Avoid swirl marks with my random orbit sander?
I will tell you exactly why and how to avoid swirl marks when sanding with a random orbit sander.
You’re sanding too fast, too random, and not working through grits of sand paper properly. I mean, they don’t make so many different grits just because it’s fun, they all serve a purpose.
Fortunately, it’s an easy fix. So put your sander down and read these tips on how to avoid the dreaded pig tails.
First step: I use 80 grit to strip paint or varnish and stain, or sand raw wood for stock removal. Most of my pieces I can start with 150, you will eventually get a feel for this and know where you need to start. Don’t be afraid to get aggressive in this step just keep the pad flat and keep moving.
Make sure you remove all of the old finish before moving on.
Second Step: Clean your surface. Any build up on your paper can leave marks while sanding. Your sandpaper also leaves grit behind on the surface, try to stay neat.
Now is when you need to slow down, take your time, and be patient. It is very important you do not skip grits. If you sand with 80 grit and move straight to 180, the 180 is too fine to remove the marks the 80 grit left behind, you will need to sand a really long time to remove them.
Move on to the next grit, start on one edge of the surface and gently guide the sander down the length of your surface going with the grain.
Don’t get crazy with the sander moving it back and forth. Don’t push down too hard on the sander. A firm grip is all that is needed, let the sander do the work. Guide the sander to the other end, do not force it and keep it flat.
When you reach the end, start back the other way, overlap your last path about 1/4 of your sanding disk. Think of it like mowing a lawn. You don’t start your mower and run around the yard
without any kind of pattern right? So, I have a table top that is 60″ long. I want to start on one edge and be down the table in about 40-50 seconds. If you’re a perfectionist like me, you will do this twice with each grit.
Step three: Rinse and repeat. Do not try to skip a grit just because you can’t see the swirls. They will haunt you as soon as you apply stain. Finally, I hand sand using a sanding block wrapped with 220 to remove any big rings the sander sometimes leaves. If you’re able to use a vacuum connected to your sander, do it. That will help keep your paper and surface a lot cleaner.
I should mention, I sand to 320 grit when I use an oil finish (which is always).
Here is a small break down of what we just covered.
Take your time, be patient.
Sand 1 – 2″ per second
Clean as you go.
Do not skip grits.
So, there it is. How to avoid swirl marks when sanding.
Follow these steps and you should end up with a professional looking finish you will not be ashamed to show off. I never have to check for swirl marks by wiping the surface with mineral spirits. I follow these tips and apply my stain or oil. It comes out perfect every time. If you choose to test your surface, never use water it will raise the grain. If you do use water make sure you do a final sanding with 220 to knock down that raised grain.
I’m always happy to share any tips or tricks I may have to save you a headache and a little time. I hope this guide clearly explains how to avoid swirl marks when sanding.
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