How to get the most from your Rotex , (The Basics)
Okay, so you’ve done. You’ve bitten the bullet, spent the bucks, and now, sitting on the bench in front of you is possibly the best sander thus far to emerge from the melting pot that is European power tool engineering.
So; now what?
The first thing you probably want to do is whack a sheet of paper on it and sand a piece of wood until it’s paper thin. If you need to, go ahead, but make sure to clamp down your work first; there’s not much worse than being hit in that tender part of the anatomy by a piece of rotex propelled timber.
Once you’ve got that out of your system, let’s start by having a good look at your new machine. Hopefully the salesman you purchased the machine from fully explained all the functions to you, but in case he didn’t, lets start from scratch.
The rotex 150 is a dual mode sander with an aggressive, gear driven mode, (Rotex mode) and a random orbital mode with a 5mm orbit.
You switch between these modes by pressing the green button on the top of the machine, down & to the left When the button
is in the upright position the sander is in the rotex mode.
To test this, make sure the power is turned off, then turn the base plate with your hand. You should feel some resistance and hear a “growl” coming from the sander. Now, push the top button down and to the left. This puts the sander into the random orbital mode. Turn the base plate again so you can feel and hear the difference between the two modes.
You’ve probably noticed the small green button on the right side of the rotex just above the base plate. This is the spindle lock and it’s used when we need to change the base plate, because it’s either worn out or you need to change to a pad of a different density for a specific application.
It’s a bit of a bugger to change, particularly the first time, but it will get easier to practice.
To use this function, first make sure the rotex is unplugged, then put the sander into the rotex mode. Hold the sander upside down in your left hand so that your left thumb can depress the spindle lock button. Depress the spindle lock button with your left thumb and turn the pad anti-clockwise with your right hand until you feel the spindle lock engage, ( the spindle lock button will depress an extra couple of millimeters).
Continue holding the spindle lock and turning the pad anti-clockwise until the pad comes off.
To put on a new pad, depress the spindle lock, put the pad on the machine and turn it clockwise until you feel it drop into position and the locking mechanism begins to engage. Once this happens, grip it firmly and turn it clockwise until it locks fully. Now put the machine down and give your hands a shake. Told you it was a bit of s bugger to do; but trust me, it will get easier with practice.
At the rear of the machine just above the plug it lead is the variable speed control for the sander and the green button on the inside rear of the “d” handle section releases the dust extractor port so you can polish the car without running the risk of it accidentally banging into the paint surface.
Using the Rotex.
Now, whatever your project, having a good understanding of how to use the functions of the sander will always help you to achieve the best finish possible on your work.
Rotex and Random Orbit Modes
One of the most common questions I field when showing people the rotex is, “how do I know which mode, I should be using?”
Well the simple answer to this is that you should always use both modes. Let me explain.
The rotex mode will, with coarser papers, raise the grain whilst the random orbital mode cuts the grain back. From experience I’ve found that if, for instance, you’re starting with 60 grit, whack it into rotex mode and sand your work then stop, put the machine into the random orbit mode and sand it again. It’s important not to try to change from rotex to random orbital mode whilst the machine is running; it’s like trying to change gears on your car without depressing the clutch.
Then change up a grit to 80 and repeat the process. As you progress through the grades, getting finer and finer, you’ll see the surface start to develop. It’s really important that you feel the wood with your hands as you’re sanding. Getting a good feel for the timber will help you gain a greater understanding of how a surface develops.
Continue sanding with 120, 180, 240, and 400 grit abrasives, being sure to repeat the rotex, then random orbit modes
To achieve the best result results in your work, speed is another important factor to consider. The main things you have to remember are, the coarser the paper the higher the speed.
Coarse paper on slow speed tends to dig in and ‘bite’ the work, which can lead to scratches and swirls than can be bloody hard to get out. Coarse paper on high speed tends to ‘skim’ over the work and while it may take a little longer you’ll achieve a more controlled result.
When you start sanding and are using, a 60 grit paper start with the sander on speed 6 and use the rotex, random orbit method as described above. As you start moving into progressively finer grades, gradually begin to lower the sander speed. Use the chart below as a rough guide for sander speed related to sanding grit.
Sanding grit. Speed
1500 & finer 1
This chart is a suggested range only and results can vary depending on the type of timber that you choose.
The transition point when sanding is 400 grit. This is the stage where you stop sanding the timber and start burnishing it. From 400 up you’ll start to see the surface of the timber develop and become smoother with every sanding stage that you complete. Don’t forget to feel the timber as you sand it so that you become more familiar with how each sanding grade contributes to the overall finish. Keep using the rotex / random orbital sanding technique until you pass 1000 grit. From experience, I’ve found that when you reach 1200 grit switch to using the rotex mode only. You should begin to see the timber surface begin to develop a lovely luster and the surface will begin to shine. This happens, because the super fine grits that we have been using are burnishing the timber surface and closing off the pore of the wood which gives us this glass like finish.
That’s it for part 1 of this post, in part 2, I’ll go thru how to apply a burnished wax finish to your piece.
Cheers for now