Spray-on hard coating

[biff44]

Most people are familiar with hockey pucks. Hard, round, made of a tough rubber to endure slap shots in the game of hockey. For a hockey player, it is desireable to practice various parts of the game (stickhandling, shooting pucks at a target, etc) by yourself until you get so good at it that the movement is effortless. However, ice time at a local rink is very expenxive. One has to resort to trying to stickhandle on the basement concrete floor, or shoot pucks at a target outside in the driveway. Standard hockey pucks, made of rubber, are too "grippy" to be able to do either. Various types of balls have been tried to simulate a hockey puck's movement on the ice, but they are somewhat unsatisfactory.

My question is: Is there some sort of very hard plastic that can be sprayed onto the flat sides of a standard rubber hockey puck that will greatly reduce the coefficient of friction? It would have to be hard, like a plexiglass surface, and tough enough to not crack when shot or it hits a concrete wall. If there was some sort of magic can of spray-on plastic out there, a player could take a bucket of 50 pucks, spray on the stuff, and have a cheap/effective way to practice his game.

 

[mcgyvr]

How about an industrial silicon spray/dry film silicon?

 

[CoryPad]

mcgyvr means to say SILCONE, or an organic elastomer, of which the most popular kind is polydimethylsiloxane. Silicon is an element, one that has semiconductor properties and is used for integrated circuits.

Silicones can have non-stick properties, which could be helpful for your application, but rough, sharp surfaces like concrete will chew up an elastomeric coating.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[mcgyvr]

yes sorry meant silicone.

Teflon pucks?

 

[btrueblood]

Why not polyethylene pucks - buy a chunk of extruded rod stock of the approximately correct diameter, and saw off pieces as needed. Recyclable, too, once they get too chewed up for hacking around.

The other approach I've seen (and used) is ice pucks - they slide real good on concrete, but shatter easily. We started with any old random chunk of puddle ice, but some neighbor kids used to freeze their own. You could probably put some cloth, straw, sawdust or other reinforcement into the water before freezing, they might last a bit longer.

 

[biff44]

Silicone will not last long enough to be useful. These pucks are going to get ABUSED in a hurry! Teflon will tear up immediately on the concrete.

I like the idea of polyethelene rod stock. Hockey pucks are 1 inch thick and 3 inches in diameter. Is there any place out there where I can get an affordable length of 3" dia rod stock. I checked ebay, but nada. The highere the polyethelene density, the better, for toughness.

 

[patprimmer]

UHMWPE or ultra high molecular weight polyethylene is what you want, but nylon or polyester will also do PTFE (Teflon) might do a lot better than you think

Regards

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[CoryPad]

McMaster-Carr has 3" diameter rod of various plastics, including UHMWPE.

Regards,

Cory

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[SincoTC]

If you're thinking of making them out of plastic rod stock rather than a spray on coating on a regular rubber puck, then don't forget that some of these plastics are a lot denser than rubber and one made from PTFE would weigh in at nearly ten ounces (about double the weight of a regulation puck), the Polyethylenes would be too light but Nylon would be pretty close. I don't really know if it's that important, but I guess that you dont want to do a lot of practice and get used to the dynamics of something that may behave differently on match day with the genuine article!

Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK

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[biff44]

That is a good point. Sometimes for stickhandling only players do use heavier pucks--it builds the muscles. But certainly for shooting practice you want the right weight.

That is why I originally was thinking of only coating the surfaces with a hard material to reduce glide resistance. You would have the exact same characteristics of the original rubber hockey puck for weight, size, resiliance.

 

[Demon3]

Yep, UHMWPE is the way to go. Please tell us how it works!

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[patprimmer]

To reduce weight you could make a doughnut shape.

The difference in surface friction will have a big effect on puck behaviour so accurate shooting practice and glide range characteristics will be out the window anyway.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Demon3]

There is in fact a US Patent on an UHMWPE practice hockey puck for use on hard surfaces.

http://www.patentstorm.us/patents/6638188/fulltext.html

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[btrueblood]

Uh oh. I will have to redflag my post now...

Seriously, try the ice puck. I'm starting to remember now that we had good luck with frozen cow pats too...except that nobody wanted to play goalie...

Another thought: try building a dry ice "air puck" like we used to use in physics lab. Closed container, with a smooth bottom and a few vent holes. Fill the container with dry ice pellets, which sublimes and vents thru the holes, levitating the puck. Darn near frictionless.

 

[patprimmer]

I can't see using UHMWPE for a hockey puck passing the innovation test. After all I just thought of it of the top of my head without prior knowledge. It was pretty obvious to somneone reasonably skilled in the art.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[dwightdixon]

As long as you make the HDHMWPE pukes for your own use and not for sale, the patent laws do not apply. You will need to buy compression extruded rods from a local distributor and a chop saw for manufacture (and it will take more time than it may be worth) but you will have your pukes. Patents are a useful tool (even if they are potentially invalid) as a legal economic barrier to entry into the market.