Gluing by hand

[Bill McDermott]

Woodworking by hand? Maybe. Idle curiosity, definitely.

When normal, water-based PVA wood glue gets on your hands, it dries really quickly. Latex paint is the same. Much faster than on wood.
I have no scientific facts supporting my hypothesis, just my experience.

What is the reason for this? Is it body heat, or does your skin soak in the water? Or is it something else? Can you explain it scientifically?

Thanks.

[Lee Schierer]

I would think it is body heat. Try spreading some on a piece of wood that is 98 degrees with your fingers and see which dries first.

[Kevin Rich]

The first thing people do when they get glue on their hands is to spread it out by wiping their hands together. This decreases the amount of moisture for the area covered. With the typical water based glues, it is all about the moisture leaving the solution. Once it does, the pva is not suspended in the solution (technically dispersion) and solidifies. The thinner the glue, the faster it dries. This is part of the reason we spread the glue out. It works better in a thin film.

Also, how fast the moisture is pulled out changes depending on what the glue is touching. Skin is not a great barrier to moisture... chapped lips, dry skin on less humid days, those wrinkled fingers when it is your turn to wash the thanksgiving dishes... wood is better than air though which is why glue can set in 10 minutes but drips are still damp for half an hour.

[Jason Martin Winnipeg]

I think Kevin nailed it. Try putting a blob on your hand and a blob on wood, and see which dries faster. I think they'll probably dry at the same rate.