minute of silence for gel-coat

Let's have a minute of silence for "gel-coat". She served us well, was a pain in the butt to use, and for only fair scratch resistance, and SHRINKAGE...... No more......

Let's have a hand for what's next

!!!!POLYUREA!!!

Tough, non-shrinking, epoxy compatible, water impermeable!! No print-through!!!


http://www.specialty-products.com/resource-library/potential-uses-list/

 

No word there about UV-resistance... ?

 

We had a customer whos business is spraying polyurea in a variety of applications, i had him apply a Bra on the front of my VW Vanagon Westphalia camper to protect it from stone chips, its doing the job much better than the ones you buy,its black and afyer a couple of years it has a kind of chalky finish much like old gelcoat which comes off when you wipe it, i probably need to wax it. Im sure there are different formulations.Im very happy with it for this application.Its a lot like spray in bedliner.
Steve.

 

Also, this is a frightening quote from the website:

"The following list is presented to stimulate the thinking of potential users of these unique polymers. No guarantee of suitability in any specific application is implied or intended customer."

 

How's the cost hold up against the products it will displace?

 

UV- resistance is a given..sorry

It's a (relative) new product, they're still figuring out uses and testing..

cost like epoxy, 50us+/gal

The only negative I've been told is no brilliant whites, more like sand and they'll guarantee a perfect match each batch, something about the environment....and cost of Graco spray equipment. $30,000US

K5 is being used on the bottom of aluminium boats to allow running over rocks...

EPL can a applied with a brush or conventional spray equipment etc.

 

wonder if this would work for coating SOF kayaks. Probably want something more moisture tolerant with a slower setting time.

 

It fills a different niche than gelcoat. In what capacity do you work for SPI?

 

No I don't.

Guess when you see moulded production boats with it you'll come around.

 

http://www.youtube.com/watch?v=gX6oR13qUv8 http://www.youtube.com/watch?v=Dd8-VlFKyHk&feature=related

 

Polyuretanic paint coat works very well over waterline, much better than gelcoat when exposed to UV, but to my knowledge, goes really bad under water. Isn't it?

 

So that will be one part of the VW that wont rust ...better get the rest done....

 

Claims by an Australian supplier - seems to be OK under water
http://www.assetsystems.com.au/poly.htm

1. Polyurea surface coatings and linings possess ultra fast cure properties which dramatically reduce shutdown times.

2. Polyureas are elastomeric products with enormous impact, tear and elongation properties suited to many high abuse applications where substrate movement can be expected. Suitable substrates include:- Steel, Concrete, Timber and Geo-membranes.

3. Polyureas are environmentally friendly with gel times of 5-20 seconds (tack free in 10-60 seconds) and very low odour. Materials are rapidly inert upon plural impingement mixing (mix at gun tip). Minimal material wastage.

4. Polyureas offer excellent resistance to thermal shock, mechanical impact, mild acids, caustic and hot water.

5. Polyureas remain flexible and provide good crack bridging qualities >3mm. Ideally suited for secondary chemical containment bunds and concrete structures holding potable water.

 

General chemistry and a performance comparison

 

It's been available commercially since 1950. It hasn't become very popular because it requires expensive equipment to apply and as a coating applied over a surface it has very poor wetting properties and when it does disbond it peels off in large sheets. It needs highly trained operators to apply it well.

It's also mixed with polyurethanes to make it more user friendly.

Seems there's a few manufacturers giving it another hard push recently but a new product it isn't.