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Flat belt repair

Hi Everyone,

A search on SmokStak found some old threads about flat belt repair. They didn't contain info about folks that fix belts.
My 'go to' belt broke last summer and I would like to fix it.

P_20191116_151522.jpg

Yes, I know I can cut it and install a clipper lacing. I would rather find someone that can repair it and make it an endless belt like is was before.
A fellow somewhere in the New Ulm, MN area used to do that type of repair. Does anyone know if he still does?
Does anyone know of another person that could do such a repair?

Later,
Jerry Christiansen
 

GreasyIron

Subscriber
Last Subscription Date
12/28/2019
Hi Everyone,

A search on SmokStak found some old threads about flat belt repair. They didn't contain info about folks that fix belts.
My 'go to' belt broke last summer and I would like to fix it.
I would rather find someone that can repair it and make it an endless belt like is was before.
A fellow somewhere in the New Ulm, MN area used to do that type of repair. Does anyone know if he still does?
Does anyone know of another person that could do such a repair?

Later,
Jerry Christiansen
You're likely thinking about Danube Shoe/Upholstery Repair. I believe they are still in business. We had a belt there about 5 years ago, nice work, but it seemed like a long wait, as they have plenty of backlog on work matching their title.

You can do it yourself - it doesn't really take fancy equipment, but the adhesive I found takes doing several at once to justify. Peeling the layers takes a balance of skill and patience that I don't plan to try again. Also, after getting it back together, you are faced with the choice of finding somewhere with an industrial sewing machine, or using brass rivets, to prevent the outside layers from peeling.
 
Hi G.I.

Teach us more about the peeling of the layers.
How far back does one need to peel? Is this done mechanically? Or, are solvents involved?
What type of adhesive is used? Where does a person get it?

I am often amazed at the amount of torque and horsepower belts can transfer. Some of those belts have clipper lacings in them. Those little staples put up with a lot! The wire that holds the lacing together must be made of something stronger than titanium. :)

Thanks in advance for any information,
Jerry Christiansen
 

Ronald E. McClellan

Subscriber
Last Subscription Date
01/05/2020
If you don't like the clippers , you can do it your self doing hand stitching , but then you would see the thread where it was sewn together. Is it really worth it ? Ron
 

GreasyIron

Subscriber
Last Subscription Date
12/28/2019
Hi G.I.

Teach us more about the peeling of the layers.
How far back does one need to peel? Is this done mechanically? Or, are solvents involved?
What type of adhesive is used? Where does a person get it?

I am often amazed at the amount of torque and horsepower belts can transfer. Some of those belts have clipper lacings in them. Those little staples put up with a lot! The wire that holds the lacing together must be made of something stronger than titanium. :)

Thanks in advance for any information,
Jerry Christiansen
Before I forget, I've also heard of an Amish place in [I think] eastern Iowa, but no idea of name or contact.

To your questions, Jerry, I recalling telling the people who knew I did the one that I'd vehemently deny any such ability, or even knowledge of the process. But if you're going to give it a try, that's more options out there, so here it goes...at least from some vague memories!

I'm sure the pros have better tools or procedures too, but except the adhesive, I used things already in the garage.

I squared the ends (or maybe it was to final angle) so that I could see good material in each layer. Then gripped it between a couple 2Xs in a vice and a quick clamp. No solvent. I enlisted some help from Mrs for both peeling and squaring. We used a utility knife to help lift corners, and occasionally get through tough spots, but a couple vice grips & elbow grease did most of the work. If I recall correctly, slightly dull jaws, but not completely worn was a good balance if you have such choices around. I also recall maybe two inches out of the boards at time then indexing.

For distance, I don't remember which was the driving factor on ours, but a little Google search will yield you equations or rule of thumb targets based on width and layer count. I somehow remember going with splice length twice the belt width. I also remember keeping cuts of each layer each at least an inch from another, and believe we staggered them so no adjacent layers were less than double that. Of course, you probably only have like 4 or 5 layers, so less thinking than the picture my description here paints.

Really stretching memory here, I think we used 30 degree cuts for easy math. My non-expert opinion is peeling an inch longer than your furthest cuts so you have some room to work with. But too much is just more to glue and sew. I believe we secured it right behind the peel depth to a 2X10; maybe had a couple 2X4s screwed down crosswise. Maybe had a board cut to 30 degrees as a guide, but I recall a tape measure and carpenters square involved too, so that may have been an after thought. Likewise, with a thin steel shim stock you can probably protect underlying layers for each cut, but again remember trying the cuts with measuring tools first.

So each joint is really depending upon the next adjacent layer(s) not the butt connection. The strength is layers minus 1. However, despite having no precedent, knowing how belts get abused in a baker fan, I added a layer on the outside. I don't remember whether the donor section for that was from the section I removed, or another belt - completely optional anyway, and have not seen it done before or since. This could mess up some of the thresh-machine style aligners, but didn't seem to hurt. That does also put the minimum pulley diameter to the next belt thickness. That belt is now showing bad spots everywhere but the splice!

Nearly certain the adhesive was a Rema TipTop product. Definitely two part. Cold vulcanizing for both fabric and rubber - the combination of materials really narrowed the options for cold vulcanizing adhesives. I believe SC 2000. Again vague recollection, but think I did put down some wax paper then a board on top with some clamping pressure. There are specific recommendations for scuffing the surface, and maybe even a chemical primer. I don't recall most of the layers needing much scuff after the peeling, and cannot remember using a specific primer, though vaguely do remember dusting with wire brush, then paint brush, and maybe wiping with some common solvent.

I was working at place doing industrial fabrics at the time so I sewed it on the outside after curing for a couple days. The belt being somewhat unwieldy, I just stitched the long way, and slightly angled over in reverse, maybe a half dozen times until reaching the opposite side, instead of any fancy pattern.

Once you're the expert and go in business, I can be less cautious belting! :D

Regarding the clippers, I am a big fan anywhere, but a drive belt. I've used gators too, but the clippers look much nicer to me. The wire isn't really under unique stress - but for the ends, double shear throughout. You probably know the math better than I, but at 40ft/s it doesn't take 15lb per HP. So on a threshing machine, even the blower belt is seeing less than 300lb. Even a 4" belt and say only 16 teeth in it, still not 20lb each. It's more impressive to me that teeth don't pull out of the belt more often, but have seen it.

A drive belt that might be getting 1000lb on a brake, or double or triple that? Yeah, I want an endless splice! Even on a threshing machine only pulling 30HP.
 
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Harvey Teal

Subscriber
Last Subscription Date
07/22/2019
Before I forget, I've also heard of an Amish place in [I think] eastern Iowa, but no idea of name or contact.

To your questions, Jerry, I recalling telling the people who knew I did the one that I'd vehemently deny any such ability, or even knowledge of the process. But if you're going to give it a try, that's more options out there, so here it goes...at least from some vague memories!

I'm sure the pros have better tools or procedures too, but except the adhesive, I used things already in the garage.

I squared the ends (or maybe it was to final angle) so that I could see good material in each layer. Then gripped it between a couple 2Xs in a vice and a quick clamp. No solvent. I enlisted some help from Mrs for both peeling and squaring. We used a utility knife to help lift corners, and occasionally get through tough spots, but a couple vice grips & elbow grease did most of the work. If I recall correctly, slightly dull jaws, but not completely worn was a good balance if you have such choices around. I also recall maybe two inches out of the boards at time then indexing.

For distance, I don't remember which was the driving factor on ours, but a little Google search will yield you equations or rule of thumb targets based on width and layer count. I somehow remember going with splice length twice the belt width. I also remember keeping cuts of each layer each at least an inch from another, and believe we staggered them so no adjacent layers were less than double that. Of course, you probably only have like 4 or 5 layers, so less thinking than the picture my description here paints.

Really stretching memory here, I think we used 30 degree cuts for easy math. My non-expert opinion is peeling an inch longer than your furthest cuts so you have some room to work with. But too much is just more to glue and sew. I believe we secured it right behind the peel depth to a 2X10; maybe had a couple 2X4s screwed down crosswise. Maybe had a board cut to 30 degrees as a guide, but I recall a tape measure and carpenters square involved too, so that may have been an after thought. Likewise, with a thin steel shim stock you can probably protect underlying layers for each cut, but again remember trying the cuts with measuring tools first.

So each joint is really depending upon the next adjacent layer(s) not the butt connection. The strength is layers minus 1. However, despite having no precedent, knowing how belts get abused in a baker fan, I added a layer on the outside. I don't remember whether the donor section for that was from the section I removed, or another belt - completely optional anyway, and have not seen it done before or since. This could mess up some of the thresh-machine style aligners, but didn't seem to hurt. That does also put the minimum pulley diameter to the next belt thickness. That belt is now showing bad spots everywhere but the splice!

Nearly certain the adhesive was a Rema TipTop product. Definitely two part. Cold vulcanizing for both fabric and rubber - the combination of materials really narrowed the options for cold vulcanizing adhesives. I believe SC 2000. Again vague recollection, but think I did put down some wax paper then a board on top with some clamping pressure. There are specific recommendations for scuffing the surface, and maybe even a chemical primer. I don't recall most of the layers needing much scuff after the peeling, and cannot remember using a specific primer, though vaguely do remember dusting with wire brush, then paint brush, and maybe wiping with some common solvent.

I was working at place doing industrial fabrics at the time so I sewed it on the outside after curing for a couple days. The belt being somewhat unwieldy, I just stitched the long way, and slightly angled over in reverse, maybe a half dozen times until reaching the opposite side, instead of any fancy pattern.

Once you're the expert and go in business, I can be less cautious belting! :D

Regarding the clippers, I am a big fan anywhere, but a drive belt. I've used gators too, but the clippers look much nicer to me. The wire isn't really under unique stress - but for the ends, double shear throughout. You probably know the math better than I, but at 40ft/s it doesn't take 15lb per HP. So on a threshing machine, even the blower belt is seeing less than 300lb. Even a 4" belt and say only 16 teeth in it, still not 20lb each. It's more impressive to me that teeth don't pull out of the belt more often, but have seen it.

A drive belt that might be getting 1000lb on a brake, or double or triple that? Yeah, I want an endless splice! Even on a threshing machine only pulling 30HP.
Jerry, what width is your belt? How many plies does it have? What material is used on the faces (canvas, rubber etc)? What caused it to break? Harvey
 
Hi Harvey,

This rubber belt is 7 inches wide. If I counted correctly, it is four plies.

This is the drive belt I have used when running my wife's Prony Brake. (My wife owning everything is another story.**)
I gave the worksheet for calculating horsepower to the owner of the engine after the belt broke. If I remember correctly, we were over 100 horsepower. I have measured over 140 horsepower with that belt.


I have often wondered what horsepower and torque a belt this size is rated. I am pretty sure the belt broke from being abused.

Later,
Jerry Christiansen


** By the way, my wife owning everything is not a bad thing. My key still fits in the door when I come home. There are a few things I own, such as the cap she gave me for Christmas.
 

Harvey Teal

Subscriber
Last Subscription Date
07/22/2019
There are charts for the different belt materials and sizes... and the speed and power that they can transmit.
7” and 140 hp is stretching things past the safety margin. lol
In a former lifetime I spliced these belts. A vulcanized splice is possible but costly. The reason I asked how the belt failed is: The cost to repair your belt may not be worthwhile if it ia prone to fail again under the same conditions. Pretty good probability that the new splice will not fail. Consider buying a new belt that is sized for the load, maybe use your existing belt in less demanding service.
Harvey
 
Hi Harvey,

Your points are well stated and understood.

I think I got away with the abuse is because the high horsepower runs don't last a long time. I need to find the charts Jeff talked about and learn what is reasonable for the belt.

Thank you for your input,
Jerry Christiansen
 

Harvey Teal

Subscriber
Last Subscription Date
07/22/2019
Hi Harvey,

Your points are well stated and understood.

I think I got away with the abuse is because the high horsepower runs don't last a long time. I need to find the charts Jeff talked about and learn what is reasonable for the belt.

Thank you for your input,
Jerry Christiansen
Jerry,
as a reference point a professional vulcanized repair on that belt could run you 250 bucks. About 75 in materials and the remainder in labor. Are your pulleys wide enough to handle a wider belt? What are the driving & driven pulley diameters, and what rpm is the engine running? Harvey
 
Hi Harvey,

Thank you for the estimate for repairing the belt. The rest of the belt probably needs to be looked at carefully to be sure it is worth repairing.

The pulley on the Prony Brake is at least 10 inches wide (I should know the width, another old age thing.) with a 36 inch diameter. The steam engines we run have 36 inch to 44 inch diameter pulleys. The Brake typically runs about 290 rpm when testing a steam engine.

Yes, we could run a wider belt. Then I will need to find some young, strong folks to lift the thing up.

Thanks again for the info,
Jerry Christiansen
 

Harvey Teal

Subscriber
Last Subscription Date
07/22/2019
Hi Harvey,

Thank you for the estimate for repairing the belt. The rest of the belt probably needs to be looked at carefully to be sure it is worth repairing.

The pulley on the Prony Brake is at least 10 inches wide (I should know the width, another old age thing.) with a 36 inch diameter. The steam engines we run have 36 inch to 44 inch diameter pulleys. The Brake typically runs about 290 rpm when testing a steam engine.

Yes, we could run a wider belt. Then I will need to find some young, strong folks to lift the thing up.

Thanks again for the info,
Jerry Christiansen
I realize that in the old iron community the aesthetics of a vintage rubber/canvas belt are important. For many of us an old belt can be like a favorite garment, like an old pair of shoes that we just can’t let go of. Many of these old belts are older than their owners.

Modern flat power transmission belting is thinner, lighter, more durable, has better friction, can handle more horsepower with higher efficiency, is more readily available, and in many cases is cheaper than the old rubber/canvas that we covet. The only reason that I might decide not to use it would be that it looks too modern. It is available in many colors such as black, red, green, yellow, white etc but it simply does not look like an old canvas belt. Now if some enterprising young buck were to set up a business to print a canvas pattern on this new belting....well....
 

FWurth

One Millionth Post
Last Subscription Date
07/29/2019
One thing for sure, for safety sake , never use a metal pin ( Clipper type ) lacing on a main drive belt. The lacing can be a snag hazard and anyone too close can get grabbed, that and if the splice fails, the belt becomes a missile! More places to supply the endless splice are definitely in need for this market. I still use a few ancient balers and combines that require a fairly short 4 or 5 in flat belt on the main drive from the engine to the first drive( 6-7 ft . These are somewhat high speed and the engine pulley is somewhat small dia., any clipper lace will only last a few hours. Really haven't found a supplier yet.
 
Hi Harvey,

Good points. I am not married to the black belt and I am not stuck on having an historically correct belt.
The problem is, I am frugal. (My wife says cheap, but I don't understand that.)

I am guilty of looking for a low cost way to get a good belt.
If a person pays $250 to get the belt fixed plus shipping, that person could easily have half the cost of a new belt invested in a belt that is still an old belt.

The black belt was a gift to me in 2007. It was an undamaged, endless belt. It has served us well. Maybe it has reached the end of its life as the drive belt on the Prony Brake. Maybe it is time to use an alligator splice and use it elsewhere.

Is it possible to determine what a reasonable maximum power rating would be for this belt if it was in its original condition?

Later,
Jerry Christiansen
 

G Willikers

Subscriber
Last Subscription Date
06/03/2020
Mr. Christiansen?
Is it possible to use a belt with alligator splice or other mechanical splice in your brake testing? I ask, because I do not know.
Thanx.
 

Harvey Teal

Subscriber
Last Subscription Date
07/22/2019
Mr. Christiansen?
Is it possible to use a belt with alligator splice or other mechanical splice in your brake testing? I ask, because I do not know.
Thanx.
GW and others, 140hp at 2700 feet per minute is a significant amount of power to put into a belt. While this can be handled with mechanical lacing, the lacing may not be the safest way to go, especially in open, unguarded service where spectators may be present.

Jerry, please verify the width of your pulleys and the length of the belt that you need; that is, the total length of the belting, (not the center to center distance of the shafts). Email or PM me your address and I’ll send you samples and quotes for alternative belt materials.

I’m no longer a Smokstak sponsor and no longer in the belting business, but some of my cronies are still in the game. Harry & Moderators, I realize that we’re not supposed to sell in the forums....Thank you...Harvey
 

GreasyIron

Subscriber
Last Subscription Date
12/28/2019
GW and others, 140hp at 2700 feet per minute is a significant amount of power to put into a belt. While this can be handled with mechanical lacing, the lacing may not be the safest way to go, especially in open, unguarded service where spectators may be present.

Jerry, please verify the width of your pulleys and the length of the belt that you need; that is, the total length of the belting, (not the center to center distance of the shafts). Email or PM me your address and I’ll send you samples and quotes for alternative belt materials.

I’m no longer a Smokstak sponsor and no longer in the belting business, but some of my cronies are still in the game. Harry & Moderators, I realize that we’re not supposed to sell in the forums....Thank you...Harvey
Fwurth pointed out the same as I've found: the mechanical splices on an original belt just cannot stand up to drivebelt loads. Add the safety consideration of flying metal, and endless quickly becomes more attractive.

The Case Threshing manual shows 8" X 5 ply for 50HP. Of course, threshing is a fairly continuous load with potential for added abuse with a slugged cylinder.

I think I've seen more like 3HP per inch per ply, but may be my imagination.

The new materials, of course, more load per ply. This also equates to less forgiving on equipment from an overzealous throttle hand though.

Just from the small area shown, I'd think your belt deserves a proper repair, but probably semi-retired to some lighter loads.
 
Last edited:
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