Jim Pitman
From:
Waterbury Ctr. VT 05677 USA
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Posted 15 Jul 2021 9:23 am |
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I thought I would pass along my experience making custom cases for musical instruments using 5mm thick Luan Plywood, glue, rivets, and 1/16" thick angle aluminum.
To me Luan is the perfect candidate for lightweight case making. It's a simple three ply lamination ie, two thin mahogany plies with fiber board sandwiched between. This makes for a stiff and mostly durable panel, or more durable than an equivalent cloth case for example. It is only slightly heavier as well. As wood products go, it is relatively inexpensive too.
It is easy to cut. I started out using my table saw but quickly realized this left a chipped raged edge. A little research indicated you can avoid chipping if you score the cut with a razor knife first and cut to the unused side with the saw afterward. This is when I realized you need no saw at all. Simply score through the thin mahogany layer on both sides of the Luan with a razor knife and straight edge. So long as you are careful the score is in the same location on both sides, you can simply snap the two haves apart. Sometimes the inner fiber board ply is left ragged, however it is easy to clean up with a sanding block or block plane. You may want to make the pieces a bit oversize for this reason. (table saw does this too)
So how do make a strong 90 degree angle joint? Use 1 x 1 x 1/16" angle aluminum and rivet/glue it in place. This is also light weight. I would carefully line up the angle aluminum on the edge of one of the halves to be joined. I would use double sided tape to hold it in place then I would drill the holes for the rivets through both the aluminum and lauan at the same time ensuring perfect alignment. I use the smaller 1/8" rivets. So the rivets don't protrude much, I don't use the pop rivet post. I simply remove it and use a peening tool and hammer to peen over the rivet. I give it a couple good whacks after to make sure it lays flat. In this manner one can even attach the aluminum to the interior walls (as shown) without occupying much space. Even a 1/4" thick medium to high density foam on the interior is enough to ensure the aluminum/rivets don't protrude such as to damage your instrument. See the attached photo of a case I made for my Roland AC33 portable PA amp. In retrospect, it would have been easier to attach the angle aluminum to the outside and it would also serve as corner protection. You get the idea anyway.
I plan to make a lightweight case for my Infinity U-12 PSG. The current flight case weighs about 20lbs. It's great for flying but I can reduce the weight by 70% I estimate using this method and it will be adequate protection for hauling my PSG to local gigs. |
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