Structural steel, well prepared

Published

Upgrading to automated shot blasting has reduced surface preparation times at Steelway Building Systems in Ontario, Canada, by 80%.

Company Profile

Steelway Building Systems is a privately owned Canadian company, which manufactures steel building systems, building components and material handling equipment for use in industrial, commercial, agricultural, recreational and institutional applications across North America and around the world.

Défis

Steelway’s building systems are made up of simple shapes of raw steel.

These hot-rolled structural steel elements are typically primed or painted to prevent them from developing rust during storage or during transit to the customer.

All surface preparation at Steelway used to be undertaken manually, wire-wheeling each steel element using power tools – a slow and messy affair that created a dusty and dirty production environment.

And the method wasn’t doing the surface preparation job Steelway needed it to do either. The resulting paint issues on site, problems with adhesion as well as with rusting all were time-consuming to deal with or resulted in occasional back charges from customers. A better, cleaner method was needed.

Solution

To achieve the quality paint finish they wanted, Steelway decided to upgrade surface preparation operations at its 155,000 sqft main facility in Aylmer with a 10’ wide, 18’ high and 59’-4” long (including conveyors) automated shot blast machine from Wheelabrator.

Using four powerful blast wheels with 20hp each and operating at a constant 3600rpm, the machine removes rust and scale continuously, foot by foot.

The machine is designed with a work opening of 2’ - 10” wide and 4’ - 6” tall to accommodate a range of geometries. All material handling (apart from the Steelway-made crane) is part of the machine, including a roller conveyor onto which the structural sections are placed to then pass through the machine at the correct pace, which can be varied depending on the desired finish and the condition of the scale, usually between 3 and 6fpm.

A highly beneficial and unexpected side effect for the team at Steelway was that the cleaner, more even surface achieved through the blast process also improved weldability of the material during fabrication. The surface put in front of the welder after shot blasting is completely free from millscale and other contaminants, providing a better, easier and faster weld.

Résultat

Beyond weldability and paint finish, the new process has also had an impact on quality control. David Smith, Production Manager at Steelway, explains:

“One of the often overlooked benefits of blasting before fabricating is that on the rare occasion (maybe once or twice a year) that we get a beam in that suffers from delamination, cracks or other hidden imperfections, it’ll immediately show up after blasting. It doesn’t happen often, but it’s very important for us to catch those few faulty beams.”

“The main benefits, however, are the quality of the paint job and the weld quality. The latter is also better visible when the paint is good, which in turn delights the quality inspectors.”

Manual surface preparation at Steelway used to keep up to three people occupied for 30 – 60 minutes per beam. This is now done by the shot blast machine, manned by one operator, in five to ten minutes: a time saving of over 80%. With savings on back charges, reduction of the number of rejects and time savings on shopfloor clean-up, welding and painting, the machine at Steelway paid for itself in less than two years.

Case Study Video

Reduced surface preparation times at Steelway Building Systems