Is Resorcinol glue really necessary? Ive used polyurethane glue in the past, and it seems quite strong?
Perhaps the experience of one of my builders will help answer this question. He decided to user polyurethane glue to attach the rails to the pin blocks, and wrote the following: “…for the last ten or twelve years I have been using Gorilla Glue (a polyurethane glue) without any failure ever.” But after completing and stringing the dulcimer, he then wrote: “In future printings of your book you may wish to use my experience as a bad example. Since I have made quite a few dulcimers and never had a problem with Gorilla Glue, I used it instead of Resorcinol. You guessed it. Shortly after its first tuning the joints began to fail. First the top right corner gave and then the bottom right one shifted.” Click Here for the full story. My recommendation is that you use Resorcinol on all stress joints where the rails attach to the pin blocks. You can use wood glue or polyurethane glue for everything else.
