20" Disc Sander or a 6" Edge Sander?

[Keegan Shields]

If you only had room for one, which one would you choose and why? I'm thinking the disc sander is capable of higher precision tasks like fitting miters, but I've never used an edge sander so what do I know?

What does each sander do well? Which one would you pick?

Thanks!

[Jeff Roltgen]

As usual, reply starts with the qualifier:
"depends on how you use it"

Never have been compelled to head to a sander with a mitered stick in hand. Didn't need it, and certainly have never had one on hand that lead me to believe it could out-perform accuracy of cut from either miter or table saw with miter sled and a heck of a good blade.

However, I'd hate to be without an edge sander.
I did upgrade from a 6 to a 9" edge sander a few years ago so I could more easily sand up to 9" dovetailed drawer boxes after assembly. Just makes that clean-up a snap.
Naturally, all the other levels of versatility, like sanding curves on the idler drum table, straight and tapered legs on the platen after sawing. Door/drawer panel edges. Even quick prep for stain sampling on scraps.

I do have a very small bench-top VS 5" disc sander. Uses: cleaning up putty knives, grinding edges off small cabinet latches, shaping glue and wood filler sticks tailored to odd applications. I imagine if I had a large 10-12" cast iron version, I may find some more accuracy and inspiration to use it.

IMHO, the sheer number of operations I do almost daily on an edge sander lead me to conclude hands down, it's the one I couldn't give up.

jeff

[Kevin Jenness]

What do you want to do? A 20" disc sander with abrasive closely adhered to a flat platen will be slightly better at producing a very flat surface and will give a greater height capacity. The force is down into the table so no kickback potential (unless you stray into the wrong quadrant), and the sanding pattern will often be crossgrain and need further cleanup before finishing. Changing the discs with psa or hand applied stickum can be messy and time-consuming. If I can't get a perfect miter off the saw (and I can with a sliding table saw and finish blade) I go to a block plane, sanding block or shooting board.

A 6" edge sander is very versatile for putting a finish sanded surface on parts as long as the platen (can be used on longer pieces with some cleanup at the join). The platen does need to be truly flat for good results and may need some attention. Tapering, sneaking up on a fit of doors and drawers, cleaning up sawn edges accurately without tearout, sanding the face of small parts, sanding end grain, sanding inside curves on the idle roller are all possible. It does pull pieces toward the drive roller so caution is needed there. Belt changes are fast. You rarely see a large disc sander in a cabinet shop, and you will rarely see one without an edge sander.

An oscillating edge sander is best for abrasive life, but not essential. I have a 3 phase edge sander with a vfd which allows slowing down the belt speed for woods prone to burning, especially on end grain when the belt is not fresh.

[Jim Becker]

I'm in agreement with the others...they are very different tools, even though you "can" do some cross processing between them. What the majority of the work you need to do is going to help you make your choice.

[Aaron Inami]

In my opinion, I would pick edge sander. Several points:

On your 20" disc sander, there is a limited amount of sandpaper. If you think in equal terms, the 20" disc sander only has about 12-40" of sandpaper length (when you compare to an edge sander). This isn't an exact figure becase the disc sander is a circle, but the circumference of your 20" is 62". On a 6" edge sander, you have anywhere from 90-108" length of sandpaper to work with. While you can clean the paper of either machine, the edge sander will last longer.

If you have a long edge you need sanded, this becomes difficult on a disc sander. As far as precision is concerned, not all edge/belt sanders are created equally. I'm not intending to push a specific model, but I decided to buy the HS950 myself. This video was very influential:

https://www.youtube.com/watch?v=fhsxQG9FbnE

Further on in the video, he shows the accuracy possible with the HS950 by sanding a perfect end on a piece of wood using the miter gauge. Of course, you can do compound angle on a miter since you can adjust both the miter gauge angle and the table angle (obviously, you can do this on a disc sander as well).

Probably one of the biggest points for buying the HS950 is the ability to sand an angle anywhere from 90 degrees all the way down to 0 degrees. The sanding platen on the HS950 will tilt all the way down to flat (essentially becomes parallel with the table). This means you can sand a very extreme angle. Most all the edge sanders or disc sanders I have seen only allow a tilt angle down to 45 degrees.

Another thing about the edge sander is the abiilty to create a perfectly flat edge up to about 36-40" long. On many edge sanders, the end-cap can be flipped up if you need to run a longer edge through the sander (sliding the board from right-to-left).

Edge sanders also provide convex sanding inside of a curve using the end of the belt.

Changing the sandpaper on a disc sander is somewhat painful because you have to completely remove the table and sometimes the case cover. Getting the sandpaper off the disc is somewhat of a hassle. On the HS950, switching sandpaper is quick and easy. This allows you to work with multiple grits very conviently.

If you are looking at edge sander, don't go cheap. The Hammer HS950 is going to be close to $3k once you have the miter gauge, sandpaper and tax included, but that's about the average price of a 20" disc sander anyways. On the cheaper edge sanders, such as the $1500 Jet, there are several areas where the machine is difficult or a hassle to work with. I can expound on these if you want.

It's up to you, but I would avoid the 6" Grizzly edge sanders because the platen is just sheet metal without any backing support structure. These are often bent and deformed.

The 9" Grizzly edge sanders might be okay because they are a copy of the Powermatic, but they are huge and the table does not tilt more than 45 degrees.

[Aaron Inami]

A note on the Hammer HS950. It is a European machine, so the sanding belt is 150mm x 2515mm. The translated size is a 5.9" x 99" sanding belt. The sanding belts are available from Felder and not that expensive ($32-42 for a box of 5 belts). What really sold me on this machine is:
- Quality and accuracy of machine
- Ease of use of the machine (after watching the video, it felt like there wasn't many complex moving parts, but it is designed extremely well to be easy to use).
- 90 to 0 degree angle adjustment
- oscillation of the belt works better than other machines (such as Jet)

If you want a larger 9" machine, they can be nice, but they are HUGE! Though, there is a Powermatic that has been up for sale for many months for a good deal:
https://woodweb.com/exchanges/machinery/posts/537263.html

[Jonathan Jung]

For woodworking, an edge sander hands down. I have both. Unless you only want to fit miters, the edge sander will be invaluable for a host of other tasks.

[Keegan Shields]

Jeff, Kevin, Aaron, Jonathan - Thank you for your thoughts! These are great insights and are very helpful.

I'm looking at a used 20" disc sander and an old Powermatic 13 6" edge sander. I am mostly into chair making but do plenty of other projects.

Using the edge sander's idle drum for inside curves would be a great upgrade. I currently use the desktop Ridgid drum/belt sander and am looking for an upgrade.

Its an interesting point that edge sanders are far more common than large disc sanders. There are likely many good reasons for that.

[Robert Hayward]

I have both, a 20" disc and a 6" edge. For years I had a Rikon 50-120 and had always wanted a large disc sander. When I was upgrading my shop in anticipation of retirement I chose to sell the Rikon and get the big disc sander thinking I would not miss having a belt sander. Regretted that decision almost from day one. Really liked and used the Powermatic DS20 but missed having a belt sander. About a year and a half later made the room in the shop and ordered a 6 X 99 edge sander.

Both machines get used and I would not want to be without either one. Side note, when I bought the 20" disc sander it was a little more than $1000 cheaper than the current price. The edge sander went up in price almost $700 from when I first looked at them, from ~$1000 to ~$1700. In hindsight I should have bought both back when I first started looking.

[Aaron Inami]

It sounds like you are budget limited, since you are looking at used machines. I'm not directly familiar with that Powermatic 13, but it is another variation on the Jet / Laguna / Baleigh / Oliver / Axminster design. Same machine design, but small things might be different. Two things to keep in mind on this machine design:

- The stopper for the 90 degree upright position of the sander/platen was a problem on the stock Jet sander. I'm not sure if this is the same on the Powermatic, but you might need to fabricate a custom stopper.

- The table can be slanted (which is not common on most edge sanders). However, the table is also difficult to adjust up and down by yourself. It requires loosening of two hold down knobs and then you have to support the table fully when moving it up or down or slanting it.

[Warren Lake]

edge sander oscillating if possible

[Richard Coers]

When you sand something a bit wider on a disc sander, you are dealing with different rates of surface speed. It will remove material faster on the larger diameter section. The belt is consistent. Priced 20" discs? Outragous!

[Tom Bain]

I have both, and the edge sander gets a lot more use … but I really like having the disc sander (16”), too.

[Bill Dufour]

Seems like an edge sander takes up double the room?
Bill D

[Joe Calhoon]

I also have both and the edge sander gets used way more. The disk sander is better for fussy end grain work but in most cases the edge sander does fine on this. The disk offers a little more control on sanding outside curves but then you have to deal with the cross grain marks. I do use the disk sometimes for fine tuning miters from curve mouldings to straight. Normally though the double miter on the sliding saw takes care of any miter work. The drum on the edge sander works about as well as a OSS for inside curves and that’s another bonus of a edge sander.
I have a nice Kundig now but for years got along fine with a simple non oscillating Rodgers sander. I built a angle table and some other accessories for it that worked well for many tasks.