How Important is Surface Preparation?

by | Sep 2, 2021 | Expert's Corner | 0 comments

Good surface preparation is a key to obtaining a stellar finish. Milling marks, fine scratches, and thin slivers of dried glue that may be barely visible prior to finishing will stand out like a sore thumb after the finish is applied. Stearate papers are flexible yet tough, cut quickly, don’t clog up too much, and are reasonably long lasting.

For power sanding nothing beats a variable speed random orbital sander (ROS). Use one that comes with a dust bag or that can be connected to a dust extractor. These sanders have an offset drive bearing that causes the sanding pad to move in an elliptical orbit, which reduces scratching against the grain. You can move the sander any direction on the wood: with the grain, diagonal to the grain, and even against the grain. We highly recommend Surfprep’s 5” ‘brushless’ Electric Sander.

It is the lowest profile, operator friendly, power packed, energy efficient random orbital sander. Lightweight at just 2.5 pounds.

For both hand and power sanding the most frequently used grits are 150, 180, 220, and 320. Finer grits are best used for rubbing out fine finishes. It’s much more economical to purchase the four basic grit sizes in boxes of 100.

Card scrapers are also a useful and relatively inexpensive tool to have on hand. They’re handy for quickly removing mill marks, dealing with minor tear-out, and working on narrow stock where sandpaper would round over edges. You’ll eventually need to acquire the tools to maintain a scraper – a single cut file and a bench stone. For a burnisher you can use a 1/4″ steel rod.

Before you get ready to put your finish on your project, make sure the surface is clean from contamination.  If you are planning on spraying a water-based finish like Acrylacq don’t use a tack cloth or cotton cloth as this will leave oil and lint on the surface and end up causing fish eyes.  When spraying water-based finishes always use a low count microfiber cloth for the best results.  Microfiber won’t leave lint on your substrate.

https://thefinishingstore.com/shop/finishing-supplies/spray-gun-cleaning/fs1700-micro-fiber-cloths-10-pack-12-in-x-12-in-green/

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