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biscuit joiner basic question?

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  • biscuit joiner basic question?

    Bought a close out craftsman biscuit joiner with no box or manual and its my first one. Does the "cut" have to be dead center in the stock? I did a little test run and I couldn't get it right in the middle (thin stock, 1/2") but it seemed to line up fine.Any info would be appreciated....thanks

  • #2
    There is no real reason that the biscuit needs to be centered. The critical measurement is the distance from the top of the piece to the biscuit slot. If that measurement isn't the same for all the pieces being joined, your pieces won't be flush to each other and you'll end up with extra work. A biscuit really doesn't add strength to the joint, it's more for alignment than anything else.
    I decided to change calling the bathroom the "John" and renamed it the "Jim". I feel so much better saying I went to the Jim this morning.


    • #3
      No the cut does not have to be centered. Just lay the 2 boards that you want to join side by side. Mark your biquit locations on both pieces at the same time. Line up the alignment mark on the joiner with each of the marks on the wood and cut them. Just make sure you are not so close to the edge that the cutter runs out of the wood. When I join thick wood,6/4- 8/4 I will double the bisquites by cutting from both sides.
      info for all: --- "I like long walks, especially when they are taken by people who annoy me."


      • #4
        Badger Dave,

        I have to take exception to the statement "A biscuit really doesn't add strength to the joint, it's more for alignment than anything else."

        It won't add strength to a panel glue up or any long grain to long grain glue up and in this case it is used mostly for alignment.

        It will add strength when gluing end grain to end grain or end grain to long grain (mitered corners for example).

        Bob R

        [ 08-09-2005, 09:20 PM: Message edited by: Bob R ]


        • #5
          One thing to remember when using biscuits in thin stock is that the beech biscuits swell as they absorb water from the glue. This can cause the surrounding wood to expand as well. If you sand a thin panel before the moisure evaporates (about 24 hrs) you may see slight depressions above and bellow each biscuit, this becomes quite visible if you use a gloss finish


          • #6
            While I usually agree with you on most topics, I think you need to qualify your statement about biscuit strength.

            Biscuits always cause some debate among woodworkers, but anytime I can I try to resolve it. The answer to whether or not biscuits add strength depends on the joint. There are times when biscuits do add strength. I'll say up front that in most cases, I have replaced biscuits with another type of joint in my own work, but biscuits do work.

            In bookcases, using biscuits to join the shelves to the walls is strong. I built some bookcases with this system years ago, and after a lot of use and abuse they are still strong. I no longer do this myself, preferring dadoes. But I switched to dadoes only because I now find it easier, not because of strength concerns.

            Biscuits add strength when attaching table legs to aprons, but make sure to also use a corner brace. Mostly, I now prefer mortise-and-tenon joints here, which are actually faster than biscuits once you're set up. I do occasionally still use biscuits for small tables, and it is definitely strong. Maybe it's not as strong as a mortise-and-tenon joint, but as long as you're not having a party on the table top it will be fine.

            Biscuits add strength when doing frame-and-panel walls for cabinets. I now use groove-and-tenon joints because that's what I'm set up for and I like the system better, but biscuits are strong enough for this.

            Any small face-grain-to-edge/end-grain joint is strengthened by biscuits. In lots of projects, I will use biscuits here with no worries.

            I never use biscuits on stock thinner than 3/4".

            I never use biscuits on miters. They tend to make the joints more difficult to bring together. Instead, I use mitered mortise-and-tenon joints.

            I never use biscuits on long-grain-to-long-grain glue-ups, such as a table top. They actually make the joint more difficult to close up and there is no need for extra alignment help once you have a proper system set up for this.

            I never use biscuits for any kind of doors or mirror frames. These are high-stress joints, and I want the greatest strength possible. So I prefer pinned mortise-and-tenon joints here. I have heard of people using biscuits for this, but when I build an entry door or a 36x60 mirror in someone's bathroom, I want joints that are indestructible!

            Bottom line: biscuits should not be used as a catch-all solution to joinery, and there is often a better option. But for certain joints, they are definitely strong enough. For those times when you want ultimate strength, biscuits are not the best option.

            It all comes down to recognizing when they are appropriate.

            [ 08-10-2005, 08:47 AM: Message edited by: MSchenker ]


            • #7
              the catch-all joinery method would be pocket hole screws. Not pretty, but gets the job done


              • #8
                "It all comes down to recognizing when they are appropriate." That statement in your post pretty much says it all when one is considering the use of biscuits or not.

                In some of the examples you cited the use of biscuits may well be a viable options but not necessarily the best option under the circumstances at hand. I may have understated the ability of biscuits to act as a joint strengthener mainly because I've never considered biscuit joinery as anything but an alignment guide. I can assure you that my intentions are never to deceive anyone but the world is full of opinions and that just happens to be mine where the use of biscuits is concerned. [img]smile.gif[/img]

                [ 08-10-2005, 12:37 PM: Message edited by: BadgerDave ]
                I decided to change calling the bathroom the "John" and renamed it the "Jim". I feel so much better saying I went to the Jim this morning.


                • #9
                  kenny, although it's not necessary to get the biscuit slot in the middle, i've found that by taking some extra time in getting it centered (flip a test piece after you make a cut and see if it lines up), it makes the biscuit joiner even easier to use since you don't have to keep track of which way the biscuit joiner was facing on the particular piece of wood that you were cutting thus eliminating problems with alignment later during the glue-up.


                  • #10
                    If anyone is interested, here is a link to an article where biscuit joints were tested to see if they actually provided any strength:

                    biscuit test

                    The tests were performed at Sandia National Labs and I thought it was pretty interesting.

                    Bob R


                    • #11
                      I want to thank everyone for their reply on this subject....I learned a bunch, quick! I used it once on a small table and was happy with the results. The stock lined up fine and it seems very strong at the same time. I can see that I will enjoy the biscuit joiner. Thanks again gang. Kenny g.