Biscuit Joints vs. Box Joints for pine cabinets?

Have any of you used biscuit joints for a cabinet? I know the traditionalists among us (including me) might be aghast but they are very accurate to cut. I saw a cabinet that a friend and fellow amp maker had recently that used biscuit joints. It looked very substantial and very structurally sound. It would be quicker than a box joint and also the cabinets could all be the same size as cut! LOL

If you want to make the cab faster,biscuit joints are good. IMHO box joints are stronger and may be sonically better.If you want a lot of strength,make the baffle dadoed into the cabinet sides.

I used to do plain butt joints, before I knew biscuit joints existed. with a liberal coat of yellow glue, they worked great. biscuits make lining up joints during glue up faster. these simpler methods are superior on cheap woods that break up to much during cutting.
But there's something very satisfying about producing snug fitting box joints.

I think the box joint is mechanically stronger. I've built boxes using both methods. Do I think either one matters sound wise? Not really. Another way that is pretty simple is to rabbit two sides and dado the other two sides to accept them.

I use a Kreg pocket hole jig.

Corey

i prefer dovetail joints for cabs. combos and heads.

click the image below to see me build the cab ...

http://img.photobucket.com/albums/v82/rfdee/cabs/dovetail2.jpg (http://frettech.com/cab)

Any of you guys doing box joints on a table saw ?
Must be a jig for that as well.

Box joints on a table saw are usually done with a dado blade and a spacing sled.

I've done some on the table saw. Pretty simple jig. I just screwed a long board on to my miter gage. Cut the slot with a dado blade. Cut a piece an inch or so long that is the exact height and with as the cut you just made. This is used to register your cuts. Glue it into the slot you just cut. Slide the board over the exact width as the original cut, and tighten back to the miter gage.

But the board against the key for the first cut. Place the key in the cut you just made for the rest.

Now for the boards that mate to the first ones, don't move the board all the way to the key for the first cut. Line up the board so the dado blade takes off a full cut on the corner. Then proceed like you did above.

You need to look at this from an engineering standpoint. When an engineer develops specifications and design criteria they look at the requirements of the user. Note that basic home use is different than rolling the amp down a set of stairs. From a structural standpoint they then add a build factor. For example 1.5 times stronger than the actual requirement.

I think most here would agree that box joints are stronger. Most would also agree that a cab built out of 2x12 material box jointed together would also be stronger but is way excessive for the requirement.

So the question goes back to is a pine cabinet joined by biscuits strong enough? In addition to the cabinet joined by biscuits keep in mind that there is a baffle attached to the front to hold the speaker and usually 2 baffles in the rear that add to the structural integrity of the cabinet. Is this strong enough? From an engineering standpoint I would suggest that it is.

To take it a step further, glue up 2 small boxes joined by biscuits. Add baffles to one. Try to break them and report back your results. This could be a cool youtube video.

The sound difference could be argued for days. See all the posts on maple vs. rosewood, nitro vs. poly, alder vs. whatever. My "opinion" is that it would be undetectable. If your opinion is different then take the time to box joint your cabinets.

The two cabinets I have made are box jointed. The only reason that my future cabinets might be box jointed would be from a re-sale standpoint. Kind of like using orange drop caps.

Note that basic home use is different than rolling the amp down a set of stairs. From a structural standpoint they then add a build factor. For example 1.5 times stronger than the actual requirement.

Very true!!! I work with a lot of high end commercial cabinet companies (on the design end). All the cabinet and millwork specifications I read are based on the cabinets being anchored to the wall, and floors in some cases. When a client tries to save money by using economy grade joints, the cabinets are lucky to make it off the truck without falling apart (i.e. glued and pin nailed or doweled without enough glue). Usually the installers end up fixing them in the field before installing them. Once they are installed they are usually fine. I used to question the need for finger or dovetail joints for amps, because done right a basic square butt joint can work, but probably not for someone who will be doing a lot of transporting and heavy abuse. If using a square butt type joint, it is key for the back panel and baffle to be mounted in such a way to add stability. Just my 2 cents.

Thanks Sharp5 ! I may have to reread that a few times but I think I got it.
I know I saw Norm on PBS do box joints that way. I should'a recorded it.
(I do most woodworking with a 371 Husqvarna)

I make all my cabs with a box joint as well, with a similar jig to this:

http://www.youtube.com/watch?v=lmrGa_LDxoE

Nice work, Rob.

Nice Jig, G-Log.

So the best engineering advice I get is to do both types and then do destructive testing. Then decide if it meets the needs of the end user. Thanks you all for your input. Especially onenotetom for the engineering suggestions. I'm not sure that I want to spend $200+ for a biscuit jointer right now as I can almost buy two sets of Heyboer transformer for that $200.LOL. The router table is already setup to make box joints with a home made sled. I'll post a picture when I run the next batch.

I lucked out with a friend who bought a bisquit tool. If you think about it, a top resting on the sides has no force against the joint until moved. All the weight of the chassis is supported by the sides, and when lifted, the chassis is bolted to the top.
Bisquits are fast, and glue is strong.

biscuits work fine, for most amp/cab boxes. heck, butted and cleated boards work just as well. but dovetails and box joints look best if the box isn't covered and the wood is stained and clear coated. i prefer dovetails - the strongest and lightest of all joining methods.

Good thread.

Gave me something to do while the kit and parts are in transit.

I think that if you are building for customers, you should give them the best joint possible, as long as they are willing to pay for quality. If it is in the cards for you to provide details that mirror the original equipment, it's money in the bank (or at least a feather in your cap).

If it's a personal build, what ever makes you happy is all the rage.

But what do I know, this is going to be my first build! :oops:

Here's the results of a couple hours of hanging out in the shop.

Mark

I prefer dovetails if it needs to look good, but biscuit joinery is more than strong enough. Good wood, Tite Bond, and clamps, and all is good.

Wow, Woodbutcher, is this your first try? It took me about ten cabinets and a lot of hammering before I could get the joints to look like that. The Key for me was to buy a digital caliper to measure the 1/2 inch from the router bit to the 1/2 inch block on the sled assembly. The best I could do with a ruler or tape measure was .486. Too much error accumulated over about 10 cuts. With the caliper? .500 on the nose and the joints fit perfectly! This over about a year of experimenting. You get it first try. My hat's off to you!

I prefer dovetails if it needs to look good, but biscuit joinery is more than strong enough. Good wood, Tite Bond, and clamps, and all is good.

I agree dovetails and finger joints may be stronger but biscuit joints are well and truly strong enough and all you need. Plus they are simple which is their major selling point.

So the best engineering advice I get is to do both types and then do destructive testing. Then decide if it meets the needs of the end user. Thanks you all for your input. Especially onenotetom for the engineering suggestions. I'm not sure that I want to spend $200+ for a biscuit jointer right now as I can almost buy two sets of Heyboer transformer for that $200.LOL. The router table is already setup to make box joints with a home made sled. I'll post a picture when I run the next batch.

Your original question was whether biscuits joints were strong enough. You also stated that "It would be quicker than a box joint and also the cabinets could all be the same size as cut!" I incorrectly assumed that you already had a biscuit jointer.

My suggestion was to build two "small" boxes not actual cabinets using scraps. The test would allow you to see for yourself how strong the biscuit joints actually were. This would be easy if you had a biscuit jointer which we now know you do not have. It is always nice if we can test our theories before going to production.:smile:

Your original question was whether biscuits joints were strong enough. You also stated that "It would be quicker than a box joint and also the cabinets could all be the same size as cut!" I incorrectly assumed that you already had a biscuit jointer.

My suggestion was to build two "small" boxes not actual cabinets using scraps. The test would allow you to see for yourself how strong the biscuit joints actually were. This would be easy if you had a biscuit jointer which we now know you do not have. It is always nice if we can test our theories before going to production.:smile:

True but wouldn't you say biscuit joints have passed the realm of theory and are now well and truly tested? The furniture industry has used them for a long while now.

Your suggestion to try it on scrap first is still a thoroughly good idea though because there is nothing worse for a first timer learning to use a biscuit joiner to not think it through properly and put the slot on the wrong side of the wood :lol:

This is a really interesting woodworking site which did some stregth tests on joints with the finger joints being a bit stronger http://woodgears.ca/index.html

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Check out his finger joint jig,

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That is what I am talking about Sheperd. Run a test then you know. 162 vs. 170. Much closer than I would have expected.

If you have a router table the newer locking miter bits are also a sturdy option, quick and easy too.

Not quite as pretty as box or dovetail, but if you are going to tolex then that becomes immaterial.

If you have a router table the newer locking miter bits are also a sturdy option, quick and easy too.

Not quite as pretty as box or dovetail, but if you are going to tolex then that becomes immaterial.

Immaterial! I see what you did there!:lol:

Guys, I'm having my carpenter friend build me a 2x12 using 12mm (1/2") okoume ply that I bought. He claims all these fancy joints are not necessarily and plans to just do plan butt joints using glue and screws or nails.

I've also read somewhere that in the old days glues were not nearly as good as modern ones, so the fancy joints were actually needed, but these days glues are much better.

I will use the cab for gigs so I will transport it but won't throw it around or anything. So I wonder should I insist on one of the stronger joint techniques or not ? I understand those help if you mistreat the cab, but what about actual sound pressure does sound itself produce enough pressure to cause problems ?

Oh and I will tolex the cab, so visually joints are irrelevant, I only inquire about actual construction strength.

Doug Stowe, a famous box-making guru, makes 1/8" finger joints on the table saw. It's very fast. You use a simple sled with a 1/8" drill bit or piece of drill rod inserted to register the work as it slides over the blade. Because the drill bit is the same size as the kerf, you end up with fingers and slots that fit together perfectly. Woodworker Kelly Mehler does the same thing in one of his videos. I'm considering doing this for my first serious cab.

I just made my first cab, and I used plain old butt joints with Titebond III and 3/4" red oak strips screwed into the interior corners. Worked very well. A good glue joint will be stronger than the wood it holds together. I wouldn't dream of doing it this way for an exposed joint, but it seemed pointless to buy and master a dovetail jig in order to build a simple box that would later be covered with vinyl. And it allowed me to use some pretty awful plywood.

i've built cabs with simple cleated butt joints, finger joints, and dovetail joints. remember, too, that a good part of a cab's strength is in the front and back panels, and any component cleats used.

anyhoo, i'll take a locking dovetail joint any day. tapped together without glue it'll be sturdy enuf to sit on. this joint combines locking fingers and glue, and i think it looks best if the cab isn't covered. plus, i can do dovetails lots faster than finger joints. i think some folks shy away from dovetails because they can be complicated to lay out, i.e. - which board side and edge is the "pins' and which is the "slots". here's my dovetail cheat sheet ...

http://img.photobucket.com/albums/v82/rfdee/cabs/dove.gif

the video test posted above isn't particularly valid to me as the number of glue joints alone is a major part of the overall strength of a wooden box, which is why the "winning" many fingered test piece was most difficult to part as it was more ply wood than box wood.

....

Guys, I'm having my carpenter friend build me a 2x12 using 12mm (1/2") okoume ply that I bought. He claims all these fancy joints are not necessarily and plans to just do plan butt joints using glue and screws or nails.

I've also read somewhere that in the old days glues were not nearly as good as modern ones, so the fancy joints were actually needed, but these days glues are much better.

I will use the cab for gigs so I will transport it but won't throw it around or anything. So I wonder should I insist on one of the stronger joint techniques or not ? I understand those help if you mistreat the cab, but what about actual sound pressure does sound itself produce enough pressure to cause problems ?

Oh and I will tolex the cab, so visually joints are irrelevant, I only inquire about actual construction strength.

I used to build large bass cabinets this way. all the corners were also cleated. the key was using a generous coating of glue on both surfaces before joining and clamping. this prevents possible hissing or buzzing that could occur if light lines of glue, like used in typical cabinet work, are used. with the back and the baffle glued in. and the speakers front mounted. they held up under abuse like a tank.

(so basically i am agreeing with your carpenter friend)

Guys, I'm having my carpenter friend build me a 2x12 using 12mm (1/2") okoume ply that I bought. He claims all these fancy joints are not necessarily and plans to just do plan butt joints using glue and screws or nails.

I am sure being a carpenter, he will be able to work his magic on your cabinet. I actually like the use of screws if the cabinet is being covered with tolex or tweed.