Heat Swirls, Wet Grinding and Over Densifying

This article is based on an episode of the WorX+ TechTalk series. You can watch the full episode here.

In this TechTalk article, we’ll be delving into several critical aspects of the concrete grinding and polishing process: wet grinding, heat swirls and over-densifying - so you can feel confident out on the floor.

WET GRINDING AND POLISHING

Slurry, slurry and slurry. That’s what we talk about when we talk about the wet process and that’s what the boys at WORX+ don’t want to see. Though the process is fast, it’s messy, because the slurry created needs to be cleaned from the slab, machines, and surrounding area.  The team in the maintenance shop don’t appreciate chiselling away “archaeologist style” on the machines to get slurry off. At the end of the day, this is creating more cost for contractors.

While wet grinding can appear faster than dry grinding, the overall process ends up taking longer when the contractor factors in cleanup and the rest of the process, such as grouting and polishing. With modern-day advancements in tooling and machinery, dry grinding is the more efficient and best option in most cases. That’s why Josh's response to a contractor wet grinding is: “why are you going back to the dark ages!?”

HEAT SWIRLS

These swirls are often caused by excessive heat generated during the polishing process, especially when using higher grit resins. 

This heat can be caused by:

• Using tooling that is not suitable for the surface or profile being worked on.
• Applying excessive pressure or speed during polishing.
• The presence of residual densifier on the floor.

Let’s look at a common scenario where heat swirls occur: The floor is looking highly polished at a lower grit level, like 400-grit, so the operator moves to an 800-grit. At this point, there’s just no profile to work with. If you’re running the machine with the same parameters at this grit (high speed, high head weight and high tool pressure), it’s going to create a lot of heat and swirls. “And that should be your telltale. If it's looking that good at 400, 800's not going to work on it.” - Josh

Some suggested solutions for avoiding heat swirls:

• Assessing the floor's finish level and choosing the appropriate grit resin, even skipping a grit level if the floor is already sufficiently polished.
• Increasing the number of pucks under the machine to reduce pressure and heat.

OVER-DENSIFYING

A densifier is a chemical treatment applied to concrete floors to increase their hardness, durability, and resistance to wear. It is important to apply a densifier appropriately to ensure optimal polishing results and avoid wastage. Over-densifying occurs when more densifier is applied than necessary, leading to a thick layer that needs to be removed. This excess densifier can make the polishing process slower and less effective. 

Over-densifying can also contribute to heat swirls if the thick layer of densifier prevents the tooling from making proper contact with the concrete surface. To avoid these situations, it’s important to use a measured approach to densifier apllication by using only the amount required to achieve the desired level of hardness and durability.

KEY TAKEAWAYS

Ultimately, the WORX+ team encourages contractors to invest in appropriate equipment and master the proper techniques of the trade. That’s how you get the best results – there's just no way around it!

On that note, part of our mission here at WORX+ is to help you feel totally confident in your concrete grinding and polishing results. So if you would like detailed teaching on the proper techniques and get access to concrete grinding and polishing experts, our seminars are a great way to do this.

BOOK A SEMINAR

If you have any questions, give our friendly staff a call on 1300 897 873. We’re here to help.

Hang on, we’ve got even more for you!

Check out our other TechTalk articles below, where we address common issues you might be facing and the nitty gritty of the concrete grinding and polishing industry.