Finger Joint Glue-Ups

[Rob Luter]

A question for you seasoned box makers. I just finished a little box that was primarily an exercise in finger joints.

http://www.sawmillcreek.org/attachment.php?attachmentid=93716

I'd never used them before and was impressed with the strength of the glued joint. I had some trouble however, as the glue wanted to hook up during the assembly process, and prior to getting all the finger joints seated completely. All that face grain really sucked the moisture out of the glue in a hurry.

I used plain old Titebond glue. Should I be considering something with a longer open time to give me a chance to get everything assembled? What about moistening the finger prior to glue application? I'm getting ready to build a large box and want to get it right the first time. Any advice would be appreciated.

Thanks in advance,

- Rob

[Mike Malott]

I build +/-100 finger jointed pine boxes per year. My take is that the waterbased glues (Titebond) cause the fingers to swell.
This makes assembly of well fitted joints difficult, at best.

I've been using Gorilla Glue on finger joints for about ten years, with excellent results. I use an acid brush to spread the GG on two sets of fingers (lets say one finger set on the ends of two side panels) then spritz a bit of water on both sets of mating fingers of one end panel. I quickly knock them together with my hands, apply the cauls and clamp. Repeat for the opposite sides/end.

The GG foamy squeeze out is a mess, but when dry, I shear off the bulk of it with a Veritas glue scraper or chisel, then belt sand the fingers flush to the outer box faces.

I first mask the inside corners from excessive GG squeeze out with tape. Regular masking tape just gets glued to the wood and filament packing tape leaves strings of filament glued to the joint. I have found that 3M69 electrical tape with a woven fiberglass substrate pulls off well and takes most of the GG foam with it.

If you aren't familiar with polyurethane glues such as GG, wear nitrile or similar gloves as poly glues cause staining of the skin. Not permanent stains though, as they do wear off in a few days. Scrubbing with a pumice stone with soap & water will also remove the stains.

Mike


A
question for you seasoned box makers. I just finished a little box that was primarily an exercise in finger joints.

http://www.sawmillcreek.org/attachment.php?attachmentid=93716

I'd never used them before and was impressed with the strength of the glued joint. I had some trouble however, as the glue wanted to hook up during the assembly process, and prior to getting all the finger joints seated completely. All that face grain really sucked the moisture out of the glue in a hurry.

I used plain old Titebond glue. Should I be considering something with a longer open time to give me a chance to get everything assembled? What about moistening the finger prior to glue application? I'm getting ready to build a large box and want to get it right the first time. Any advice would be appreciated.

Thanks in advance,

- Rob

[John Thompson]

Excellent suggestion by Mke. I just did around 80 on a 5 drawer chest on the rears and use Tite-bond III with an acid brush to spread. I put the glue on with a syringe plunger and needle I get from P'tree WW. Others have them as they are much easier to use applying a dab on each joint.

But.. I will usually assemble only two drawer sides at once.. then come back for the remainder. Under the circumstance you created Mike's idea of a much longer open time glue would be best.

Sarge..

[Doug Shepard]

I usually go with Titebond II Extend for an extra 5 minutes open time. I Quik-Grip clamp the opposing sides together and spread glue on the fingers 2 at a time with an acid brush. I used to have the same problems with the glue starting to set up before I got everything together but since going with the 2-at-a-time thing, it's gone a lot smoother. After the glue is on, pop the clamps, assemble, and clamp it together.

[Wade Lippman]

I use Titebond II extended on tight glueups. Not so much to get the extra time, but because it is thinner and works better on tight joints.

[Mike Henderson]

No glue advice but that's a beautiful box. Very well done and good wood choice.

Mike

[Chris Friesen]

As an alternative to using poly or hide glue, Chris Schwarz suggests using thin cyanoacrylate glue and wicking it in to the cracks after the joint has been clamped together.

The Chair Doctor glue can be used this way as well, but apparently it wicks deeper into the endgrain of the fingers and shows up when using transparent finishes.