I have several different types of sanders in my shop but I definitely use
the random orbit sander the most. In this video I want to find out 5 sanding
mistakes that we've all made and by we've all made I really mean me, but if
my incompetence can prevent just one person from sanding through a plywood
veneer it will have all been worth ruining some of my projects
nah, not really out of all of the things to screw up in woodworking sanding
errors could be the most infuriating because we mostly sand near the end of a
project after we've spent hours being so careful building and assembling it's
kind of like if you lost a wheel on the last mile of the Indy 500 that could
happen right hi I'm Steve welcome to Woodworking for Mere Mortals the channel
dedicated to helping beginning woodworkers learn woodworking without a
lot of space or expensive tools if you're brand new to this hobby I've
created a tool buying guide that will show you how to set up shop for under
$1000 download yours at MyToolList.com also be sure to check out my sanding
basics video to learn everything you need to know about sanding there's links
to both of these resources down in the description in the real world woodworking
joints aren't always as perfect as they are on every Instagram post ever
so let's say you've joined two boards together that aren't exactly flush hey
it's just a little off and a couple of minutes of 60 grit sandpaper will smooth
it right out you fire up your sander and attack yay both sides are flush but now
you have a cupped board because you neglected the middle and if this was the
bottom of a box or something now you've got a rocker there's nothing wrong with
sanding uneven joints just make sure you sand equally along the length of the
board making a pencil mark along the entire board can help sand until it
disappears evenly by the way whenever you want to test if something is flat
use your table saw it's table is probably the flattest surface in your
shop this is a really common one a sander is a simple way to ease over the
sharp edges of a table top if you're gonna do
this pay close attention to the corners it's very tempting to maintain the same
sanding motion and just hit those corners right? well two things can
happen first you're a bit too enthusiastic and you basically removed
the corner it only takes the power sander a second to just nerf that corner
sure it won't poke an eye out but rounded corners can look kind of weird
second when you sand the vertical edge of a corner you might be left with a big
bulge the main reason this happens is because there's a flex to the sanding
disc when you press the sander against a corner there's concentrated force on
just a small part of the sander and the disc cups a solution is to use something
rigid like sanding sticks and ease over these edges by hand this is a free paint
can stirring stick from the hardware store
I used spray adhesive to stick some sandpaper to it we sometimes think the
only purpose of sanding is to remove gouges scratches and other rough spots
and while these are important try not to think of sanding as a spot procedure the
entire project needs to be sanded in order to achieve a good finish treat the
sanding phase of a project with as much attention as you give to making accurate
cuts probably the most neglected parts are wide faces say the top of a table or
the sides of a bookshelf we might spots and a few glaring problem areas then
just give the rest a quick once-over these surfaces might appear nice and
smooth but often times surface imperfections won't appear until you
apply a finish the main purpose of sanding is to prepare all surfaces to
accept a finish so get some headphones and some music and spend some quality
time in the sanding zone and everything I just said about not
neglecting the faces here's the exception and it's a big exception
plywood most plywood you will use for a woodworking project is presanded it may
need a little sanding but not much feel the surface with your hand if it feels a
little fuzzy you can knock down those wood fibres with 120 or 220 grit
sandpaper I definitely don't ever sand plywood
with anything more coarse than a 120 grit sandpaper and even then I just
lightly sand be careful not to hold the sander in any one spot the problem is
that plywood is made up of multiple layers of cheaper wood and then a thin
veneer of good wood on top if you use hardwood plywood say cherry or walnut
that veneer is even thinner and it doesn't take long to sand completely
through this paper-thin layer and just ruin the surface and this could be
exceptionally devastating because not only is it usually on a very visible
surface but there's really no way to fix it this might occur when you use solid
wood edging to hide the plywood edges and it isn't flush with the top or maybe
an inset top like this one since that edging is solid wood sanding it down is
no problem but as soon as it gets close to flush your sander will start abrading
the plywood and a second later you've got a nasty spot in that corner to avoid
this try sticking some painters tape to the plywood to protect it while you're
sanding and of course try your best to align the edge banding flush to begin
with the second problem that can lead to over sanding is trying to remove dried
glue if you get any glue on the plywood you can sand it off with 120 grit
sandpaper but just be super careful whenever I build with plywood I try to
be more diligent about glue and just wipe off any excess right away with a
damp cloth it doesn't take long to figure out that a round disc will not be
able to sand inside corners but what we might forget is how difficult it is for
a random orbit sander to sand all the way to the edge of an inside surface
let's say you're sanding the bottom shelf of a bookcase
the non-removable one you might want to sand right to that back edge or the side
edge so you run the sander along the surface pressed against the
perpendicular side and what you discover is a gouge all along that surface where
the edges of the sanding disk rubbed usually if you do this a couple of times
you'll learn not to make this mistake but if you're really prone to doing this
you can run some tape along that edge to protect it it's probably just fine to
avoid sanding that close I mean you're gonna have to sand the corners by
hand anyway and it'll just take a little bit longer to hand sand right up to
those inside edges plus these inside surfaces are usually secondary and won't
be visible usually just a light sanding is fine as with all sanding pay the
greatest attention to your primary surfaces the ones that people will see