Tap, Track, Eyelet, Weld

Gary Plant Tubular Steel Corporation - photo by M. Marshall

My sculptures will be a permanent integrated part of the reading terrace fence at the ElectraC. Doren library. But how to integrate them?

Beyond the practical aspect, ensuring that the attachment is secure, I had two additional goals: aesthetics and reuse.

Aesthetics: My design is to replace the section of fence railings between posts with my sculptural metal panels. The pieces will be permanently integrated into the fencing supports as part of the fence, not as an attachment or overlay. This is done so that sunlight will puncture through the cutouts giving them shape and background without the added patterns of vertical fence railings confusing the image.

Reuse: I wanted to make the panel attachments something that would not stand in the way of future use. Twenty years from now when the library reading terrace gets remodeled I want the library to have the option to take the sculptures out of the fence and attach them to a window to let light through, to a wall, or to mount in some other free-standing place.

My thoughts were to use attachment methods I had used in the past. I suggested screw taps, slotted tracks, or even eyelets that could act as a locking hook mechanism. All of these could be anticipated in the design and built into the sculpture itself as an integral part of the metal during fabrication.

At the time of the proposal I did not know the actual fencing and post support system that will be used. I planned to work with the architects and the fence fabricators to determine the best way to install the sculptural panels. And I needed to resolve this before the panels were designed because the attachment method might impact the visible area of the panel, or what structural shapes I could do or not do.

After discussing these options with the architects and fence fabricators they had two different and insightful concerns: safety and resistance to tampering.

Safety: To ensure that the attachment mechanism will hold up to extended normal use the fabricator suggested welding the panels into the fence instead of an attachment mechanism that can be undone. This would still meet my aesthetic goals because we can place the railing mountings and secure the welding inside the fence components where it can't be seen. It makes reuse somewhat more difficult. Twenty years from now the library will only have to disassemble the fence and cut it at the welds which won't interfere with the sculpture itself, and they may not even need to do that if the welded components can be part of the new installation.

Resistance: I had thought about making the metal I used unattractive to those who may want to steal it for scrap metal; that's why I thought of steel and now of aluminum. But I didn't think about making the attachment mechanism undesirable to deal with. By welding the sculpture in place it makes it more trouble than it is worth to remove the sculpture. If someone could inspect the fence and see screw taps they might invest the time to try to remove it, but if they see welds they'll know that it will take a lot more work to remove.

So welds it is. Welds meets my goals and the goals of my project partners. 

Decision factors for switching metal for sculptures

When the metal fabricators for my sculpture suggested switching to aluminum from steel, and from laser-cut to water-cut, I had several questions. I needed to research these things to find the switch acceptable. I’m familiar with molten aluminum from casting sculptures but I've never worked with sheet aluminum. I'm sure more questions will come up as we proceed but here's what I started with:

• Why are the fabricators suggesting a thicker aluminum (1/4 inch) instead of thinner steel (1/8 inch)? In what ways is 1/4 inch aluminum equivalent to 1/8 inch steel?

• What is a comparison of aluminum and steel on durability, strength, and impact resistance?
• Does the fabricator have example photos of their previous cut sheet aluminum at this thickness that I can compare to steel?

• I'm familiar with laser cut metal, but what kind of edge does water cutting aluminum leave? Are there any burrs on the far side? How clean is the cut edge?

• I know cast aluminum has fracturing issues especially when thin. I’d like to know if there are any restrictions on how small an area of aluminum I can put in my design without risking fracturing under normally expected impacts. I’d also like to know if directionality of the shapes is an important factor at all with respect to fracturing.

• Does the fracturing of aluminum change with age and exposure to weather?
• What are the different possible surface finished for sheet aluminum? Smooth, brushed, etc.

• What is the comparable cost of a sheet of aluminum and a sheet of steel?
• Related to cost is it attractive for people to steal aluminum? Will the switch to aluminum make it more likely that someone would steal the sculpture for scrap metal?
• Attachment method: If we switch to aluminum what attachment methods can be used and what can't be used?

• Are there aluminum alloys that are better for outdoor use like there are with steel?

• I want to see and touch a sample of the sheet aluminum in the thickness proposed. I want to take this sample with me. I need that tangible object to help me imagine what the final piece will look like. I'd like to cut a mockup of a portion of my design in the proposed metal.

• How does the aluminum age? What will the surface look like over time? What coating we can put on the aluminum?

• What maintenance is required for the aluminum especially if it is not coated or colored?

Shifting from Steel to Aluminum

Crucible_steel_button By Jlahorn

I chose to use steel for my sculptures for the Electra C. Doren library. But now they will be made from aluminum. Here's how I got there:

Aluminium_bar_surface_etched - by Heinrich Pniok  

I had two concerns and two goals when picking the metal. The concerns were theft, and the cost/size tradeoff. The goals were aesthetics and relevance.

Theft: Since this is an outdoor sculpture I didn't want to create a sculpture that was attractive to theft. The panels are big (about 2 feet by 4 feet) but not so big that their size would deter theft. At that size they look cartable (if you could get them out of the fence). So I didn't want to use copper, bronze, or brass since I was concerned that the value of those metals would be an invitation to theft. If I use steel, and leave it unpainted, it looks unattractive to steal. It's not worth the effort to steal it for scrap metal.

Cost / size tradeoff: The Dayton Metro Library set a budget for this project in the ReImagining Works initiative. As I chose metals I knew that the base costs are widely different. As the cost of the metal choice goes up the number of panels or the panel sizes I could create would go down. I felt that there needed to be a significant number of sculptures to complement the size of the reading terrace. I thought that one panel out of an expensive metal would not be sufficient - better to have more panels of a less-expensive metal.

Aesthetics: I wanted to use a metal that would look appropriate for the setting and steal would work well with the earthy-colored pavers, red brick of the library, and a dark colored fence. It would age well starting off bright and patina over time to a strong warm color. Plus it would not take much maintenance other than soft cleaning.

Relevance: Steel fits in with Dayton's manufacturing history perfectly. And it worked with the industrial theme of the Sheeler painting I used as inspiration.

However, in working with the Dayton Metro Library, their architects, construction company, fence installer, and fence fabricator an overriding concern became obvious. The library would get a 30-year warranty for the fence from their fence fabricator if that company was the one who fabricated and integrated my sculptures into the fence. I couldn't easily match that using my fabricator and negotiate a similar warranty with the other companies to join in a warranty - not in the time or budget allocated to me. As long as I could have artistic control and quality assurance on the fabrication it was the better decision to go with their fabricator.

Somewhere along the way as part of design changes the fence went from being a steel fence to being an aluminum fence. Plus when we considered how the panels would be attached we settled on welding. Since we're welding we didn't want to be joining dissimilar metals by welding a steel sculpture into an aluminum fence. When two dissimilar metals are connected they create an electro-chemical reaction which causes one of the metals to corrode faster. Steel and aluminum in combination outdoors are highly prone to corrosion.

So given the concerns about corrosion of dissimilar metals and the 30 year warranty we switched to making the panels out of aluminum. We lost the strong relevance to Dayton but aesthetically I've looked at the aluminum and, depending upon the finish that we use, it should be aesthetically pleasing. Cost and size still have to be worked out but they should be close. And aluminum will be no more tempting to steal than steel.