Tag Archives: TIG

Top of the cart

La Boheme Crepe Cart

Today I thought I would go retro and show you a cart I built back in 2007. La Boheme at the Santa Fe Opera required a whole bunch of push carts during the outdoor scenes, so the other prop carpenter and I set to work constructing them.

Drafting for "La Boheme" crepe cart
Drafting for "La Boheme" crepe cart

The first one I built was a crepe cart. The structure was simple enough, but the wheels were all custom-sized, so the first thing I had to do was fabricate the wheels and the axle system.

Closeup of wheel
Closeup of wheel

I built the wheels out of metal because the diameter of the spokes and the rim in the drawing was small enough that I was afraid wood might not be strong enough. I TIG welded the rods to the hub to keep the welds as visually-unobtrusive as possible. The rim of the wheel was a length of bar stock bent into a circle and welded together. It also had a strip of rubber glued along the outside to cut down on noise and keep it from tearing up the stage floor.

Jig for positioning front wheel
Jig for positioning front wheel

The front wheel stuck way out to the front of the cart. I first assembled a jig to hold it in position. I then cut the four bars that held it in place and welded them to the axle while the wheel was in position. This ensured that the wheel was centered, at the correct height, and completely parallel with the direction the cart traveled. I thought I was very clever until it came time to remove the jig and I realized I had built the cart around it; I had to cut the jig apart to get it off.

Bottom of the cart
Bottom of the cart

Above is a picture showing the bottom of the cart with the front wheel in place and the axles for the back wheels. If you look close, you can see the back axle is actually separated in the middle; when the cart is turned, the wheel on the inside of the turn spins more slowly than the one on the outside, so they need to be able to spin independently of each other.

Adding the decorative hub
Adding the decorative hub

I added a circle of wood and a decorative rosette we had in stock to cap off the hub.

Top of the cart
Top of the cart

The top of the cart was pretty straightforward; it consisted of a plywood box, a thick “counter”, two handles I shaped out of solid alder, and a metal box to serve as the oven. There was also a braking system to lock the wheels in place to keep the cart from rolling into the audience when the artist walked away, but that is a post for another day (In opera, the singers are called “artists”, rather than “actors” or “singers”).

Finished cart prior to painting
Finished cart prior to painting

A number of accouterments completed the look. A box with a hinged lid was placed on front for artists to take crepes from. I welded a tube in position to hold an umbrella at a jaunty angle; the umbrella needed to be removable to facillitate storage backstage. Finally, I placed some molding around the edges to match what was in the drawing.

Crepe cart from "La Boheme"
Crepe cart from "La Boheme"

Here is the final cart after the paint shop finished with it and the props master dressed it. Bon appétit!

The finished headboard

Steel Headboard for “In the Wake”

The next play to open here at the Public Theater is “In the Wake”, by Lisa Kron. One of the props they needed was a headboard. The design was based off of an existing style of headboard, but as the bed was a custom size to allow it to fit between the scenery, the headboard would also need to be a custom size. In addition, the bed moved to the middle of the stage where the headboard would be freestanding, and I was told the actresses would be leaning against it. For those reasons, a store-bought headboard would not fit the requirements. It had to be built, and it had to be built out of steel.

Since the design of the headboard was based around a repetitive pattern, the first thing I did was break it apart to make a cut list. I divided the pieces so the cut list would be as straight forward as possible, with as few angles as I could get away with. I managed to come up with a way where most of the pieces were straight cuts, and only a third of the pieces would need 45 degree angle cuts.

All of the pieces of steel
All of the pieces of steel

Before I could begin welding, I needed to create a jig. As you may already know, a jig is a device to maintain the spatial relationships between your materials, or between your tool and the materials. In this case, I wanted a jig that would allow me to lay my pieces of steel down in a consistent pattern while welding them together.

A jig for my headboard
A jig for my headboard

I thought I was being clever by making only one section of the jig. The idea was that it would keep everything consistent. In hindsight, I should have made a jig of the entire piece. Then I could have dry-fit all the steel before welding it together, and adjusted the pieces individually to ensure they all fit. The way I did it, the piece as a whole ended up just slightly “off”, with the minute inconsistencies in my jig being amplified through repetition. Even someone as talented as me can still have learning lessons.

As you can see in the following photograph, I had to clamp it to make it fit even after adding just a few pieces.

Overcoming the problems with the jig
Overcoming the problems with the jig

I decided to TIG weld this project. In theatre, the majority of welding we do is MIG welding steel. TIG welding is useful if you need to weld stainless steel, aluminum, brass, or if you need to weld two different kinds of metal together. In this case, I was TIG welding regular steel; even though it takes a lot longer, I could weld with little to no filler rod, which left me with very clean welds, and no spatter. I felt it was important for this piece since the cleanliness of the lines was an important part of the design. Plus, I wanted to brush up on my TIG welding skills.

A close up of the welds
A closeup of the welds

Even though I had TIG welded before, I still learned some new things about it. For one, the difference between using Argon and using an Argon/Carbon Dioxide mix is astounding. If you aren’t using pure Argon, you can literally watch impurities form on your tungsten electrode while you weld. Another tip I learned was that it is important to grind your electrode parallel to its direction, as opposed to in circles. TIG welding is so precise and exacting that little piddling tips like these really go a long way. Its actually a very Zen way to weld, if you have the time.

The mostly completed headboard
The mostly completed headboard

Once all the pieces were in place, my next step was to add Bondo to smooth over all the welds and fill all the holes. Bondo will cause nerve damage over time, so you must work with adequate ventilation and wear a respirator with cartridges that filter organic vapors. You should also wear gloves and sleeves to keep it off your skin, as it is a skin sensitizer as well. Remember that even after it hardens, you still need protective equipment while sanding it, as you release dust and fumes that can still harm you. With the proper safety precautions, Bondo is an incredibly versatile material for many projects.

Filled and sanded
Filled and sanded

After I sanded it all down, all that was left was to attach it to the bed, prime it, and paint it.

The finished headboard
The finished headboard