Hello,
I am assembling a trunk of 5/8′ maple container is 30’x 14′ X 14′. I am using the box joint, or finger joint for assemble. I built a “glue up aid” of smaller fingers to aid in the assembly. I clamp the 2 glue up aids on top of the fingers to apply pressure in the right areas. My cuts where neat, but perhaps a bit tight and the fingers where cut about 1/32′ longer then needed so direct pressure will not work.. I hope I made my situation understood. FYI I am using a bit of glue, so time is an issue in assembly. <!—-><!—-><!—->
My question is this. Do you have any other methods that have worked well for you in gluing up finger joints?? I had thought of not using glue, but I am not the woodworker I would like to be and glue is necessary I fear. <!—-><!—->
RIch
Replies
Rich, in my experience a simple block placed right behind the fingers is quite enough to apply clamping pressure. If you place the blocks accurately, on all the corners at once, you will not have any racking in the box. If you need to exert more pressure than this, I'd say your fingers are too tight. It should not require extreme pressure to close the joints.
David Ring
http://www.touchwood.co.il/?id=1&lang=e
Clamp the opposing sides together so you can spread glue on the fingers two at a time. Racing the glue setup can be a real challenge.
If you build it he will come.
Just want to update and show you the piece as it turned out. This is pre finish. I am waiting on the customers choice.
Also, How large is it safe to usw this joint with... what i mean is this is 15" tall is 20" to large for this joint type??? is there a formula??? and help would be appreciated. I am thinking of making a Queens size hope Chest of cherry with this joint.
Rich
I'd say it is time to start dovetailing....
Do you mean do too the the size issue and strenght???
They're also fun to make and they look nice. I don't mean to imply that box joints don't look good as they do too. I use them on some jewelry boxes I make.
Right now I'm attempting a mitred box (all sides, top & bottom) which I plan on adding dovetail keys.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Good evening,
Have a ? concerning Box joints. I'm using 3/4" pine. I realize most books suggest you cut the fingers to 1/2 the thickness of the material you're using. But I'm going to cut my fingers 1/2" wide instead of 3/8".
I set the dado blade height 1/32nd higher than the thickness of the stock. Some articles recommend setting the blade height to the exact thickness of the stock. (3/4") Does that make a difference?
Now If I want to make sure that I start with a pin and end with a notch (making sure they are uniform in size.... How do I calculate the widths??? The books I've read make no mention of this. I need to know how to size my boards before I begin cutting.
For ex. If my pins are 1/2" wide... And I'm using a 6" wide board.. I need to know if I will end up with pins and notches that are uniform in width. I have a feeling the last notch will be a wee bit narrower. So I was thinking of using a 6 1/8" board. That should leave me with a full size notch at the end of my first piece (side A)
Wanda
PS Is a less expensive stack dado set good enough for making box joints or would I be better off in investing in a dedicated box joint cutting set such as the Freud box joint cutters set SBOX8 Series.
Edited 9/21/2007 8:21 pm by Wanda200
Wanda,
Here's a couple resources for you:
http://www.beesource.com/plans/boxjoint/boxjoint.pdf
http://www.thecraftsmangallery.com/<!---->document/Digital_Scale_Box_Joint.pdf
I'd rather have the fingers a smidgen long than a smidgen short! But that also might mean the boards have to be a tad longer............. :-)
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 9/22/2007 8:50 am ET by KiddervilleAcres
Wanda,
To answer your questions:
1. the 1/32 inch higher is to allow a protusion which you then sand off. So why do it? For the very good reason that perfectly calculated joints usually are not perfect. This 1/32 keeps you from sunken box joints (well, you could sand the entire side but that is a lot of work).
2. Widths? You do not need to allow any extra. The point is to have the joints fit exactly. So for 12 box joints of 1/2", a 6" height is perfect. (You can go higher and then trim if it makes you feel better.)
3. Dado set? Actually, I think this very important. To step back, what is the worst thing that can happen to your joints? Well, obviously, you cannot fit them together if they are too tight. Too loose? At least with the woods I've used, the problem is tear out. Chips and splinters around your box joints look terrible. So you need a dado set that will do the job. Sharp--yes. Flat top cut--yes. (Mine has been resharpened a leaves unsightly grooves.) A few months ago the Freud rep on this site told me to watch out for hook angle--less agressive is better in reducing tearout. Also, I have found that it is worthwhile to be anal retentive about the backing board for the box joint cuts. Maybe other people get away without worrying about it, but with my particular Freud dado set I found it best to use MDF (very sharp corners) and even to shift the backing board on a regular basis so the blade was cutting through new backing material. Also, clamping. Maybe others have been able to get away with holding the piece by hand, but I clamp it from both the left and the right so that everything is snug. Yes, this is anal retentive, but the alternative, in my experience, is tear out.
Box joints are surprisingly difficult. The "surprisingly" comes from two factors: a) the mistaken impression that they are lesser, more primitive joints than the heavenly, esoteric dove tail, and 2) the hearty, off-hand assurances that "aw, don't worry, it'll work like a charm!" Actually, Box Joints are difficult. Part of making them work is a slow-setting glue (e.g., Titebond III) if you have quite a few box joints to glue. Taping or holding the two matching sides together so that you can glue both joints at once saves a little time. Another thing that helps is custom cauls. If you've just picked a four-leaf clover, all your joints will work and you can simply clamp cauls just behind the box joints. But, if it is a normal day, you might want to have ready custom cauls that match your joints. Then when the joints don't fit quite right (for many reasons), you can apply hundreds or thousands of pounds clamping pressure directly on the joints, and maybe save the look of the corners.
I hope this was helpful.
Jim Bell
"Thousands of pounds of pressure". Now there is a statement I can relate to. If I was a better woodworker it would be tens of pounds. Ooh well.:)
I guy can make notched(to fit around the 1/32" protrusion) cauls at the same time you cut the joints. Tape these to the joints, then you can really clamp the snot out of it.
Hi,
Just finished reading the Beesource.com article. Wonderful article! After reading that article I have no more ?'s concerning box Joints. :)
Wanda
Wanda, I have the SBOX box-joint cutter set and it is fantastic. I think well worth the money to have a perfect box joint cutter. It's oh so easy to set up, the slots are dead-on and it cuts super-clean. Don't do yourself in by getting a cheap dado for box joints. As mentioned above, you want the joints nice and clean.
One trick I gleaned when asking about BJ's here at Knots is to scribe a line where the base of the slots will be. It helps prevent those little "flags" that occur in plywood.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Hi,
I think you guys are right. After cutting several test cuts yesterday I noticed a bit more tearout than I would like on the box joints. Probably caused by my dado set. Otherwise the cuts weren't that aweful. But when making box joints the joints have to fit perfectly. I also noticed minor "gaps" in my joints when I fitted them together. I'd like to think it's not my skill but the blades that are to blame. LOL
Forest Girl Would I be able to cut precision box joints using the Freud SD200 Pro Series or SD300 Series dado blade set? Only reason I ask. I can't afford both. And I think I'd be better off investing in a quality set of dado blades. Since my dado blades get a lot of use. Would be great if I could afford a SBOX8 box joint cutter set and dado set..
So I have a decision to make... Box joint cutter set vs Freud dado set.
Can't remember now if the SBOX has the capacity to cut 3/4" fingers ...
Wanda
Wanda,
Curious about the tearout problem and am assuming that you're using a backer. I started making box joints with the router table but couldn't eliminate tearout. Went to the TS and it was better but not quite there.
Made a box joint crossscut sled with a registration pin - close, and no tearout, at least for the first few cuts. Extended the pin and added a 1/4" backer board and no more tearout. Used a handscrew clamp to keep the boards tight; have since adapted a quick release clamp.
It's a PITA but it works!
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
SBOX cuts 1/4" or 3/8" Don't think you'll need 3/4" very often, LOL.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Those would be Big Toe Joints, rather than Finger Joints.
-Steve
Yes, I guess they would be big Toe joints. :) I like the look of 1/2" pins.
I had some tear out but not a great deal. I do use an auxillary fence (3/4"plywood). MDF might be a better choice. Anyways it's a lot cheaper.
Wanda
Too funny, I see a whole line of Box Joint Cutters on the market, one named "Sasquatch" -- 1.5". ROFL!!!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
I have a feeling the last notch will be a wee bit narrower.I'd plane off that 'wee bit'!
Hi WillGeorge,
Yup, you're absolutely right.. it was a wee bit narrower. So I will use the bandsaw to fix that.
Wanda
You can make a glue up aid (caul?) shaped that looks like your finger joint pins. Each caul pin goes above the area between the tails of your finger joint...then clamp. You can use a slower setting glue like Titebond slow set available from Woodcraft or Rocklers.
Each caul is custom made to the individual finger joint. This puts the pressure from clamping directly above the finger joint. Clamping next to the joint does not always work.
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