Q: Is it fun making sheet metal ducks?
A: Fun is a relative term don’t you know…Creating razor sharp three dimensional useful items out of a single dimensional sheet of metal sounds like fun, doesn’t it? Actually, it can be extremely rewarding but you have to put up with the uncertain period of utter frustration. To be honest there are many in our field that take to fabrication like ducts to water. A person’s ability to formulate in one’s mind what the basic shape and size will be and translate that to the individual metal shapes requires “conceptualization” (and skill really, really helps). It is one thing to have the knowledge to properly size ducting, then you need to accurately measure for the application, and then conjure up angles; acute, obtuse, and otherwise, to bring form to something so cold and flat. We have an apprentice that is currently working out all the above details and wondering when the fun part starts. Honestly, he does enjoy it despite the moments of bloodletting and pulverizing your fingers between metal and hammer. This learned trade of sheet metal fabrication has been around for a least a couple of centuries. Going back further, some of the earliest depictions of an actual “rolling mill” used to manufacture sheets were drawn by Leonardo Devinci himself. I would like to think right after he painted the Mona Lisa, finished the last supper, then went out to his sheet metal shop to build some absolutely fantastic fittings. Perhaps someday they will be discovered and Leonardo will finally be recognized for the genius he was. Boiling down the process of sheet metal fabrication will have one quickly noticing it’s a lot like connecting the dots. Transferring your field measurements to the sheet of metal, these numerous points required for each side of a fitting must be accurate or the whole thing is headed for the scrap pile. Given correct points the patterns are created and the cutting can commence. Using specific tools for this purpose increases accuracy and makes the whole thing closer to being “fun.” Shear, slice and nip to your hearts delight just keep your blood where it belongs. Beautiful pieces on the layout table are still a long way from three dimensions and lest we not forget to mark one as to its side, front, back, top or bottom. “Breaking” the individual pieces requires the final visualization of how each piece connects to the other. Countless fittings end up inside out and upside down from rushing to the finish line. Patience prevails (but time is money) as an incorrectly bent side will often have to be re-made wasting time (and money). The moment of truth occurs when the parts are formed and ready for assembly. Will it indeed even remotely resemble what you had envisioned? Careful coaching with your sheet metal hammer closes the seams, and for goodness sake, NO DENTS (what would Leonardo say). And there it is, an offset transition, center lined front to back, hem flanged, and hammer locked, Leonardo would certainly have been impressed. However romantic sheet metal fabrication sounds, this skill is being replaced by computers and plasma cutters that will have most of this knowledge going the way of the dinosaurs. Even the need for such products is fading due to the technological advancements such as ductless heat pumps. So it goes, but there is still no better way to give blood besides the American Red Cross.
