The Myth of Wiping Wet Glue
The craft is clogged with so many counter-productive myths and practices that someone could make a career out of a “Mythbusters”-like approach to woodworking.
If I could eliminate one myth from the national wood-consciousness, it would be that you shouldn’t wipe off wet glue from a joint and should let it set to a more solid state.
Lots of people – including glue technologists and working craftsmen – have studied the problem. Here are the facts.
- Wiping wet glue away with a wet cloth will not dilute the glue at the joint, starve it or weaken its bond (unless you use a fire hose).
- Wiping wet glue away with a wet cloth will not dilute the glue and cause “glue size” or a clogging of the pores and ruin your finishing efforts (unless you are sloppy about cleaning up the glue or don’t dress your surfaces with a sander or handplane).
- Wiping away the wet glue will allow you to see any gaps in your joinery while you can still take things apart and fix them.
- Semi-hardened glue can be tricky to remove. Let it get too hard and you can tear away chunks of wood fibers at the joint. Remove it when it’s only skinned and you will just make a second more difficult mess to clean.
- Letting the glue harden completely before scraping it off is more work than I like to do. And you can tear out chunks of wood.
- To wipe away wet glue, take a clean cloth that is wet but not sopping wet. Clean the glue away from the joint using circular motions, like waxing a car. Don’t be a snowplow. When you start to see glue smears, dunk the rag in water again to get the glue off.
- Regular surface prep with sandpaper and/or handplanes will remove any glue-clogged fibers. In making many many panels since 1993, I’ve never once experienced glue size (or a joint failure).
- Ignore anyone who tells you different.
- Live happily ever after.
- Yes, this applies to hide glue, white glue and yellow glue.
- No, I don’t know about poly glue or epoxy. Those aren’t typical furniture-making glues.
— Christopher Schwarz