Finger joint questions

[jere]

I did one the other way.... had to re-glue a few fingers. But in the end it was easy to plane!

[ATTACH]22094[/ATTACH]

I like your tissue? box, how did you attach the top and bottom? I have to figure out what I am going to do for the sides I made.

[jere]

Yep! looks like your fingers are nice and tight! They look good!

Your frustration using screws to make adjustments was mine also. That's why my present box joint jig is adjusted with hammer taps. This is a tip I got from an old TV show about routers. Works fine with a saw too!

IMO - screws are fine for 1/4" box joints that are up to 5 or 6 inches long, but in order to get joints of up to 12" or so, you need hammer taps.

I will keep that hammer tap idea in mind, sounds like the way to go for larger boxes. I ended up changing my jig, for some more consistency, and it is working better now.

I added a board with two bolts, to act as a clamp/slide so I don't have to keep unclamping and reclamping the C clamps I was using.

I also made the screw advance all thread fixed, so that an L bracket moves like jaws in a vice. Then I screwed a piece of wood on as a track for the L bracket.

Not the greatest pictures but maybe they are better than my explanation.





The best part is I can cut multiple boards at the same time. I made the four sides of my box in two passes. It helps make up for all of the small cuts.

[nuhobby]

I like your tissue? box, how did you attach the top and bottom? I have to figure out what I am going to do for the sides I made.

The top was just epoxied on.... and no bottom to it. Not very sophisticated as I recall. On other tissue boxes that I did with mitered corners, I put the top into some grooves. I must have been trying to avoid stopped dados on that finger-jointed version .

[nuhobby]

I stumbled across this info on the Gerstner forums. I'd assumed that the lower box joints found on those Gerstner machinist chests were there throughout history. Actually they weren't.... comments per their Admin:

Quote:
The machine that we used to make the finger joints took about 30 saw blades and spacers. Every time we sent out the blades to be sharpened the blades would come back in a little smaller in width due to the sharpening. We would have to spend most of a day trying to setup the saw with the newly sharpened blades to keep the finger joint spacing correct. We would have to add shims between the blades to keep the spacing correct. If 1 of the blades was damaged, we would have to grind them all down to match or purchase new blades for the saw. We would waste quite a bit of wood with test cuts as we were setting up the saw.

In the 1970's we changed to the tongue and groove construction on the bottom of the chests that we were already using on the top, front rail and back rail of the chests.

[apexsunguitars]

i subscribed to this genius guy's page for the coolest wood jigs/tools ever!

https://www.youtube.com/channel/UCckETV ... 80B36aP9vw

he has some nice finger/box joint tool ideas and a once and for all test showing that the strength of a properly glued joint will be far superior in strength than the surrounding wood. I point people to it when they question the strength of a scarf joint used in the construction of a guitar neck.

[charlese]

Maybe we are learning the difference between box and finger joints. Finger joints have sloped fingers and are usually used to glue/fasten boards end to end. Most often we can see these when we buy 2X2s made from pine.

We can make finger joints using special router bits. http://www.carbideprocessors.com/whites ... uter-bits/

Box joints are what we have been discussing here. They get their name from their use making corners in wood boxes. Mentioned above are Gerstner Tool Boxes. The boxes I always bring to mind are Kraft Cheese boxes of year gone by.