Lacquer VS Poly = Confused Individual

[Caloute]

Hi there,

Another post from a noob I guess…I have been doing some reading on the forum lately, pickup a few tricks but just would like some additional info on some stuff that has been bothering me for a long long while.

Years ago while I was visiting a cousin of mine overseas, which is a builder, I visited his workshop…and he does all his cabinets for the houses he builds, well his employees build…anyway the finish was really nice, white and seemed really thick and glossy…so I asked him how they were doing them, so he told me they were sprayed…which I kind of have imagined…but then I not if he said that they used car paint…or if he said it was the same process, or if he said it was lacquered or something in this lines…surely the paint job looked very similar to a car paint job.

My questions are:

What is the difference between polyurethane and lacquer? I imagine it is a different material, but why choose one over the other.

Why would you use car paint? which I suppose is for metallic surface, it is probably why it is called car paint, bizarre…

Do anyone of you know of any Australian publication that illustrate the car paint process and the different coats and product used?

Now I am off to paint all the interior door of the house, and I’d like to achieve a very similar glossy white…I was thinking sanding back the existing paint, it is probably a oil paint rolled as far as I know, doors are all flat, then when they are all sanded I was thinking primer, the color (white) water based paint, then I was thinking finishing with polyurethane.

My questions are:
Do you think it an okay process to paint the door?

The problem I have is where to get polyurethane I never seen it in Bunnings, what brand is good?…I read here Poly 400 from Wattyl…Any suggestion? Preference would be something that cures quickly, BUT wouldn’t mind waiting to get something that look’s like a car paint job or at least know a few of the best product to use. The Poly 400 seems like one pot…just not understanding what “2 pac” stands for, is something that have to be mixed together?

Something really important I would need a mask to spray poly, do you think I should be able to get something decent from Bunnings or even ebay?

I’ve got a sanding machine, just a cheap gmc one, since they are a lot of doors, I would not mind investing in a proper sanding machine to do flat surfaces, is rotary/orbital better? Anybody could recommend some decent model.


I read an interesting article on the forum as well about MDF waterproofing but like an idiot did not save it and cannot find it again, I have got some pergola seats that need waterproofing coz sometimes they get wet, what would be the best product, I remember reading it was important to do the edge coz that is where water was going in.

Anyway thanks for your help in advance…and I apologize if you have to repeat yourself, I know I should be reading the entire forum, but just running out of time it seems.

Cal

[journeyman Mick]

Cal,
"two pac" refers to any paint that has two components that are mixed just before application. There is a wide variety of different types on the market.

Polyurethane is a type of coating and comes in single pack and two pac, also comes as a clear finish or paint.

"Lacquer" generally refers to a nitro-cellulose based coating, usually clear. It's generally single pack but you can get one that is two pack (acid cure).

Automotive paints nowadays are generally either polyurethane or acrylic lacquer and more often than not are two pack. While many (all?) of them will work on timber they are designed for metals and it's better to buy a product specifically designed for application to timber.

If you want that smooth, glossy perfect looking finish then IMO you're wasting your time trying to repaint your existing doors etc. Most of these finishes are applied over MDF which is already smooth and grain free. If you don't fill and sand until you have a flawless surface you'll just end up with a glossy door/whatever that highlights any imperfections. Also, unless you've had a bit of experience applying these coatings you'll most likely end up with a very poor end product. They're not easy to spray. The other problem is finding somewhere to do the actual spraying. Most of them are two pack with a cyanocrylate (sp?) hardener. It basically gives off cyanide gas (or something very similar) when you spray it. Not the sort of thing you want to spray in your garage.

Mick