Adhesives for Round Rubber Belting

[lkrestorer]

I have a need to shorten a couple of round neoprene drive belts for model use. They are 1/8" and 3/16" diameter belt/cord and I'm hoping someone knows of a type of glue that will fasten the ends together and not break loose when stretching them a bit. There is a place to buy almost any size that you need but they have a minimum order. My need is way below their limit plus I have some that are in very good condition - but too long. Plus I would rather buy a tube of some kind of glue and be able to experiment with what I've got.
I know you can buy o-ring kits to make your own sizes by gluing the two ends together but will that adhesive stand up to some stretching? If it would work, what is it?
I have been searching for something that will work but I've been hitting a lot of dead ends. Is there something available?

 

[Brian Rupnow]

That would be super-glue (cyanoacrylate). Available at almost any hardware store or pharmacy.

 

[lkrestorer]

Brian,
Interesting that you should answer because I've pretty much finished building your Double Oscillator (and it works!) and now I'm making a 3-ball governor to hook up to it. The 1/8" belt is what I was going to use to drive the governor mounted on top and I found some 3/16" to try to run my rendition of your "Crazy Joint". So you could say that this is all your fault!
I had thought of super-glue but didn't know if it would handle the flexing and stretching. I thought that there might be something else on the market that would bond onto the neoprene and flex like the rubber itself. I'll give the super glue a try. I've got some on hand.
Is that what they use in the o-ring kits?
Len

 

[neil.r]

With drive belts, you can usually heat both ends up until very soft and then push them into each other as a weld, then trim the ends with a sharp blade.

 

[goldstar31]

With drive belts, you can usually heat both ends up until very soft and then push them into each other as a weld, then trim the ends with a sharp blade.

I agree. I have THREE home made tool and cutter grinders with plastic(?) round belting joined this way.
The one on my Quorn is 'batting along' quite merrily at 7000 rpm and Prof D.H. Chaddock claims that with a bigger wheel( out of plywood) with axial magneto bearings it can stand being upped to double that.
That is old hat stuff and my recent set of plans and instructions for the revised Hemingwaykits Mark 3 Quorn suggests another alternative motor and gives a write up on how the suggested joint should be made.
What more can be said? Well, dear old and similarly pedantic Geo Thomas describing how he modified his Universal Pillar Tool to take a high speed drilling head-- and uses the same techique.

 

[stackerjack]

The way to heat them is by heating up a piece of metal plate while it is being jammed in between the two ends of the belt you wish to join. As soon as the plate is hot, pull the ends away, the plate drops on the floor (careful) and push the ends together again.
Loctite used to make an adhesive which contains minute pieces of rubber. It was black, Might be worth checking out.
Jack

 

[thompsms]

I have a need to shorten a couple of round neoprene drive belts for model use. They are 1/8" and 3/16" diameter belt/cord and I'm hoping someone knows of a type of glue that will fasten the ends together and not break loose when stretching them a bit. There is a place to buy almost any size that you need but they have a minimum order. My need is way below their limit plus I have some that are in very good condition - but too long. Plus I would rather buy a tube of some kind of glue and be able to experiment with what I've got.
I know you can buy o-ring kits to make your own sizes by gluing the two ends together but will that adhesive stand up to some stretching? If it would work, what is it?
I have been searching for something that will work but I've been hitting a lot of dead ends. Is there something available?

I have a need to shorten a couple of round neoprene drive belts for model use. They are 1/8" and 3/16" diameter belt/cord and I'm hoping someone knows of a type of glue that will fasten the ends together and not break loose when stretching them a bit. There is a place to buy almost any size that you need but they have a minimum order. My need is way below their limit plus I have some that are in very good condition - but too long. Plus I would rather buy a tube of some kind of glue and be able to experiment with what I've got.
I know you can buy o-ring kits to make your own sizes by gluing the two ends together but will that adhesive stand up to some stretching? If it would work, what is it?
I have been searching for something that will work but I've been hitting a lot of dead ends. Is there something available?

Neoprene Cement is the stuff used to butt-weld neoprene in wet-suits. Stretching and salt water immersion a matter of day to day routine.

 

[Charles Lamont]

I think neoprene will need an adhesive. Hot welding is for polyurethane belting, so surely a red herring?

 

[Steamchick]

For viton O-Ring material I use ordinary superglue with a mitre joint. Belts on my Unimat work OK that way.
K2

 

[Poppy Ott]

There is a brand of belting called Bond-a-band that comes in 1/4” and 1/8”. Granger carries it, though it might be under another name. Fastenal might have it as well. Cut it to length and weld the ends by the metal plate method. I hold the plate in a vise and slide the melted ends up from the plate so they contact each other. Press and hold the welded ends together for a minute or so, test that the weld is good (solid weld bead all around, no sign of separation) and trim with sharp blade. I use them on both of my Logan and Jet lathes to drive independent lead screw feeds of (if my memory is correct) Professor Chadwick variety, the George H. Thompson pillar tool and my filing machine. They go years, decades actually, before the weld or belt fails.

 

[petertha]

Not sure if this is the same belt material, but Stefan video shows the heat join method. Assuming heat works on your material, I think one could jig the alignment & heat source a bit more reliably. I used to solder battery cells together end-to-end configuration in a simple 90-deg vee section jig. One cell is constrained, hold a solder tip between cells, then very quickly remove heat & join in one motion. The cell slides down the vee so its self centering. You might be able to adapt the principle to circular shaped belt.

I've used CA on O-rings & it works. But maybe a consideration is that O-rings are usually being constrained within a groove of a typical part, so not quite the same forces as putting in some tension & rotating around a pulley. It might be worth a try but you would be the better judge.

 

[goldstar31]

There is a brand of belting called Bond-a-band that comes in 1/4” and 1/8”. Granger carries it, though it might be under another name. Fastenal might have it as well. Cut it to length and weld the ends by the metal plate method. I hold the plate in a vise and slide the melted ends up from the plate so they contact each other. Press and hold the welded ends together for a minute or so, test that the weld is good (solid weld bead all around, no sign of separation) and trim with sharp blade. I use them on both of my Logan and Jet lathes to drive independent lead screw feeds of (if my memory is correct) Professor Chadwick variety, the George H. Thompson pillar tool and my filing machine. They go years, decades actually, before the weld or belt fails.

Respectfully, might I make a couple of small corrections,;ease?

It was George H Thomas in Workshop Techniques and edited by Dr W.A Bennet and Professor Dennis H Chaddock writing in his excellent The Quorn Book.
Again , there is the stent from Blackgates Engineering and as I have ALL of them and the bits, I used the stuff in 3 sizes from Chronos Tools. nd Ken2, I bought the Unimat( actually for the clone) again from Chronons Tools.


I joined the Chonos belting with heat as recommended.

Wandering off further--- rubber is NOT black, it comes as a latex which is creamy white from rubber plants. We grew a couple for shade in Menorca- along with a date palm that lived with its feet in the septic tank.

 

[TonyM]

If you are sure it's neoprene then use wetsuit glue.

 

[goldstar31]

If you are sure it's neoprene then use wetsuit glue.

And if it is, it will cost more for the glue than the belt. In addition, all that is needed is enough to cover about a ' square centimetre'

Strange way to do arithmetic

 

[Ken I]

I built a Van Der Graaf generator some 6 years back and glued the gum rubber belt with "Chemvulc 2002" - as recommended by the rubber supplier.
This is a two part contact adhesive - you apply one layer on both surfaces and let it dry completely (overnight), you then and another layer and once tack dry you squeeze the two surfaces together as per normal contact adhesives,
I scarfed the joint (±30° cut) and it has been under continuous tension for six years without failure - now that's impressive.
I fully expected the belt join to be an ongoing problem.
I am so impressed with this adhesive that I now use it for any of my industrial application involving rubber to rubber or rubber to metal bonding.
Hot versus cold vulcanising for conveyor belts | Chemvulc
This is a South African product meant for "cold vulcanising" of industrial conveyor belts - there must be similar equivalents elsewhere.

Clue: The catalyst smells like Trichloroethylene.
Regards, Ken

 

[lkrestorer]

The original packaging that these odds-and-ends rubber belts came in says neoprene on it (I must have gotten it in one of my ventures into scrap-land somewhere). I haven't had a chance to get back to that project yet but I think I'll try the super glue idea first and if that doesn't work I'll get some wetsuit glue. I did some searches for that and found a quality comparison article that mentions "Gear Aid Aquaseal NEO Contact Cement" as being their choice for flexibility and long life. A 1.5 ounce tube is available for $6.95 from Amazon.
A bonus for using a bonding method like this for this particular project is that the only way to install a belt is to remove one of the cylinders and connecting rods from the side of the engine, install a belt and then reassemble it again. Splicing the belt in place would save that extra complication. If you are not familiar with this "Double Oscillator" engine look at the picture. The drive pulley is inboard of the connecting rod at the flywheel and the governor will be mounted on top of the flat plate at the rear. It will be a pain in the butt to take it apart once everything is assembled.



I want to thank you all for the excellent information. When I finally (soon - I hope) get a chance to try these methods I will post my results.

 

[MRA]

Just in case this doesn’t work out, or to encourage others, I just made a urethane round belt for a small pillar drill by heating a knife blade, melting the two ends on either side of the hot blade, and then sliding them off the sharp side and into contact with each other. Little clean up on a belt, and the join is invisible and very, very strong even though the belt stretches a lot in use. I am impressed with it. M

 

[DickG]

Hemingway sell round belting by the metre. Joined by the ‘hot knife’ method. They do include a drawing of an easily made jig that ensures a good joint properly aligned. Alternatively, why not just search eBay, or your local ‘bearing’ stockist, for a suitable O ring?

 

[lkrestorer]

Hemingway sell round belting by the metre. Joined by the ‘hot knife’ method. They do include a drawing of an easily made jig that ensures a good joint properly aligned. Alternatively, why not just search eBay, or your local ‘bearing’ stockist, for a suitable O ring?

To answer this question I have to refer you back to my previous post (#16). I will take a look at what Hemingway recommends for a jig. It may be a handy item. However, buying more isn't my best solution. I've already got the round material and it would work out best if I could cut a piece and splice it back together on the pulley without disassembling the engine.
I did try to make one today with super glue. It's going to spend the night curing in my shop and I will test it for stretch-ability tomorrow. My next test will be with the heated knife idea. If either of those work for me I will be happy. If not I will order some of the "wet suit glue".

 

[Steamchick]

Good luck! My home repaired shoes just fell apart (again!) as the rubber replacement treads just won't stay stuck with the "proprietary" glue, super glue or staples. Anything not flexible just breaks and becomes detached, the "rubber" vulcanising adhesives just decide the day they will fail and trip me up. But my O-ring drive belts on the Unimat lathe must be much less stressed, though run for thousands more cycles than my shoes. No real pre-tension, I let the V pulleys make the grip when on load. And I simply Superglue the VITON O-rings using a 45 degree splice.
Hope you have success too!
K2