This may well be the most valuable luthier trick on this website. Works for any guitar having the truss rod nut accessible at the gear head.
Say you are preparing to steam off the neck on your vintage Gibson. That vintage finish still looks great. You want to avoid steam damage.
You have taped off every place where the steam might affect the surrounding finish. Or you are using the wipe down method to avoid steam damage. Gibson guitars have very tight dovetail joints. It may well take a lot of steam. Hopefully you have your shop vac set up to vacuum away any steam blowing out around the neck heel. Bad news when steam pops out there.
I bet there is one place you have not thought of. What about the truss rod nut cavity in the gear head? On most vintage Gibson guitars steam is going to gush out that location like crazy and will destroy that nice gear head face.
What’s to do?
Make a gasket! Find a small bit of rubber sheet at least 1/6 inch thick. Trace around the little half-moon shaped truss rod washer, punch a hole where the truss rod has to poke through, slide the gasket over the truss rod threads, add the half-moon washer, screw on the nut, tighten and you should be good to go. You should use a very small hole punch to make the hole in the gasket since steam can escape there too. I used pond liner rubber sheet to make my gasket. You can go to any nursery that builds fish ponds and they will probably give you a piece of scrap. They may have a pile of the stuff in the trash.
Gibson Gasket shows below. As you can see, the hole for the truss rod is well eaten out. That is because I forced it on to the treads for a tight fit.
©2017 D.R. Hanna