# How To Properly Mark A Butt Joint For Biscuit



## breakfastchef (Jan 14, 2008)

*Project Photos Added - How To Properly Mark A Butt Joint For Biscuit*

I am looking for suggestions as to how I can align the cabinet pieces so I can mark where the biscuits will go. The joint will be a butt joint, but I cannot trust my bench to be 'true'. This is likely a pretty basic question, but it is important to me as I am building cabinets for my new high efficiency speakers. I basically need to have the sides and front at a 90 degree angle so I can pencil in a mark for the plate joiner. Any suggestions for 'best practices' would be appreciated.


----------



## Rob (Oct 31, 2006)

If I'm understanding your question, I would just put tick marks on either the front or the side pieces and then use a tape measure to measure each mark and transfer that measurement to the corresponding piece. One you have the marks, go back with a square and extend the line a little, so you can see it.
Or, put your marks on one piece then lay down the corresponding piece and extend the line onto the unmarked piece.
If you are using a biscuit jointer, you will have a little "wiggle" room if the cut is off a tad.


----------



## breakfastchef (Jan 14, 2008)

Rob said:


> If I'm understanding your question, I would just put tick marks on either the front or the side pieces and then use a tape measure to measure each mark and transfer that measurement to the corresponding piece. One you have the marks, go back with a square and extend the line a little, so you can see it.
> Or, put your marks on one piece then lay down the corresponding piece and extend the line onto the unmarked piece.
> If you are using a biscuit jointer, you will have a little "wiggle" room if the cut is off a tad.


Thanks very much for your reply. I thought of doing this, but the instructions with my plate joiner show the two pieces clamped into position for the pencil marks. This seems like the best way to do this. Perhaps having the pieces a 90 degrees is not as important as ticking a register mark for the plate joiner on each piece.


----------



## Rob (Oct 31, 2006)

A couple of things...
Make sure your stock edges are square before jointing them...
Make sure your jointer fence is 90* before plunging the cutter.
As always, practice a few times on some scrap so you get the desired results when you go for the money cuts.


----------



## cabinetman (Jul 5, 2007)

Just an unrelated suggestion that I hope doesn't make you pull my membership.

Butt joints by themselves are a very weak joint, and biscuits don't add much at all. A rabbeted edge fitted with glue would allow easy alignment and considerably more strength.


----------



## GeorgeC (Jul 30, 2008)

By butt joint I assume that you do not mean end to end. Rather you are joining one piece perpendicular to the other.

I just lay the two pieces in the position that they will be joined in. Then I just tick a pencil mark on each or use a square and draw a line that includes both pieces.

As Rob noted there is a lot of slop in biscuit joining. I am not careful in making my marks and I have never had the two slots so far apart that the biscuit and the joint did not fit.

Good joining.

Merry Christmas

George


----------



## breakfastchef (Jan 14, 2008)

Yea, George, I was looking for some ideas on how to hold the two pieces together so I can mark them. I don't have a bench vise to hold the perpindicular piece so I was looking for a quick and dirty method to hold the two two pieces in alignment while I make the marks so they do not fall apart before I am done.

To the omnipotent cabinetman, I had considered rabbeting for the joints, but glue and clamping should be plenty strong enough. The biscuits are more to get me in the ball park while as I get the clamps in place. This type of constuction seems to be pretty prevelant in DIY speaker building circles. I hope to have the project nearly complete before XMas and will, of course, provide photos.

Thanks for your comments, all.


----------



## breakfastchef (Jan 14, 2008)

Rob said:


> A couple of things...
> Make sure your stock edges are square before jointing them...


Rob, That is funny. When I ever get to that point, I will throw a huge party.


----------



## Rob (Oct 31, 2006)

Uh, whatcha' got in the tool arsenal to make the cuts?


----------



## GeorgeC (Jul 30, 2008)

breakfastchef said:


> Yea, George, I was looking for some ideas on how to hold the two pieces together so I can mark them. I don't have a bench vise to hold the perpindicular piece so I was looking for a quick and dirty method to hold the two two pieces in alignment while I make the marks so they do not fall apart before I am done.
> 
> To the omnipotent cabinetman, I had considered rabbeting for the joints, but glue and clamping should be plenty strong enough. The biscuits are more to get me in the ball park while as I get the clamps in place. This type of constuction seems to be pretty prevelant in DIY speaker building circles. I hope to have the project nearly complete before XMas and will, of course, provide photos.
> 
> Thanks for your comments, all.


The two pieces do not have to be tightly held together to mark. I just lay them on a flat surface and hold with the fingers of my left (I am right handed) hand while I mark with my right.

G


----------



## breakfastchef (Jan 14, 2008)

Rob said:


> Uh, whatcha' got in the tool arsenal to make the cuts?


Forthe plywood I use a circular saw and home-made sled. When pieces are more manageable, they move to the portable contractor saw. I often square up ends with a router and DIY dado jig.


----------



## firehawkmph (Apr 26, 2008)

quote:The two pieces do not have to be tightly held together to mark. I just lay them on a flat surface and hold with the fingers of my left (I am right handed) hand while I mark with my right.

I agree with George. All I have ever done with biscuits is get the two pieces in the ballpark and make a slash with a pencil. That was half the reason to use biscuits and the other half the reason they were marketed that way to replace doweling. You don't have to be spot on side-to-side. It is far more important to make sure both cuts are the height as each other so the pieces end up flush with each other. What I used to do was center the slot on the thickness of what I was joining. Do a test on a scrap, then flip the piece over and make another cut next to it to see if I hit the center. In lieu of this you could be off center I guess, as long as you mark the pieces to make sure you are slotting them all from the same side, face up or face down. All right, enough about biscuits, mine are growing mold on the shelf from lack of use. Pocket screws I say......:laughing:
Mike Hawkins


----------



## breakfastchef (Jan 14, 2008)

I taped together the speaker cabinets today and used my square to mark all the biscuit locations. The 100+ biscuit slots I cut were worth the effort as I could easily dry fit the parts and the whole thing stayed together. It made it much easier to make small adjustments when the cabinet stayed in one piece. Tomorrow is glue up, Monday is serious sanding, Tuesday is finishing...just in time for the speaker components to arrive via UPS.


----------



## breakfastchef (Jan 14, 2008)

*Update: Completed Speakers (with Photos)*

Update:

My speaker project was 90% finished on Christmas; enough for me to sample them on my sound system. Below is one 'nudie' picture of the inside of one of the cabinets and another of the completed speakers with the system. Thanks for everyone's suggestions and comments.


----------



## Rob (Oct 31, 2006)

Nice job! Those look great!
You should be proud of that setup. I don't have a clue what it all is for, but it sure looks nice!
Great music shown also. I was a drummer for 16 years and love the jazz.


----------



## TooPicky (Apr 12, 2009)

Pretty good result with the tools you listed.....Looks like a tube amp setup. Did you make amps? A couple years ago I made 6L6 amp housed in a walnut & Spanish Cedar case....


----------



## bzbatl (Feb 10, 2009)

I recently finished two rather large subwoofers using only butt joints (I know, a cardinal sin here). Thing is, with the polyurethane glue and the internal bracing of these designs, these things are freaking bulletproof.

No biscuits or dadoes at all. Just used some scrap pieces as braces to keep everything square as it was assembled.

Used 1/2" baltic birch panels. Plans at billfitzmaurice.com. These cabinets are unbelievable.

The bottom cab is the one I finished in early December. It's already gone through 5 or 6 gigs, so it's got some scratches in the acrylic. The top one has truck bed liner on it, and it's been to only one gig, but after I beat it up there are zero scratches in the liner.










This is what they look like on the inside.


----------



## woodnthings (Jan 24, 2009)

*Hey, joonya*

Thanks for that link: www.billfitzmaurice.com. Those are some awesome specs on the speaker cabs. I have some older Electrovoice 18" woofers in a bass reflex or ducted cab. Do you think they would work in one of his designs? I didn't see a plans for 18's only 15's. :thumbsup: bill
BTW where's the speaker in your cabinet go? I guess butt joints are strong! :laughing:


----------



## breakfastchef (Jan 14, 2008)

TooPicky said:


> Pretty good result with the tools you listed.....Looks like a tube amp setup. Did you make amps? A couple years ago I made 6L6 amp housed in a walnut & Spanish Cedar case....


The tube components are from Bottlehead (www.bottlehead.com). The setup includes two monoblock amps driven by 300b tubes, a phono preamp and a line stage.


----------



## bzbatl (Feb 10, 2009)

woodnthings said:


> Thanks for that link: www.billfitzmaurice.com. Those are some awesome specs on the speaker cabs. I have some older Electrovoice 18" woofers in a bass reflex or ducted cab. Do you think they would work in one of his designs? I didn't see a plans for 18's only 15's. :thumbsup: bill
> BTW where's the speaker in your cabinet go? I guess butt joints are strong! :laughing:


Nope, nothing for an 18". Horn loading puts too much pressure on the cone, apparently, and they go pop.

The driver is loaded in the top left corner of the internals pic. These have only 10" drivers, and they outperform my 18" B-52 subwoofer... which weighs almost 10 pounds more than these two do combined (54 and 57 lbs each).

The butt joints are amazingly strong with this polyurethane adhesive. There is zero rattling or vibration from these cabinets. Girls can dance on em without me yelling at them to step down  Some guys claim you could drive a truck onto em. I'm not willing to risk my tires to try, but I'm inclined to believe it.


It's amazing how many woodworkers there are over there at the billfitz forums. Lots of former cabinetmakers. Those guys take on insane projects (like a bunch of you guys do here).

I was highly skeptical about the sound you can get out of the cheap DIY cabinets, but I'm VERY impressed. The subs sound better than anything I've ever owned or heard around Atlanta that was part of a national touring act.

I was also skeptical about the butt joints, knowing what I know from here, Norm, and the mess of books/mags/plans I've read, as well as the projects I've done. But I'm a believer now on that too. A butt joint has its uses...


----------

