Reible Joint

[reible]

Last June I was working on a new shelving system using wire rack and some special designed wooden parts. Since the load on this could be quite high I looked into making some joints that would help hold everything together.

This is another of the Flickr photo areas about to be removed so I'm sharing it for what it is worth...

Joint on which the New Joint is based.
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Basic joint
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This photo is for display purposes only. The actual joint is centered on the thickness of the wood and not exposed on the surface..
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Again this photo is for display purposes only. The actual joint is centered on the thickness of the wood and not exposed on the surface..
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I built just one shelf unit and it is under test since June. So far so good on the joint and cabinet.

As you might guess there is a bit of a secret to making the joint work but I'll let you figure it out if you decide to build one. If you can't let me know.

Ed

[JPG]

If there is a secret, I am missing it. It looks simple to me.. Am I MISSING something?????:o

[a1gutterman]

I have been studying, looking for that secret. The only thing that I can think of, is you have to use a wide enough board, that after you notch for it, you can still get the biscuit cutter into place. Is that the secret?

[dusty]

Reible Joint

My guess. The direction of the biscuit application with respect to the stress factor, the side of the notch carries the weight not the biscuit.

[Ed in Tampa]

I like the notch idea! But rather than a biscuit why not use pocket screws or a long screw from the rear of the upright into the horizontal board.

I don't see the biscuit adding anything to the equation other than perhaps some lateral support. Where either a pocket screw or long screw from the back would hold put a mechanical fastener in place to hold the joint together.

[dusty]

I like the notch idea! But rather than a biscuit why not use pocket screws or a long screw from the rear of the upright into the horizontal board.

I don't see the biscuit adding anything to the equation other than perhaps some lateral support. Where either a pocket screw or long screw from the back would hold put a mechanical fastener in place to hold the joint together.

I like pocket screws but under certain circumstances. Face frames I believe are the claim to fame for pocket screws. They allow the article to be moved and manipulated immediately.

As far as strength is concerned I am not convinced.

I am waiting to hear what relible's secret motivation is. Properly assembled, I suspect this joint will be every bit as reliable as one with pocket screws in lieu of the biscuit.

The biscuit, BTW, is there only to limit lateral movement. Biscuit joints used by themselves where weight must be supported don't do well.

[reible]

The uprights of the shelf system are 3-1/2" wide, the cross pieces are 1-1/2" wide. One shelf has 24 of these joints. I used a standard hand held jointer to make the cuts on both pieces.

As we all know end grain is not very good as a holding surface for glue or nails or screws. We also know that biscuit work for lots of applications, and where you want a good glue connection like in this application they excel. When you add the notch to support the load, the glue via the biscuits to keep everything together you have quite a joint. Now add the fact this same thing is happen on the other side and that 6 of these plus a top and bottom frame the whole system becomes very stiff. The biscuits also provide alignment to the joint so the faces of the two boards flat.

Cutting biscuits is very quick, I made a jig to hold the 1-1/2 in pieces so the jointer was located and had more surface to push against. I then drop the part in cut and flipped it end for end and all 12 joints were done in very short order. (I have plans of building total of 10 to 12 of these shelf units if my test one survives well over its year long test). Making the jig took only a few minutes so it was even worth it for the one shelf unit.

The notches in the wider boards were pre cut so the locations were determined and the jointer was simply centered on the notch. Again this goes really fast with the jointer. As a guess I would say the whole process is maybe 10X faster then with pocket holes. And by the way the shelf has a lot of pocket holes as well, I think it is around 28 of them.

I don't want to go into details but the shelf has room for 14 file storage boxes, I was shooting for a load of 15 pounds per box or 210 pounds if they are free standing. If attached to a wall that number can more then likely hit about 300 pounds or more.

Here is a side shot:
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The joint in question will still for the time being be a mystery....

Ed

[Ed in Tampa]

I think the real secret or should I say strength of this joint comes from the notch rather than the biscuits.
Frankly I don't think the biscuits add any strength, but I have been wrong before.

I think a long screw driven in from the back of the 3 1/4 peice would have accomplished the same thing. Certainly a pocket screw would have.


As to speed.... well.... while biscuits are fast, I can drill a hole and put a screw in it at the same pace. If I'm doing a glue up I think, biscuits making sure I have proper glue everywhere slows me down.

Like I said I think the real secret is the notch and I intend to incorporate it in my next shelving project so thanks for the great idea.

[reible]

Hi,

Like I said I use pocket screws too. Any screw into end grain will not hold. You would need to glue dowels in or something major to get it to hold. You may not want to believe it so go ahead and test it. Make a butt joint in to the end grain then do the same with a biscuit... I'm tell you the pocket hole in the end grain will pull out with one fingers pressure... you will need to put some body weight on the biscuit joint and the wood will crack. I tend to not believe what someone tells me so I test ideas. When I tested this one it was so clear..... It is all about what you want the joint to do... the notch works for shear, the biscuit for the torque and twisting plus alignment. In 1-1/2" material you can only get one pocket screw and with 3/4" material you are limited by the length of screw... and you have nothing to deal with the twisting with a single screw.

I'm not sure if you have a glue bottle for the biscuits but if you don't I'd get one. One of my setup had a bottle with it but I'd really like to get one like Norm has. If you are trying it with a brush or plastic stick it takes a while and I can see that would be lacking in the fun department... For this frame I inserted the biscuits in the wider boards then put the cross pieces in and the other frame piece on top, the biscuits and notches help hold things in place. I put it in clamps but next time I might just tack it with the brad nailer then stack both sides in clamps???

Ed

I think the real secret or should I say strength of this joint comes from the notch rather than the biscuits.
Frankly I don't think the biscuits add any strength, but I have been wrong before.

I think a long screw driven in from the back of the 3 1/4 peice would have accomplished the same thing. Certainly a pocket screw would have.


As to speed.... well.... while biscuits are fast, I can drill a hole and put a screw in it at the same pace. If I'm doing a glue up I think, biscuits making sure I have proper glue everywhere slows me down.

Like I said I think the real secret is the notch and I intend to incorporate it in my next shelving project so thanks for the great idea.

[JPG]

Did you use biscuits between shelf and the end cross pieces also? I would think cleats would be stronger if not prettier!:D