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?

  • 3
    "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 '20 at 18:14
  • 2
    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 '20 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 '20 at 9:54
  • As I commented in an answer, belt sanders, IMNSHO, are for shaping and roughing. Never for finishing.
    – jdv
    Apr 21 '20 at 22:05

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.

  • Agreed. In my opinion, belt sanders are for shaping, not finishing.
    – jdv
    Apr 21 '20 at 22:04
  • Unfortunately, I need a belt sander to start, so it's, er, a non-starter not to use it, and the problem has been that it causes big pieces of wood to pull out, destroying everything I was working for when using the sander. Agreed that I need to eventually transition to an orbit sander; what motivated this thread is that the initial sanding with the belt sander is doing more damage than help. I know that it's a legitimate tool, so obviously I have not been using it correctly, so I am asking for advice on using a belt sander without it causing tearout.
    – JoshG
    Apr 22 '20 at 23:28
  • @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.
    – jdv
    Apr 28 '20 at 15:30
  • 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.
    – jdv
    Apr 28 '20 at 15:34
  • Thanks, @jdv. This has been a time-consuming, frustrating experience. The belt sander caused problems, and then I tried to fix those problems (dips in the surface, as well as tearout), by using a coarser grit and a faster speed, which just caused more problems. It's kind of like licking your lips when they're chapped; it just makes it worse. I really didn't want to spend hours and hours sanding. If there ever is a next time, perhaps I will look into planers, as you have suggested. I have an orbit sander arriving in the mail, soon.
    – JoshG
    May 1 '20 at 16:20

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