The first requirement for quality coating on fabricated steel is proper surface preparation.

For years, many people chose to grind, which was a reasonable method. However, we recently compared blasting versus grinding to determine which method provided superior surface preparation.

Firstly, safety with grinding. There are many safety concerns which include weld splatter, working at dangerous heights, crawling over pipes or pieces of steel weldments and the possibility of injury from the grinder itself.

And secondly, you get a better surface quality from blasting. The grinding process is unpredictable and creates less of an aggressive and more irregular profile than a blasted surface. This creates problems when trying to get a coating to adhere to the surface.

In comparison, blasting creates a surface profile, which improves adhesion by increasing the total surface area. Additionally, the angular pattern of the profile will stop any shearing. Blasting also exposes any welding inconsistencies in porosity, helping to catch any mistakes before painting.

Comparing performance speed and productivity metrics, blasting is typically 88% faster.

For instance, Heil a BlastOne customer specializing in manufacturing refuse truck bodies were recently convinced to make the switch from grinding to blasting. They transitioned from having five guys grind for 17 minutes on one box to one person blasting for 45 minutes. That is an 88% reduction in the manpower required for surface preparation for their boxes.

Here’s what they had to say.

Q: What has been your observation of grinding versus blasting?

A: It’s a whole lot cleaner.

I mean, I think it’s going to be more pleasing, way safer for our employees in the long run for getting hit on the ground. And there’s some way of slagging off that stuff like that.

In the long term, I think it’s better for our customers, you know, the paint bonding – the paint and primer bonding to the metal better. So I think in the long run is… I think that’s what the upper management looked at, try to eliminate paint defects.

A: It’s a lot cleaner.

But I mean, is this the whole safety? You know, you’re not putting guys in danger or having them up in the air. You know, one of our biggest safety issues was weld splatter you know, getting hit in people’s eyes. So that’s going to practically take that completely away.

So, I mean, but it’s cleaner. I mean, the trucks would look a lot better even after they’re painted.

So, I mean, we really are happy so far what we’re seeing.

A: So grinding, you need five people for truck and still we don’t need the the cycle time. We need 50 minutes per truck and manually grinding is around an hour or over an hour. I would say, like from an hour to 70 minutes. So with the blasting, we now see that we can meet our cycle time of 50 minutes and of course, less labor.

So we have five people in manual grinding and in, in blasting. We have one guy. So it’s a big difference We can we have seen a big improvement on as far as adhesion- paint adhesion.

I would say 20 to 40% improvement. So yes, a big difference because as you know manually you miss spots, it’s easier to miss. With blasting almost every area is covered. So yeah, it’s a big improvement as far as quality.

Conclusion:

Now obviously there are instances and projects that may still require the use of grinding. And we understand that and to facilitate your productivity and safety in those instances we do offer Trelawny hand tools. We think this video regarding a dangerous syndrome called HAVS is what you should watch next if you or your team spend a significant amount of time using those hand tools.

We hope you’ve enjoyed this tip of the month. See you next time.