laflippin wrote:I've been thinking about ways to get an outline around selected parts of inlay projects, including use of darkened glue or perhaps charring the male workpiece a little with a propane torch before gluing it up....if I ever figure out a good solution for what I' trying to do, I'll post it. I'm also eager to hear other members' thoughts on this type of problem, if it has ever come up before.
I have been thinking about this as well. I have had 2 thoughts (haven't tried either yet), and both use the Zank v-inlay technique :
1) Using epoxy, coat the sides of the female part until you get a good thickness (lets say 1 or 2mm), let it dry, and then machine away the epoxy (using an offset based on the original shape of the female part), leaving the thickness desired for the outline, and then insert your male piece. This sounds good in theory, and would work with larger parts, but I think once you get very fine pieces, you would have to recalculate to make up for the thickness of the added epoxy. The downside to this is you would likely want to leave the piece on your machine until the epoxy dries, since it is very unlikely you will get the piece lined up precisely, and if you are only leaving 1mm (or less), any discrepancies would be glaringly obvious. Quick dry epoxy is an option, but some of them cure pretty darn quick, so might not work.
2) I was also thinking about using pigments or dyes in the glue, but I wonder if those would effect the strength of the glue. Unlikely, due to the small amount of pigment required. If one were to go this route, it would probably be best to use "regular" (uncoloured) glue for the majority of the filling, and then paint on the glue for the areas it's required. It would probably be beneficial to use a shellac (or similar) to create a seal so you don't get paint bleed (from the pigments in the glue).
As an aside, I created a project that required 2 separate cutting paths, one with regular wood inlay, and then another to create the paths for epoxy. First I did the regular wood path, once that was completed (glue dried, milled/sanded flush with rest of the piece), I put the piece back on the machine. At the beginning, I created 2 reference points on the scrap part of the wood (and created a drill toothpath in Aspire for those points), and used a 30degree bit to make a shallow (1mm) hole, and recorded the exact values (I normally work in imperial, so I looked at the G-code to see where the center of the holes are (they are in metric), and recorded those exact values, and when I put the piece back onto the machine, I used those values to move the spindle over and used the 30degree bit to make sure they were lined up exactly, and adjusted the piece as required. One could also use the dowel method (as used for 2-sided machining, since its the same principle) to ensure proper alignment after the piece has been moved. After that, I did a second round of v-carving, this time to create the "trench" for the epoxy. I made it way too deep, thereby increasing the amount of epoxy, and also the cure time.
The maple leaf and sides are padauk, with main part being walnut. The epoxy and pigments (colouring and metallic) were all EcoPoxy (link
). The epoxy looks horrible because I ended up having to pour it 3(!!!) times to get it to be just proud of the surface. The epoxy is supposed to be a dark blue metallic effect, to really jazz up the design.
This one took a little bit of thinking, to come up with the best way to approach the cutting. I wanted to have clean perfect lines where the epoxy met the wood, so I was a little apprehensive about cutting into the areas that I shouldn't, if my alignment wasn't perfect. Thankfully, my initial planning (the 2 reference points marked onto wood) paid off, and the path that was cut was perfect: no extra wood to chisel out (which I had anticipated) or worse yet, I didn't cut into the areas that I shouldn't. I would really like to try these types of things on curved surfaces (think those wavy flags that people have been posting pictures of), but due to the nature of the Zank inlay technique, I can't see it working (the math/geometry would be crazy to calculate across a large, wavy piece), and it would be quite the challenge to pour the epoxy so it looks nice. You could do it in layers but that would take forever, and likely look horrible (or magnificent: it's art, baby!). I want to do a Punisher skull (picture below), in 3D, with the blue line done in epoxy as per the one posted above. I have an idea of how to accomplish that (since it's fairly simple, compared to a waving flag), and I'll post that if/when I get around to it.