Introduction & Inspiration
New StudioRossi client calls out of the blue make for fun days. We received an inquiry from a young, newly engaged couple wondering if we could design and build a moon gate. We had a few quick questions.
- How big does this have to be? (Are you to be married under or in front of the gate?)
- What will happen to the gate after the ceremony (This dictates the materials to be used.)
They were set on a ring large enough to stand under. The ring would be used in a garden at a future house. We were hooked on the challenge!
A little research was needed regarding what a moon gate actually represented and from where they came. Wealthy chinese landowners built these circular gates as a sign of invitation to their homes. The British exported the architectural element to Bermuda in the 19th century and the gates eventually became a talisman to bring good luck to newlyweds.
Given the spiritual nature of the moon gate we decided to construct our clients’ gate from single, continuous bands of western red cedar. The continuous bands (instead of separate segments) approximate a wedding band, connote an unbroken vow and overall have a beautiful aesthetic. Exterior durability dictated the cedar. That said, how long a piece of cedar would we need? How long a piece could we source? How would we make a continuous circle?
A little high school geometry and trigonometry came in handy here.
Detailing & Geometry
We started with a few assumptions:
- Inner ring radius/diameter: 48”/96”
- Ring thickness 5.5”
- Outer ring radius/diameter: 53.5”/107”
- Ring depth: 6”
- This led us to an outer circumference of approximately 336”.π* 53.5^2=336.π
The limiting factor was we could only source western red cedar in 20’ (240”) maximum lengths! Hence the following math to determine if we could create sufficient headroom for the couple to stand under while exchanging vows.
We ended with a 76” outer height which gave us enough room after we factored in temporary stands to hold up the gate.
Next we asked ourselves, “How to build it?” Bent lamination of course. If you view the making of the StudioRossi Double Arch chair, the Ipswich Library table or the audio cabinet you’ll see we have done bent lamination before. The big difference? The scale!
We needed to bend 20’ long boards in an 8’ diameter. We did some rough testing and figured 1/4” thick x 6” wide x 20’ long boards or strips of cedar would make the bend. To build up to 5.5” of thickness we would need 22 individual strips bent and laminated together. Now it was time for some tools.
TOOLS & FORM
To create the 8’ diameter ring we made a custom 8’ diameter x 6” high form. It took a bit of work but here’s how it was built up.
- Seam up two 4’ x 8’ sheets of 3/4” plywood to create an 8’ x 8’ square.
- Set up a router on a 48” long trammel and cut a 48” radius/96” diameter circle.
- Build up the outer edge to a 6” height using 2” x 4” stock and routing each layer round using the previous layer as a template.
- Sand smooth and wrap with stretch plastic to prevent the ring from gluing itself to the form.
The internal flats on the segments will give good surfaces for clamps during the laminating process.
22, 1/4” thick x 6” wide x 20’ long strips had to be sawn. We sourced 8/4 x 6” x 20’ lengths of western red cedar from one of our favorite suppliers Keiver & Willard. . We moved our 24” bandsaw to have a minimum of 21 feet of working room both in front of and behind the blade, set the blade tension just right and started resawing.
After resawing all the timbers the 22, 1/4” strips had to be run through the planer to make sure all were exactly 1/4” thick and smooth on both faces for a good glue-up. Even though the cedar was kiln dried it contained a decent amount of moisture requiring us to stack, sticker and set up fans to blow dry the stock before glue-up.
Glue-ups of all types create stress. No one wants surprises when working with glue that has a 20-30 minute working time. Consequently, we always lay-out everything needed for the glue-up and perform a dry test run. Here we laid out all the clamps, clamping blocks etc required. We decided to add little registration shelves to the form’s underside allowing all the strips to align evenly with each other when bent around the form.
We rolled an entire gallon of glue on both sides of each strip, stacked them and carefully bent them around the form. Clamps were applied starting from the middle of the ring toward each end. This allowed the strips to slide past each other as they were wrapped around the form (remember the circumference the inner strip-circle is shorter than that of the outer but all the strips are of equal length). The old saying “woodworkers cannot have too many clamps” certainly applied to this project with almost 40 clamps in place
SHAPING & TESTING
Plane, Sand, Trim
The next day we removed the clamps to begin shaping the ring. We hand-planed the top surface smooth. We slid the ring free from the form (no sticking thanks to the plastic wrap!) and carefully fed through the 16” power planer to even both faces.
All the sides were sanded smooth to 220 grit and the edges were eased with a 3/8” radius. We then trimmed the ends and coated the bottoms with epoxy to provide a bit more weather proofing.
The client wanted a natural look to the moon gate so we did not coat the cedar with a finish allowing it to weather over time. In the end the strips came together beautifully. We crafted a temporary set of stands for the wedding.
The father-of-the-bride enlisted some friends to pick up the gate. They loaded it into his pick-up truck with big smiles on their faces. The whole piece will be decorated by the couple’s florist and then stored for a future garden installation.