Following in the train of our recent series on avoiding sanding, we thought it pertinent to pass along this sage advice as well: "If you MUST sand, do it once!" Seems obvious, but admit it, we've all had to go back and do it again. So this blog is about doing it right the first time!
This starts with proper preparation. Masking off areas where glue may squeeze out is a good first step. If glue does squeeze out, DO NOT wipe it away! Even using water, it is nearly impossible to get the glue out of the pores. Better to let it dry most of the way, and carefully remove the drops with a sharp knife or chisel. Best of all is to use the correct amount of glue and eliminate the squeeze out altogether!
When finish sanding, use a low angle light source to expose scratches. The light should be set to shine directly across the top surface of the sanding area. This will cause darker shadows where scratches are hiding. It is a simple trick, but try it and you will see how well it works. Scratches you miss when sanding will instantly appear as soon as stain is applied!
Lastly, choose your "fixes" carefully. Fillers rarely match the grain perfectly, and even more rarely take stains and finishes exactly as bare wood will. Also, filling small gaps with glue and then sanding dust into the glue is an old Woodworker's trick for hiding flaws. But remember that when this trick was created, animal hide glue was the norm! It will absorb stains and finishes, but modern PVA glues will not!