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RickKr 03-29-2019 10:09 PM

Gluing Finger Joints
4 Attachment(s)
I've just gotten my Incra LS Positioner set up and in use. First thing I did was clean up the sides of some maple. Really slick how with the Wonder Fence you can take off very small amounts. With the Bosch router table & the fence that came with it, the increments are fixed at 1/16", at least with the spacers that came with it.

I started out wanting to make a finger joint box, just to figure out how the LS works. I have a set of Craftsman chisels that came from my former father-in-law. The box they are in and the plastic cradle/insert appear to be made for the set of chisels, but the box is such crap, I have a hard time believing it was original with the chisel set.

At any rate, I decided to try making a replacement box. Turns out the only router bit I have that can be used with the LS is a 1/4" up cut. So, I selected 1/4" Baltic birch plywood for the box. I was very pleasantly surprised how easy it actually is to make the finger joints using the LS. I've never made any box/finger or dovetail joints before.

New box sides with rabbets for the bottom.

I'm ready to glue these together and put the bottom in, but I am intimidated by having to spread glue on all these small fingers and getting the glue distributed to all the corners in a timely manner without created a huge mess. I'd really like to keep the glue off the sides as much as possible. I have considered clipping the head off of a Q-Tip and using the stub end. I don't want to use a Q-Tip straight as I think cotton threads will get captured. What techniques have you guys used for this sort of glue-up?

I'd like to replace the hardware (hinges and front clasp) but I am having trouble finding much of anything. I've checked Rockler, Woodcraft and MicroMark. MicroMark has some, solid bras, but they seem too small. What suppliers have any of you used for hardware like these?

Thanks for any help.


Cherryville Chuck 03-29-2019 11:39 PM

I agree Rick. I don't think that's the box they came in if they ever came in a box at all as I don't recall much of Sears small tools that were sold that way. Lots of people use a small paint brush for that type glue up. I have some plastic paddles that I got from Lee Valley that are good for spreading a drop or two of glue that you drop onto the surfaces from a glue bottle.You don't want much glue and not much is needed. You also normally only glue the sides of the fingers and not the bottom of the gullets. That helps prevent squeeze out.

This is also a good time to talk about using a glue with enough open time to allow you to get all the surfaces glued and assembled in time. Titebonds 1 and 3 have short open times. T2 has a longer open time and there is also a Titebond Extend which has a longer open time still. If you are well organized you may be okay with one with short open time. You can also consider gluing just 2 sides together at a time and then joining those two halves together after but make sure they are drying square as you proceed to the second step. I often enlist my wife's help in situations where time will be pushed close to the limit.

DesertRatTom 03-30-2019 12:05 AM

6 Attachment(s)
Pretty good so far. One thing you can do is use a slow curing glues as Charles suggested, or one of the brown glues that take hours to cure completely.

I suggest you use a small metal brush Pix below, to apply the glue. These give you pretty good control of the glue. Generally you can wipe off any excess using a damp cloth for a couple of passes on the inside and outside. If you made the fingers a little proud (desirable), you will be using a block plane or sanding to get rid of the excess.

The other challenge is to keep the box square as the glue sets. If the bottom fits tight, you can insert it to help hold it square. Another option is using box joint cauls (pix) and a belt style band clamp (Pix). The cauls stand clear of the slightly proud fingers of your box joints. The picture of the orange band clamp already has a standoff and should work well

You could make your own L shaped cauls on a table saw, adding a strip to each inside edge so they make room for the proud fingers. The L drawing is an end view. Start with a 2 inch square piece. Make certain your saw blade is exactly 90 to the table. Make one cut about 1 3/8ths high, flip the piece and cut the same amount on the other side. Use some aged and seasoned wood so it will stay stable. Glue some strips on the inside edges as shown so they stand clear of the glue. Use a band clamp as shown to hold the box together. Cut the cauls into about 6 inch long sectons and wax the holy crap into the inside so the glue doesn't stick!

You could also use some reliably 90 degree L brackets, clamped with small clamps, into each inside corner. Make sure the brackets don't touch the glue. The second diagram shows how simple it is to make someting to hold corners square on a table saw, using 2 inch square material. Cut square by having the blade be exactly 90 to the table, then make a 45 degree cut as shown. I would use some 4 inch F clamps--five bucks each at Home Depot--see pix. It will take at least 8 clamps for a box like yours. You could use the small Harbor Freight F clamps for this instead, but I like the Bessey clamps better.

Finally, what you have made is a box joint. Finger joints are different. Each finger tapers and they are usually used to glue two short pieces together end to end to produce longer lengths. Many inexpensive items are made from this kind of joint. Because finger joints are tapered and come to a point, they cannot be used for box joints. Just a little woodworking lingo. And here are a couple of links.

There are a lot of ways to glue up box joint boxes, these represent a few that will do the trick for you.

RickKr 03-30-2019 12:17 AM

Thanks for the info, guys. The only wood glue I have is Titebond 3. I have a number of those metal handle brushes. Use them mainly for putting cutting oil on lathe turning/milling/drilling in metal. They seem too large and cumbersome for these 1/4" "box" joints. Thanks for the clarification on finger vs box joints. The bottom does fit tight, enough to use it for keeping things square. I was going to glue it in at the same time.

I recall looking at some of those clamping fixtures at Rockler a couple months back, and thinking "I don't have any need for those..." :smile:


DesertRatTom 03-30-2019 12:31 AM

Really easy to make those cauls, especially the simple one you put on the inside corner. Once you have the tools to make boxes, it seems to trigger a flurry of box making. Great for gifts and only take a weekend. I liked the idea of having the wife help with the glue ups.

Here's a link to the extra long open time Titebond glue. Definitely a good choice. I'm going to order a bottle myself because I'm itching to start using my new Incra Box Joint Jig.

DaninVan 03-30-2019 01:37 AM

Rick; you might find the hinges you need here...
Check out the whole site; especially clock parts and scroll saw blades.

ger21 03-30-2019 07:51 AM

Assemble the box dry, and apply blue painters tape in the corners, on each board. This will keep the inside clean

Then use small brushes like those show above, and glue up. After the glue dries, peel off the tape inside. You may need to run a chisel into the corners if there are any small beads left over.

DesertRatTom 03-30-2019 11:00 AM

You inspired me. Off today to buy some nice figured hardwood to make a fancy box. I already have some invisible hinges, but not sure I'll make a hinged box. May have several available for remembrance boxes for Christmas gifts.

Cherryville Chuck 03-30-2019 11:38 AM


Originally Posted by RickKr (Post 2009059)
They seem too large and cumbersome for these 1/4" "box" joints. Thanks for the clarification on finger vs box joints.


Never make assumptions about which type joint it is. If you do a web search on finger joints about 75% of them come back as "a finger joint also known as a box joint". All of Fine Woodworking's contributors refer to a box joint as a finger joint first. Most of older woodworking literature also refer to it as a finger joint. The tapered fingers were specifically referred to as a tapered finger joint or as a splice joint since that is the only function of that type joint i.e. end joining two boards together. That is the main clue about which type joint is being discussed is whether it is the splicing type or not.

RickKr 03-30-2019 12:17 PM


Originally Posted by DesertRatTom (Post 2009111)
You inspired me. Off today to buy some nice figured hardwood to make a fancy box. I already have some invisible hinges, but not sure I'll make a hinged box. May have several available for remembrance boxes for Christmas gifts.


I'd be interested in info about your invisible hinges. I've been searching various sites for small hinges and am not that satisfied with what I've found - for this particular box.


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