Thread: Dowell's Vs Biscuits

I prefer 90mm framing nails, with PVA of course, Im not a total bodger.


Al

I agree with your summation Lou but here are my comments.
Biscuits are faster than dowels for some work such as face frame work
Dowels are more accurate than biscuits
Dowels can give a strong alternative to mortice & tenon in some applications such as attaching table legs to frames where a biscuit would be unreliable.

I have a biscuit joiner but down the track I will also get a GMC twin dowelling machine. I will set it up permanently on a bench with a sliding table so ends or edges can be drilled fast and accurately with minimal setup.

I read a fantastic reveiw of the relative strengths of a variety of jointing techniques by professional doormakers. What surprised them and pretty much everyone else is that the biscuits were significantly stronger than anything else!
It came down to long grain to long grain contact, and the entire surface of the biscuit acts as long grain, thereby giving much greater strength. The amount of long grain to long grain on a dowell is only a tiny percentage of the surface of the dowel, most of the circumference is not in contact with long grain.
I made a variety of joints using differing techniques, just to see if the reveiw was relevant to what I was doing. Testing the joints to destruction showed that biscuits are very strong, much stronger than dowells. I still use mortice and tenon for joints that require strength but will use biscuits whereever else I can.
Suresh

Dowel joints and mortice & tenon joints have mechanical strength without any glue. Biscuits rely upon glue. In the case of table legs to aprons biscuits are not suitable

Our local council had a hard rubbish collection last week. As a result, I joined the group of people checking out what the neighbours are chucking out, so I can collect their stuff and chuck it out next collectilon.

Well, as it turned out I found two wooden framed beds at different locations being turfed. Last Saturday I spent a good portion of the afternoon pulling them apart, then trimming the timbers on the saw bench to add them to my collection for projects.

Both bed frames were made of pine and seemed to be of about the same vintage. I guessed they were only about 5 years old, makes you wonder eh?

Anyway I tried to gently tap the joints apart with a hammer, the dowelled one I did first and it came apart relatively easily. Get a crack, then wedge a cold chisel in and pry, followed by a jemmy, easy.

The second one was extremely hard and I couldn't get a crack in any joint without massive hammering, not good for the timber, let alone my arm and shoulder. The next step was a brickies chisel and a steel mallet, this only started to pull the timber in and made me start to think it had been glued with liquid nails.

After careful inspection I decided that there were no nails or steel, so I ripped them with the saw bench. The bed heads were 90 x 40mm pine and at each join there were two small biscuits holding them in place as well as glue on the rest of the joint. The biscuit joins were the last thing to go and I even tried to pull one of the biscuits apart with a morticeing chisel, but it seemed to be a part of the timber it had been glued to. I was becoming more interested about biscuit joining, by the minute.

The next day I attended the local Triton owners group and was able to watch people making biscuit joints on Triton equipment. I was able to see how the Triton manufacturer has designed their system to fit onto the Triton router table and reckoned that this is really the way to make small and large tabletops quickly, and easily, as well as a multitude of other joins.

I think, after using dowelled joints for small projects, mortice and tenon for heavier stuff, I may consider a biscuit system for some applications in the future .

Mick.

Our local council had a hard rubbish collection last week. As a result, I joined the group of people checking out what the neighbours are chucking out, so I can collect their stuff and chuck it out next collectilon.

Well, as it turned out I found two wooden framed beds at different locations being turfed. Last Saturday I spent a good portion of the afternoon pulling them apart, then trimming the timbers on the saw bench to add them to my collection for projects.

Both bed frames were made of pine and seemed to be of about the same vintage. I guessed they were only about 5 years old, makes you wonder eh?

Anyway I tried to gently tap the joints apart with a hammer, the dowelled one I did first and it came apart relatively easily. Get a crack, then wedge a cold chisel in and pry, followed by a jemmy, easy.

The second one was extremely hard and I couldn't get a crack in any joint without massive hammering, not good for the timber, let alone my arm and shoulder. The next step was a brickies chisel and a steel mallet, this only started to pull the timber in and made me start to think it had been glued with liquid nails.

After careful inspection I decided that there were no nails or steel, so I ripped them with the saw bench. The bed heads were 90 x 40mm pine and at each join there were two small biscuits holding them in place as well as glue on the rest of the joint. The biscuit joins were the last thing to go and I even tried to pull one of the biscuits apart with a morticeing chisel, but it seemed to be a part of the timber it had been glued to. I was becoming more interested about biscuit joining, by the minute.

The next day I attended the local Triton owners group and was able to watch people making biscuit joints on Triton equipment. I was able to see how the Triton manufacturer has designed their system to fit onto the Triton router table and reckoned that this is really the way to make small and large tabletops quickly, and easily, as well as a multitude of other joins.

I think, after using dowelled joints for small projects, mortice and tenon for heavier stuff, I may consider a biscuit system for some applications in the future .

Mick.

I have 2 types of dowelling jigs: a self centering jig and a corner dowelling jig. Until I got these I used to set out and drill dowells by hand. In recent times I have bought a biscuit joiner as well. Having used a lot of dowells and now with 12 months of a biscuit joiner, the biscuit joiner gets my vote by a long way. Joining frames with a biscuit joiner is dead easy. If you join a rail to a stile by 2 number 20 biscuits it will be very strong joint indeed. The biscuits fit into the slots tightly and the gluing area is substantial. I also appreciate mortice and tennon joints but (I cannot prove this) I suspect that in this application the biscuit joint is as strong as a m&t joint. I have a large panelled cabinet where all the frames are biscuited together and I am very happy with it. In the construction of large glued up panels a few biscuits along each joint gives perfectly flat panels with no dendency to creep out of alignment as the clamps are tightened. The popularity of the biscuit joiners is at least in part because the joint formed is a strong one.

BUT and this is a big but (even bigger than mine) at the risk of becoming philosophical we wood crafters who mostly work for little or no financial gain and mostly from our homes in our moments of leisure carry the task of preserving a heritage of skills which have been largely lost in commercial production techniques. We have the time to develop the skills which history has handed down from ancient times and by one means or another (eg this forum) these skills are passed the next generation. I value these old skills as being worth something. So while I like my biscuit joiner and my jointer and my thicknesser (etc...) I hope I never cease to practice and improve that relationship with timber that can only come through the use of hand tools. It is a wonderful ( I use the word wonderful deliberately) thing to feel the timber take shape as practiced hand and eye work with a saw and a chisel. I hope that most people on this forum feel the same way. I have seen men and women at the shows touch and smell timber or balance a saw in the hand like the wine buff swills his wine.

Anyway children the lecture is over now. You may all take your bags, push in your chairs and go to bed.

IMHO its not a case of "dowels or biscuits". they both have their place. With the modern glues available the strength contributed by either one, in most cases, is almost irellevant. The main thing I use either one for is an aid in ligning things up, and each has its advantages depending on the situation.

Originally Posted by Termite

IMHO its not a case of "dowels or biscuits". they both have their place. With the modern glues available the strength contributed by either one, in most cases, is almost irellevant. The main thing I use either one for is an aid in ligning things up, and each has its advantages depending on the situation.

Damn straight. While having used both biscuts and dowels i have never got into either of them because with a good glue and a clean joint with good contact, you don't need them.

unless there's end grain involved, in which case I prefer to use Mortice and Tenon or some other integral joint.

Can't vote because there is no option for "both" or "depends on the situation"

As Termite stated, it is not a question of one verses the other. Both have a place.

The best joints are made by hand. No argument. Mortice-and-tenon joints, dovetail joints, etc. Where it is possible to use such - AND you have the skill to make them - then do so. Neither a biscuit- nor a dowell is a substitute either in strength or aesthetically.

However, sometimes it is not necessary or practical to use traditional joints, such as when joining edges for table tops or, especially, when using composite materials such as MDF. Since I mainly build in solid timber I use dowels and biscuits for alligning edges only.

In my experience dowels are more satisfying to use, but they require considerably more care in cutting. Biscuits are fast-and-furious. Pretty accurate too. But if you are going to dowel, and you use the correct tools, then you will end up with accurate results. I suppose that this would be true of biscuits as well if you approached them with the same attitude.

I use a Stanley #59 dowelling jig and own a GMC biscuit machine. I get exellent and reliable results from both. BUT the GMC is noisy and dusty and an invasion into my private world, while the Stanley is quite and calm.

Regards from Perth

Derek

Biscuits for me . They are much quicker than dowelling and give some lateral adjustment which is sometimes handy . I bought a "Lamello" biscuit M/C some 20 plus years ago when it was about the only one on the market . Cost an arm and a leg at the time - around $ 900 - but has paid for itself many times . The on;ly downside is the amount od sawdust that gets sprayed around . At least some of the modern M/Cs have dust bags

I use both.
Biscuits are convenient when edge joining boards as you do not need to be as accurate with the positioning. However I find it very easy to cut a slot that is 'thicker' than it should be. I can do this whether I use the Triton biscuit joiner, a slotting cutter in the router bench or a dedicated biscuit jointing machine. It seems to be very easy to widen the slot when withdrawing the cutter making for a loose biscuit.
Dowells when used for framing have the same value as an M&T in strengthening the stile. The long dowell helping to stop the stile splitting.
As to how easy any of them are to pull apart - I think that depends more on the type and age of the glue used than any other factor. I recently dismantled some dining chairs which were dowelled and glued with hide glue. Some were falling apart, others required a lot of effort, some the dowells 'slivered', (the outer skin of the dowell stayed with the inner pulling out) and in one I split a chair leg as the dowell stayed firmly in its hole and the timber beyond the dowell broke away. Incidentally, none of these chairs had actually broken, loose joints but no fractures!
For dowelling I use either a Stanley dowelling jig or a Record 148 2 hole dowelling jig. That is a great tool for framing just as long as you can get your head around keeping all the faces the right way - hi.
Cheers