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I'm very new to woodworking and am mostly learning from my numerous mistakes. At home, I have two pine boards that sit atop my table and function as a tabletop and also as a work surface for all of my projects. (My apartment has limited space, so I wanted the table to do double duty.) The table top consists of two identical pieces of pine held side-by-side via clamps that clamp to the table beneath them.

At this point, the pine boards are pretty marred from stains and cuts (since my old polyurethane coating is gone by now), so I want to sand the boards, stain them, and re-polyurethane them. The sanding has been a nightmare, though. I have been using a belt sander with 40-grit on high power, because my previous sanding at higher grits left tearout, and I wanted to even everything out and start again. Anyway, after my first goofs with tearout (at a considerably higher grit than 40), I put putty into the tearout places and sanded with 40-grit paper using the belt sander. So far so good. Then I progressed to 80-grit, and huge tearout re-occurred! What can I do to successfully use a belt sander on pine without all of this tearout?

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    "mostly learning from my numerous mistakes" Welcome to being a human. Answer: do not use a belt sander. Random orbital sander is your friend.
    – Alaska Man
    Apr 19, 2020 at 18:14
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    I think we might need to see some pics here as I'm not sure if you're using the word tearout the way others understand the term. Tearout is generally seen only using edged tools, not when sanding — to the point that sanding is one of usual remedies for tearout. But the quality of the 'pine' (most pine sold can be a range of softwoods, many of which aren't pines) might be a factor if the wood is particularly dreadful in some way. [contd]
    – Graphus
    Apr 20, 2020 at 9:51
  • Anyway that said, if there is tearout what does it matter if it's a working surface for projects? Many people don't resurface often-used workbenches for years and sometimes a decade or more and by then the surface is heavy marred, much much worse than any tearout could be but it doesn't really matter.
    – Graphus
    Apr 20, 2020 at 9:54
  • As I commented in an answer, belt sanders, IMNSHO, are for shaping and roughing. Never for finishing.
    – user5572
    Apr 21, 2020 at 22:05

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Belt sanders are rough tools and the end result is never going to be good enough for polyurethane.

Use your sander carefully to get the tabletop as flat as you can, then switch to either a random orbit sander or sanding by hand.

Hand sanding gives better results, but it's slow. Wrap the paper over a block of wood especially for rougher sanding.

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  • Agreed. In my opinion, belt sanders are for shaping, not finishing.
    – user5572
    Apr 21, 2020 at 22:04
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    @JoshG a belt sander would be the last tool most woodworkers would reach for -- I'm not even sure I know of any woodwork that has one. Even if they do, I can't imagine anyone using it on a table surface of any kind, even a "rough" double-duty one. If you need to do this a lot, a planer (hand or otherwise) would be infinitely a better purchase. In your case I'd invest in some card shapers and just smooth it out that way if you have to -- scrapers are way better than sanding for removing material fast and leaving a pretty good first surface.
    – user5572
    Apr 28, 2020 at 15:30
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    In short: there aren't any techniques I know of to eliminate tear-out with belt sanders for certain kinds of wood. Go slow, use smaller grit than you think, and take your time. By the time you are finished working with finicky wood and a belt sander you could have used a scraper and done so without all the noise and dust.
    – user5572
    Apr 28, 2020 at 15:34
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    @JoshG in my experience, once someone uses a belt sander on a table they've just created more work for themselves. Seen more ruined tables that way than any other technique. Just give it to a friend, and let them ruin stuff.
    – user5572
    May 1, 2020 at 16:24
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    @jdv , that would make me some friend, eh? Since I've already got the belt sander, what kind of uses is it appropriate for?
    – JoshG
    May 2, 2020 at 17:32

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