A wall-mounted display case for my guitar

[Gene Davis]

I'm not an instrument maker, but I sure admire those that build.

My 1971 Martin D-18 needs a case that can be used to help keep it humidified. We moved to the front range area of Colorado 16 months ago and it is way too dry here for instruments. I want to build a case to hang on the wall, display the guitar, and hopefully keep it humidified.

Climastand is the brand name for a line of cases that are built reasonably air-tight and with a gasketed door. The doors are full-glass, hung with a piano hinge, gasketed, and kept closed with snap-locks. One puts humidity-pacs inside that regulate the moisture content of the interior.

My plan is to dovetail-join four boards together in the truncated pyramid shape that is common to this brand, fit a 1/4" plywood back to it into stopped dados in the sides, and do a four-sided frame of 1x2s for the glass door.

Any advice on details for helping with the air-tightness would be appreciated. Source for gasketing? Joint sealant? Finish? Alternative to the ugly full-length piano hinge? Species for sides? OK with BB plywood for back?

[Scott DelPorte]

Hi Gene, I have never made one of these, but I was thinking you might get some tips on sealing etc. if you do a search on here and look at humidor construction threads. They must have some of the same issues you mention.

[Chuck Raudonis]

I will tell you that if you have never done it, dovetailing angled boards is a SIGNIFICANT endeavor! The geometry there is complex. You might want to think of another joinery method for the case. Polyurethane would be a great finish but make sure you let it cure for a couple of weeks to let the remainder of the solvents flash off before you lock your precious Martin in there. No sense taking a chance with the finish on the Martin.

This quote from finishing site explains it:

Q: What is the difference between drying and curing?
A: Drying occurs when the solvents evaporate from the surface of the film and it becomes tack free. Curing is when the residual solvents leave the film and it begins crosslinking with oxygen in the air to develop its strength, toughness, abrasion resistance, and chemical resistance. Although most finishes reach 90% cure in seven days, full cure takes up to thirty days.

Polyurethane should reasonably handle sealing the joints. I think you're stuck with the hinge. You might be able to make it less obtrusive by using a black one:

http://www.amazon.com/Larsen-amp-Ls1119E04-1--50In-X72-Coated/dp/B00B512H8G/ref=sr_1_1?s=industrial&ie=UTF8&qid=1462836992&sr=1-1&keywords=black+piano+hinges

Sides can be any species you want. Not sure what you mean by BB plywood.

I just started a thread about the standing guitar case I just finished. Have a look. I'll answer any questions as you go along.

Good luck!