# biscuits or mallet?



## TravisN (Jan 15, 2019)

Hi all,

I'm preparing for my first large glue-up. I'm edge joining some planks to make a large panel. Pieces are about 5' by 6" and final size will be 5'x18". I've glued up smaller panels, but never anything as long as 5'. I'm worried about keeping the planks lined up flat on the long edge over such a long distance. I've seen some woodworkers use a rubber mallet during the glue up to pound things down where they need to be and I've seen some use biscuits.

I know biscuits don't add to the joint strength, but have heard they can be really helpful in aligning and maintaining position during glue up. For those of you who have used biscuits, are there any downsides? Does it complicate the glue-up any? With the mallet, it seems you have some flexibility in positioning the wood, whereas with the biscuits things are more locked into place, for better or worse.


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## CWWoodworking (Nov 28, 2017)

IMO if the boards are not flat enough to get flat with clamps, you need flatter boards. I never use biscuits.


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## wapakfred (Jul 29, 2011)

The biscuits are useful for alignment. The only downside might be they should be more or less centered across the thickness. If not they swell a little, then some folks sand down the swelling (on the surface) then the biscuits shrink and you wind up with football shaped divots in your top. The problem I've had using a mallet to fine tune the alignment is you need a flat surface to lay the workpiece on to line things up. For me that piece is usually sitting on a couple of clamps, which doesn't always work out that well.


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## JayT (May 6, 2012)

Use some clamping cauls. They will help align all three boards for a good joint without biscuits or having to pound on them.

Edit: Here's an article to read up on them.


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## TravisN (Jan 15, 2019)

> The biscuits are useful for alignment. The only downside might be they should be more or less centered across the thickness. If not they swell a little, then some folks sand down the swelling (on the surface) then the biscuits shrink and you wind up with football shaped divots in your top. The problem I ve had using a mallet to fine tune the alignment is you need a flat surface to lay the workpiece on to line things up. For me that piece is usually sitting on a couple of clamps, which doesn t always work out that well.
> 
> - Fred Hargis


Thank you for sharing your experiences. I had not heard about the swelling issue. If the biscuit does end up swelling, should I just not sand it down and trust it will shrink?

I have similar concerns about the mallet approach. I also envision myself playing a never ending game of "whack-a-mole" as my hammering in one spot causes displacement in another.


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## TravisN (Jan 15, 2019)

> Use some clamping cauls. They will help align all three boards for a good joint without biscuits or having to pound on them.
> 
> Edit: Here s an article to read up on them.
> 
> - JayT


I've used cauls in the past for smaller panels. I anticipate that I would need probably 4 sets at least for a panel this long, and that starts to get crowded and is a lot of clamps I have to manage before the glue starts to dry. I was hoping biscuits would simplify things.


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## PPK (Mar 8, 2016)

I've used all the methods, and they all work fine, depending on the situation.
One thing to keep in mind if you do decide to use biscuits, is that you need to think about their placement. If you end up shaping the glued up panel and cut into a biscuit, it'll look pretty bad.


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## ArtMann (Mar 1, 2016)

In my opinion, the most fool proof method would be to use dowels and a good quality dowel jig. I am not talking about the cheap self centering kind but rather the type that references one surface for flush and has an indexing mechanism for longitudinal positioning. I use the Dowelmax but there are a few other good ones. None of the good ones are cheap.


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## Hondo03 (Nov 13, 2018)

I have used biscuits for years when gluing up panels and I have never experienced an issue with "swelling". The biscuits do offer help in aligning the boards to be joined and keep them the way you have oriented them during the jointing/planning process.


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## SMP (Aug 29, 2018)

> Use some clamping cauls. They will help align all three boards for a good joint without biscuits or having to pound on them.
> 
> Edit: Here s an article to read up on them.
> 
> - JayT


I would also recommend cauls. Biscuits "can" help align things, but depending on what kind of clamps, most people want to "make sure" the clamps are nice and tight, inadvertently overtightening and putting a bow/concave into the glue up. Biscuits don't help that at all.


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## LesB (Dec 21, 2008)

I have used biscuits without any problems but another nearly fool prof way is using a router glue joint bit to cut a inter-locking edge on the joining boards. This also increases the gluing surface. 
Here is a Woodworker's Journal article on it. https://www.woodworkersjournal.com/making-router-bits-glue-joint-bit/


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## HokieKen (Apr 14, 2015)

I'm a fan of just get it as good as you can then hand plane it flat. I have yet to glue up a panel that came out of the clamps ready to use. Biscuits are helpful for alignment, as are cauls but, IME, a handplane and/or scrapers still have to touch it afterwards. Which, may sound like extra work but, it takes a lot less time to make a few swipes with a hand plane than it does to cut a bunch of biscuit slots ;-)


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## wapakfred (Jul 29, 2011)

> Thank you for sharing your experiences. I had not heard about the swelling issue. If the biscuit does end up swelling, should I just not sand it down and trust it will shrink?
> 
> - Travis


I have only had this occur on plywood, which I didn't sand down; and after the moisture in the glue evaporated, the bumps went away. I've heard the same from guys who use them in hardwood and have that happen. The bumps are usually because (IMHO) the biscuit slots are placed too close to the surface. So if I ran into this, I would wait a few days and see what happens, then smooth it out.


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## TravisN (Jan 15, 2019)

> I ve used all the methods, and they all work fine, depending on the situation.
> One thing to keep in mind if you do decide to use biscuits, is that you need to think about their placement. If you end up shaping the glued up panel and cut into a biscuit, it ll look pretty bad.
> 
> - PPK


Yikes, that would be unsightly! I won't be shaping this piece.


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## TravisN (Jan 15, 2019)

> I have used biscuits for years when gluing up panels and I have never experienced an issue with "swelling". The biscuits do offer help in aligning the boards to be joined and keep them the way you have oriented them during the jointing/planning process.
> 
> - Hondo03


Thanks for your experiences


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## TravisN (Jan 15, 2019)

> I m a fan of just get it as good as you can then hand plane it flat. I have yet to glue up a panel that came out of the clamps ready to use. Biscuits are helpful for alignment, as are cauls but, IME, a handplane and/or scrapers still have to touch it afterwards. Which, may sound like extra work but, it takes a lot less time to make a few swipes with a hand plane than it does to cut a bunch of biscuit slots ;-)
> 
> - HokieKen


That does sound simple. I am still developing my hand plane skills so at this point, for a meaningful piece, my post glue-up touch-up is the ROS


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## TravisN (Jan 15, 2019)

> Thank you for sharing your experiences. I had not heard about the swelling issue. If the biscuit does end up swelling, should I just not sand it down and trust it will shrink?
> 
> - Travis
> 
> ...


I just read a Popular Woodworking article about this that suggests the biscuits swell from moisture in the glue and after the glue dries, the swelling is reduced. They even mentioned, as you did, that sanding too quickly after gluing can result in the football shaped depressions. Seems like an easy solution is to not put it too close to the surface and/or just wait for the moisture to dry.


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## pintodeluxe (Sep 12, 2010)

Skip the biscuits - they are great elsewhere - but I don't use them for panels. Just glue it up in stages. Make intermediate planks that can fit through your planer. Then glue the planks together to net your 18" final width.


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## RichT (Oct 14, 2016)

This is a good time to invest some time into making cauls. However, biscuits do aid in alignment. The potential gotchas were discussed nicely above.

Don't rule out dowels. There's no risk of swelling and divots, and they are far tighter than biscuits, so you get better alignment. The JessEm really excels at drilling holes for panel glue ups.


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## ibewjon (Oct 2, 2010)

I have the glue joint cutter for my shaper, and use it for all panel projects that are not for raised panels


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## pottz (Sep 15, 2015)

ive been using bisquits for over 25 years and have not had any problems mentioned thus far,they work great keeping boards aligned.it always seems the camp that doesn't like them has horror stories to scare away anyone wanting to try them.


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## TravisN (Jan 15, 2019)

Lots of good advice on here, I appreciate all the comments. You've given me much to think about. As in most things, it seems there are multiple ways to do this well and I'm sure I will try them all in time.


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## tynewman (Mar 10, 2019)

I have used splines in a few of my large glue ups, like a table top. I just made sure I didn't go close enough to the end that it might show after squaring/shaping, it also alines the entire length very well. 









As for the swilling, technically any glued joint will swell. The longer you wait after gluing to plain and sand the less likely it will be an issue.


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## oldguy2 (Jun 29, 2014)

great replies here. Hmmm. you are in AZ. biscuits swelling…only if you use too much glue. use a small amount on one side to hold it in place for alignment. that was your goal. too near the edge…poor setting on the tool, not centered on the board. like cutting boards, glue larger pieces up in 2 or 3 parts for handling and best use of clamps. dry fit the last glue together edges check the fit and dry clamp before glue up. use chalk to mark areas for rework. no staining and it wipes off. if you have some boards that are warped then you will see it in the dry clamping, and not have to smash it down. patience when doing these is a big learning lesson but it pays off, very hard teacher but big results.


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## CWWoodworking (Nov 28, 2017)

> my post glue-up touch-up is the ROS
> 
> - Travis


I will adjust my theory of biscuits are not needed. I send all panels through the drum sander so alignment isn't as critical. If I had to ROS them flat, I would entertain biscuits.

Travis, I glue up a panel extremely close to that size(19×63.75) 1-5 times a week. This is how I go about alignment-

Position clamps 4 ft apart. Lay out your boards and apply glue, but no pressure with the bottom clamps. Lay a clamp on top in the middle. Press firmly down with this clamp, aligning the middle. Tighten middle, then work your way towards the ends. I find it's easier to work with the 2 halves than trying to adjust the whole thing.


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## TravisN (Jan 15, 2019)

> I will adjust my theory of biscuits are not needed. I send all panels through the drum sander so alignment isn't as critical. If I had to ROS them flat, I would entertain biscuits.
> 
> Travis, I glue up a panel extremely close to that size(19×63.75) 1-5 times a week. This is how I go about alignment-
> 
> ...


Ah, a big drum sander, that would be lovely! I appreciate the recommendation to start in the middle. I've always started on one end. Beginning in the middle makes a lot of sense. I'll do that from now on


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## ssnvet (Jan 10, 2012)

If you have a biscuit jointer, why not use it?

I would argue that it does add strength to the joint, but that it's not really necessary as the long grain glue joint with good glue should be plenty strong. But as noted, they do aid with aligment.


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## TravisN (Jan 15, 2019)

> If you have a biscuit jointer, why not use it?
> 
> I would argue that it does add strength to the joint, but that it s not really necessary as the long grain glue joint with good glue should be plenty strong. But as noted, they do aid with aligment.
> 
> - Mainiac Matt


Short answer is I don't have one yet, but I thought this might be a good excuse to get one


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## EarlS (Dec 21, 2011)

Travis - it's not an excuse, it's an opportunity.


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## CWWoodworking (Nov 28, 2017)

> If you have a biscuit jointer, why not use it?
> 
> I would argue that it does add strength to the joint, but that it s not really necessary as the long grain glue joint with good glue should be plenty strong. But as noted, they do aid with aligment.
> 
> ...


Well if that's the case you absolutely need a one to glue up panels. Can't function without it.


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## TravisN (Jan 15, 2019)

> Travis - it s not an excuse, it s an opportunity.
> 
> - EarlS


lol, it's all about phrasing. Yes, an opportunity!


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## TravisN (Jan 15, 2019)

> If you have a biscuit jointer, why not use it?
> 
> I would argue that it does add strength to the joint, but that it s not really necessary as the long grain glue joint with good glue should be plenty strong. But as noted, they do aid with aligment.
> 
> ...


Haha, exactly. It IS a necessity!


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## RichT (Oct 14, 2016)

I recommend the PC 557. It mounts to jigs nicely and you can purchase that absurdly priced FF blade that's very handy to have. Makes face frame glue ups a breeze.

It's got several other advantages over its closest rival. Here is a short review: http://ahsaws.com/porter-cable-557-vs-dewalt-dw682k-review/

Here is a fixture I made for it: https://www.lumberjocks.com/projects/365481


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## DRWard (Apr 13, 2019)

I too have used biscuits and have never experienced the "swelling" problem. That said, I do know a few experienced woodworker that have seen it and as they have explained it to me, it can occur when the biscuit slots are cut too shallow (close to the surface of your boards). While I do not use biscuits as often as I use to (I now prefer dominos), 0.5" boards are the smallest I would try to join and when using boards that thin I always used the small biscuits.


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## Hondo03 (Nov 13, 2018)

Oldguy2
I couldn't agree more with everything that you said. If your biscuits are too close to the surface than you are not taking your time and aligning/adjusting your tools properly. User error can't be blamed on the tool.


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## Kirk650 (May 8, 2016)

I use biscuits and cauls on panel glueups, and the longer the boards, the more you need alignment help from the biscuits. Never have seen any swelling issues.


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## farmfromkansas (Jun 16, 2019)

I use 2×4's for cauls, but have been considering laminating some hardwood instead of lumber. Also keep a rubber mallet handy as cauls do not always force everything even. And some C clamps for ends that do not line up perfectly. Cauls do help you make nice flat panels.


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## robscastle (May 13, 2012)

Travis,

An interesting read thats for sure, and I see you have replied along the way so you you must be interested in all the different opinions.

I made a table top for No 1 son and its possibly the biggest project I have done furniture wise.
I used biscuits and as Hokieken said you will still have ro plane the finished product by hand.
Buy a bicsuit cutter and see how you go its a tool a bit like a HCM it sits around most of the time, bt when needed its a great tool.
Althouht the table top is not a panel as such but I think the process would be similar.

I did a fairly detailed blog on the construction if your interested in checking out how I did it.

https://www.lumberjocks.com/robscastle/blog/90082


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## OSU55 (Dec 14, 2012)

For panel glue ups nothing beats cauls. How to make


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## TravisN (Jan 15, 2019)

> Travis,
> 
> An interesting read thats for sure, and I see you have replied along the way so you you must be interested in all the different opinions.
> 
> ...


Hi Rob,

How did that table turn out? It looked like you did some end-to-end joining, as well. How did you do that? I'm currently working on some built-in bench seating that requires end-to-end joining. I was planning on using half-lap joints, perhaps with some drawbore dowels.


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## TravisN (Jan 15, 2019)

> I use 2×4 s for cauls, but have been considering laminating some hardwood instead of lumber. Also keep a rubber mallet handy as cauls do not always force everything even. And some C clamps for ends that do not line up perfectly. Cauls do help you make nice flat panels.
> 
> - farmfromkansas





> For panel glue ups nothing beats cauls. How to make
> 
> - OSU55


I have used cauls in the past and gotten some benefit but not as much as I hoped. That said, I never took the time to make a proper set, just used scrap wood I had that seemed "flat." That's probably my problem 

I had decided to try dowels since they are supposedly stronger than biscuits (if you're looking to strengthen a joint), are tighter than biscuits, more affordable for a quality jig (or easy to make your own), and can be used for a variety of joints.

But maybe I'll try making a real set of cauls and give them one last chance….. A good set of working cauls would save time over dowels.


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## OSU55 (Dec 14, 2012)

If you go with dowels have a big ass mallet ready to get the boards together dahik. Flat boards dont work for cauls, even the set I made with steel square tube, with on the clamp side, worked much better when I added a slight radius


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