# Biscuit Joinery



## mfhall (Aug 28, 2017)

Hi folks,

Trying to decide if I need to go buy a biscuit joiner or if I should just go ahead and try it with a router. I don't anticipate using a biscuit joiner much, but I do have a job it would be good for right now. Any jigs out there? Any thoughts?

Floyd


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## jerryminer (Jun 15, 2014)

If you already have a router, a 4mm (or 5/32") slot cutter will make a biscuit slot. No jig necessary, but you could make a jig to limit the length of the slot if you wish.


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## wapakfred (Jul 29, 2011)

I'd also go with the slot cutter.


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## Loren (May 30, 2008)

The joiners are more versatile than a router,
especially the ones with tilting fences. If you
are meticulous in your approach to using them
precise results can be had.

You can get round Lamello biscuits that go
deeper than a standard biscuit. I've used 
them on frames.

Cheaper plate joiners may be frustrating to use.
The weak link in them tends to be the fence.
The pricier ones have more reliable fences in
general. I had a Freud one with a fence that
wouldn't hold its settings.


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## mfhall (Aug 28, 2017)

Yeah, I got one already, that's why I was thinking about it. Just not sure how to steady the router.

Floyd



> I d also go with the slot cutter.
> 
> - Fred Hargis


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## mfhall (Aug 28, 2017)

A Makita just came up on CL, but he wants a little too much for it. The reviews suggest a DeWalt or a Porter Cable, but I've become frustrated with my Porter Cable tools over time. And slippage seems to be the main issue.

Anyway, I was thinking about just trying the router for now and maybe look at a Festool when I've died and gone to heaven.

Floyd



> The joiners are more versatile than a router,
> especially the ones with tilting fences. If you
> are meticulous in your approach to using them
> precise results can be had.
> ...


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## LesB (Dec 21, 2008)

Before the biscuit cutters became available I used a slot cutter on my router and cut my own biscuits. In some cases I cut the slot almost the complete length of the boards I was joining and either inserted several biscuit size pieces at points along the slot or used a full length piece of plywood or masonite that filled the entire slot. You could also make slots using your table saw.

Be aware that biscuits do not add much strength to the joint but primarily keep the boards aligned, particularly during the glue up process.


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## mfhall (Aug 28, 2017)

Yeah I was thinking about using 1/4i plywood splines and cutting the slots with a slot cutter on a router.

What I' doing is building a work table with 1 1/4i. So I was thinking about two splines. I would like to attach 6/4 hickory aprons around the table top. I do need it to be pretty sturdy.

Floyd



> Before the biscuit cutters became available I used a slot cutter on my router and cut my own biscuits. In some cases I cut the slot almost the complete length of the boards I was joining and either inserted several biscuit size pieces at points along the slot or used a full length piece of plywood or masonite that filled the entire slot. You could also make slots using your table saw.
> 
> Be aware that biscuits do not add much strength to the joint but primarily keep the boards aligned, particularly during the glue up process.
> 
> - LesB


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## Rayne (Mar 9, 2014)

If you want a relatively cheap alternative, Harbor Freight's biscuit joiner isn't too bad at all. Most of the plastic parts that had complaints in the past were fixed and replaced with cast aluminum. There is some play, but very manageable. Just need to buy a better cutter. I bought Freud's and it works like a charm for me. My 2 cents for a once-in-a-while tool.


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## woodbutcherbynight (Oct 21, 2011)

Depends on your approach. A dedicated tool like a biscuit joiner is set up and with an adjustment for depth and setting the fence ready to go. Using your router if you have only one means changing the bit and doing the other set up process. Doing splines or half splines get the job done. All of these methods get the job done. Each has pros and cons so it boils down to which would you rather have.

I have a biscuit joiner, and no I do not use it all that regularly but when needed it is set up and ready to go. Like many others I have several routers, some set up for certain work and also have a router table.


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## CaptainKlutz (Apr 23, 2014)

Hmm..
Biscuit construction is like any other type of joinery? Each one has pro/con; and a loyal fan base.
Some prefer splines or dowels over biscuits?

If you have never used biscuit construction on a project before, suggest you try using router with 5/32 slot cutter and bearing. Unless you snag a porter or dewalt biscuit joiner from Craigslist cheap (which happens often), router method is cheapest method to determine if you need/want/like using biscuits.

You mention joining 5/4 top to 6/4 apron? 
For workbench application were strength is goal, I would use mortise & tenon, loose tenon, or spine to attach the apron. Biscuits are great for 4/4 lumber, but if you are using thick lumber then you have room for a thicker tenon/spline.


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## mfhall (Aug 28, 2017)

> You mention joining 5/4 top to 6/4 apron?
> For workbench application were strength is goal, I would use mortise & tenon, loose tenon, or spine to attach the apron. Biscuits are great for 4/4 lumber, but if you are using thick lumber then you have room for a thicker tenon/spline.
> 
> - CaptainKlutz


I was thinking about two 1/4i plywood splines or maybe one 1/4 spline and a second series of biscuits. I could use a cross-cut sled and cut both biscuit slots at the same time so they match up.

Floyd


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## John_ (Sep 23, 2013)

If you haven't seen this Lamello Video it is worth watching


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## pintodeluxe (Sep 12, 2010)

Get the biscuit joiner. I use a few biscuits on most projects, and it's super handy. 
It's no substitute for mortise and tenon joinery, but there are many useful applications.


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## Loren (May 30, 2008)

In the 80s and 90s the woodworking magazines
went a little hog wild with designs using biscuit
joints in place of mortise and tenon. Some were
better designs than others but by today's standards
there was some dubious stuff out there.

There's a mistaken idea going around that biscuits
provide no strength. They provide *no relevant
strength* in edge to edge grain gluing of solid 
wood when making things like panels and table
tops. Those joints are stronger than the wood 
anyway when using modern glues. Biscuits can
provide plenty of strength in frame joints, carcase
joints and miter joints, basically most situations 
involving plywood or end grain.


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## jimintx (Jan 23, 2014)

Loren has made the point above. Biscuits do improve joint strength in many cases, as he explained.

I still use my very old Ryobi biscuit jointer for quite a few projects. I'm very happy to have it and use it. Maybe I should consider and compare it to a current model like a Dewalt, or similar.


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## John_ (Sep 23, 2013)

I always go back to the fine woodworking joint strength test they did back in 2009. A biscuit is just below domino. (About an 8% difference) Also note, a biscuit is rated higher than pocket screws. The test involved joining 2 pieces of wood at 90 degrees - like a face frame


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## jimintx (Jan 23, 2014)

John, that is of interest. I am going to see about finding that whole article in FWW. It looks like they did some insightful testing. Two quick comments from looking at the picture you provided for us:

I. What I see is that the strength of the pocket screws is listed as better than the Domino or biscuit, although not a particularly significant amount.

II. Isn't that a picture of a domino joint that is highlighted in the blue text shown for "beadlock"?


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## 000 (Dec 9, 2015)

Beadlock Joint, (pretty much the same as a domino, just beaded down the sides)


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## John_ (Sep 23, 2013)

> John, that is of interest. I am going to see about finding that whole article in FWW. It looks like they did some insightful testing. ..
> 
> - jimintx


Here is a link to their page which has an interesting video showing the machine they used and how they tested the joints to the point of failure:
http://www.finewoodworking.com/2009/02/25/joint-strength-test

The full article is in issue #203


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## Ted78 (Dec 3, 2012)

I like my HF biscuit joiner, and also, what Loren said.


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## AZWoody (Jan 18, 2015)

> I always go back to the fine woodworking joint strength test they did back in 2009. A biscuit is just below domino. (About an 8% difference) Also note, a biscuit is rated higher than pocket screws. The test involved joining 2 pieces of wood at 90 degrees - like a face frame
> 
> 
> 
> ...


Am I reading it wrong? It says that pocket screws have a strength of 698 pounds while a domino and biscuit are 597 and 545 respectively. That has pocket screws stronger than both of them.


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## AZWoody (Jan 18, 2015)

dbl post


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## MrRon (Jul 9, 2009)

I have a 30 year old PC biscuit joiner that doesn't see much use. I find that with biscuits, the two edge joined boards do not match perfectly. I think there is too much clearance in a biscuit joint. Dowels or splines are much better at insuring an aligned joint.


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## jerryminer (Jun 15, 2014)

> Yeah, I got one already, that s why I was thinking about it. Just not sure how to steady the router.
> 
> Floyd


A tear-drop router plate (or other offset sub-base) helps a lot with keeping the router steady


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## mfhall (Aug 28, 2017)

> Yeah, I got one already, that s why I was thinking about it. Just not sure how to steady the router.
> 
> Floyd
> 
> ...


It's kind of an awkward thing I'm doing. I'm building a work table. The top will be 1 1/4i MDF and then I was going to put a sheet of 1/4i plywood and 1/8i whiteboard on top of that-a throw-away top that I can write and mark on. Anyway, I'm trying to put a 6/4 skirt/apron around it. It's probably going to take a pounding, so I was going to use 1/4i plywood splines all around maybe a 1/4i down from the top, since that's were the stress will fall, and then below that run a series of biscuit joints for added strength. I could also just run a second (maybe thinner) plywood spline a little below the first.

Anyway, I was thinking about maybe building a cross-cut router jig that I could later use to flatten slabs (the primary work I'll be doing for now). That way I can line up the slots for the table top with the slots for the shirt/apron, which will be hickory.

Of course it might just be easier to cut a second, thinner slot for a second spline.

Anyway, I'm putting together two of these tables, one small and one big so I can set them apart to accommodate various slabs. They run just a couple feet up to 14ft.

Floyd


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## John_ (Sep 23, 2013)

> Am I reading it wrong? It says that pocket screws have a strength of 698 pounds while a domino and biscuit are 597 and 545 respectively. That has pocket screws stronger than both of them.
> 
> - AZWoody


No, you are right. I just looked at this again, and I don't know what I was thinking when I wrote that. Sorry


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## mfhall (Aug 28, 2017)

Hi all,

One last question. I've decided to go with splines. I have some crap crate-grade plywood. Would that be good enough for splines? Or should I find something better?

Floyd


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## jerryminer (Jun 15, 2014)

Not sure what "crap crate-grade" plywood is, but as long as you can get a decent glue joint, you should be fine.

Note that a single spline will be a lot easier to manage than two parallel splines, but if you're careful with your set-up, two splines can work


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## oldnovice (Mar 7, 2009)

The first thing I tried was a router bit from Woodhaven and their biscuits that worked great for picture frames as these biscuits are small.

I purchased DeWalt that I used for heavier assemblies, and now I found it very useful for cutting hold down slots into the edges of material that is to be mounted on my CNC for milling (works really great and makes it easier than my TS!


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## mfhall (Aug 28, 2017)

> Not sure what "crap crate-grade" plywood is, but as long as you can get a decent glue joint, you should be fine.
> 
> Note that a single spline will be a lot easier to manage than two parallel splines, but if you re careful with your set-up, two splines can work
> 
> - jerryminer


Just have some plywood that was used for crates sitting around. Decided I best just go buy some new stuff. I cut into it and there were bugs.

Floyd


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## AxkMan (Jan 20, 2018)

The biscuit jointer would be a nice addition to any shop. If you don't mind adding on to the shop constantly then you should try one. Make sure to get a nice one and not a cheap one. They usually start at $200.00 and do quick work of biscuit joints.

If your worried about cost or use, then you could have tried something by now. The good ole way is to drill two holes and then chisel out a hollow matching the biscuits.


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## mfhall (Aug 28, 2017)

> The biscuit jointer would be a nice addition to any shop. If you don t mind adding on to the shop constantly then you should try one. Make sure to get a nice one and not a cheap one. They usually start at $200.00 and do quick work of biscuit joints.
> 
> If your worried about cost or use, then you could have tried something by now. The good ole way is to drill two holes and then chisel out a hollow matching the biscuits.
> 
> - AxkMan


I have a slot cutter for my router. I was thinking about cutting slots with that and using store-bought biscuits. If I find a regular use for one, I'll go out and buy it. Reviews seem to say Porter Cable or DeWalt. Or I could wait for and get a Festool instead.


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