Introduction: Sutro Tower Coat Rack Process From Manufacturing to Delivery
Finally, a place to put all your layers. From coats, to hoodies, to scarves, to bags, and umbrellas, this rack can hold it all. Our love of Sutro Tower's minimal lines inspired us to create a beautiful art piece that also functions to declutter your environment. Drawing from Sutro Tower's actual architecture we designed a highly stable yet elegant form that serves as a backbone for a modular storage rack system.
The rack has been very thoughtfully designed to create as little waste as possible and to utilize sustainable materials. Inspired by the strength and durability of a laminated skateboard deck, the rack’s legs are created from laminated pressed bamboo. The metal wireframe supports utilize bent steel rod. This creates an strong, yet lightweight piece that is easy and cost efficient to pack and ship.
Step 1: Pressing the Bamboo Legs With 10k Lbs!!!
Bamboo is a great material for bending as it naturally is already very flexible and incredibly strong. Most other types of woods can not bend as easily and still stay in one piece. I did a ton of research online to figure out the best way to bend bamboo with the tools I had available. I ended up deciding to use a 10,000 pound press over any other method utilizing positive and negative molds made from inexpensive wood. This by far was the best solution where I could control the bend of the wood to exact tolerances every time.
So I went to my local Bamboo supplier PlyBOO (http://www.plyboo.com/) and bought some Saharad Stranded Bamboo Ply in 1/4" thick sheets. I then tried various methods of construction from simply bonding large sheets to bonding thinner strips. I found the best method for my project was to cut out the stirps of wood to just a 1/4" wider than the final leg. This way I reduce waste incredibly and it also made it very simple to run a edge router along the piece for finishing. Once I had these strips of bamboo cut out I layered them in a 4 ply stack up with a special glue from West System called Gflex. This epoxy was great as it still allowed for the bamboo to have some natural flex and expansion over time. I applied the glue over the ply and then layered the plys as even as possible. Once they were stacked I placed them into my home-made mold there I created a negitive and positive shape on both ends of the press. I did try various methods from just cutting out huge pieces of wood to thinner ribs as you see here in the photos. I found that the ribs worked fairly well and actually prevented any shifting /sliding of the piece.. The big plus was I was also able to press multiple legs in one go.
Once I had the legs pressed and cured I went ahead and started the finishing process. I used some simple powered hand tools like a router, and sander to get the roughed out shape. Once I had the rough shape I went through and removed any imperfections by hand with several different grits of sandpaper from 80-200. When the sanding was all done I moved onto either putting them into the RAW pile or the pile for Carbonization.
Step 2: Bamboo Carbonization + Finishes
To get that rich Walnut color with Bamboo I discovered the best way was to do this through carbonization. For those who don't know (I didn't know) carbonizing bamboo is the process of caramelizing the sugars in the bamboo to get various effects of wood stain like appearances. This was the best was and easiest way to color the bamboo in various colors as traditional wood stains really won't take evenly in bamboo.
I constructed various homemade ovens until I landed on just using a standup oven where I can throw all of the legs pieces in there for about 3 hours for the Walnut color. If I wanted to do a black color I basically just burn the sugars by leaving it in the oven for about 4 hours at 250 degrees. I played around with high temperatures up to 400 degrees but found it quickly melted the glue and separated the legs while having little effect on the color itself.. I ended up doing some legs at the TechShop where they have a very large Standup oven, but it was hard to keep the temperature consistent because everytime you opened the door you would loose 60-100 degrees.
I ended up offering 4 colors where I just kept the RAW bamboo raw and used some Boiled Linseed oil and experimented with some Tung oil. I found the Linseed Oil gave a nice satin sheen to the finish and I quite liked the natural aroma it offered as well.
Step 3: Creating the Steel Rungs for the Legs
This process was quite difficult to get done correctly. I had to bend Stainless Steel rod into exact triangular shapes then weld mounting tabs at specific angles so the whole rack assembled perfectly. Using rod benders, vices, and brute force I was able to pull off some beautiful triangular shapes inspired by the rungs of Sutro Tower itself.
To create a butt joint of the rods I filled a grove on either ends of the rod hoping that would help reduce the amount of welded metal on the outside of the rod i would ultimately have to grind off. It worked out really well and I was able to make some virtually seamless looking pieces.. I also powered coated the stainless in a variety of colors, and did a few home plating with copper per customer requests. The copper plating was a tone of fun as you can get everything you need from homedepot and online. We used Muriatic acid found at most hardware stores, copper anode, and a cheap power supply found on Amazon(https://www.amazon.com/gp/product/B000CSQK5E/ref=oh_aui_search_detailpage?ie=UTF8&psc=1), and a copper wire spool also found on amazon. after about 10-20 mintues the copper came out beautifully.. It definitely helped to thoroughly degrees the pieces and also the polish of the piece will reflect how well it shines.
Step 4: Creating the Metal Mesh Shelves
Creating the metal mesh was not exactly that easy so I had to get outside help on this one, but we used a laser cutter and I was shown the process on how to setup my files from CAD to be cut on the machine. It was very expensive to do this and we virtually sell this with zero profit. However we loved them so much we did make a small run of these for customers. I powder coated them myself and assembled the bamboo rails using the same West System Gflex epoxy along with 3 tiny little set screws for each bamboo edge rail.
Step 5: Final Assembly and Delivery!
After everything is properly finished we take the legs and the metal frames and simply use a cheap hand held battery powered screwdriver to thread in the allen key button head bolts. We use the cheap screwdriver because of its low speed and size making it very quick to assemble without over tightening the hardware. Once we had them ready to go we either hand delivered the racks or shipped them to happy customers. Our racks can be seen in furniture stores like Zinc Details of SF, used a display racks for RickShaw Bagworks in SF, and in the homes of Sutro Tower Fans all over the nation. It was a very rewarding process and now with only a handful left of the 115 rack we made this piece may be produced again, but for now we like that it is a timeless limited edition.