Building the blank
Started making the pieces for another cholla bowl this morning, and figured there's been enough interest in what I've done that I should write it up.
The first step is building a base on a faceplate for my lathe. I've been aiming at bowls that are 6-10 inches in diameter, so I generally put a pine 1Ă—6 on the faceplate, and then put a couple pieces of 1Ă—6 across that to get up to the size I want.
Then I cut it round-ish on the bandsaw, and turn it round (and about 10 inches in diameter) on the lathe.
I stick blue tape on the joints. That helps keep the epoxy from running through the joints and making a mess in my shop.
Next, I stick a piece of blue tape around the edge of the base. Just one or two turns, but I try to stick it to the edge of the base as best I can. I'm going to be pouring epoxy into this and I don't want a leak.
I should note that I've already cleaned the cholla. If there's any material in the middle of a piece, I poke it out with a long screwdriver.
Next is putting in the cholla. In my first two bowls, I stood pieces of cholla on end. This time I'm going to try laying them circumferentially.
If the pieces go a little beyond the tape, that's ok. And if there are gaps, I plan to fill them with the next layer. So now it's time to mix up some epoxy. 50ml of System 3 Fast Hardener, 100ml of System 3 General Purpose Resin, and 22 drops of TransTint Aqua for the first pour. That makes a fairly pale almost sky blue.
Second pour is another 150ml of epoxy (5 oz), this time with about 35 drops of Aqua, and 5 drops of TransTint Lemon Yellow. Definitely green, but I think still thin enough that it'll let light through. I pour this aiming to hit areas that didn't get any epoxy in the first pour (cholla will form dams) and I concentrated on pouring over pieces of cholla that looked dry inside. I also stuck in a few more pieces of cholla (small broken chunks) to fill any small gaps that looked wrong to me.
At this point, there are still a few spots where I can see the dry pine base. But after this epoxy cures overnight, I'll put on another few wraps of tape, building the sides up to 1.5 to 2 inches high, lay in more cholla, and then pour the next two colors of epoxy. I'll probably set the base slightly off-level so that the epoxy pools more on one side. I'm guessing I'll have a total of four pours of two colors of epoxy (they mix a little, but the cholla will segregate the colors a bit, plus the first of two pours starts to harden before I get the second poured), and I'm leaning towards red and violet tints for the next batch.
Started making the pieces for another cholla bowl this morning, and figured there's been enough interest in what I've done that I should write it up.
The first step is building a base on a faceplate for my lathe. I've been aiming at bowls that are 6-10 inches in diameter, so I generally put a pine 1Ă—6 on the faceplate, and then put a couple pieces of 1Ă—6 across that to get up to the size I want.
Then I cut it round-ish on the bandsaw, and turn it round (and about 10 inches in diameter) on the lathe.
I stick blue tape on the joints. That helps keep the epoxy from running through the joints and making a mess in my shop.
Next, I stick a piece of blue tape around the edge of the base. Just one or two turns, but I try to stick it to the edge of the base as best I can. I'm going to be pouring epoxy into this and I don't want a leak.
I should note that I've already cleaned the cholla. If there's any material in the middle of a piece, I poke it out with a long screwdriver.
Next is putting in the cholla. In my first two bowls, I stood pieces of cholla on end. This time I'm going to try laying them circumferentially.
If the pieces go a little beyond the tape, that's ok. And if there are gaps, I plan to fill them with the next layer. So now it's time to mix up some epoxy. 50ml of System 3 Fast Hardener, 100ml of System 3 General Purpose Resin, and 22 drops of TransTint Aqua for the first pour. That makes a fairly pale almost sky blue.
Second pour is another 150ml of epoxy (5 oz), this time with about 35 drops of Aqua, and 5 drops of TransTint Lemon Yellow. Definitely green, but I think still thin enough that it'll let light through. I pour this aiming to hit areas that didn't get any epoxy in the first pour (cholla will form dams) and I concentrated on pouring over pieces of cholla that looked dry inside. I also stuck in a few more pieces of cholla (small broken chunks) to fill any small gaps that looked wrong to me.
At this point, there are still a few spots where I can see the dry pine base. But after this epoxy cures overnight, I'll put on another few wraps of tape, building the sides up to 1.5 to 2 inches high, lay in more cholla, and then pour the next two colors of epoxy. I'll probably set the base slightly off-level so that the epoxy pools more on one side. I'm guessing I'll have a total of four pours of two colors of epoxy (they mix a little, but the cholla will segregate the colors a bit, plus the first of two pours starts to harden before I get the second poured), and I'm leaning towards red and violet tints for the next batch.