Bandsaw tyres

[Gary WoodingParticipant @garywooding25363]

I inherited a Clarke CBS355 bandsaw. The 3 rubber tyres needed replacing, but I couldn’t find a supplier for them so I purchased a roll of, what appeared to be, a suitable replacement material. I cut off 3 lengths to fit and joined the ends with superglue. They fitted perfectly, but after a couple of months they all broke. The glued joins hadn’t failed – the rubber had perished.  The remainder of the original length is still fine – no sign of perishing.

Any ideas as to why the 3 home-made tyres perished?

[peak4Participant @peak4]

I use strips of gasket material, with scarfed ends and affixed with contact adhesive.
The stuff I have comes in sheet form, in various thicknesses, and is a bonded mix of granulated rubber and cork.
You will often see it used for car engine sump gaskets.

Bill

[DiogenesParticipant @diogenes]

If they are 165mm wheels, you can buy new tyres online.. (is it a generic 3-wheel 14″ B/S such as Draper, Burgess, et al?)

What is / was the material that you used?

[noel shelleyParticipant @noelshelley55608]

I used old inner tube ! Noel.

[Clive Brown 1Participant @clivebrown1]

I used Pirelli upholstery webbing cut to appropriate width and attached with contact adhesive. That was years ago, looking a bit worse for wear now, but still doing the business. (the webbing that is! )

[gerry maddenParticipant @gerrymadden53711]

That looks like ozone-stress cracking! Some rubbers get sensitive to ozone when under too much stress. Sometimes just background level that exists in the atmosphere is enough to start the process but you might be adding to it by something you are doing in your workshop. Do you make a lot of sparks ?!?

Gerry

[DMRParticipant @dmr]

It may be heat related. Depends what and how aggressively you may have been pressuring the blade to warm it up, thus melting your tyres. If your material is some kind of foam rubber draught strip, then it is not suitable anyway.

Dennis

[Bo’sunParticipant @bosun58570]

Hello Gary,

Another cause could be the age of the material you purchased.  It may be just approaching it’s “use-by” date.

I’ve considered using the “splinter guard” for a Tracksaw guide rail.  If I remember correctly, Dewalt and Makita SG’s are 20mm x 2mm.

[SillyOldDufferModerator @sillyoldduffer]

My guess is the type of rubber is unsuitable, or – less likely – something in the workshop is attacking it.  More information would help:

1. What sort of rubber is it? (There are at least 5 different materials described as ‘rubber’, plus additives.)
2. What’s the rubber tape normally used for?  (Sealing, shock absorbing etc.)
3. How much use does the bandsaw get?  (Big difference between rubber that perished on a barely used saw, and rubber tyres that are heat and mechanically stressed by regular cutting.)

If the rubber tape is a soft type, not intended to take a friction load, it may be physically damaged rather than perished.  Possibly an unlucky choice such as an un-Vulcanised rubber.

Accidentally using the wrong material is an occupational hazard in Model Engineering!  We often use whatever we have rather than scientifically sourcing the best material for the job.   I’ve come a cropper with scrap metals that turned out to be horribly difficult to machine, and have botched a few projects by using the wrong type of glue, wood, plastic, paint or solvent.

Dave

[jaCK HobsonParticipant @jackhobson50760]

I got my stuff from https://www.scosarg.com/catalogsearch/result/?q=tyre

The don’t seem to supply the basic rubber strip anymore – some fancy cork rubber instead.

[Diogenes]

On Diogenes Said:

If they are 165mm wheels, you can buy new tyres online.. (is it a generic 3-wheel 14″ B/S such as Draper, Burgess, et al?)

What is / was the material that you used?

Yes, it’s a generic 3-wheel 14″ B/S. The wheel are 165mm diam. I’ve not managed to find a source of replacement tyres online – any suggestions.

I don’t have any details of the material I used other than it’s rubbery. The unused remainder has been stored right next to the B/S and seems totally unaffected – ie. no sign of perishing.

I deliberately sized the tyres to make a good, tight, fit on the wheels. Could I have overdone the stretching?

[Gary Wooding]

On Gary Wooding Said:

I’ve not managed to find a source of replacement tyres online – any suggestions.

What did the Google say when you fed it “CBS355 tyres”?

Maybe it does not like you because it tells me that Solent Tools stock them as well as a US seller selling the Gucci version, made from urethane (Blue Max).

[DiogenesParticipant @diogenes]

..could be that the rubber is not up to the constant ‘working’ that the bandsaw is giving it?

I see that American-made urethane tyres are £33/set from

https://bandsawparts.co.uk/urethane-tyres/urethane-bandsaw-tyre-to-suit-wheel-diameter-165mm-6-1-2/

..might be worth it for a regular user (if you’ve already had a look at Scott&Sargent’s prices for larger saws, it will seem pretty good)..

…if not ‘bandsaw tyres’ on Ebay will turn up an array of larger sizes that you could probably cut and join for considerably less..

[Gary WoodingParticipant @garywooding25363]

I found the order for the material I used;  it was described as 1.5mmX12mmx5m Black Neoprene. Could the initial stretching (at least 65mm on a length of 455mm) be rather too much?

I didn’t fancy £33 for the three tyres so if the Neoprene isn’t suitable in it’s stretched state I’ll take the suggestion of getting the bigger (and cheaper) larger ones and cut them down. What do you think?

[Michael GilliganParticipant @michaelgilligan61133]

65mm does sound like a lot of stretch

I am no expert on band-saws, or neoprene; but I suspect you have triggered what is known as “stress corrosion” … where a tiny defect develops into a big crack under stress.

MichaelG.

.

Edit: __ Wikipedia has a good overview

https://en.wikipedia.org/wiki/Stress_corrosion_cracking

[Bo’sunParticipant @bosun58570]

Hello Gary,

If you’ve got enough material, trying again with less stretch has to be worth a go.  By how much?  The length of a bit of string springs to mind.

It might even be worth trying just the smallest amount of stretch, and a little contact adhesive between the wheel and tyre.

[Howard LewisParticipant @howardlewis46836]

Pure gueswork, but 40 – 45mm would probably quite sufficient stretch.

Howard

[Gary WoodingParticipant @garywooding25363]

I’m trying with a stretch of slightly less than 4%. It will take a few weeks to see if it works.

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