I’m starting my second ever woodworking project (the first one, I did about 20 years ago), and it involves the use of the biscuit jointer.
I’ve been going nuts trying to find some rules of thumb about using biscuits, specifically figuring out what size biscuit I should use. Most advice is to use the “largest biscuit possible”, but that’s too vague.
Obviously, if my biscuit slot is so deep it goes through the face of the wood, that’s too deep, but is anything short of that OK? Or should my slot depth be only a certain percentage of the depth of my board?
(I’m intentionally not stating what the depth of my material is because I don’t want someone to tell me what size biscuit to use, but to find out how to figure it out for myself in the future – remember: if you build a man a fire, he stays warm for the night. If you SET a man on fire, he stays warm for the rest of his life.)
Replies
Maybe, but how long is "the rest of his life"?
Don't sweat it.
If it doesn't go thru the board you're fine. Aything else is like asking how many angels dance on the head of a pin.
http://forums.taunton.com/tp-knots/messages?msg=24866.2
http://forums.taunton.com/tp-knots/messages?msg=24866.6
I'm naturally lazy and don't like to re-type. Here's some replies to a similar question a while back on making a biscuit guage stick to check the slot depth and width to figure out what size will fit.
Waddaya mean it wont fit through the door?
>> Most advice is to use the "largest biscuit possible"
For strength, that's the best answer. If you are using the biscuits for alignment only, then any size will work.
Take you joiner and press the face against the area of the joint and see how much the blade comes out. As long as the blade will not get closer than maybe a 1/4" to the opposite edge, you are fine.
I'm not sure because I do not use them very often. (That does NOT mean...At All)..
I just grab one and lay it on the sticks and see if it sort of looks OK... Like somebody posted.. If it don't go out one or both of the sides it's OK to use..
I just use the largest one that will fit.. And I like using two if I can get away with it.
Just me but I'm a Nut...
EDIT:: I forgot.. Sorry
and it involves the use of the biscuit jointer.
BE SURE YOU KEEP IT TIGHT TO THE WOOD... Hands out of the way!
They say routers are bad.. Ya talk about a 'Climb Cut!' Biscuit jointers can be wicked!
Edited 9/14/2005 12:21 pm ET by WillGeorge
J,
The best answer is, "None!" If you've never used 'em, don't start. There is no joint whose strength benefits from biscuits.
They are a boon in a production environment as alignment devices, nothing else. They have caught on in other working environemnts as a result of misunderstanding of their role, tool envy and the desire of every manufacturer to jump on the crazy bandwagon of popularity that just exploded a few years ago. Can't blame them for the desire to make a buck. But recognize the tool for what it is.
Learn to make joints properly. You'll be glad you did.
Rich
Don't ever learn anything new. Rather than give you satisfaction that you know more than you did, it will only confirm you know less than you thought by opening horizons to things of which you had never dreamt and which you now must explore.
I do think your dismissal of the usefulness and functionality of biscuit joints is a bit harsh Rich.
I'm highly amused by your seemingly Luddite advocacy of only the old tried and true joinery when juxtaposed against your enlightening closing signature, viz, "Don't ever learn anything new. Rather than give you satisfaction that you know more than you did, it will only confirm you know less than you thought by opening horizons to things of which you had never dreamt and which you now must explore."
Biscuit joints have been around for quite some time now-- thirty years or so, almost as long as I've been whacking wood for a living, and they've gradually proved their usefulness to me. They probably started to impinge on the North American consciousness only about 12 or 13 years ago.
If we think about joinery there are really only two joints learn about; the mortise and tenon and the dovetail. Almost every other joint is a variation on those two types or a combination of the two. That's a simplistic view of course, but it'll do for now.
I put the biscuit joint in the same bracket as tongue and grooves, tongue and housings, dowel joints, loose tongue and grooves, and so on. Basically a hole is dug out of one bit of wood and a correspondingly shaped and sized protrusion is worked on the other bit, and they fit together-- which neatly describes the mortice and tenon based family of joints.
Biscuits are very useful for assembling carcases, in both solid wood and in man made board. The can effectively replace the tongue and housing at the corner of cabinets and for intermediate dividers. Are they stronger than the tongue and housing (US dado)? It's hard to say, but I see no reason why they shouldn't be all things considered.
This is just one example of an alternative use for a biscuit other than as only an alignment tool. There is also the need to consider joinery that is 'fit for the purpose.' Here what has to be weighed up is cost of production against what the customer is willing or able to pay and the life expectancy of the item being built.
For instance, some might say the 'best' joint to assemble a solid timber carcase is a hand cut secret mitre dovetail. I can knock these out all day long and I charge 2-1/2 hours per linear foot length at £40 per hour to do it. One corner of a 24" deep carcase is going to get charged out at 5 hrs, or £200 leading to a labour charge of £650 for all four corners which happens because there's a bit of discounting going on due to my pricing structure for multiples of the same operation or process. I'm not going to go into pricing here, but that's how it works out.
Is solid wood and secret mitre dovetailing a good choice for kitchen cabinetry? Unlikely, especially as most kitchens (like all commercial joinery projects) are usually only expected to last about 10- 15 years before fashion and other factors dictate a change. A better choice would probably be man made board knocked together quickly and cost effectively with something like biscuits, dowels, tongue and housing, etc.. Slainte.Richard Jones Furniture
Richard,
Um, yeah. I was a bit harsh, wasn't I?
Pedantic, even.
Yeah, they are useful. I described tham as alignment devices and I'm sticking to my story, there. I don't think they add anything to a joint that could just as easily be made otherwise, and probably better.
I think they are greatly overused, and in our equipment-oriented craft, looked upon as essential by many workers, who will because of their use, never learn "real" joinery. But why is that surprising? So many people think that dowels in wood furniture are a sign of quality construction.
At worst, biscuits can cause real problems in the surfaces of flat panel goods, where they tend to get used a lot. I have seen lots of amateur work resulting in tell-tale hollows over the biscuit locations because the surface was sanded and finished much too soon after the joint was made and the biscuit and glue swelled the panel thickness.
Interestingly, I have never seen that problem in commercial goods where speed of construction is at a premium, but apparently time to "cure" is also honored.
Anyway, in the hands of a craftsman, almost any technique turns out well. (Hell, the artists who taught me the little I now know could acheive better results carving with a screwdriver than I could with a sharp chisel.)
Rich
Would it be fair to say that bidcuits are the easy way out of using a spline? IMHO It is not much more difficult or time consuming to use a spline vs. biscuits. Using a spline saves having to buy a specialized tool and the paraphenalia that you need with it.
I am curious if there is any valid argument to be made that using a spline from the same wood as that being joined is a worthwhile advantage over the mystery wood of biscuits?
just my 2cents;)
For the record, biscuits are made from compressed beechwood with diagonal grain as a good engineering compromise, to join any grain-directioned wood.
Since they swell from glue and lock inplace, they are as strong or stronger than a spline when used appropiately. As I've said long ago, every joint has its place, else the joinery would not exist.
Biscuit joints provide plenty of strength.
You could not be more wrong.
And frankly I grow tired of this silly debate.
This is definetely not true. There is strength in a properly used biscuit, as much as a dowelled joint. It's great for table tops and similar constructs. Beyond that, use a different joint. If you have the time and skills, a spline or tongue and groove is a better choice, but they both leave the ugly marker at the ends of the boards of your choice of joints.Scott
Slacker Extraordinaire
Specializing in nothing but knowledge in everything.
The best answer is, "None!" If you've never used 'em, don't start. There is no joint whose strength benefits from biscuits.WRONG WRONG WRONG..I do not use them often.. I usually just use loose tenons.. Router..I have made several tests with different woods I usually use with both..They just seem to break in different places and I think they are better than OK for most things..Just me!
The best bicuits is whole meal bicuits. I love to eat them.
Yum!I like 'em with maple syrup.Rich
Laughter is good medicine we can'td be serious all the time
Biscuits are fine for not too important jobs i would never use biscuits on good furniture. my specially is Vienna clocks
I hope you'll forgive me for saying so, but I think you're making a mountain out of a mole hill.
There are only three sizes of biscuits available (0, 10, and 20) unless you have a PC jointer, which has a blade you can use for a narrower biscuit, intended for face frames. The differences in depth among the three is so small as to be insignificant. Thus, you can choose the biscuit according to the width of your stock.
The #20 will be sufficient for perhaps 95% of the joints biscuits are commonly used for.
I think you would get more helpful answers if you were less coy, and just stated how you want to use the biscuits.
********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
Thank you all for your help. I didn't want to simply ask how to use biscuits because, as I said before, I want to know WHY I'm using a #20 biscuit, rather than say "because I was told to use a #20 biscuit"
I had a feeling that as long as my biscuit slot didn't penetrate the opposite face of the wood that I would be OK, but I wanted to make sure.
For those of you concerned about biscuit strength, none of these biscuits will be load bearing. I'm building a 3x5 grid of cubby holes and the biscuits will be used on the vertical dividers. The horizonals will be dadoed into the sides.
Again, thank you all for your help. If all goes well, my wife might allow me to build other things in the future. If I screw this up...that's another story.
At some point back in the dark ages, I took a board of about 6-8" and ran the blade along the edge at each of the 3 settings for biscuit size (0, 10, and 20). I then wrote the slot width above each cut. I still keep it with my biscuits so I can reference the minimum slot width for each size biscuit. You could also register the slot depth for each with a depth guage. Something simple like that might help you determine which biscuit size would be best for a given application. If you have a table saw, it might be easier to just run dados for your cubby hole dividers.********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
Actually Lamello has an S6 biscuit (in addition to the H9 FF biscuit to which you refer on the PC) which is about 50% larger than the #20 biscuit. The downside is that unless you have a Lamello jointer, I don't believe it will do you any good. I got a sample of the S6 at the last IWF and it is one big honking biscuit. I have not tried it though.
When I use biscuits, I use the largest size possible and that is usually the #20. On occasion, I have used them for structural joints but, I normally only use them for alignment for glue-ups. They are very effective at aligning and re-enforcing miter joints.
With respect to comparing biscuit use with splines it is important to look at the grain direction when the joint is in tension. Since the grain on a biscuit is at a diagonal ,the stresses are not directly cross grain and would be stronger than the cross grain situation. For a typical spline joint, this stress is typically cross grain and the spline on a per surface area basis should therefore be weaker. On the upside, the spline will typically have more surface area to handle this load so it could ultimately be stronger than the biscuit joint.
Steve
I've only looked at Lamello from afar -- so I didn't know they had a biscuit bigger than the #20.If you have a Lamello, I wonder if you could give me some idea of what makes these machines so special. The last time I looked, the regular model was somewhere around $600 -- which is about 3 times the cost of a PC.********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
I purchased the C2 three years ago for $300. I wouldn't really go for the Top 20 since the only difference between it and the C2 is paint and a micro-adjust for blade height. With respect to differences between the Lamello and other brands, the primary difference is that Lamello surfaces are machined dovetails which at least in theory should provide more accuracy. I know that with the DeWalt I had the biscuit slots were not exactly parallel to either the fence or the baseplate. With the Lamello, they are. I can't say for the PC or others. Whether this is a real problem in application or not I am not so sure. There are also differences in the fence systems but I believe that this is just a matter of personal preference. Other than that, they all do the same basic job.
Steve
I had lots of trouble with biscuit alignment with the Dewalt -- so much so that I finally put it aside and bought a PC. It's way better, but still not perfect. How would you rate th C2 in this respect -- say on the alignment of boards for a table top?********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
I would rate the C2 as excellent on slot alignment. While I have not put the dial calipers to the parallelism, I have noted no issues with alignment whatsoever with it. On the PC, I seem to remember someone had developed a fix for the alignment problem by installing shims somewhere but, for the life of me, I can't remember where I read it.
Steve
I have two models of ELU. The first is the model that was on a pivot and swung into the board and the second model is like the current model of Dewalt that you push into the board. I recently purchased the base model of the Lemello, I find the machining a big improvement and it seems to cut a whole lot smoother. Someone earlier mentioned climb cutting and this machine does not seem to have this tendency like the Elu's. They seem to accomplish this with their cutter design. You can sometimes find them for about $369 CDN in the Great White North. Well worth the money.
Roscoe
This is an interesting question and really depends on circumstances and application.
Lets say you're having a plate of biscuits and gravy - in this case I would go for the "cathead" buttermilk biscuit, topped with a white gravy with freshly ground black pepper and cajun sausage chunks. This is typically a large biscuit, as big as an average cat's head - indeed, pretty much a meal in and of itself.
On the other hand, let's say you're bass fishing and you want to take a sack of ham biscuits to tide you over during the midday. Now you want maximum portability and the ability to eat with one hand while you're still fishing with the other. Your hands are probably coated with fish slime from the bass that you've been catching, so you want to manipulate this biscuit with the fingertips only. I would recommend a smaller biscuit here, with a slice of country ham fried in an iron skillet. Just a light daubing of red eye gravy and maybe a little tabasco sauce. Bon appetit!
I think my new biscuit policy will be only to use the ones you can put gravy on;)
Ed, I see that the quality of this thread has just only now been up-rated by you and Nail-thank you so much-these days a laugh or two are most welcome.
I must also say that as I only try to make better quality furniture most of the time I enjoy my biscuits at tea times or when playing with my dog.Philip Marcou
This forum post is now archived. Commenting has been disabled