3x21 or 3x24 Belt Sander

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Forum topic by nek4life posted 08-15-2020 05:49 PM 323 views 0 times favorited 5 replies Add to Favorites Watch
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29 posts in 569 days

08-15-2020 05:49 PM

Topic tags/keywords: question sander

I’m looking at purchasing a belt sander, looking at Makita because of the high ratings and it’s flat on the top so I could use it upside down as well in the shop.

I thought the 4×24 is probably overkill for my purposes, though feel free to try and talk me out of that…, so I’ve been looking at the 3×21 or 3×24 models. My inclination is to get the longer of the two in order to have better flattening capabilities. I’m thinking this must work similar to a hand plane, the longer the belt, the flatter you’re able to accomplish more easily. I also went to the store and the 3×24 seemed to be more balanced in my hands while holding it sideways if I want to sand down to a scribe line or something.

However, I noticed that most places don’t carry the 3×24in belts, which I probably won’t be going through them too, much, but it does worry me that in time I won’t be able to find them at all anymore.

So… should I just get the 3×21? I’m going to be using this for a house project, but would like to buy something that would work double duty in my shop as well.

5 replies so far

View JackDuren's profile


1324 posts in 1812 days

#1 posted 08-15-2020 06:12 PM

The smallest in cabinet shops in 3×24. Obviously the larger the sander the less work it is to flatten something.

Most inexperienced woodworkers do more damage with a belt sander than good.

View WoodenDreams's profile


1125 posts in 764 days

#2 posted 08-15-2020 06:15 PM

I have three 3×21 belt sanders, each with a separate grit on them. saves time from changing belts. I also have a 4×24 belt sander. I find that I’ll use the 4×24 almost every time verses the 3×21. For sanding large panels I find I end up with a flatter surface with the 4×24 verses using the 3×21. Maybe it’s me but with the 3×21, I sometimes end up with the 3×21 digging in on one side edge of the belt. Causing me to do more sanding to sand out the grooves made.

If you have the 3×24, you can cut the 4×24 belt down to the 3” width with a pair of scissors or metal shears (I use a regular pair of scissors to cut sand paper to size all the time), if you can’t find the 3×24 belts. We have a tool store in town that I if you look at their 3×24” belts they sell, They sell them not packaged and looks like they cut the 4×24 belts to 3” width themselves.

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John Smith

2682 posts in 1015 days

#3 posted 08-15-2020 06:24 PM

x2 with Jack D.

all I have ever had was four or five Rockwell 3×24s and one Skil 4×24
until last year, I had to buy a new one and got the plastic B&D 3×21.
going from a commercial model to the hobby model wasn’t that bad.
it got the job done. but, I really miss the larger footprint
for sanding the larger square footage projects.

I know of no reason why the 3 or 4 x24 belts are not common in your area.
other than the Covid Carpenters are coming out of the woodwork and buying
more than usual woodworking accessories.
also, I have no foresight that the 3×24 or 4×24 belts will ever disappear.
there is always the Online Ordering if you can’t find what you need locally.


-- there is no educational alternative to having a front row seat in the School of Hard Knocks. --

View Kelly's profile


3128 posts in 3797 days

#4 posted 08-15-2020 08:16 PM

I’ve had 3” and 4” belt sanders for about 45 years. I’m down to one now, a Porter Cable 3×21 and a their detail belt sander (better than a cat’s meow for scribing in a counter top).

I gave the Dewalt (of questionable quality) to a buddy, along with the case and stand it came with.

My old Bosch was a monster. It had enough weight it could be ran one handed, until you had to lift it at arm’s length, but went with the shop I sold thirty or so years ago.

I had a [disposable] Skill I loved because it was light and I could even use it overhead, but I had to rebuild it several times.

I’ve been in many places where I could drop into a store and get an emergency 3×21, but not a 4×24 belt, so I just stayed with the 21’s. It was a “ain’t broke and don’t need fixing” thing.

As was said, you can do a lot of damage with a belt, but you can also do a lot of good. Just as with the Porter Cable Siding Sander, with a 24 carbide grit metal plate I use to knock down a burl, slab or such. So too it goes with my 3-1/2 electric hand plane.

To me, it doesn’t take long to get pretty good at getting to where you can get to close to a flat most will call flat.

One of the tricks is, you can use the mean stuff (coarse) to get down there, but drop way back to where it takes a lot longer to bring things in (say 320) so you have to work harder as screwing up. That same concept has worked well for me, even on wood floors.

View Bill White's profile

Bill White

5303 posts in 4813 days

#5 posted 08-15-2020 09:04 PM

Just a quick point of info if ya will. Don’t buy a bunch of sanding belts because of joint failure Shelf life on ‘em is about 1 year.
Klingspor has all the sizes you’ll ever need.

-- [email protected]

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