How I finally got layered CNC guitar bodies right - steps that actually worked

I started doing the similar stacking approach last fall when I got a new 3018 and wanted to move beyond simple flat pieces. My experiance with the alignment trick you mentioned was a huge help. I found that running the entire stack through a drill bit set to a diameter just slightly smaller than the outer profile diameter helped keep everything concentric before I ever started the gluing. It's a small thing, but it realy helps keep the relief from wobbling on the lathe later on.

My biggest breakthrough came with the finishing. I used a very light sanding technique between each layer, mostly 220 grit, to knock down any tiny splinters or rough edges that the CNC might have left. Instead of just applying the stain, I actually sealed each layer with a thin coat of shellac before staining. This made the color pop much more cleanly.

I found that the dry time between these sealing steps was critical. If I rushed it and applied the next layer before the previous one was completley cured, the finish felt tacky and smeared. Waiting til it was totally hard before I moved on to the next piece in the stack made all the difference in the final look of the piece. It took me about three solid weeks for my first finished model, but I'm feeling much faster now with the process.

I've only ever cut flat shapes out of thin plywood with mine, so the whole stack idea is new to me. I drew a mountain scene on paper and thought about doing it in wood layers, but I got stuck picturing how it all goes togehter. When you cut each layer, is the back of it totally flat so the pieces sit on each other like pancakes, or do some layers have bumps that need a spot carved out for them? Also curious how thick you make each one, since my machine seems happier with thin stuff.

One thing that helped me early on was going thin on the glue. I was slathering it on like a rookie and every joint showed a dark squeezed-out line that ruined the whole layered look. A notched plastic spreader fixed that, barely enough to wet the surface. I also leave each layer a good 1/16 oversized on the profile and let the flush trim bit clean it all up after the clamps come off, so the outer edge reads as one continuous piece instead of four stacked ones. Curious what you're using for the artwork side of it, I've been drawing everythign myself in vectors and it eats more time than the actual cutting does.

Update: finally ran number five through the stack and tried the notched spreader trick for the glue. Night and difference, no more dark lines showing up at the edges of the layers. I had been using way too much and just wiping the excess, wich clearly wasnt cutting it. Down to a thin wet coat now and the joints basicly disappear once the finish goes on. Wish I'd known that one on build one.