cushion forklift steer tire detached from integral rim

[tommj]

I have a forklift with cushion type tires, which are solid urethane rubber bonded to a steel ring. The steel ring/tire assembly is normally pressed on to the wheel; the ring/wheel assembly is intact. The tire has become detached from the steel ring. The plan is to bond it back to the ring with sika p2g automotive windshield adhesive. I was wondering if this is the best product for the job or if something else would be better. Its an interim repair on an old lift, new tires are not an option

 

[GregLocock]

That's not a very good choice, Loctite and Weicon make adhesives for rubber to steel bonds.

Cheers

Greg Locock


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[lucky-guesser]

In my experience, window adhesives can be scraped off with a spoon if you try hard enough. You may get lucky with being able to set the machine down with the repaired tire but turning, dynamic loading, hitting a bump, I would be shocked if you got your first pallet on the truck.

While I would tread lightly at first to build up some confidence with such a technique, GregL's suggestions may have better results.

 

[TugboatEng]

You need to use a catalyzed cure adhesive here. You need something with a long enough working life to allow you to slide the tire back onto the rim. You need something that can cure without being exposed to air. A polyurethane or silicone moisture cure adhesive such as you mentioned may take too long to cure at the center of the tire.

Belzona 2141 would be ideal in this application. However, judging by the condition of the tire, the cost of Belzona 2141 would be too high.

With that said, there isn't a lot of flexing happening where the tire meets the rim. You don't need to use a rubber adhesive. For this job, I would suggest using any two-part epoxy that has a sufficient working life to allow you to mount the tire.

 

[tommj]

I did consider epoxy, I may still use that. The fit between the wheel and tire is not super tight, in fact I will be able to easily mount the tire with a large rubber mallet, no press needed, in less than 30 seconds so I don't think curing will be an issue. If I use a relatively thin epoxy I would probably need to dam the bottom so I don't lose any. When the tire is on I can jam a big screw driver in between, stretch it away from the metal and pour more in. The counterweight on this lift weighs 5000lbs, and the tire contact patch in back is pretty small, 6" wide on an 18" OD tire, 12-1/8" ID rim band. I'm more worried about the epoxy bond to the rubber failing under that pressure than about urethane not curing or pot life. The Belzona stuff is polyurethane, maybe there is a similar commercial product that is not so expensive, maybe in a caulk tube?

 

[CapriRacer]

I am going to guess you won't find anything that works.

Forklifts generate a lot of torque and the bonding between rubber and steel isn't very good, so many times the steel is coated with brass or bronze. The copper in those adheres well to rubber.

Let us know what happens. We could all learn from this.

 

[TugboatEng]

Devcon has a polyurethane product that is half the price of the Belzona option. You're looking at $600 USD for the Belzona option and $250 USD for the Devcon.

 

[GregLocock]

Some rubber bushings use cyanoacrylate for bonding rubber to metal. Surface prep is important for both materials. I used to use a Raychem 2 part in a similar application.

Cheers

Greg Locock


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