After looking through some other blogs here on LJ and watching some Youtube videos I thought that the tumbling block cutting board was something that looked challenging, cool and something I wanted to try. I learned some good ideas from these other blogs and wanted to share some of my experiences having now made three of these, my setbacks and discoveries to better produce these tumbling block patterns.
I purchased a Wixey digital angle gauge as it looked like you really needed to be accurate with cutting. I first started off checking that my table saw blade was 90 degrees to the table with a machinist’s square. I then set the Wixey gauge to zero and then 30 degrees.
I made a 30 degree table sled to safely and accurately cut the wood strips. The jig first started off 30” long with 3 toggle hold down clamps…that would change as my procedures evolved. Once again, it is imperative that the sloped edge is exactly 30 degrees to the table.
After making the sled I tested it out on a small pieces and measured them and they looked great. I tested them further by cutting one long plank each of the 3 different woods (cherry, maple and black walnut) and checked how they fit together and it was a nice tight fit. I saved those test pieces and went out to buy enough of the 3 wood colors for a cutting board.
I then got in “production” mode to cut all of the blanks and got careless. The first thing I did was to thickness plane each plank to the same thickness, so I know they’ll all be consistent. I cut the blanks 30” long and I wasn’t paying too much attention to how the blank was seated in the sled. As a result of this, I wound up with pieces that weren’t all 30 degrees and they were basically firewood! You can see how they didn’t fit and I soon after determined that the blanks were not seated properly in the sled. I needed to move the clamp contact with the blank further away from the slope to put pressure straight down where the slope angle wouldn’t pinch and skew the blank away of 30 degree slope. By simply making that adjustment and by reducing the length of the jig to 20” with 2 toggle hold downs I was able to cut these accurately and repeatable for a larger quantity.
So with only 1 set of accurate cuts that I made for the test cuts, I redesigned the cutting board and made a coaster set until I came back from vacation and could buy more wood. I previously posted this project:
Now that I had the technique to accurately cut the blanks, I went out again to purchase more wood and I was ready to roll once again. As before, I thickness planed each plank to the same thickness, so they would all be consistent.
The cutting went well and I had 17 blanks of each wood color.
With all of the blanks cut I started checking the thickness measurements. In order to get perfect looking cubes, each side of the diamond shaped blanks had to be equal measurements. So with my digital calipers, I measured the various edges.
I noticed that there were some small variances on them. I numbered the edges so I could keep things straight as I started the sanding process of over 50 blanks. I setup my drum sander to get each plane thickness to be identical in length. Not only within each blank is this necessary to get the perfect 30 degree diamond shape, but for all of the blanks to be the same exact measurements to each other . It is important to run ALL of the pieces through the sander on the appropriately numbered edge BEFORE adjusting the drum sander thickness or switching to the other plane. (edge 1 and 3 are on the same plane the edge 2 and 4 are on the same plane) Again, consistency between each blank is critical for accurate fitting on later.
I then painstakingly taped each outside exposed edge with painters tape (2 out of the 4 sides) so that no glue would squeeze out onto them….that’s over 100 edges.
The reason for this was that I took such care to make sure each edge and plane was symmetrical in the diamond shape that I didn’t want to have to scrape or sand any glue that squeezed out during the clamping process onto a live edge which could slightly change those dimensions or angles when removing the glue.
After all of the blanks were taped on two sides I began the glueup process. I used Titebond III which seems to be the glue of choice here on LJ for cutting boards because of its waterproof properties. I used some thick rubber bands I bought at an office store to serve as clamps and provide even pressure all the way around the logs. I doubled up on each rubber band to make sure they were extra tight. This wound up working out great.
When the glue had dried I removed the glued up rubber bands and cleaned the bands up from the excess glue squeeze out that caked on them pretty good so I could use them again on the rest of log glueups. Removing the tape from the glued up logs revealed a very clean log ready to slice into cube looking pieces.
The first 30 degree rip cut you make on a starting plank of wood is basically scrap, because the initial edge is 90 degrees, but it does serve a purpose; that of an angled back support extension of my miter gauge. I didn’t take any live pictures of the slicing, but this after shot gives your the idea. I cut these on my bandsaw which has a smaller kerf than my table saw and I was concerned about getting the most pieces out of each log trying to make 3 complete cutting boards.
I also numbered each slice from each of the 17 logs, so if there were some color variations between the various pieces of wood within the same species, I could identify that and group them together to look visually appropriately.
After all of the slices were cut, I hand sanded each edge to remove the fuzzies and tearout from the cutting process. Do this lightly and only to remove the fuzzies, you don’t want to get aggressive with this and change the integrity of the angle or 90 degree edges. Once that was done, I had to tackle the actual board glueup.
On the first board, I wasn’t quite sure of the glueup method. Having some experience with intarsia, I used a similar type of procedure. I first dry fit the entire board, making sure the color variations were laid out in a sensible manner. I then taped the top side joints together to see how the fit was. It fit pretty good, but not dead on perfect.
So I started gluing the pieces from one corner gluing a few blocks at a time across until I had two full length rows. I noticed a slight bow to the initial two rows, but it wasn’t too major so I continued on.
I then used these first two rows as a clamp support to glue in more pieces at a time and rubber bands to hold down the last row.
I wound up using a clamp for each piece (I only have 6 of them) and once the glueup became larger than 12” I ran out of hand grip clamps to do the job, so I had to use very large Bessey clamps and/or oversized rubber bands I bought at a big box office store.
The problem with this method was that I didn’t use a straight or square reference for the first pieces and they were slightly off which exponentially increased with each successive layer. So, even though the initial first row was only off less than 1/16”, by the time all 8 rows in the height were glued up, they were off about 3/16”. Also because of this, some of the joints weren’t perfect due to the fact that the first row was out of perfect alignment and I took most of the pieces in the successive rows to my disk sander on my sanding station and changing the angles slightly to fit piece by piece…this was painful and unnecessary looking back at it. The alignment issue became apparent when I cut the board to a rectangle and the pattern which should have been parallel and perpendicular along with the tumbling block pattern, but it had deviated about 3/16” over the 13” or so height of the rectangle. The board also had some small gaps that I filled up with glue. Filling those and sanding them down was also very time consuming. This method also required a lot of clamps and I could only glue up 6 pieces at at time which took a lot of time.
Still being said, the board looked great, the average person looking at it wouldn’t have even noticed these issues, but I strive for perfection and I had some ideas after board #1 glueup which I’ll describe below after I walkthrough completing this first board.
I purchased a magnificent piece of Cocobolo to use for the border/gravy moat. It was 12×24×1.75. It was about an inch too short in the 24” to use solid bordered pieces and miter them together…a big mistake. So I wound up cutting the Cocobolo into small blocks to emulate the width of the cubes in the tumbling block pattern design. I also kept the end grain orientation on the borders pieces as well. I glued those up into 4 strips, mitered them to a perfect fit and then glued them to the board. I did wipe down each Cocobolo glued edge with acetone as I read it helped to create a better glue bond with the oily characteristics of Cocobolo.
I didn’t take any pictures of milling the borders, but here’s what I did and why. I fully intend on using this any other cutting board I make and I don’t understand why people would want a board without a gravy moat…cutting any meats/poultries on it would make a huge mess otherwise.
I built a set of plywood guides (both the inner perimeter and outer perimeter leaving a .75” gap for the router bit) to router out the gravy moat accurately with a dish carving bit. I attached the inner perimeter guide to the cutting board with double sided tape. I built up with some scraps on an outer shelf equal to the exact height of the cutting board to act as a support extension around the outer perimeter of the cutting board to then attach the outer perimeter router guide pieces of scrap wood. If I didn’t do this I would only have about .375” to attach the outer perimeter guide onto the board and it would failed and moved.
I then routered out some finger holds on each side border with the same dish carving bit. I had to be careful to establish a safe depth of cut not to break through the gravy moat which was .25” deep. I then knocked off all of the hard edges with a standard roundover bit. I sanded up to 220 being sure to not close up the end grain pores going finer. I wiped on quite a few coats of mineral oil and then attached some rubber feet with some stainless steel screws and I was prepared for the big Thanksgiving meal.
After cutting 40 lbs. of turkey and 12 lbs of tenderloin over an hour and 15 minutes, I gave this board a thorough workout and it was soaked corner to corner and all through the moat. You can see the after shot when all of the carving was complete.
I soonafter began to notice that Cocobolo border was cracking in several of the joints where glued to each other…not where glued to the tumbling block rectangle.
Unfortunately, to save the board I cut off the borders and substituted a solid walnut border. I milled it in the same manner as before with the gravy moat, finger holds and eased edges and I also added a multi-laminated spline using my new spline cutting jig.
I still have to test the new border with a thorough soaking of meat juices. After I do this, I’ll follow up to this blog.
Nevertheless, after the first board glueups, I want to make sure I walk through the better method I developed while going up the learning curve. I didn’t take any pictures while doing this live, but I did take some shots with some scrap leftovers to illustrate the technique. I was able to keep the deviation to about a 1/32” over the 13” height, which I’m very happy about.
The key here is to start off with a perfect straight edge to clamp against on two sides and clamp an entire row at a time. The initial row is of course the most important to setup correctly. Once that is done accurately, the successive rows just kind of fit into place like a puzzle…in other words, you don’t have to do that much extra work if it starts off accurate in the initial row.
When clamping the initial row between the two straight edges I used 3 Bessey clamps being sure to evenly apply the clamping pressure and used straight edge materials where the Titebond III glue wouldn’t stick to. You want the pressure enough to cause the glue to squeeze out, but not too tight to bow up the pieces. I also used a hand squeeze clamp to apply slight pressure across the row. It is important not to make this clamp too tight in that excessive pressure could buckle the row upwards in the z axis. The pieces need to stay flat on the bottom surface. I also put a sheet of wax paper underneath the glueup for easy removal between layers. Of note here was I only needed the same 4 clamps to glue up the entire board, not the mess of clamps used with my initial method. The clamps also stayed in the exact same position, only opening up larger to accommodate each new row.
Also a very important detail is to carefully and fully scrape out the glue squeeze out in all of the joints in one row before laying in the next row. If any dried up glue is leftover in the exposed joint, it could affect the accuracy of the next piece to fit into that space. I happened to have a 30 degree angled insert that fit into my scraper and I also use a flat edge scraper to accomplish this.
I hope this helps take out some of the mystery of how to make these tumbling block boards. I learned a lot in making these three boards and hopefully I can have success with the borders. I know that the wood moves when taking on moisture and getting thoroughly soaked after usage, but I still like the idea of a separate looking border/gravy moat. If this proves to be a problem on my fix, my future cutting boards will just be larger in both dimensions with the block pattern and I’ll skip the different border altogether and just rout a moat in through the block pattern itself.
A few more of the finished pictures are on my project page:
Thanks for making it through this long winded blog and I hope this inspires others to give it a try!
-- ---Joel; Central MD...rookie empter nester and getting back into woodworking!