good biscuit joiner and good biscuits, they will not ensure a perfect joint - there is always some play, and good jointed edges & good clamping technique is really the only way you'll get it perfect. Good clamping technique requires the right setup & a bit of practice.

On the alignment front - last weekend I built a bookcase for my office in black melamine, 1200h x 600w a 400d. Don't have the time nor inclination to build in solid timber for my office. I always have a fun old time aligning butt joints in melamine to screw, so I thought 'why not try the biscuits'. Damn good idea. Cut biscuit joints 2-300mm apart all around, a little glue inside each to help them hold, put the thing together and then screwed. Damn site easier to assemble it, and it came out nice & square for a change.

Echidna and Bob S,

When I said I did not have the equipment to flatten wide boards, I was not referring to flattening the edges for edge joining - I can do that well enough on my 6" jointer, followed if necessary by a little touching up with a jack plane. I meant that I don't have a long wide jointer that could flatten completely a board whose face is bowed along its length. Unless such boards are badly bowed, they can usually be brought back into alignment by using biscuits.

By the way, I do have some fancy-schmancy clamps - Bessey K-body clamps, which, in my opinion, do an excellent job in providing square clamping pressure and are well worth the money if you intend to make a number of cabinets.

Rocker

When to use dowels/biscuits and when not to?

For the most part this is only a consideration for myself when I am joining boards that are irregular or not perfectly flat. As I said early, there is no actual need for dowels/biscuits in terms of strength, nor is there any need if you begin with nice flat stock of equal thickness.

The purpose of my initial piece was to describe the pros and cons of dowels and biscuits if they were used. I thought that I might add a few more observations in this regard.

The problem with the biscuits is not the machine, per se. The GMC is not the flashest machine, but it is acceptable. It has the same fence as the de Walt and, on mine at least, it cuts accurately. But that is not to say that I use it optimally. In hand held operation, using the fence to guide the cut, there is a forward and a downward movement required. I suspect that my downforce was a little erratic here and the penalty was a slight variation in the height of the cut.

While drilling for dowels is a slower and more finicky process, it can also be more accurate in one important area. This is a result of the dowel jig I used, the Stanley #59. Those old timers really knew what they were doing when they designed it a century ago. Now this is not the jig you would turn to and use if you were joining a shelf (i.e. joining boards perpendicular to one another). But for edge joining it is the best! The reason I say this is that it aligns itself from a edge (and when you tighten the jig's screw-down, it minimises user-error), and it is possible to drill accurate, repeated holes along the edge. Once one has a little practice with the #59, it is actually a very quick jig to use. Still much slower than a biscuit (position the jig, clamp it down, drill the hole, unclamp, position the jig, clamp ....), but not too bad.

So when I need help to align boards my preference is for dowels. More tedious but, with the right jig, more accurate than biscuits. I guess I need to work on my biscuiting strategy to reduce user-error. If I could cut biscuits as accuartely on the vertical as I can with dowels, then biscuiting would be my choice since it is so much quicker and easier.

I have two dreams in my fantasy workshop: firstly that all my blades were always sharp, and secondly, that all my boards were perfectly flat!

Regards from Perth

Derek

Originally posted by Rocker
Echidna and Bob S,

When I said I did not have the equipment to flatten wide boards, I was not referring to flattening the edges for edge joining - I can do that well enough on my 6" jointer, followed if necessary by a little touching up with a jack plane. I meant that I don't have a long wide jointer that could flatten completely a board whose face is bowed along its length. Unless such boards are badly bowed, they can usually be brought back into alignment by using biscuits.

By the way, I do have some fancy-schmancy clamps - Bessey K-body clamps, which, in my opinion, do an excellent job in providing square clamping pressure and are well worth the money if you intend to make a number of cabinets.

Rocker

My appologies..I didn't answer you very well above.

I have a couple K-Bodies, too, and find they benefit from spacers just like any other clamp. True, they are better than Jorgies as far as square pressure goes and work alone on a few average glueups with thick boards...but nowhere near with the precision I'm talking about....especially on thin boards and with a difficult glueup cause by a twisted board.

Just like biscuits/splines/dowels won't hold an untrue edge gluejoint in alignment, they won't keep that twist from reoccuring either...the boards have to be flattened. I also only have a 6" power jointer...that means any untrue stock for edgejoining either has to be flattened by hand with scrub and smoothing planes, or they have to be ripped to 6" to fit my jointer. Depending on what I want....I do both.

Bob

You raise an important issue, one that I think requires more attention than has been given to date. That is, the problems with joining twisted boards, and the need to flatten the boards before joining them at the edge.

The discussion above was aimed at getting reasonably flat but irregular boards level on one side. Then comes the task of flattening the other side. But you have raised the issue of trying to level boards that are twisted and the increased tensions that result. That is, twisted boards, when force-joined, can be expected to come apart over time, and that the panel itself may move out of alignment.

Care to say more, as well as the degree of flatness needed to avoid such failures.

Regards from Perth

Derek

My only experience using a dowel jig was back at school.
A combination of testosterone charged adolescent, crappy worn out and abused jig, crappy twisted, warped, cupped, bowed pine and as you can guess the results were as expected.
The unfortunate part is, this experience sorta put adowna on dowels for me.
I now own a GMC biscuit joiner and have edge joined a few panels with it. The first turned out sorta OK, the latest, a panel for a table top came out almost perfeclty flat, I can't see biscuits being able to get a better result. While I accept dowels are more accurate, for me a least, biscuits allow for error, and to have the ability to correct that error right up to clamp time is a big benefit for a complete mug for me.

if Bob would care to enlighten a poor backward boy, i would like to talk, (read listen attentively) about the use of sized spacer blocks, clamping momentum etc.