Professional grade dual action sanders vs. cheaper ones

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Forum topic by gauntlet21 posted 07-25-2018 07:09 PM 2132 views 0 times favorited 17 replies Add to Favorites Watch
View gauntlet21's profile


69 posts in 819 days

07-25-2018 07:09 PM

Topic tags/keywords: sanding finish dual action pneumatic sander

I’ve been working on a bookshelf for the better part of 8 months now and all of the measuring and cutting has been done for 2 months. I’m having a heck of a time as a beginner to woodworking with, the finish. I’ve stained the boards (Maple Veneer Plywood) and have applied numerous coats of water based polyurethane. I’ve got a relatively smooth surface but have “hills and valleys” that are really only visible when light bounces off of it. The hills and valleys are parallel to the grain of the wood. I’m interested in purchasing a pneumatic dual action sander that has adjustable sanding speed and then I can hone in on the finish better with various Scotch-Brite pads that remove just enough material to smooth it out. My big dilemma is that there are sanders that are nearly identical in looks (I realize that doesn’t matter one bit), but the pricing can vary from $65-$400+. I’m interested in a Dynabrade model that I can get for a little bit cheaper than the going rate but don’t know what sets the “professional” models apart from the cheaper counterparts. Of the popular manufacturers, there are “entry level” and “professional” level sanders with nearly similar size and function made by Dynabrade, Ingersoll Rand, 3M, Sioux, Aircat, Bosch, etc… What could possibly be present in all of these models that separate the prices by so much? All of the bullet point details don’t seem to “add up” to the substantial investment necessary but I am battling to achieve excellence in my finish. I don’t mind spending money on tools but I like knowing what I’m getting at least. If you’re familiar with any of these tools, please educate me! I’d greatly appreciate it.


17 replies so far

View Aj2's profile


2650 posts in 2406 days

#1 posted 07-25-2018 07:19 PM

Let me guess you stained it dark maybe a espresso color. Two things to think about .
Are you sure it will be noticeable when you bring it indoors.Shop lighting can be very unforgiving
Sanding stained veneer is usually not a good idea. To easy to burn right through
Good luck

-- Aj

View Rich's profile


5146 posts in 1197 days

#2 posted 07-25-2018 08:19 PM

Why pneumatic? Remember you’ll need a pretty big compressor for that. You can get a really nice random orbit sander for $50 to $80.

I’m with Aj. Any sanding you do at this point to level the surface is risking a burn through. Besides, my experience with the sort of Scotch Brite pad you’re talking about using is that they don’t level the surface — they simply follow the contours and smooth it. That’s exactly what you want at times, but I don’t think it’s going to do much to get rid of the waves in your surface.

If it were me, I’d cut my losses and stop there. Maybe rub the finish out a little and do some wax if you want, but trying to get that surface completely flat is likely to cause more problems than it fixes.

Rather than the 3M pads, I much prefer Mirlon Total by Mirka. They come in 350, 1500 and 2500 equivalent grit, last for a long time since they’re washable, and give a better result. I’ve tried both and the Mirka stands out.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View John Smith's profile

John Smith

2135 posts in 771 days

#3 posted 07-25-2018 08:38 PM

the pneumatic sanders and other tools that I have used have a nasty habit
of spitting out oily water through the exhaust onto the workpiece.
just food for thought.

and – I have a 6” pneumatic HF sander that takes the PSA sticky pads some lucky
member can have just for the postage. I will probably never use it again.



-- I am a painter. That's what I do. I paint things --

View Bill White's profile

Bill White

5242 posts in 4568 days

#4 posted 07-25-2018 08:44 PM

Next question(s).....Why dual action, why pneumatic?

-- [email protected]

View OSU55's profile


2507 posts in 2598 days

#5 posted 07-26-2018 12:19 PM

Forget sanding out the waves. At this point, being plywood, you get what you get. It may be more optical illusion, ie varying gloss levels on the surface. Rub it down with steel wool to even and reduce the sheen, and the waves will go away or be less noticeable.

View dhazelton's profile


2839 posts in 2905 days

#6 posted 07-26-2018 12:28 PM

The hills and valleys you see parallel to the grain of the wood IS the grain of the wood. Let it be and just finish the bookshelf. When you put stuff in it you won’t see it.

And on plywood I would not use an orbital sander, just a pad sander.

View gauntlet21's profile


69 posts in 819 days

#7 posted 07-26-2018 01:18 PM

Let me just clarify a little. The surface of the wood is beautifully smooth. It is likely the lack of proper lexicon that I mentioned “hills and valleys” but what I am seeing is streaking in what should be my final layer of top coat (water based polyurethane). You’re right in that I can only see it when I hold it at a reflective angle to sunlight or bounce my flashlight/worklight off of it but I’m being a stickler I guess and I am not sure, as a beginner, what is a reasonable result. I do own an air compressor already so that wouldn’t be an issue. I guess I was thinking that the professional “finish” sanders were going to be the solution to attaining the best possible results. I’ve been using the various grades of Scotch-Brite pads which have shown some promise but I haven’t conquered the battle yet. The red Scotch-Brite pad is sufficient in removing very little top coat and not breaking through while the gray and white aren’t abrasive enough to remove much at all. I’m going to try and attach a photo that shows a little of the streaking/hilly/valley reflection that I am battling.

If you look at the glossiest area of this board and zoom in, you can see the streaking that I’m trying to smooth out and eliminate. Aj was right in that I picked a dark color.

View Rich's profile


5146 posts in 1197 days

#8 posted 07-26-2018 01:57 PM

If you look at the glossiest area of this board and zoom in, you can see the streaking that I m trying to smooth out and eliminate. Aj was right in that I picked a dark color.

- gauntlet21

You’re worrying way too much about it. It looks great, leave it alone. Like I said above, you’re likely to make it worse instead of better. Also, don’t point it out when people compliment your work.

Take away a good lesson though; never, ever put any finish on your final product without doing test boards first. Sand them to the same grit, color them the same, top coat it exactly the same as well. Document your steps as well so you can repeat it on the final piece. It will save you a ton of headaches.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View Jeff's profile


516 posts in 3802 days

#9 posted 07-26-2018 02:12 PM

It may be more an issue of the type of finish you’re using and how you’re applying it. Some brushes are better than others. If it’s water based poly then a foam brush may be better. What are the conditions in your shop? Hot and humid may make the finish dry too quickly, leaving streaks.

View waho6o9's profile


8812 posts in 3185 days

#10 posted 07-26-2018 02:14 PM

“You’re worrying way too much about it. It looks great, leave it alone”

^ Wise

View woodbutcherbynight's profile


6052 posts in 3017 days

#11 posted 07-27-2018 02:01 AM

We are our own worst critics at times. Food for thought. Most people have no idea how something is made, how much time went into the project, and what looks wrong. They just see a nice table and are happy to use it.

-- Live to tell the stories, they sound better that way.

View ChefHDAN's profile


1499 posts in 3458 days

#12 posted 07-27-2018 10:54 AM

Yep!, ^^^ My wife always says “you’re the only one that will ever see that” BUT I know exactly how you feel, I refinished a table with QS oak and I spent a month trying to flatten out the imperfections from the grain, re-coated and sanded over and over but it never “leveled” like i assumed it should. I do now know about grain fillers, so lesson learned. A good orbit sander for around $100 should be your best sanding option for quite a time, best tip I can offer is one I learned the hard way, don’t be cheap with your abrasives and WORK the Grits, it’ll will save you a lot of time and time is money.

Welcome to LJ’s and the hobby

-- I've decided 1 mistake is really 2 opportunities to learn.. learn how to fix it... and learn how to not repeat it

View OSU55's profile


2507 posts in 2598 days

#13 posted 07-27-2018 12:22 PM

So it is sheen variation as suggested before. You can leave it alone, or very light hand sanding/rubbing. You can keep at it with red pads but those will leave a fairly coarse finish. Best is to wet sand with mineral spirits. Light touch, 1000 grit, then rub out with gray pad or steel wool. There is a risk of sanding through. Problem with steel wool is if you needed to recoat, any pieces left behind, and there will be will rust. I use gray and white pads on a buffer, but it can be done by hand, just takes a lot of time.

View gauntlet21's profile


69 posts in 819 days

#14 posted 07-27-2018 06:56 PM

Wow. Thank you all for the kind compliments. I didn’t expect that and am grateful for your chiming in. I work alone on these projects and am self-learning so I don’t have any other resources but the internet and forums. I very much appreciate it and will do some minor touch-ups and finally assemble it (I dry assembled it and it fit together beautifully). I’ll post a picture when I am done so you can see it if at all still interested. I didn’t think that there was a serious issue with the finish but I was just trying my darndest to get a showroom finish like the rest of my professionally bought stuff. Thanks again! Very much.

View tomsteve's profile


988 posts in 1827 days

#15 posted 07-27-2018 09:06 PM

justa note on the air sanders:
if you decide to get one at some point, it will require a large capacity compressor- minimum 60 gallon,2 stage, 5 hp.
the eat a LOT of air.

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