# First time biscuit jointing - advice please



## labougie (Jun 11, 2014)

I've made a couple of acoustic guitars as well as some pub benches so I'm not a complete newbie, but I've never used a biscuit jointer. I have 5 iroko boards, 1000 x 100 x 30mm and I want to make a larger board of 1000 x 500 x 30mm so I can then cut a shaped thwart (boat seat). Hardwood biscuit jointing with epoxy edge gluing (and lots of sash cramps + weights!) would seem like the answer, but given my dimensions, can I get some guidance on what size biscuits, what spacing and a single or double layer of biscuits? Thanks in advance.


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## cabinetman (Jul 5, 2007)

We have an introduction section where you can say a few words about yourself. If you fill out your profile in your "User Control Panel", you can list any hobbies, experience, occupation, or if retired…from what, or other facts. You can also list your general geographical location which would be a help in answering some questions. In doing that your location will show under your username when you post. 

I wouldn't use biscuits at all. Edge joint the boards so they are square and flat to the faces. Use Titebond III and just clamp together. Use cauls on top/bottom across the boards, clamped to keep all the boards flat.






















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## labougie (Jun 11, 2014)

OK Cabinetman - intro and profile sorted and thanks for your input. I used Titebond for guitar-making and it's fantastic stuff - I just didn't know it was recommended for a marine environment, nor did think that it would be able to fill. The 5 iroko boards have been thicknessed and squared but I thought that given the inevitable tiny grain gaps and tears in iroko that epoxy would fill those gaps better than aliphatic resin. The biscuit idea was to increase the glue area in a belt and braces manner. I would of course use cauls in any case. Would using biscuits weaken the joint?


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## cabinetman (Jul 5, 2007)

labougie said:


> OK Cabinetman - intro and profile sorted and thanks for your input. I used Titebond for guitar-making and it's fantastic stuff - I just didn't know it was recommended for a marine environment, nor did think that it would be able to fill. The 5 iroko boards have been thicknessed and squared but I thought that given the inevitable tiny grain gaps and tears in iroko that epoxy would fill those gaps better than aliphatic resin. The biscuit idea was to increase the glue area in a belt and braces manner. I would of course use cauls in any case. Would using biscuits weaken the joint?


IMO, yes. They aren't necessary, and utilize edges that should be flat and tight. You could use epoxy, as it is good if you have gaps. For well mated edges TB III would be my choice.


















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## labougie (Jun 11, 2014)

OK, so that's one firm old school opinion. Does anyone who approves of biscuit jointing have an answer to my original post? Thanks


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## Trav (May 30, 2011)

In the application you mention, in my opinion, biscuits will offer little in structural integrity. A properly jointed long grain to long grain edge will be just fine glued with Epoxy or titebond III. If you would like to strengthen the joint anyway look into making loose tenons or a splined joint. Again IMO both are not necessary. .


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## labougie (Jun 11, 2014)

There's no way I would trust myself to use even the longest plane to make a square edge over 1 metre, so this joint would be straight from the thicknesser on both edges. Iroko picks up a little rough from the thicknesser. Are you guys saying that Titebond or epoxy and a properly cramped edge joint is all I need?


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## cabinetman (Jul 5, 2007)

labougie said:


> There's no way I would trust myself to use even the longest plane to make a square edge over 1 metre, so this joint would be straight from the thicknesser on both edges. Iroko picks up a little rough from the thicknesser. Are you guys saying that Titebond or epoxy and a properly cramped edge joint is all I need?


The edges need to be jointed to mate. That can be done on a jointer, or done with a handplane. A 'thicknesser' refers to a planer which surfaces sides (usually the width), and ideally, can make both surfaces parallel to each other.


















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## labougie (Jun 11, 2014)

Completely confused now. What's the difference between a jointer and a thicknesser?


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## labougie (Jun 11, 2014)

Stupid question. Let me retire and consider


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## woodnthings (Jan 24, 2009)

*jointer vs thicknesser*



labougie said:


> Stupid question. Let me retire and consider



The jointer removes material off the bottom of the board making it flat and straight.

Then with the flat side down, you use the thicknessesr/planer to remove material off the top of the board and making it a uniform thickness.

They art quite different and are used in the order above. :yes:


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## Trav (May 30, 2011)

labougie said:


> Stupid question. Let me retire and consider


It Wasn't a stupid question. 


Yes I am saying that titebond or epoxy applied to a properly prepared joint should work fine.


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## gideon (May 26, 2010)

I use biscuits mainly for aligning glue ups, not for anything structural.

If you are really concerned about that join, use splines,


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## Al B Thayer (Dec 10, 2011)

When building any boat or anything marine related West System Epoxy is best. Never saw a boat made with Titebond. All surfaces to be joined must be all covered with epoxy type resin in order to be waterproof. 

Could someone get a letter out to Fine Woodworking and the rest of the leading mags out there and inform them that the biscuit jointer they use and recommend no longer adds strength to a joint. I now realize after reading threads like these I have for 30 years been using my biscuits the wrong way. Who would have ever thought you can cut a slot in the wood quite a bit wider than the biscuit and it would still aid in aligning the boards. 

Lamello must be closing its doors as we speak.

Al B Thayer


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## sawdust703 (Jun 27, 2014)

*first time biscuit jointing*

I would have to agree with Mr. Al. A biscuit cutter & biscuits would work for join Alignment. And if its going in the water, regardless of the type of wood, is still going to need to be waterproofed. Envitably, if it doesn't suit ya, don't use them. And also, the only STUPID question is the one ya don't ask! good luck, & be safe!:yes:


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## jjrbus (Dec 6, 2009)

*Axminster Hobby Series AWEPT106 Planer Thicknesser I believe this can also be adjusted to use a a surface planer.
*


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## bauerbach (Mar 25, 2012)

yeah... why wouldnt you use biscuits? Dont currently own one and dont want to drop the bucks for a 1 time use might be a reasonable answer... but thats about it...

Even so, you could use a router, though you could also do a nice tongue joint if you can obtain the proper bit. 

Wood glue on a boat? I know titebond 3 is waterproof... but even that has limits, I dont suggest you submerge your boat seat or you may have bigger issues, but... 

I mean, telling the guy to do a box joint would be stupid, some biscuits and waterproof epoxy is very reasonable and quite prudent IMO.


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## FrankC (Aug 24, 2012)

If you have a biscuit jointer and feel more comfortable using it why not, don't let these guys intimidate you. There will likely come a time when you feel confident enough to do your glue up without biscuits, that will be your decision when you are ready. Just remember there are a lot of guys around here with the "older I get the better I was" syndrome.


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## epicfail48 (Mar 27, 2014)

Yeah, don't listen to the naysayers, biscuits with fine. That don't add overmuch to the strength of the joint, and they aren't a substitute for a properly joined edge, but for alignment they work fine. As far as what size to use, whatever size is best for the size of board. . is recommend against doing a double row of biscuits though, I thing that would cause more alignment issues and negatively impact strength. As far as glue goes, I like titebond3 for outdoor stuff though a marine grade epoxy would work fine


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## TimPa (Jan 27, 2010)

agreed, edge to edge joinery properly done is very acceptable for interior work. however in exterior applications, with expansion and contraction playing a much, much larger role in the game, why not increase glue surface area and use a proper marine grade glue.

biscuits are good at doing that. but a spline or *tongue and groove* would be better yet, imho.


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## larry0846 (Feb 20, 2013)

sorry to get in so late to this thread -- made a dining room table last fall -- maple -- used biscuits -- thought i was getting structural support -- compounded the issue by not glueing the joints correctly -- table was about 47" x 66" -- two of the long joints spread after 1 month -- table had 3 under cross supports and breadboards at the ends -- maybe a wood drying issue, maybe poor technique in joining -- (getting to the point) -- discovered 4 wing slot bits -- any long joint i now do -- i use the slot bits to tongue and groove -- piece of cake -- joints are perfectly aligned -- and have to be plenty strong with tIII glue up -- richard at routerbitworld.com helped me get started with the technique -- maybe i'll get to the point where i would have the confidence to just flat glue long joints -- but i am not there yet --


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## Hubshooter (Jul 26, 2014)

woodnthings said:


> The jointer removes material off the bottom of the board making it flat and straight.
> 
> Then with the flat side down, you use the thicknessesr/planer to remove material off the top of the board and making it a uniform thickness.
> 
> They art quite different and are used in the order above. :yes:



So why exactly do you have to use both and why in that order? If the jointer takes material off the bottom making it flat and straight, why couldn't you flip the board over and do the same to the other side?

Thanks,
Brad


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## epicfail48 (Mar 27, 2014)

Hubshooter said:


> So why exactly do you have to use both and why in that order? If the jointer takes material off the bottom making it flat and straight, why couldn't you flip the board over and do the same to the other side?
> 
> Thanks,
> Brad


A jointer makes a face flat, and there's no reason you couldn't make all 4 faces on a board flat using a jointer. The problem with that is that while the faces may be flat, you won't have a nice square board. Odds are, you'll end up with a triangle. 

A thickness planer will also make a face flat, but the difference is in how it does it. A jointer uses an offset set of tables across a blade to shave off the high point on a piece of wood, just like a hand plane. A thickness planer, however, has a blade mounted a set distance above a table, to that whatever is run under it against the table will have a consistent thickness across the board equal to the distance of the blade to the table. 

In short, a jointer flattens a face, a planer creates a second face on the board parallel to the first, as well as making the board a consistent thickness. 

I'm horrible at explaining things. If you're still confused, The Wood Whisperer has an excellent video explaining the process of milling boards from raw lumber that breaks it down better than I can, I'd recommend checking it out


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## rayking49 (Nov 6, 2011)

Epic, in my opinion you explained it perfectly. I would just add, after getting both faces flat and parallel, going back to the jointer to do an edge will square it to to the board, and give a good glue joint.


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## epicfail48 (Mar 27, 2014)

rayking49 said:


> Epic, in my opinion you explained it perfectly. I would just add, after getting both faces flat and parallel, going back to the jointer to do an edge will square it to to the board, and give a good glue joint.


Ive always cut the second face on the jointer to get the square edge before sending it through the planer. I think the ordering for that particular step is more personal preference than one is better than the other though

EDIT: before i forget, thank you for the kind words


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## fareastern (Sep 19, 2014)

What we have here is a classic case of two nations separated by a common language.In England the machine that makes the face of a board flat is known as a planer.The machine that reduces a board to a specific thickness is known,not unreasonably,as a thicknesser.The original poster is from London,England and I can understand why he feels confused.

I happen to agree that biscuits probably aren't necessary for the job in question and being beech they are not exactly the material best suited to a marine environment.The adhesive could be epoxy or a polyurethane that is rated for D4 grade bonding,as these are much less expensive and don't have the sensitisation risks that go with epoxy.


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