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Lad View Drop Down
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    Posted: 18 November 2014 at 7:35am
Hi,
I'm about to get some paint for my cabs, but I got dilemma now. The LineX guys are quoting me for 1,5mm coat thickness and looking at datasheet for polyurethane paint, one layer is usualy 100um.
How many layers do you use guys or better for what thickness of paint do you aim for?
To get at least 0,5mm I would have to use 1l of PU paint per m2, which would get bit expensive.

This is the paint I was considering: http://www.tikkurila.com/industrial_coatings/metal_surfaces/metal_surfaces/metal_products/temadur_20.3318.shtml
with regards, Ladislav
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MarjanM View Drop Down
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Points: 7816 		Post Options Post Options   Thanks (0) Thanks(0)   Quote MarjanM Quote  Post ReplyReply Direct Link To This Post Posted: 18 November 2014 at 10:45am
That paint is hardly comparable with the Linex. Dont mix polyurethane and polyurea paints. They are not same. Linex is dry in about 15 seconds.
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Very different things, polyurethane "dries", polyurethane "cures". Over simplified to make the point, but you get the idea.

LineX is two hot reactants that touch for the first time, as they exit the spray nozzle, they start reacting in the air, and start to get sticky as the head towards the surface. As Marjan says, once on surface, they finish polymerization, to a "plastic", in about 15 seconds. Part of the surface finish being rough, is that the "air" phase, between gun nozzle and surface, allows particles to "skin" (cure on surface), so you end up spraying stickle droplets onto the surface.

Think mixing epoxy resin up (Araldite or similar), but with faster setting components that you are spraying on.
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Lad View Drop Down
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Points: 153 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Lad Quote  Post ReplyReply Direct Link To This Post Posted: 18 November 2014 at 2:12pm
Thanks guys for info, I know that polyurea is hard to beat regarding quality. I need to work out the economics...
So lets forget for a while at Linex. What interests me is how many layers or how thick should polyurethane paint should be to give reasonable protection, better than water based paints, that is.

Cheers.
with regards, Ladislav
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geoSal View Drop Down
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I usually apply 2 coats of polyurethane paint (two parts paint) and a third coat with reduced pressure for the splatter effect.5mm minimum nozzle and the higher the temperature the faster it will dry.
Also if you use 2 parts paint u better let the coat dry before u apply the next one cause if you mix two coats the catalyst will react badly in the second coat so the paint can be peeled off as it dries.
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Points: 567 		Post Options Post Options   Thanks (0) Thanks(0)   Quote RobinMatrix Quote  Post ReplyReply Direct Link To This Post Posted: 19 November 2014 at 1:36pm
Originally posted by Lad Lad wrote:

Thanks guys for info, I know that polyurea is hard to beat regarding quality. I need to work out the economics...


Don't forget to factor in the cost of the coating equipment and minimum purchases with polyurea,  you are looking at least at £17K for the application equipment and another £2500 for two barrels of the goop, so unless you have significant quantities to do, its a going to be WAY cheaper to do polyurethane or water based.

Don't dismiss water based, it has significant advantages in the application process, and is a lot easier to handle.  Once applied, it cures just like solvent based paints do. It is also easier to touch up on site if  you need to. Many of the quality German PA brands use Warnex and as far as I know, all the Martin stuff as well, so done right it can be an exceptional coating. 

Water based paints have a bad reputation, but largely due to poor application or materials ... however, almost all cars have been painted with water based paints for the last 20 years, including metallics, and you don't see those washing off in the rain :) 

I think Thomann do the Warnex stuff these days too, so its not even that hard to get hold of anymore.
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Originally posted by RobinMatrix RobinMatrix wrote:

Originally posted by Lad Lad wrote:

Thanks guys for info, I know that polyurea is hard to beat regarding quality. I need to work out the economics...


Don't forget to factor in the cost of the coating equipment and minimum purchases with polyurea,  you are looking at least at £17K for the application equipment and another £2500 for two barrels of the goop, so unless you have significant quantities to do, its a going to be WAY cheaper to do polyurethane or water based.


I was meaning to get it painted... it's 270 Euros for LineX and something between 150-170 Euros for PU paint for 4 boxes.

Today I have spoken to lady from LineX shop, she wasn't sure if I redrill holes and maybe reroute some rebates for flytrack after painting, that it might start to peel off. Really?
with regards, Ladislav
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MarjanM View Drop Down
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Whatever you chose the paint need to be thick if you want good results. 
With Warnex my norm is about 1.5-2kg per 12inch+hf box. More on the touring boxes.
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MarjanM View Drop Down
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Not sure how big those 4 boxes are, but 270 eur does not seems too expensive to me.

Edited by MarjanM - 19 November 2014 at 3:34pm
Marjan Milosevic
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Originally posted by Lad Lad wrote:

[QUOTE=RobinMatrix]Today I have spoken to lady from LineX shop, she wasn't sure if I redrill holes and maybe reroute some rebates for flytrack after painting, that it might start to peel off. Really?


Yeah, if you are designing the box for polyurea, you really need to include an allowance for that right from the start, you don't really want to be breaking the skin on a polyurea coated box if you can help it.
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SamV View Drop Down
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Also if it's for hire stock etc factor in respray etc in a year or two especially for subs unless you use LineX.
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Points: 153 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Lad Quote  Post ReplyReply Direct Link To This Post Posted: 20 November 2014 at 6:15am
Originally posted by RobinMatrix RobinMatrix wrote:

Originally posted by Lad Lad wrote:

[QUOTE=RobinMatrix]Today I have spoken to lady from LineX shop, she wasn't sure if I redrill holes and maybe reroute some rebates for flytrack after painting, that it might start to peel off. Really?


Yeah, if you are designing the box for polyurea, you really need to include an allowance for that right from the start, you don't really want to be breaking the skin on a polyurea coated box if you can help it.


Ouch, I didn't do that. But does it mean it's better to drill holes for flying hardware and mounting speaker afterwards? Got T-nuts already in place.

Just to complete the info, it's 12"+1" box. Photos will come sometime.
with regards, Ladislav
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