Applying Scuff Sanding Correctly
April 25, 2012 | 3:50 pm CDT
More on pre-cat and post-cat wood coatings

Applying Scuff Sanding CorrectlyIf you missed last week's blog, take a few minutes to wander back and look at the discussion on scuff sanding. It will help you by giving some background. We will explore further today. Last week’s question of why we scuff sand leads to this week’s about how you accomplish that and do it well. Here we go!

How does Bernie scuff sand?

Scuffing is an art form. Sorry! It is and I practice it every long. I create presentation samples for our clients. Those need to represent the best that my coating systems can provide. Each must say clearly, “This is the standard you can attain. Here is what this product can do to your business’ reputation.”

One moment please. I want to make it clear that whenever you pick up the gun or the sandpaper or turn on the saw, you are practicing your art form. For those of you who had a teacher or a coach in your past who inspired you, I’ll bet they encouraged you to never waste your time practicing bad habits. Let me be that voice for you right now. Don’t waste anybody’s time practicing bad or poor habits when you work!

I approach each piece looking for these defects and I use sanding to remove them.

• Fat edges

• Fat pores

• Runs and sags

• Pimples and blemishes from “wild hair” fibers

• Cross-grain scratches

• Blemishes that I didn’t see until the coating was applied

• Shiny spots amid the sanding scratches

• Dust left over from the sanding process

I like paper for 90% of my work. And, for the record, I like really good, sharp paper. You get what you pay for. Dull paper and sponges waste time and time is money. I’m not a fan of sponges or gray paper. Sponges aren’t sharp enough long enough and the gray paper loads up too quickly and doesn’t cut to my liking.

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Yet, sponges, I admit, have their place when dealing with routed details, etc. because they conform to them. That can be good. Yet, the most important thing a paper should do is to cut off the high spots. Sponges tend to ride over them even when new and sharp.I also use maroon and gray Scotch-Brite-type pads for fine work.

For almost all of what I do, I use 320P paper. Let’s not go into the discussion about sandpaper grades here. If it says 320P on the back, chances are it is. If there’s no P after the number, chances are it’s not P grade and you need to know what that means.

Paper-wise, I will start with taking a full sheet of paper and cutting it into quarters. Then, I take that quarter and fold it into thirds along the long axis. That fits well in my hand. I have something for my thumb to hold onto to control the paper while my index and middle fingers apply pressure. My ring finger, pinky, and thumb act as “feelers” on the wood surface and tell me where there are defects that I need to go over as I move across the surface.

If scuffing is an art form then it must be applied correctly. For the guy who is afraid to burn through edges, I say that’s a healthy fear and it will guide you through that delicate application of pressure. Also, the less strokes that you take in these areas to accomplish your aims, the better off you are.

Also, when you apply that seal coat, how about a “painter’s two-step?”Spray your initial coat. Let it tack up a bit. Then go back and spray another coat. Then set things aside to dry prior to scuffing. Put an extra mil or two between you and the stain. Scuff a thicker seal coat. Use that to help protect your edges. But, developing a “light hand” while you sand is vital regardless of the mils.

Develop a routine for scuffing things. I start with the edge of the door and work to the center. No more than three strokes on a door edge. Always sand the faces of the rails before you sand the stiles. Why? Because that gets rid of the cross-grain scratches at the joint.

Doing a mitered door or wanting to be really careful about those scratches in the corners? I swear I should buy stock in some masking tape company. I use it all the time. Mask off where you don’t want scratches. If a really quality finish is what you want, take the time with this stage to get it right.

Use a light source to guide your sanding. Hold the door up to the light so that you can see the dull areas where you have scuffed. If there are still shiny spots amongst the no longer shiny, then you haven’t gotten to the bottom of the issue. Remember, the paper will continue to ride the high spots until they are gone. The goal is to get to the bottom with as few strokes as possible without burning through. Once it’s all dull…STOP! Not one stroke more. The light will guide you to where more attention is needed. Get rid of those shiny spots.

I have never been a fan of machine scuffing. Most guys with a random orbital in their hand scare me. But my buddy Dave taught me something the other day that changed my thinking. He was scuffing some fixtures for me. I had hired him to put the final coat of conversion varnish on a project of mine. I went in to see him and he was scuffing my fixtures with 320 grit Abranet. Wow! Those turned out soooo smooth! Light pressure along with the net abrasive’s ability to dispose of the sanding dust really created a smooth surface for that final coat. But again, you have to have a gentle hand to use that equipment well without burning through. My project was flat plywood panels with no detail. That’s a perfect opportunity to use a sander…especially after a painter’s two step.

Last thing! I carry a chip brush in my apron. I use that in conjunction with the air hose to get the dust off of my work right before I spray. The air moves the dust. The chip brush knocks it loose. Pay special attention to inside corners between stile/rail and panel but dust can be anywhere. Give the piece a complete dust off while you have the air going across its surface. Most times I just use the air from the spray gun and do this final inspection before I start to spray. Gun in one hand, brush in the other…git’er done!

I hope that you found something in this that will help you to raise the standard of your art form. And remember…don’t waste time practicing poor habits!

Until next time…spray on!

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