SNIPS Industry Icon David Daw reviews the developments of the HVAC Sheet Metal Industry in the 1970s – including the transition from sheet stock to coil.

Saving labor was a priority in the 1970s as much it is today. One of the biggest developments in the ‘70s (and ‘80s) came from transitioning away from fabricating rectangular sheet metal duct “straights” using galvanized sheet stock, instead using12,000 pound, 48” and 60” coils. Using sheet stock required the worker to hand cut each blank and walk around the shop to hand fabricate each piece using machines to “cross break” the duct; form the longitudinal seams (snap-lock and Pittsburgh); and prepare the end, or make, transverse connection(s) that were either specified or the “shop standard.” It was a very labor intensive process, stepping up costs.

The development of duct lines or coil-lines by Welty-Way Products in Cedar Rapids, later re-named Iowa Precision Industries (IPI) and Engel Industries from St. Louis, required coil stock that would feed through the machine – forming most all the functions necessary to complete a straight piece of duct while reducing scrap.

In the ‘60s, the first coil-lines entered the market, but with limited functions and with 48” capacity – it was basically a shear, notch and bead machine. Beading replaced cross breaking for reinforcing, but many times that became an issue, job by job, as the mechanical engineers‘ specs were late to catch up with this design. But it was the ‘70s that saw the big switch: moving to 5’ duct with complete roll-forming functions for seams and transverse connections along with breaking the flat sheet into half-sections, or “L” ducts.

However, missing was the ability to add internal duct lining. Imagine job specifications calling for 30% or more of straight ducts lined: The worker would have to stop the line after the seams were formed, then pull each piece off the line and load them onto a rolling table. This would then  move to the duct-lining area for glue spraying, placement of the linger onto the sheet metal and mechanical fastening: weld-pins or GRIPNAIL. And that’s where I came in.

Learning that Welty-Way was working to add this feature, I somehow found my way into Cedar Rapids,Iowa in 1970. That was my first of many visits to a great area with great people. To this day, it’s the site of one of the Mestek Machinery manufacturing plants that produce IPI ductlines. I also tried my luck crashing Engel in St. Louis, and met Herb Fischer, head of engineering.

As Vice President of Sales and Marketing for GRIPNAIL, I knew that any manufacturer of mechanical fasteners that couldn’t or wouldn’t rise up to the challenge to supply fastening machines to work in both Welty-Way and Engel’s duct-lines, well, their market would eventually die off. At the time, there were five of six suppliers of equipment and pins. Only Duro Dyne and GRIPNAIL took up the challenge.

In June of 1973, both Welty-Way and Engel held shows at their respective plants for contractors to come see this new technology: Welty-Way’s Insulmatic® and Engel’s Line-O-Matic®.  Today, 50 years later, almost all duct-lines go out with automatic duct-liner cutting knives; glue-spraying heads; and multi-head pinning machines included in the purchase. And out of that development came single-head machines from Duro Dyne and GRIPNAIL, the only two companies who survive today with viable machines and pins. Every sheet metal contractor has one or the other.  

Working with the employees at Welty-Way, Engel and Chicago based Lockformer, I was fortunate early on to make many friends in the industry, even those of competitors: like one Primo Rossetto – Duro Dyne’s sales executive and father of current president, Patrick Rossetto, and a close friend of Milt Hinden, president and founder of Duro Dyne. I won’t “gloat” over the success GRIPNAIL had from the opening gun with automation, let’s just repeat what Primo told me years later after I resigned from GRIPNAIL: “Milt broke out the Champagne.”

Trends in Sheet Metal You Can Still See Today

Some commentary on past industry trends that continue today: When I first entered the industry with a vested interest in internal duct liner, the talk was that the big glass (fiberglass) manufacturers, Owens Corning, Johns Manville and Gustin-Bacon would put metal duct out of business by promoting a new product for making ducts call “ductboard." For many reasons, it never took off, other than in residential and for some light commercial jobs. Other recent types of non-metal ducts have faced a similar fate. It seems galvanized sheet metal is the best material.

And, a word about round and flat-oval duct:  One might ask about round ducts verses rectangular and the machinery to fabricate. I’m sure you’ve seen ads using a round red circle with a diagonal line through it depicting a piece of rectangular duct inside. To me this just doesn’t add up. There’s a place for both. When I started in the industry, the ratio of rectangular to round was somewhere between 60 and 70%. From my sources, it’s the same today. Why? Designs of buildings. Round is cost effective over rectangular when ceiling space is not an issue. If architects designed buildings around the HVAC system’s ductwork, then that ratio would certainly switch. But that hasn’t happened in the past half-century and I feel confident it won’t in the next.  

Additionally, since round fabricating machinery is pretty basic, the only development over the decades has been for faster output and the ability to make larger diameter ducts.

In my opinion, Herb Fischer was the engineering brains behind Engel Industries, a leader in automation in our industry since the ‘60s. As mentioned, while I didn’t know Herb during my early GRIPNAIL days, we butted heads over the years due to my relationship with Welty-Way, Iowa Precision Industries, Lockformer and Mestek Machinery. However, though we were on opposite sides for many years, I respected him and was pleased to have gained his respect.

Now that he’s part of the Mestek Machinery team, it’s nice to be working with him in lieu of competing. We’ll hear more about Herb and his invention, the E-Z Connector, in the last decade covered here for SNIPS, the 2010s.

“Engel built machinery that made pretty accurate ductwork in the ‘70s,” Fischer says. “It was hydraulically driven, it started and stopped for the matching and the shearing. IPI used a system that typically used air and converted on the fly. Then in the late ‘70s, they converted over and began using start and stop systems, and now they’re actually using SERVO drives. And they’re extremely accurate.”

What About SMACNA?  

You can’t be in this industry without hearing the acronyms SMACNA and ASHRAE. Being a nosey young guy in the industry, of course I had to find out all about these associations, starting with the Sheet Metal and Air Conditioning Contractors' National Association. I got GRIPNAIL to join in 1970 as what were then “Affiliate Members.” Affiliate I would later learn was a designation to keep manufactures at arm’s length, due to some chapter members fearing manufacturers gaining too much influence.

However, in 1972 SMACNA National invited me, Q. D. Miskell of Welty-Way and Boyd Bennet, founder of Hardcast, to their D.C. headquarters for a discussion titled: “Contractor – Manufacturer Relations” on how a more close relationship might look. We were tasked with presenting a report to SMACNA at the at the 1972 fall LA Convention. It was subsequently tabled.

That attitude changed in 1976 and we again were invited to Washington. This time it was presented as a serious effort looking toward an elevated status for all associates. After that initial meeting in early 1976, Q. D., Boyd and I worked the phones contacting virtually every affiliated company in the industry; presented a platform which included an annual trade presentation at the annual convention; and the elevation from Affiliated Members to Associate Members. It was accepted by SMACNA’s board and kicked off at the 1976 Miami Convention. After the success in Miami, both SMACNA and the Associate Members never looked back. The association has grown stronger and stronger with each passing year – beneficial to all – with the trade show a resounding success.  

A few decades later, this success spurred talk on establishing a “Premier Partnership.” In the 2010s, Mestek Machinery became the inaugural member. Today, to see the close working relationship between contractors and the Associate Members not only has been rewarding in itself, but the positive results speak for themselves. That I had a hand in all this is one of the “highs” of my long career. But with my industry time now on the short side, I am equally pleased to have had another hand in introducing Mestek Machinery’s Senior V. P. of Sales, Mike Bailey, to the SMACNA – where he has picked up where I left off. It was he who helped get the Premier Partnership off the ground.

"Today we have six members of the Premiere Partnership. It has introduced me to so many people across the country. I've made a lot of close friends and it's been great for the business too," Bailey says, noting Mestek has sold more coil lines over the past five years than it did the 20 years prior.

“Before we got involved in SMACNA, they didn’t know us as well – you could come off as a sales guy rather than a friend looking out for mutual interests,” he adds. “That’s changed for us now.”

An even more important function of SMACNA is its work developing specs for moving air and that is accomplished in SMACNA’s DCS (Duct Construction Standards); today under the direction of what I would call another industry ICON, Eli Howard. In 1972, I along with Duro Dyne, other fastener companies and most of the adhesives manufacturers were invited to SMACNA’s headquarters to form a committee to assist SMACNA in developing a duct-liner standard. That was accomplished as a stand along document referenced in the 1975 DCS. It was formally included in the 1986 DCS. In the 1990s, I was fortunate again to have had an influence getting Lockformer’s TDC into the DCS – now referred to as T-25A.

David Daw is a SNIPS Magazine Industry Icon. To read more from his continuing series on the history of the industry, follow along on SNIPSMag.com.