Gluing green wood and DNA soaking

[Glen Blanchard]

I have some 3" thick blanks from which I'd like to make hollow forms. As the blanks are only 3" thick, I'd like to maximize every bit of that thickness and would prefer not to lose it to the tenon. As a result, I am thinking glue block. I also plan on soaking these in a DNA bath for approx. 24 hours after rough turning as well. So I'd like to do the following:


remove wax from long grain of turning blank
glue the glue block in place
clamp and let glue set
rough turn
soak in DNA bath for 24 hours
dry blank wrapped in newspaper (approx. three weeks)
finish turn

Is there a glue that will bond well to the green wood and also survive the DNA bath? If so, how long should I keep it clamped prior to rough turning?

[Scott Hackler]

Glen, Titebond3 is waterproof and so I would assume the Dna wouldn't have an effect on it.

Although I don't fully trust it because of the lack of shear strength, CA glue seems to survive dips in the Dna bath when I have soaked cracks, so maybe use CA if the tenon is wet down with water first.

[Reed Gray]

Well, CA glue will stick to wet wood, and so will the urethane (gorilla) glues. There could be a problem with shrinkage while drying. The wood will move, but the glue won't. That will cause cracking. With a good glue joint, the glue is stronger than the wood.

robo hippy

[Bill Bulloch]

You might not need the DNA if you are going to finish it with an oil. Glue up the blanks with one of the titebond glues. turn to finish size, wet sand with the oil you are going to finish it with then apply the oil finish. When it dries [somewhat] apply wax and buff. Some warping may occur but, what the hey, it will probably be minimal and will add to the natural look.

[Pat Scott]

Gorilla glue needs moisture to cure, so I would think it has an edge over Titebond.

[Dennis Ford]

In addition to surviving the DNA bath, the glue joint has to survive the stresses of the blank warping in different ways than the glue block. I suggest that you plan on removing the original glue block. Once the rough-out is dry, put it between centers and true up the bottom for another glue block.
IMO, the two best choices for gluing to wet wood are CA and poly-urethane (Gorilla glue).

[jwjerry w kowalski]

Glen, let's say your tenon doesn't survive the DNA bath, no big deal, if after you rough turn your piece you take a 1/16 in drill and run it through the mark made by your tail stock center and let it penetrate maybe another 1/16 in into your piece, then you have a registration mark on your piece so if it comes apart you can reglue another piece of wood onto it for a tenon. On the piece of wood for the new tenon drill a 1/16 in. hole into that and let your drill bit project a little out of the end, then you can line it up with the mark you made on your piece and reglue with thick CA and use an accelerator and it bonds in seconds, then you can cup chuck you piece, run the tailstock up to your drill hole and return a tenon on the piece. It won't be off much, if at all, but if it is your finish turning will take it out. If the bottom warps after the DNA bath and the tenon comes off, then just cup chuck the piece (having no tenon now) and return the bottom flat and then reglue the new tenon on. You might have to drill into your nib a small amount to keep your registration mark, so that after you remove the nib you can still find the mark. Sounds more complicated than it is, I've done this before and it works fine.

[John Beaver]

A while back I did some pretty extensive research on gluing green wood - contacting Titebond and others. The conclusion I came to is there is no glue that will work properly on green wood. Additionally, since DNA is alcohol, I would be very careful about the potential for it to dissolve any glue. Lastly, the wood movement will most likely destroy any glue joint.

When I have your issue, I just turn a tenon larger then the future shape of the vessel and leave room to remove it when finishing the bottom. Just picture where the curve is going to be and create the tenon as a step outside that curve. You might also get away with a recess that is inside the final shape and just let it remain.

[robert baccus]

CA glue is the only glue that holds well on green/wet wood. I recommend thick--requires no clamping and is gap filling which no regular wood glues does. It has the same strength as the best wood glues--gorilla is about the weakest glue made according to a big study by Fine woodworking. I glue on 100#+ end grain vase blanks with no problem. I would go around the DNA complication.