Quite awhile ago SPALM posted his project for a 3D cutting board: http://lumberjocks.com/SPalm/blog/17488 the more I followed his progress the more I wanted to build one myself and thanks to SPALM’s ripping jig and his idea I began building. Along the way I found myself in need of various clamping jigs that would make this project as easy and as accurate as possible.
The journey begins:
I built the ripping jig that Spalm built and ripped my stock with the blade set at 30 deg. using scrap stock and creeping up on the width until I had tight joints in the center of the triangle as SPALM recommends.
Once I had the ripping sled adjusted I cut the strips:
Once I had ripped all the stock (MAPEL, Chery, & WALNUT) I tried to figure how I was going to clamp them in order to get the triangle with tight fitting joints. I started with MDF and built two cawls out of laminated MDF and cut them at 30 deg. I covered a base plate and the cawls with heavy duty packing tape and then attached one cawl to the base plate with course wood screws, the other cawl will float so to speak. Once the clamping jig was built I arranged the strips in the pattern laid out by SPALM. I then taped all edges not receiving glue, applied glue with an ink roller and clamped the assembly in the jig.
Once the triangle stock was cured I cross cut the stock to the desired thickness and arranged the triangles into their correct order. I cant stress enough you must label all the pieces so you can keep them in their correct position in order to see the 3D effect.
Once I had all the pieces laid out I started working on ideas for gluing the pieces together that would be manageable and I came across CALGARYGEOFF’s version of this board and he had the solution for clamping the triangles: http://lumberjocks.com/projects/54280 With Geoff’s design I built two with minor modifications. I used 2 bolts per triangle base and I used a straight edge along one edge and only used bolts, “T” nuts and thread protectors along one side. I also added flexible cutting mat under the triangles and 3/8” cutting board material between the bolts and the triangles and I taped all triangle areas that I didn’t want glue on with blue painters tape.
Before glue up I dry fit all the pieces and any that didn’t have tight joints I sanded on a belt sander belt cut and adhered to a piece of MDF to insure a flat surface. I then glued all pieces and clamped and allowed to cure. Because of the short open time for TIGHTBOND III, I found that TIGHTBOND II EXTEND gave me the open time I needed to apply glue, assemble and get into the jig without the glue skinning before clamping. TIGHTBOND II EXTEND is FDA approved for indirect food contact but you wont find it on the bottle or their website, I had to call them and ask. You only need light to moderate clamping pressure. If you can’t close any gaps then you need to sand the mating faces more. I had 8 sections to glue.
Once all the pieces were cured I then placed them in correct order and checked for gaps and lightly flat sanded on the MDF & sand paper board. Once I had tight joints and checked all the intersecting angles I built a large clamping board using two pieces of MDF 3/4” X 24” X 24”. I then applied heavy duty packing tape to the top surface I then attached a large straight edge to one edge with bolts & “T” nuts, again heavy duty packing tape was applied. I then attached another straight edge the same way but this one has “T” nuts and bolts and nylon acorn nuts to act as clamps. Under the 8 board sections I laid down a fabric cutting mat of which glue wont stick to this either and added a 3/8” piece of plastic cutting board material to act as a cawl between the acorn nuts and the board sections to prevent denting the sections.
I also constructed a vertical clamping jig in order to insure a flat glue up. I made it with UNI-STRUT, bolts, “T” nuts, nylon acorn nuts and wooden blocks that hold the “T” nuts. This is attached through dog holes in my work bench that way it won’t have a warping effect on the board clamping jig.
Again as long as you ensure you have tight joints you only need light to moderate clamping pressure.
After the board is cured it’s off to the drum sander then the RO sander and finish. I’ll post pics once it’s sanded and oiled.
I owe a debt of Gratitude to SPALM & CALGARYGEOFF for their ideas, designs and willingness to share. Without them I would not have been able to build this project. THANKS GUYS!
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