My woodworking business includes a fair amount of repair work. Often, I’m confronted with how to force glue into a hairline crack or a bit of loose veneer. I’ve tried using old business cards but that’s like spreading glue with a wet noodle.
I finally found the answer in metal shim stock I use to align machine parts, e.g., the cutter head to the outfeed table on my jointer. Metal shims are available at any machinist or automotive supply store. Buy a variety pack; it contains several thicknesses and only costs a few bucks. The thinnest shim is almost like aluminum foil and the thickest is similar to card stock. You’ll only need a few scraps to use as glue applicators. I keep mine in a small jar. The shims can be used over and over again. Just wipe the glue off the shim with a damp rag before it sets.
Watch these related videos for more gluing tips –
I like the Machine shim idea. However, I have a crack in a rocking chair that is not linear for any length of time. so I reached in my toolbox and pulled out a feeler gauge. It is narrow enough to get it down in a cracked it’s not straight.