What brand 3x21 sanding belt that doesn't break prematurely?

[mike sato]

I need to restock the sanding belts for my 3x21 inch belt sander. I only sand wood.

The belts that I've bought over the years either break apart right away, when they get hot, or as they age (like less than 2 years). Some belts broke apart after a few minutes of use even when just purchased (though I don't know how long they might have been on the store's shelf or in storage).

I remember using my dad's belt sander (like 50 years ago) and the belt joints were overlapped so had to be installed per the directional arrows. Don't remember them ever breaking apart, just discarded due to grit wear. The belts I see now are all taped so no directional arrows, and the ones I've bought so far don't last long.

What's a good brand of 3x21 inch sanding belt that doesn't break apart?

Also, what grits and grit type do you use? I've been using 50, 80 and 120 grit aluminum oxide belts.

EDIT:
I neglected to mention that I do always adjust the belt tracking so that the belts do not rub against the metal or track too far out. So that's not a cause of my belt breaking problems.

[Cary Falk]

I have just used whatever brand Home depot or lowe's sells without issue. They get dull or gummed up long before they break.

[glenn bradley]

I've got belts leftover from a Klingspor Bargain Belt shipment almost a decade ago. Used one just the other day without issue. They are stored in my SoCal garage so temp swings and humidity changes are minimal.

[Steve Peterson]

I've got belts leftover from a Klingspor Bargain Belt shipment almost a decade ago. Used one just the other day without issue. They are stored in my SoCal garage so temp swings and humidity changes are minimal.

Humidity changes might be the issue. I have no problems with belts breaking and some of mine are over 10 years old. I am in northern CA, so also minimal humidity changes.

[Bruce Wrenn]

The tape used to hold belts together ha a ONE YEAR life expectancy. Klingspor keeps it in a freezer until they are ready to use it. Belts are one of the few items it doesn't pay to stock up on. Once on a factory tour (not Klingspor), I bought a case of belts. Turned out to be the most expensive belts I ever bought. Most broke upon first use, due to age.

[Mike Circo]

The tape used to hold belts together ha a ONE YEAR life expectancy. Klingspor keeps it in a freezer until they are ready to use it. Belts are one of the few items it doesn't pay to stock up on. Once on a factory tour (not Klingspor), I bought a case of belts. Turned out to be the most expensive belts I ever bought. Most broke upon first use, due to age.

Bruce may have something here. I had not used my belt sander for a very long time and finally pulled it out for a small project. I killed 4 old belts in about 10 minutes. All broke at the tape junction.

[Frank Pratt]

I've never had a Klingspor belt come apart & my stock is easily 10+ years old. And they sometimes get thoroughly abused.

Humidity in the shop ranges from very low in winter to about 30% in the summer. I don't know what the answer is, because some folks do have problems with them.

[Steve Jenkins]

You’re talking about a scarfed lap joint. I haven’t seen one in a looong time. Don’t know if anyone still makes them. I’m sure that the tape used on butt joints does have a life span as I’ve also had many older unused belts break.

[mike sato]

Cary Falk
I have just used whatever brand Home depot or lowe's sells without issue. They get dull or gummed up long before they break.

glenn bradley
I've got belts leftover from a Klingspor Bargain Belt shipment almost a decade ago. Used one just the other day without issue. They are stored in my SoCal garage so temp swings and humidity changes are minimal.

Steve Peterson
Humidity changes might be the issue. I have no problems with belts breaking and some of mine are over 10 years old. I am in northern CA, so also minimal humidity changes.

Frank Pratt
I've never had a Klingspor belt come apart & my stock is easily 10+ years old. And they sometimes get thoroughly abused.
Humidity in the shop ranges from very low in winter to about 30% in the summer. I don't know what the answer is, because some folks do have problems with them.

Interesting that your experiences are no problems. Maybe it is storage temp and humidity related.

Bruce Wrenn
The tape used to hold belts together ha a ONE YEAR life expectancy. Klingspor keeps it in a freezer until they are ready to use it. Belts are one of the few items it doesn't pay to stock up on. Once on a factory tour (not Klingspor), I bought a case of belts. Turned out to be the most expensive belts I ever bought. Most broke upon first use, due to age.

Very good feedback. I suspected a one year life expectancy due to the experiences I mentioned in my first post. Pretty shameful on the belt manufacturers to not use a better glue and charge a few pennies more.

Mike Circo
>> Quote Originally Posted by Bruce Wrenn View Post
The tape used to hold belts together ha a ONE YEAR life expectancy. Klingspor keeps it in a freezer until they are ready to use it. Belts are one of the few items it doesn't pay to stock up on. Once on a factory tour (not Klingspor), I bought a case of belts. Turned out to be the most expensive belts I ever bought. Most broke upon first use, due to age.<<

Mike said:
Bruce may have something here. I had not used my belt sander for a very long time and finally pulled it out for a small project. I killed 4 old belts in about 10 minutes. All broke at the tape junction.

Yep Mike, same thing has happened to me.

Steve Jenkins
You’re talking about a scarfed lap joint. I haven’t seen one in a looong time. Don’t know if anyone still makes them. I’m sure that the tape used on butt joints does have a life span as I’ve also had many older unused belts break.

Thanks for letting us know the name of the lap joint. That was like 50 years ago when I used to use my dad's belt sander. And thanks for confirming that you've also had older unused belts break.

SUMMARY:
Any other sanding belt brand recommendation other than Klingspor?

[John K Jordan]

The belts that I've bought over the years either break apart right away, when they get hot, or as they age (like less than 2 years).

Yikes, I've never had a belt come apart. I'm wondering about the "when they get hot" comment. Could you be using too much pressure? I've touched a belt after use (turned it off first! ) and it was warm but not hot.

Do you sand a lot where the belt curves around the end pulley? That might apply considerably more pressure than where it is flat. If that is the case, a spindle sander might be good. I use an oscillating spindle sander and I thing the up and down motion keeps things cooler (besides distributing the abrasive wear more evenly.)

JKJ

[Nick Decker]

I've never had a belt come apart either. I've been using the Mirka belts sold by Amazon, on the Ridgid OSS. Lately, I've been doing bandsaw boxes, so they do get a workout.

[Curt Harms]

I have belts from Industrial Abrasives in Reading PA. on the small Porter Cable belt sander and 6 X 48 machine. I haven't had one break yet and some are several years old. They are stored in a basement shop so temp. and humidity are pretty stable.

[mike sato]

I have belts from Industrial Abrasives in Reading PA. on the small Porter Cable belt sander and 6 X 48 machine. I haven't had one break yet and some are several years old. They are stored in a basement shop so temp. and humidity are pretty stable.

Thanks for sharing your experience with the Industrial Abrasives belts not breaking. I'm going to try the Mirka brand first but will keep your post in mind in case it's needed in the future.

Thanks,
Mike

[Curt Harms]

Thanks for sharing your experience with the Industrial Abrasives belts not breaking. I'm going to try the Mirka brand first but will keep your post in mind in case it's needed in the future.

Thanks,
Mike

Mirka is good stuff too. I have some Mirka ROS discs and 1" metal sharpening belts. No problems.

[mike sato]

I've never had a belt come apart either. I've been using the Mirka belts sold by Amazon, on the Ridgid OSS. Lately, I've been doing bandsaw boxes, so they do get a workout.

I checked Mirka belts on amazon and wow! Customer reviews are: 5 stars=91%, 4 stars=3%, 3 stars=3%, 2 stars=3%, 1 star=0%. Outstanding! Many reviews mention that these belts last without breaking.

It was funny that one 5 star review said: "I had previously bought diablo brand 80 grit and It didn't take much for them to rip at the seam. ...snip..." This mirrors my experience. The belts I have now are Diablo brand and they are breaking.

I'm going to order some 80 and 120 grit, 3x21 inch Mirka belts and see how long they last. Looks pretty good and I'm encouraged.

Thanks for sharing,
Mike