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Old 06-23-2005, 12:42 AM
engineerscott engineerscott is offline
Amateur Metal Finisher
 
Join Date: Mar 2003
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Thanks for the info. I'm sure that's a fine product for what it is, however it looks to be a single component solvent based polyurethane paint of some sort. I don't think this will compare with the binary component polyurea coating that the big chain bed liner companies like Line-X do. It would be much like comparing a paint coating to a powder coat. The non solvent based polyurea can be applied much thicker and will produce a much tougher coating.

I've done some further investigation on the feasibility of this type of product. When I started looking at it I was afraid that the raw materials (chemical components) would be some proprietary mix that the Line-X and RhinoLiners had developed themselves. This does not appear to be the case. It appears that the raw materials are commercially available (in 55 gallon drum quantities) and that they are reasonably easy/safe to handle.

The system would be composed of two holding tanks with heaters. The two pre-mixed chemicals have to be maintained at 160ºF. Each tank would have a pump (which would be either air or electrically powered). The pumps need to do around 1800 psi. This sounds pretty intimidating, but pumps that will do this are readily available. In fact, your fairly inexpensive electrically powered high pressure spray washer will do this pressure (of course you need a pump whose internal components are compatible with the base chemicals). You have two insulated high pressure hoses connecting the pumps and tanks to a spray head that has a proportioning valve. The two components are mixed in the head and you are spraying pure polyurea plastic which solidifies quickly (say 10 seconds).

What all this gets you is a coating system that has most of the positive attributes of powder coating without it's major drawback - the need to oven bake the finished product. The coating can be applied even thicker than a power coat if desired and at equal thickness it is at least as durable (most likely more durable) than powder coat. Not having to bake means that the size of object you can coat is no longer limited by the size of your oven. It also means that you can coat substrates that can not take the temperature required to bake a powder coat. I would say that the only downside of this coating compared to powder coat is that you can't achieve as smooth of a finish. For bed liner applications they actually take steps to ensure a somewhat rough textured surface - it helps keep loads from shifting and it hides damage better. You can get a smoother coat than what you see in a bed liner but not as smooth as powder.

If Caswell is interested I would be happy to share what I have found. I am seriously considering attempting to build up something myself. The hard part appears to be the spray gun. Companies like Gusmer sell these systems commercially including the spray gun. Maybe I can pick up a used one on ebay. The pro systems are extremely expensive, but I don't see anything that would inherently prohibit you from doing a smaller system that would not see daily use much more cheaply.
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