abrasive 1x30 belts: lap or butt joint?

[cprstn54]

I would like to use the Harbor Freight 1x30 belt sander and knife sharpening angle accessory sold on Amazon.

I was looking for some belts with lap joints but couldn't find any, only butt joints.

I am concerned that the butt joint will fail in seconds, with a blade edge digging into the seam.

Anyone know a vendor selling 1x30 belts with lap joints?

Any other useful info?

Ken C

 

[thebrain]

All the 1×30 belts I've been able to find have angled butt joints, I don't sharpen edge towards the direction of rotation. They run pretty smoothly but that size belt sander cannot achieve the belt tension that a large professional grinder can and would probably dig into or cut the belts.

 

[Rob Babcock]

I'll confess I don't pay a lot of attention to the joints. Nearly all the sharpening in my shop is edge leading on a 1x30 and so far I've never cut a belt. Of course, I go through them at a decent pace. A lot of my sharpening has been for restaurants and the average knife is in stunningly bad shape!

 

[Bill DeShivs]

Sharpening edge-up is asking for trouble.

 

[Rob Babcock]

If that was the case I'd have known it several thousand knives ago.

 

[Bill DeShivs]

What would I know?

 

[Wowbagger]

If that was the case I'd have known it several thousand knives ago.

Speaking up for Mr DeShivs but having limited experience with belt grinders and NO experience with pro belt grinders for knife making : I have thought about this a bit.

50 years ago I planned to make knives as a side income while I pursued my number one priority of self employment . . . back then , 15 years old and living with my parents I read the knife making book : Step-By-Step Knifemaking by David Boye . Unlike most people , I knew EXACTLY what I wanted to do with my life and was already well on my way to self employment .The world changed , I never got to suport my self from my number one priority and so never made knives for a part time income either. Long story .

HOW EVER I still have the book and I quote from page 76 : . . . if you turn the point or edge of the blade into the belt , the wheel will catch the blade, doing damage to the belt , the blade, and possibly to your hands . Be very careful about this .

He is working with a 40-grit belt at this stage .

I agree that with long experience , total focus and a light touch it is possible to survive edge into the belt-travel grinding . . . the novice with other things on their mind . . . could . . . quite easily GET HURT !

Personally I do all my blade thinning , on my own knives , on a "hand held " type belt grinder / sander ala Charlie Mike (fixed in place ) and almost every bit of it edge trailing .

 

[Wowbagger]

Any other useful info?

Since I am ON :
Most people smirk when I say it (most of them obssesed with talking about how much money they "saved") . . .
annnnnd maybe the company has improved ; they would have to have improved A LOT to get me to walk in the door again.
but
Stay the F away from Harbor Freight .
I KNOW good tools .
I use real pro tools every day to make my living .
I repair good tools when they begin to show their age and crap tools when they fail .
I have bought less than adequate tools from other vendors because there was absolutely nothing on the market that I could find , at any price , that would fill my requirements . Many of those went POP in the middle of a job, or the bearings seized up so bad the motor would over heat and trip the thermo over load switch while doing light work . . .
nah dude nah
Come to think of it now the machine that would stop from heat was an inexpensive 1x belt grinder bought else where . It just sits because I have never taken the time to rebuild it so it will run right.
REAL tools cost money.

When HF first opened in Colorado I went into their stores in two of our largest cities and was apauled at what I saw there.
I am not a China basher ; they can work to any standard demanded of them.
in the case of HF I have found the "demands" are very low.
At least they were ; including spray grease lube which my employer picked up there not long ago .
SUCKED
I went out and bought WD-40 brand spray grease and it worked perfectly to the end of the contents !
YOU'VE BEEN WARNED .

PS: on the 1x belt grinder ; it is all coming back to me now : the pullies are too small diameter ; it has a heavy duty automotive or lawn mower grade "fan belt" . The belt slips and needs to be overly tight and all this creates heat that travels into the bearings and they start to seize up and then it all goes to hell and the motor stops.

Fixing this would require bigger pulleys which I looked into and then spacing the base up to clear them maybe some welding .
I just bought hand held belt sanders / grinders which I needed anyway and never looked back.
I don't do enough knife work or have the room for a full on pro knife grinder .

 

[DeadPineKnives]

Sharpening on a belt sander is an awful idea, period. Especially the HF 1x30 which runs at a screaming 3600 rpm. Maybe if you had a 2x72 with a VFD and had a 600 grit belt running on the lowest setting, but with a 1x30? You're asking for a heap of trouble.

Get yourself a diamond stone.

 

[Rob Babcock]

I think there's some misunderstanding about sharpening on belt sanders. I had a HF 1x30 twenty years ago and I agree it runs too fast. That's why no one I know has used it for professional sharpening in over a decade. Of course I can't say no one does but I've not seen it. In my shop I have three Bucktool low speed 1x30 machines which run at 1750 fpm, half the speed of the HF. Rikon makes a popular 1x30 with a VFD and the popular Tooklr had a DC motor with speed controller. The bulk of the guys I know are doing edge leading with an angle guide, and there's virtually no possible way could throw a knife on it unless you were using a leather belt and even that is unlikely. If you to catch a belt it would split in an instant and fly behind the guide and the knife would be arrested by the guide, there's no physical way it could anything else. To be clear if you didn't use an angle guide I suppose what you suggest might be theoretically possible but no one that I know does edge leading freehand for precisely that reason.

For twenty years I did most of my sharpening on water stones, reserving belts mostly for repairs and thinning. My primary machine for over 15 years has been a Kalamazoo SM1 that runs at 1750, generating very little heat. Eventually I discovered the angle guide and did some experimenting and confirmed the superiority over edge trailing. Eventually I flew out to Hawaii to train at Curry Custom Cutlery. The man reason I went was to study sharpening convex shears on a flat hone but also logged some time on Cliff's knife sharpening gear, a bank of low speed 1x30s with angle guides, used edge leading. I doubt Cliff invented the technique but he's been using this system for at least seven years. He said that in that time he's cut two belts, both of them being in the first year or two. He has done about 40,000 knives this way IIRC. That's one cut belt every 20,000 knives.

It should be obvious but in case it's not he strops edge trailing, and most of the time he uses a felt belt doped with diamond, but also a leather wheel at times.

I would be curious to know how many folks here sharpen professionally, and of those that do, how many do it all on stones. I consider myself maybe a little faster than average freehanding on stones but I'm not fast enough to make much money at it. Certainly not with some of the stuff that walks into my shop. Yesterday a chef brought in all the house knives, and this batch was in terrible condition. Some may have never been sharpened, and certainly done had ever been thinned. The bolsters were mostly 1/4" or more proud of the edge and most had rounded or broken tips. He sheepishly said he wasn't sure how many were salvageable. Had I been using water stones or even my Sharpal and Atoma plates these would have been some tough sledding. I have a WEN knockoff of a Tormek and it's not really fast enough to fix stuff like this, either.

FWIW, I do offer water stone sharpening for folks that want it. And a fair amount of folks with Japanese knives do request it. My base price for that is about 3x what I charge for the standard sharpening depending on how high the polish, the size & type of the knife and what kind of condition it's in.

NOTE: I'm only referring to 1x30 belts. I wouldn't go edge into my 2x42 grinder much less a larger or more powerful one. The kind of grinders a knifemaker might use to build knives is a much different beast than the 1/4 hp machines running a 1" wide belt.

 

[Rob Babcock]

Stay the F away from Harbor Freight .
I KNOW good tools .
I use real pro tools every day to make my living .
I repair good tools when they begin to show their age and crap tools when they fail .
I have bought less than adequate tools from other vendors because there was absolutely nothing on the market that I could find , at any price , that would fill my requirements . Many of those went POP in the middle of a job, or the bearings seized up so bad the motor would over heat and trip the thermo over load switch while doing light work . . .
nah dude nah
Come to think of it now the machine that would stop from heat was an inexpensive 1x belt grinder bought else where . It just sits because I have never taken the time to rebuild it so it will run right.
REAL tools cost money.

When HF first opened in Colorado I went into their stores in two of our largest cities and was apauled at what I saw there.
I am not a China basher ; they can work to any standard demanded of them.
in the case of HF I have found the "demands" are very low.
At least they were ; including spray grease lube which my employer picked up there not long ago .
SUCKED
I went out and bought WD-40 brand spray grease and it worked perfectly to the end of the contents !
YOU'VE BEEN WARNED .

PS: on the 1x belt grinder ; it is all coming back to me now : the pullies are too small diameter ; it has a heavy duty automotive or lawn mower grade "fan belt" . The belt slips and needs to be overly tight and all this creates heat that travels into the bearings and they start to seize up and then it all goes to hell and the motor stops.

Fixing this would require bigger pulleys which I looked into and then spacing the base up to clear them maybe some welding .
I just bought hand held belt sanders / grinders which I needed anyway and never looked back.
I don't do enough knife work or have the room for a full on pro knife grinder .

I did want to mention that I agree completely. Back when I bought mine it was $35 and it showed. It runs too fast, every part is cheap on it. The Bucktools I have are cheapish at $150 or so but serviceable. And you can upgrade a lot of the parts. If I was to upgrade from them I'd love to try some Viel machines.

 

[Wowbagger]

To be clear if you didn't use an angle guide I suppose what you suggest might be theoretically possible but no one that I know does edge leading freehand for precisely that reason.

There you go !
I would add : watch out putting the blade in and out of the guide while the machine is running (who turns it off just to swap sides ?) if it is the fixed to the machine type guide instead of a guide clamped to the blade ala Tormek or Paper sharpening wheel world.
Then there is the whole blade thinning thing . . . can't clamp to that . . . and . . . I''m always going back and forth from one side to the other to keep the spine centered .

PS : with the hand held type wide belt sanders fixed to the bench , ala Charlie Mike , they almost run too slow for blade thinning . Or maybe I'm just impatient . Lots of dipping blade in water / not too much heat ( watch for bubbles on blade while grinding) .

 

[Wowbagger]

I did want to mention that I agree completely. Back when I bought mine it was $35 and it showed.

They may as well come in a pink plastic box with a white plastic handle and have Barbie embossed on the side.
No dispersions to the women reading this ; the reference was to little kids toys for make believe . Heck growing up my six year old thick little foot ball star best friend had GI Joe dolls for the same purpose . I was more of a Major Matt Mason guy my self but . . .

EDIT TO ADD : the astronaut head I just found .

 

[Rob Babcock]

There you go !
I would add : watch out putting the blade in and out of the guide while the machine is running (who turns it off just to swap sides ?) if it is the fixed to the machine type guide instead of a guide clamped to the blade ala Tormek or Paper sharpening wheel world.
Then there is the whole blade thinning thing . . . can't clamp to that . . . and . . . I''m always going back and forth from one side to the other to keep the spine centered .

PS : with the hand held type wide belt sanders fixed to the bench , ala Charlie Mike , they almost run too slow for blade thinning . Or maybe I'm just impatient . Lots of dipping blade in water / not too much heat ( watch for bubbles on blade while grinding) .

The guide is not a clamp like a tormek, it's an adjustable ramp that affixes to the platen. You rest on it and pull the blade across. I'm on my phone now so it's hard to link but if you go to YouTube and search for Curry Custom Cutlery you can see how it works.

For thinning I use a 2x42 machine oriented horizontally with the belt running away from me.

 

[Wowbagger]

The guide is not a clamp like a tormek, it's an adjustable ramp that affixes to the platen. You rest on it and pull the blade across. I'm on my phone now so it's hard to link but if you go to YouTube and search for Curry Custom Cutlery you can see how it works.

For thinning I use a 2x42 machine oriented horizontally with the belt running away from me.

I saw the guide but not on the machine as yet .

HA HA . . . The Vid I watched about the "Tune Up" of the HF machine , before I turned up the volume , the opening scene looks like the aftermath from when he had just ripped the guts out of the machine hahaha . . . and then shot it with his 45 three or four times .
I can understand that . . . ha . . ha ha .

 

[Rob Babcock]

Back before there was a large market for 1x30 machines a lot of guys used the HF as a base, replacing the motor with a DC sewing machine motor, modding the frame, adding a VFD, etc. There's less need to do this now since there are some machines that are good for sharpening right out of the box.

 

[me2]

Sharpening edge first will work but you’ll also cut belts every once in a while. Fine for your knives, not for others. Unless you’re prepared to add a cooling system I’d stay away from sharpening with a belt sander. The HF in particular will soften edges faster than you can do anything about it. High speed steels are tolerable. Nearly anything else will be noticeable under heavy use.

 

[Rob Babcock]

Belt sharpening is best left to those with the skill and experience to do it properly, that much is true.