Gluing box joints

[Joe Hillmann]

I think that a lot of people here use box joints a lot when making wood objects on the laser and I am wondering if anyone has a quick way to glue them? It usually takes twice as long to glue a project as it takes to cut it out and that adds a lot to the final cost of the project.

[Lee DeRaud]

It somewhat depends on whether the joint is on a "throwaway" object (like a gift box, as in 'box to hold a gift') or something more artistic (as in 'the box is the gift'). In the latter case, the glue-up is a tiny percentage of the after-cut processing.

Either way, I usually just lay a tiny dab of medium-weight CA in the bottom of each notch. But I usually cut the things so the notches are almost a press-fit anyway.

[Joe Hillmann]

Specifically in this case the box part of the finished object. cutting it out of 1/8 inch ply takes 5:30 minutes and 1/4 ply takes 10:20 minutes but gluing either one takes about 10 minutes. Here is a picture of the finale assembly. It is a tip down for ice fishing.

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The first picture shows it set up for use, the second picture shows it closed up and the third picture shows it open with the parts laying in front of it.

[Michael Kowalczyk]

Joe the only thing I found that saves time is to make less joints. So instead of having 1/4" tabs I may use 1/2" or 3". It all depends on the strength you need at the joint and how long it is. I have even dropped down to 1 long one in some places.

I have tried Titebond II, 3M PUR heat activated (big bucks but quick set time 1-3 minutes) and a few other PUR systems but they can be messy and did I say expensive. But for large production runs you need a quick set time and clean edges with minimal labor.

The large upfront costs aren't bad if you have the volume to deal with it. The messy part will probably dissipate somewhat over time and you can use other glues for other items also, in the same glue-gun but it is about $1000.00 for startup costs.

I was trying the synthetic to synthetic PUR cartridges because when the laser cuts the material I can only explain it as it kinda cauterizing the edge so glue can not seep into the joint and get a good bond. 3M gave me a tube that is like Locktite but it is $$$ and I think it does not cover enough surface area to last in the retail merchandising environment, at a cost effective price and low labor requirements. but that's just my opinion.

Joe if you find one, please let me know and ...

[Joe Hillmann]

Here is the quickest way that I have come up with yet but still leaves a lot to be desired.

Usually I use titebond 2 but that is at home so I am using whatever this is.and blue painters tape.
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I tape the two pieces together sided by side with a gap that is just a little bit smaller than the thickness of the wood(tape is on the good side and the bad side is up)
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Close up of taped joint
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Then I put a thin line of glue on the tabs (for a joint that is hidden there should be more glue on the joint, for one that is highly visible there should be less or you should run masking tape along both sides of the joint so when it is done you can peel the tape of and the glue will come with it)
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Close up
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Then fold the joint to 90 degrees and because the joint was taped slightly closer than the thickness of the tabs the joint will pull itself tight and the tape will clamp it.
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once the joint is folded you can either run your finger down the glue to smooth it into a nice fillet or wipe it off with a wet rag or if you taped next to the joint remove the tape. I like to use a clear drying glue and make a fillet because I feel it adds more strength.

Edit: this method can only be done on 4 of 6 sides of a cube.

[Dee Gallo]

Assuming the wood is finished already (well sealed), why not just dip the joints into your TiteBond, and wipe them off top and bottom before pushing them together and securing with clamps, rubberbands, or whatever. Further cleaning is easy with a damp cloth. I've done this with multi-part wood items and it works well. Acrylic is another story, but wood is easy.

just my two cents, dee

[Scott Challoner]

Very cool design Joe. Your gluing technique is pretty neat too. I agree with Michael on less tabs. This will save you laser time too. At least now your gluing time is the same as your laser time (with the 1/4") so if you glue while the laser is running, it's a parallel operation and you can still complete one every 10 minutes.

[Joe Hillmann]

I already have fewer tabs than I want, I like the tabs to be equal to the thickness of the wood but my tabs are 3 thicknesses anymore than that I feel looks unbalanced.

[Joe Hillmann]

Dee,
I will have to give that a try. I have tried dipping the tabs in glue in the past but used tape for clamps which makes it hard to clean up the glue, rubberbands might solve that.

[Michael Kowalczyk]

Assuming the wood is finished already (well sealed), why not just dip the joints into your TiteBond, and wipe them off top and bottom before pushing them together and securing with clamps, rubberbands, or whatever. Further cleaning is easy with a damp cloth. I've done this with multi-part wood items and it works well. Acrylic is another story, but wood is easy.

just my two cents, dee
Hey Dee,
One issue I had with doing a dip is that you have to have the joint not as tight otherwise the glue never makes it into the joint or not enough and you still have the issue of the lasered side being cauterized so glue bonding still is an issue What I was doing in my case was to leave the joint a little open, squeeze the PUR into the back of the joint and then press together. This leaves the glue in the back of the joint just like when you caulk a bathtub but it also meant less squeezed through the front side. Once the PUR dried, a quick slide of a razor would clean up any minor squeeze through. Just have to be careful not to catch it on the material and nick it. This semi worked fr my particular application but definitely would not work in all. especially if the interior of the joint is exposed.