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  • biscuit joinery

    Are biscuits appropriate for joining a table apron to a leg ? Is there any problem with wood movement when doing this ?

  • #2
    Re: biscuit joinery

    I'd be a little leary of holding a table together with biscuits. The leg to apron joint shouldn't get much stress on it, so it should probably do ok. I'd probably try to find a way to do pocket screws for that joint, however. Make the pocket part in the apron and screw into the leg. They're tremendously strong, and will clamp the piece while the glue sets, so you won't have to worry about stretching clamps across.

    Traditionally, those joints are most often made with mortise and tenon joints, which is kind of what a biscuit is. Technically, a biscuit is a kind of mortise with a loose tenon. The biscuit is the tenon.The problem is, the biscuits aren't very big. They are strong, and there is no issue of grain direction in the biscuit, so they stand up well to stresses. They would probably be fine, as long as you had at least 2 in each joint.

    I've never made a table like that, so I don't know if the biscuits would hold up. This is just my opinion from working with them in frames and other projects.
    I put it all back together better than before. There\'s lots of leftover parts.

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    • #3
      Re: biscuit joinery

      so, by using pocket hole joinery, I can just glue and screw and not worry about movement then ?

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      • #4
        Re: biscuit joinery

        Personally, I'm not crazy about pocket holes and screws. Good for frame-face stuff I suppose, but I really don't look at them as being all that strong.

        As VASandy mentioned, the strongest joint is mortice and tenon. That can be done by either cutting the tenon into the apron, or by morticing both mating pieces and using a floating tenon. That's a bit of work. It's easier if you have the equipment, of course.

        Probably the easiest and strongest joint with minimal amount of equipment would be a dowel joint. This is a traditional method of joinery and often used on tables. The dowel is quite strong and if you can drill a hole with some level of accuracy (doweling jig, drill guide, etc.) they're relatively easy to do.

        With a biscuit joint, you obviously have to have a biscuit cutter (plate joiner). You can do them with a router, but I don't think that's as easy as it look. I have a tendency to look at biscuit joinery as more of an alignment step, rather then as making a strong joint, but perhaps I can be wrong in that presumption.

        CWS

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        • #5
          Re: biscuit joinery

          I tend to agree with the previous posters. Mortise/tenon is the best bet, dowels second best, pocket holes maybe barely behind dowels, and biscuits are fourth.

          I actually am somewhat crazy to a fault about pocket hole joints, just because they are so easy to do, and make dry-fitting a snap. I used to use biscuits a lot, but have faded on them after getting my Kreg jig.

          I'm building an oak buffet table (below), and I have probably 25+ pocketholes on it. My front and back stretchers both use pocket holes. However, my top is plywood, and I have more PHS's holding the top all the way around, so it should hold it all together pretty well. The bottom shelf is dadoed into the side panels, which provides most of the structural strength anyways. If I had a solid wood top, I'd have to account for its wood movement, and would probably opt for mortise/tenon joints and use figure eights or similar for the top. But that's just me. PHS are for me what brad nails are to Norm, and tung oil to David Marks.
          Attached Files
          Last edited by steveKane; 03-17-2008, 07:51 PM. Reason: added pic

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          • #6
            Re: biscuit joinery

            I work in high end cabinet shop and we use the pocket screws for everything. There isn't a stronger joint out there that is as easy to use and have everything come out so good. I use it alot at home because i do alot of frame and panel finished ends. So instead of dadoing and then nailing the deck in place it leaves a much cleaner finish on your end panels which in the long run saves time and is just as fast as dadoing. happy cutting!!!!!!!!!!!!

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            • #7
              Re: biscuit joinery

              I would have to agree on the pocket holes being the easiest method of attaching your apron to the leg. I prefer not using dowels as I have repaired too many pieces of furniture with badly doweled joints. If your more of the purist woodworker than the mortise and tenon joint would be your best bet.

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              • #8
                Re: biscuit joinery

                A biscuit joint will hold the apron (IMHO better than pocket hole/screws). If you are in the middle of the project and you have the tools and expertise, it will work. If you want quality joinery that won't fail, you need to perfect M&T. Mortisers can be deeper and thicker than biscuits, and provide a stronger joint. That said, a good biscuit joint is probably stronger than a sloppy M&T and truer than a misaligned dowel joint and definitely better than a pocket hole unless future disassembly is desired.
                Pocket holes are convenient to use and allow future disassembly (sans glue), but it is basically a screw or/and glue butt joint; Biscuit joints are stronger and easier to reproduce in quantity with limited skill; dowels are more difficult to align, but with depth provide more lateral stress, and with multiples, provide more torsional strength; Mortise and tenon take more skill and finesse for a good joint, but are more adaptable (i.e. simple glued tenons, through tenons, haunched tenons, pegged tenons, lock tenons, etc) to a variety of jointery situations to provide strength in the joint and allow for wood movement, subsequent disassemby, etc.

                All have their place and their uses overlap.

                Go
                Practicing at practical wood working

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                • #9
                  Re: biscuit joinery

                  Dunno who else subscribes to Woodsmith, but this baby was featured in the latest issue. Given that it looks like it could give the same result as a Domino, at 1/3 - 1/4 the cost, and allows much more flexible uses, it might be the M&T dreamer's dream. www.mortisepal.com

                  I don't mean to hijack this thread, but it might be a relevant item to purchase for the original poster. As everyone has noted, M&T is the best joint there is and this makes it about as easy as using a dowelin jig.

                  PS- I don't have anything to do with this company, guy, product, etc.. other than being on the verge of buying one.

                  As a second aside, I'm also a fan of pocket hole joinery.. but I use them mostly to "clamp" and align joints that are also being glued. I would not rely on the screw by itself. Just my 2-cents.

                  I approach it like this:
                  Biscuits: flat panel glue ups, to help with alignment (adds no strength). Sometimes for carcass assembly.

                  Dowels: I rarely use dowels, except as a decorative "pin" on frames or legs. Also for putting a cap onto something (e.g. headboard cap) where the joinery must be completely hidden and biscuits might be difficult to cut.

                  Pocket holes: Alignment and holding for glued butt joints. This includes face frames, unless I don't want to see the pockets on the interior. Then I use FF biscuits.

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                  • #10
                    Re: biscuit joinery

                    That Mortisepal really looks useful. Making accurate mortise and tenon joints is always a bit tricky and fussy. They're one of the best joints around, but I've always had trouble with them. One thing the Mortisepal seems to make easier is alignment. That in itself could make this a useful little gadget.

                    One question that comes up is how to make the loose tenons for the joint. Does it come with some (like the Domino), or do you make your own?
                    I put it all back together better than before. There\'s lots of leftover parts.

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                    • #11
                      Re: biscuit joinery

                      Originally posted by VASandy View Post
                      That Mortisepal really looks useful. Making accurate mortise and tenon joints is always a bit tricky and fussy. They're one of the best joints around, but I've always had trouble with them. One thing the Mortisepal seems to make easier is alignment. That in itself could make this a useful little gadget.

                      One question that comes up is how to make the loose tenons for the joint. Does it come with some (like the Domino), or do you make your own?
                      I think it would be easy to make your own. Just cut some appropriately sized width of stock, of any length. Use a roundover or bullnosing bit on the edges... Or even just file / sand it round. Then cutoff what you need when you need it. That's my plan anyway. I asked for this for my birthday, from my wife.... she resisted. It was just for show, and she finally relented. Thank goodness it's coming up soon! I'm always hot to play with new toys... errr, time-reducing-efficiency-jigs. Yeah...

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                      • #12
                        Re: biscuit joinery

                        That's an awesome tool! Beats the heck out of my hollow chisel mortising machine! and lots cheaper too! LOL

                        Mark
                        Congratulations to Mr. "the sky is falling" Al Gore, nominated the new Village Idiot!

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