One of the projects I’ve been meaning to make since I got the e-mail saying that my Glowforge would be delivered well before Christmas is a custom cha pan or tea tray for gung fu tea preparation for a friend’s Christmas present because, for some strange reason, she’s someone I’d expect to have one already but doesn’t actually have one. Here’s the end result. The tea steeping in the gaiwan is Teabook Mao Jian.
The top and front/back edges have a traditional sashiko embroidery pattern scored over them. Holes are cut out off the top for drainage, and there’s also a poem I wrote for her scored on to the top. The cut edges and the entire top were treated with cutting board oil so the scored pattern and the edges of the drainage holes don’t absorb water that’s poured on to it.
The entire thing (well, almost… scroll down for why) is made of 1/8 inch proofgrade cherry plywood. It holds weight surprisingly well; the prototype on draftboard held up 5 pounds distributed mostly in the center for a few hours without bending, and 1.5kg is basically the maximum expected load. Yes, I weighted all the teaware that would go on it. Yes, I added their volume in water converted to mass to it.
Oh, in case anyone needs it: the kerf setting I used for cutting proofgrade maple and cherry ply boxes is 0.006in. This entire box is held together without glue, and 0.006in is the largest kerf adjustment that doesn’t make putting joints together sound painful or, worse, break the veneer.
Originally, the text was going to be etched on to the top, but after etching it on draftboard I found that with this thing being constantly wet water would just pool in the unfinished etching and soak into the wood. Here’s a closer shot of the first line:
So you probably noticed in that closeup that the bottom of the tray seems… metallic. That’s the only part of this thing that isn’t laser cut or made of proofgrade wood…
The biggest challenge in making this thing isn’t the design or getting Inkscape to do three overlapping grids (two isometric and one rectangular) perfectly or figuring out how to get the Glowforge to etch Chinese calligraphy. It’s waterproofing the thing. A proper cha pan has a top with slits for drainage to pour water into, and the water would either go into a waterproof bamboo or wooden box that’s the base of the thing or, in more modern designs, a specially made plastic tray that collects the water.
I don’t have the ability to make a plastic tray and buying premade cha pan and cannibalizing the water tray would defeat the point of this project, and waterproofing a wooden box is really difficult. (If you dig through my post history here you’d probably notice that I spent a lot of time on researching this.) The only real way to waterproof a laser cut box seemed to be Flexseal, and it doesn’t seem to be perfect either.
So I cheated.
Yep, that’s a cake pan from Kroger.
There’s surprisingly little information on how to make a cha pan from the Internet. What I was able to find suggested using a rectangular flowerpot drip pan, but those things are very shallow and would spill out into the very not waterproof box when the thing is moved. The cake pan in contrast holds like 1.5L of water so even if you accidentally spilled all the tea it’d still be less than half full.
Of course you won’t spill all the tea. Because then you don’t get to drink it. I was actually kind of annoyed at my friend because her gaiwan technique is too good and she’s not making enough accidental spills to really stress test this thing.
Since the tray is not too large—the 7" by 11" cake pan is the biggest sized pan I could find that would allow me to make a tray around it using only two pieces of proofgrade plywood—I made her a set of matching coasters as well:
And while I’m posting pictures here’s one of the prototypes which is now my personal not-very-good cha pan. (Not very good because there are actually several issues with this one including kerf/fit on a couple of the pieces and the top not being completely secured on the box. But it is functional! The tea is Bitaco Cacao Kisses.)