Replies

1. 
   beasleysevin | Oct 18, 2021 10:14pm | #1

   I don't know anyone who thinks biscuits add strength. It seems almost universally accepted that they are for alignment purposes. I think I'll call that click bait and not bother watching.

2. 
   rob_ss | Oct 19, 2021 02:04am | #2

   It's a pity he did not do formal splines, and declined to test more realistic stresses on joints likely to be reinforced with biscuits.

1. 
   john_c2 | Oct 19, 2021 05:54am | #3

   There have been a lot of joint strength tests that have included biscuits alongside mortise and tenon, half lap, etc. Biscuits have always been at the bottom. They add a little strength, but not very much.

   I'm not sure how many people still care. There are a few million biscuit joiners sitting under several inches of dust these days. I imagine that when the Festool patents on the Domino start expiring you won't be able to give a biscuit joiner away.

1. 
   rob_ss | Oct 20, 2021 02:06am | #15

   I find mine useful, but only for alignment purposes - especially when getting curves to nest together and stay co-planar when clamped - hard to beat for that.
   They are also great for aligning sheet material and face frames.

2. 
   ola_carmonius | Oct 26, 2021 05:54pm | #20

   Well, all that and more was tested in Fine Woodworkings joinery shootout 12 years ago, issue #203. More realistic load case and all kind of joints tested.

3. 
   DRBWWing | Oct 19, 2021 07:35am | #4

   John is correct a biscuit is a mainly an alignment aid. He’s gotten a lot of press, people think he’s a revolutionary and yes, he’s raised some interesting points, but he’s not changing ww’ing.

   Assume the glue is going to fail. Furniture is not simply held together with glue. He’s completely overlooked the role of joinery.

   Spagnolo did a good review. Cosman was amazed at the strength of a rabbet, you think he’s going to build a carcase with no joinery? I’m so sick of the hype around this guy. It will be over soon.

   It seemed I used the Domino for alignment more than joinery. I never got consistent results, found myself using biscuits. Sold the 500 for $250 more than I paid for it. If I wanted a joinery tool I would get an XL.

4. 
   stantheman | Oct 19, 2021 09:27am | #5

   He's not proposing changing woodworking, joinery or anything like that. Research to confirm what is suspected, is still useful. And there are people who assume that biscuits add strength - that comes up in these forums every now and then.

1. 
   DRBWWing | Oct 19, 2021 10:56am | #8

   Following his conclusions, why wouldn't biscuits add strength? There is more to a biscuit joint than just the biscuit, and his glue theory should support the use of biscuits. Splines should be cross gain not long grain, shouldn't they?

   I'm not saying that his intent is to change ww'ing but what a lot of people think he has "proved" does not translate to practical ww'ing in any meaningful way. Marc Spagnolo did an excellent job explaining this.

   I put this in the same category as the "no drift" Snodgrass bandsaw theory.

5. 
   eddo234 | Oct 19, 2021 10:13am | #6

   I agree with stantheman, there *are* people who still believe biscuits add strength. I bought the very expensive Lamello Top biscuit joiner in the early 80s, and every woodworker I knew back then believed they added strength to joints. It was testing, like what Sullivan did, that proved otherwise. Always good to be reminded. I can see why hobbyists wouldn’t want to spend money on a Domino, but why a pro wouldn’t is beyond me. An CL model, with the Seneca small-mortise adapter is one of the most used tools in my shop.

1. 
   DRBWWing | Oct 19, 2021 10:56am | #9

   How many biscuits joints ever came apart?

6. 
   _mj_ | Oct 19, 2021 10:28am | #7

   While using them for alignment in a normal long-grain panel or tabletop glueup may add little, biscuits add strength to normal applications like assembling face frames and putting them on plywood cabinet carcasses; uses for which the tool excels.

   I don't see the point of testing useless "joinery" like end-grain butts to their breaking point.. you're never going to use it that way, so do you care? I'm guessing the edge-grain glueups didn't support his conclusions or we would have see those too. Calling this video "research" is a stretch, I've watched my last.

1. 
   DRBWWing | Oct 19, 2021 10:57am | #10

   +1

7. 
   EdWeber | Oct 19, 2021 11:18am | #11

   This is the third installment in his series that does the same as the first two. It leaves people with a distorted view of the subject, in this case Biscuit joints.
   These videos do nothing more than sow confusion among those who don't know any better and some who should.
   As to adding strength, a biscuit joint is nothing more than a light duty loose tenon joint. It will be an alignment only joint parallel to the grain and it will add some amount of strength in other orientations, just like any other loose tenon, dowel domino, etc.
   A biscuit is a mechanical advantage and keeps a joint from moving, by it's nature, it adds strength to the joint. If a joint is restrained from movement in any way, it is stronger and less prone to fail.
   One last thing, Joints are used for a purpose and placement. These "tests" do not do not accurately represent the strength of a biscuit joint in a real world application.
   Testing joinery for strength that is used incorrectly or in an unrealistic orientation adds absolutely nothing to woodworking that isn't already known. Just like the end-grain and miter "tests" he has done.

1. 
   john_c2 | Oct 19, 2021 01:17pm | #12

   Yes! Well put.

2. 
   DRBWWing | Oct 20, 2021 10:42am | #17

   +1!

8. 
   mikaol | Oct 19, 2021 07:30pm | #13

   If biscuits don't add strength, why does Lomello make self-clamping biscuits?
   Mikaol

9. 
   jharveyb | Oct 19, 2021 11:41pm | #14

   Biscuits can add strength, when used on a face frame where one piece is end grain and the other is side grain. As said above, as a loose, short spline. Years ago FWW did a strength test on biscuit joints vs mortise and tenon joints for the corner joint of a cabinet door frame. The biscuit joint was fairly strong, but when it failed, it failed catastrophically, with the side grain wood splitting at the edge of the biscuit. The mortise and tenon was stronger, and failed less completely. Both are much stronger than a dowel joint.
   I also wonder what some of the tests would show if one used epoxy, which I believe is a superior gap/end grain adhesive. I have heard of luthiers using a butt joint and epoxy to attach guitar necks to bodies. Haven't tried it myself; would probably use the traditional tapered dovetail.

10. 
    user-7627473 | Oct 20, 2021 09:16am | #16

    Leaving aside the "substance" of the latest "click-bait" video by Sullivan - a mention of biscuits for solid edging on shelving e.g. I don't know that I've seen this recommended but it is fast and efficient for very small runs in my experience (note that if I was doing a large production I would most likely not consider this for fairly obvious reasons). Typically if using a thick solid hardwood edge on Birch ply e.g. one may see recommendations for use of T&G, spline, V-groove, or V-groove plus T&G. If I need to do something quick without set-up issues with router or TS - I've found this solves the problem - and gives necessary good registration.

1. 
   EdWeber | Oct 20, 2021 11:00am | #18

   I've used them in the same way, IMO it's a perfect application for biscuits.
   I would prefer people use a few small biscuits (#0) when building projects rather than CA glue on the inside then a pin nailer on the outside, but that's just me.

11. 
    user-7627473 | Oct 20, 2021 12:49pm | #19

    Yep, #0...and one or hundred less holes to fill...sold!

12. 
    [email protected] | Oct 30, 2021 08:16pm | #21

    Have used biscuits to join the corners of utility plywood drawers and boxes.No failures yet