Bench belt sander grit

[metricmonkeywrench]

I inherited a craftsman 4x36 bench mounted belt sander, it’s a pretty nice one with the 6in disk on the side. Both the abrasive belt and disk that was on it were of course shot. I had a new stick on 100 grit disk so that’s all set but now I have to figure out what to get for the main belt.

I tried google for recommendations but of course all that came up was for hand sanders and sales ads.

I’m looking for a recommendation for a good general purpose grit so I don’t have to be changing belts between tasks. I’m all over the place as far as materials from wood to steel for all the the different occasional homeowner type tasks.

Thanks in advance

[Der Gebirgsjager]

The finer the grit the smoother the finish, right? So it depends on what you want to work with, and saying working with materials from wood to steel really doesn't tell us too much other than that you'll need different grits for different materials, jobs, and expected results. A compromise might be 80 grit, but I'd get a selection from 60 to 600 grits.

DG

[super6]

320 grit is a good compromise.

[Winger Ed.]

Depending on what you intend to do with it; rapid material removal, shaping, fine finishing, etc. you might want 2-3 different ones.

[Misery-Whip]

I have 60 on mine. But i also have 80. 60 grinds with less heat than 80. Ive also tried 120 but it doesnt last long until its plugged or wore out. And will heat aluminum in a hurry and can leave burn marks on wood.

Ive used some with 40 grit, and they are a beast...so watch your knuckles....

[elmacgyver0]

I have one of the Hazzard Fraught units, love it and use it all the time.
Right now, I have an 80-grit belt on it, but it takes about 15 seconds to change a belt.

[elmacgyver0]

I have a kind of eraser thing from Popular Mechanics, hold it against the belt while it's running, and it cleans all the clogging from the belt.
What is left of the label says Granlund Sanding Insurance, Cleaner for Abrasive Belts and Discs
GranLund Engineering Co., Ware, MA 01082

Mine will most likely last the rest of my life so I do need any more, but I included as much info as I have and highly recommend it, for anyone who wants to extend the life of their abrasive belts and discs.

[country gent]

Abrasives are a unique area. To fine a grit produces heat and slows work down. To coarse and poor finish and control drops. The wrong grit material an it dulls or breaks down to fast.
Once set up and running changing belts isnt a big deal and dosnt take long. 3-5 belts on hand and spares on hand will be handy

[elmacgyver0]

As everyone here knows, you start out with a coarse grit and work your way down to a fine grit.
There is no one grit fits all.

[JRLesan]

Just today received from McMaster 4 120 grit belts. That is my grit of choice for general purpose one size fits all. Will clean burrs left from machining off steel, stainless, aluminum, brass, copper et al. Can also do wood. They were around $7.00 ea which means throw it away when it no longer works.

[405grain]

I just retired this July from being in charge of two different machine shops. I had a 6"x 48" belt sander in both shops. For 99% of everything I used those sanders on I ran 80 grit wet/dry belts. The bulk of operations were de-burring and material removal on all varieties of metals, and some occasional wood working. On those times that I needed a finer finish, I would do the rough sanding with the belt, then finish the part by hand.

There are two things that I can advise you on, no matter what grit you decide to use. First, on a belt sander, if you hold a part incorrectly, or have a part slip from your hand, and it puts a tear or hole (no matter how tiny) in the belt - stop using that belt and replace it immediately. It's a real drag when something like this happens with a new belt, but take my word for it, you need to replace that belt. If you don't, the very next time that anything you're sanding touched that hole the belt will instantly break. When it does, more often than not it will slap your hand harder than any human is capable of! I've seen this happen way too many times. (Remember; the people that do the most damage to equipment and parts aren't the one's that don't know what their doing. It's the one's that THINK they know what their doing.)

OK, the second thing. On the disc sander that's on some belt sanders. The sticky backing on the sanding disc doesn't always stick to the metal disc, especially if the metal disc is cold. The sanding disc will adhere to the metal disc just good enough for it to come up to speed, and then when you start sanding on it it will come off and fly across the shop like an abrasive frisbie. The trick I've learned to prevent this is to heat up the metal disc with a propane torch until it is just a little too hot to touch. Then stick on the sanding disc and (using some leather gloves) make sure that it's pressed on all the way around. Once the disc has cooled it's ready for months of trouble free use.

[Baltimoreed]

I’m up to 4 bench sanders. Two with belts, a 4x36 and 1x42. And 6 and 12 inch disc sanders and an oscillating drum sander. The big 12 in disc is the nicest and truest but the 1x42 inch was an old Montgomery Ward tool that I’ve rebuilt several times, only thing that’s still original is the frame and handle. I’ve used it the most.

[Handloader109]

I use a 4x36 for woodworking. I use no finer than a 120 grit, usually 100 or even 80 is good. The coarser, the longer they last. Do NOT buy a dozen unless you plan on going through them in a year or less. No matter the brand, the adhesive deteriorates and the joint will let go. Also get you a crape cleaner and use it

Sent from my SM-S908U using Tapatalk

[pworley1]

A belt sander that size is usually intended for removing a lot of material fast and not for finish work so most of the time they have 60 or 80 grit.

[xs11jack]

For do it yourselfers to clean a clogged belt a lot of supply houses have these light colored pieces of soft rubber that do a good job of cleaning the belt. But- they are kind of pricey. If you have a GoodWill store near by check the shoes there every now and then for the waffle soled shoes. The soles are the same as the ones from supply houses but a lot cheaper and really does a good job.
Ole Jack

[Mal Paso]

Get them all! 36 grit for shaping metal or anything else to 320 for finish. They are cheap for what they do. Here's a start. https://www.amazon.com/gp/slredirect/picassoRedirect.html/ref=pa_sp_atf_aps_sr_pg1_1?ie=UTF8&adId=A10061712F5LACRM9QPIS&url=%2FInch-Assorted-Aluminum-Oxide-Sanding%2Fdp%2FB08R2KPF19%2Fref%3Dsr_1_2_sspa%3Fcr id%3D31U9MWMD5TFQH%26keywords%3D4x36%2Bsanding%2Bb elts%26qid%3D1663979792%26sprefix%3D4x36%252Caps%2 52C191%26sr%3D8-2-spons%26psc%3D1&qualifier=1663979792&id=8188171178754629&widgetName=sp_atf

https://www.amazon.com/Pack-36-inch-Sanding-Belt-Sandpaper/dp/B08XZMY6M3/ref=sr_1_5?crid=31U9MWMD5TFQH&keywords=4x36+sanding+belts&qid=1663979792&sprefix=4x36%2Caps%2C191&sr=8-5

I have a 6x48 belt with a 9in disk. 5 or 6 grits 36-320. Awesome Tool!

[M-Tecs]

I also save the "worn out" belts. Once they are too worn for material removal they work well for polishing metal.

[ulav8r]

Belts made for metal will do a decent job on wood. Belts made for wood won't last long if used on metal.

[Scrounge]

I inherited a craftsman 4x36 bench mounted belt sander, it’s a pretty nice one with the 6in disk on the side. Both the abrasive belt and disk that was on it were of course shot. I had a new stick on 100 grit disk so that’s all set but now I have to figure out what to get for the main belt.

I tried google for recommendations but of course all that came up was for hand sanders and sales ads.

I’m looking for a recommendation for a good general purpose grit so I don’t have to be changing belts between tasks. I’m all over the place as far as materials from wood to steel for all the the different occasional homeowner type tasks.

Thanks in advance

If you don't care what the stuff you're working on looks like, put an 80 grit belt on it and call it good. If you have at least some pride in the work you do, you should have a progression of grits from 60-80-100-120-220(or 240)-400 and that will let you do just about anything, and have a decent finish when you're done. You can get belts for it at harbor freight if you're like me, a cheap bastrich. If you only do wood, the cheapest belts will do most everything you need. if you want to do wood and metal, you'll need the same in zirconia ceramic. They're better for metal. If all you do is coarse grinding, you can probably get buy with the first couple or three grits. If you're making furniture, or knives, you'll want finer grits once you've roughed out the blades.

I try not to work with wood, myself. I find metal more forgiving. Measure twice, cut once. Weld, repeat! Just works better on metal. ;)

Bill

[MrWolf]

I just retired this July from being in charge of two different machine shops. I had a 6"x 48" belt sander in both shops. For 99% of everything I used those sanders on I ran 80 grit wet/dry belts. The bulk of operations were de-burring and material removal on all varieties of metals, and some occasional wood working. On those times that I needed a finer finish, I would do the rough sanding with the belt, then finish the part by hand.

There are two things that I can advise you on, no matter what grit you decide to use. First, on a belt sander, if you hold a part incorrectly, or have a part slip from your hand, and it puts a tear or hole (no matter how tiny) in the belt - stop using that belt and replace it immediately. It's a real drag when something like this happens with a new belt, but take my word for it, you need to replace that belt. If you don't, the very next time that anything you're sanding touched that hole the belt will instantly break. When it does, more often than not it will slap your hand harder than any human is capable of! I've seen this happen way too many times. (Remember; the people that do the most damage to equipment and parts aren't the one's that don't know what their doing. It's the one's that THINK they know what their doing.)

OK, the second thing. On the disc sander that's on some belt sanders. The sticky backing on the sanding disc doesn't always stick to the metal disc, especially if the metal disc is cold. The sanding disc will adhere to the metal disc just good enough for it to come up to speed, and then when you start sanding on it it will come off and fly across the shop like an abrasive frisbie. The trick I've learned to prevent this is to heat up the metal disc with a propane torch until it is just a little too hot to touch. Then stick on the sanding disc and (using some leather gloves) make sure that it's pressed on all the way around. Once the disc has cooled it's ready for months of trouble free use.

Nice tip about heating the plate. Thanks,.
Ron

[metricmonkeywrench]

Thanks guys, looks like the 80 grit or so will be the default for now. This fill the gap between my bench grinder and hand sanders and give me somewhere to do non-ferrous metal stuff as well.

Yes, I am aware if the wide world of abrasives and when to use what for my various hand, palm, 1/3 sheet and belt sanders all of which already have various grits and grades on hand for tasks ranging from woodworking to metalwork. As time goes by I will of course expand the belt selection based on the task but 99% of the time this will likely be in the corner collecting dust, but available for use.

For years my go to has been a craftsman 3x18(ish?) hand held belt sander upside down with the trigger locked on. I had to chase that sucker around the workbench despite being on a rubber mat until the belt tracking adjuster broke, so this is definitely an improvement.

[KCSO]

Depending on the project I change belts just about every job I run from 80 grit to 320 same with my knife grinder. It will come with experience but I would start with 80 120 220 and go from there.

[Dio]

OK, the second thing. On the disc sander that's on some belt sanders. The sticky backing on the sanding disc doesn't always stick to the metal disc, especially if the metal disc is cold. The sanding disc will adhere to the metal disc just good enough for it to come up to speed, and then when you start sanding on it it will come off and fly across the shop like an abrasive frisbie. The trick I've learned to prevent this is to heat up the metal disc with a propane torch until it is just a little too hot to touch. Then stick on the sanding disc and (using some leather gloves) make sure that it's pressed on all the way around. Once the disc has cooled it's ready for months of trouble free use.

I've had this problem and never thought to heatthe disc....thanks!

[georgerkahn]

I, too, am most appreciative to hear and learn of the heat application trick! Thank you! I might add, too, the necessity (imho) of buying/having the rubber belt cleaner at hand. 305092 For less than ten U S dollars you may purchase a set of two -- trust me, a MANY year supply :) -- from Amazon. I do not consider the belts as inexpensive -- my unit takes 6" x 48" belts -- and the rubber belt cleaners at the least triple their usable life!
geo