Psychology of Low Grit Sanding

Written by on December 26, 2015 in Prep, Sanding and Dust Collection, Uncategorized with 6 Comments

What grit do you sand at most in the type of work you do?

low grit sanding

Understand how YOU sand.

Regardless of where your project sanding “wheelhouse” is, you likely start with low grit sanding and work up. Whatever “low” is for you, lower grits can often go pretty fast because it’s the rough work and gets smoothed out at the next grit. But most mistakes start in the low grits.

Usually, as a result of sanding too much, or not enough.

The key is finding just enough, and the best approach is to keep it simple.

Low grits are about “roughing in” the piece. When people try to get too perfect on the first step, it compounds in the next step, and the next – usually by over swirling or abrading the surface too much.

What causes under sanding in low grit?

  • impatience
  • tool not powerful enough
  • wrong starting grit selection (too high)
  • poor technique (too fast)

What causes over sanding?

  • enthusiasm
  • tool not powerful enough
  • tool too powerful
  • wrong starting grit selection (too low)
  • poor technique (too slow)

If the sander is underpowered for the task, users often go down in grit to compensate. That can cause a “mismatch” phenomenon.

Where’s the Balance of Quality and Production?

low grit sanding

Abrasive grit selection is critical.

I’ll bull and jam at 80 or under with a Rotex in short bursts knowing that I can cruise through multiple grits one handed for the next hour with a floater orbital. It’s just common sense, if you can make things easier physically, you must.

[Click here to Better Understand Rotex Sanders]

So I’ll grab a sporty one hander for mid grit sanding. It seems that the later in the day and week it gets, the more this pattern prevails. Quick moves with a powerful sander, then relaxed cruising with a finisher.

If there is much extreme low grit sanding in your life, a powerful sander is in order. The RAS115 is the “break glass in case of emergency” choice. The Rotex class is like a fleet of varying sized muscle cars in the low grit range (and they excel in other ranges too). Size of your typical tasks and degree of material removal required correlate directly to the amount of low grit muscle you may need.

If you regularly sand across a broad grit range, you do get to a point where you realize that a Rotex might not please you as the only sander in your life. The tool can do any kind of sanding you want to do. You could do everything with it, but you may discover situations where you feel like you have brought a bazooka to a knife fight – which can be as unsettling as bringing a knife to a bazooka fight.

[Related: Top 2 Production Mistakes in Finishing]

Power sanding correctly with Rotex is a physical game. Not in terms of sheer physical exertion, but more simple awareness of the physics of the tool. Remember, the larger world of sanding involves sanding in both horizontal and vertical orientations. Bench top is one thing, top of ladder is another. Bottom line, I don’t want to have to focus on the tool.

My focus is on the workpiece…

low grit sanding

Sanding with Rotex is a different discipline.

Spending the right amounts of time with the right type of sander is key. You can work harder than necessary with a less than ideal tool selection for a given task.

We don’t want numb hands on Friday when we are playing ball with the kids on Saturday. You’ll find that manufacturers of better tools share that value by pushing engineering to continue making work safer and easier (and, of course, always inherently cleaner) through tools that can work with us in a human way.

Sanding isn’t just a plug and play exercise. You have to understand the way YOU work with the tool in order to get the tool to work with you in the best way.

A healthy sander relationship is rarely built in minutes. It is measured in hours. Lots of hours over the course of lots of months. You can’t tell in 10 minutes how a sander will work with you and you with it.


  • No doing things twice.
  • Grit selection: dropping in at too low of a grit creates extra work to get to the grit you should have started at.
  • Time (and abrasive) is wasted. Quality suffers.
  • No doing things slow that can be done fast.
  • No doing things fast that need to be slow.
  • Tool selection, or combination of tools together in a project, is the definition of efficiency.

Stay tuned as we will be sharing more sanding tips in the very near future, and please add any tips you might like to offer in the comments below. And, questions are always welcome here.






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  1. I have a Ro 150, a ets-ec 150/5, and a ro90. These 3 sanders do most tasks. I use the ro150 to strip varnish/paint and use 36-80grit and only keep those grits for that sander. My ets-ec is my finish sander with grits from 60-600. 320-600 with an interface pad, eliminates the need for hand sanding between coats. My ro90 does everything the ro150 does and the ets, but for smaller surfaces and corners. I want a dts 400 req. since i do work on many different surfaces and don’t always need rotation. What do you do about detail work? I’ve been scraping, sanding by hand or routing. Is there another way?

  2. Chris Smith says:

    Hi Scott, great write ups here, I take apart sash windows, strip down the rails and stiles, and clean up the boxes before painting. I am looking at the RO90 and RTS400, from you experiance would you say the ro90 is the ideal sander for my line of work?

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