Acrylic/Enamel/Lacquer etc etc ...... etc !!

[Dialgauge]

First off, this is my first post on here - so hi to everyone

In all honesty I have done really quite a bit of spray painting over the years, mostly on motorcycles and performance cars, and some custom work too. However, even though I did it as a full time job, and consider myself to be pretty capable, there are gaps in my knowledge due to the fact that I never actually went to tech/college and did the theory side of things. This never used to bother me as I could do the job and never had a problem, well except the usual annoying bloody issues that we all have as painters from time to time lol.

Anyway, I am sure there will be other things that I would like to ask the gurus out there as time goes on (as well as hopefully being able to contribute with my knowledge too), but what I really want to know just now is in relation to my thread title. I have only ever really painted in the automotive field, and generally have stuck to the same types of product. I've used direct gloss (or 2k paints, and 2k primers etc), PPG, sherwin williams and Pro-Spray basecoats and mostly PPG Deltron D880 clear coat lacquer. However, because I have done loads of paintwork people tend come and ask for my advice from time to time. The thing is, it's quite embarrassing when they ask me things like "should I use enamel, or acrylic paint" or "should I use urethane paint" etc etc, as in truth, I don't really know enough about the various different types of paint and the reasons as to why you would choose one over another, as I really only know about what I've used to paint cars etc, and that it works. I am also lead to believe that you can not put certain paint types over others, but again I am unsure what these are. I mean I know what product I would use when I was doing jobs etc, normal primers vs 2k high builds etc, or know when I would use a direct gloss 2k paint rather than base and clear (not often!!!), but I just don't know the differences between acrylic/enamel/lacquer/epoxy blah blah blah, and therefore I feel a bit stupid when people ask me and I can't advise them Can anyone help me here ? Sounds silly, but whay category/categories would the paints I have been using fall into ? In automotive work I have only ever used a limited range, and wonder if in other applications (for a boat for example) if automotive paints are not ideal and something else should be used ?

I hope someone can shed some light on this subject for me, and look forward to your replies.

Thanks

 

[TAZ]

Welcome to the forum.

Lacquer is a pretty dated type paint.
When people ask me, I normally just tell them, that you should go with a basecoate/clearcoat type paint.
This is a urethane paint. Most paint systems have them. They all seem to spray about the same. Prices vary quite a bit for cheap clears to the expensive clears.

enamals are also kind of dated. They are cheap. The single stage enamels, can either be clearcoated or left alone.
A 'true' urethane basecoat/clearcoat has to be clearcoated since the base dries to a matte finish. Then the clearcoat is your 'gloss'.
Hope that helps you out a little bit?!

 

[chopolds]

You could write a couple chapters of a book on this subject! I'll try to add to what Taz said, with some more detail, I started paitning back in the 70's, so I'm familiar with most of the paint types..
Lacquer: early version is nitrocellulose, later (late 50"s) replaced by acrylic. Nitro is very translucent, so it looks great, nothing beats black nitro lacquer. BUt, it gets very brittle with age, eventually cracks. Needs a LOT of maintenance, polishing and waxing, to keep it's shine. Not very chemical or abrasion resistant.
Acrylic is a huge improvement over nitro. Better resistance to abrasion/chemicals, but still can be affected. Easy to spray, touch up, sand and polish. Good beginners paint. Got to put on lots of coats, as it is pretty thin and translucent, also why it looks good! Very susceptible to blushing in humid conditions. Takes a LONG time to dry/shrink. WIll show sand scratches, and imperfections as it dries/shrinks. Needs to ben sanded and polished for maximum shine, it dries kind of dull.
Synthetic enamel..the earliest paint on cars, think Ford model T. Takes a long time to dry, but is shiny when it is..no need to sand and/or polish. Stays soft for a long time, as well. Hardly ever used now, used to be the cheap paint Earl Schieb used to use, even up to some years ago.
Acrylic enamel, big improvement over synthetic, but basically the same qualities. Just a bit better with regard to dry time, shine hold out, gets hard faster. Still used today as it is spray and go...good shine without any sanding and polishing. In the 70's, an isocyanate hardener was introduced to make it dry (actually "cure") faster, with more gloss, and retain it longer. more chemical and abrasion resistant, too. Also allowed it to be touched up. Early and air dry version would wrinkle if you tried to touch them up, unless they had been dry to over a year or so. Still used on cars for low cost, and as an industrial paint. Holds up well.
Next came urethanes, polyurethanes. Very tough, shiny, long lasting finishes. Do not need sanding and polishing if applied cleanly, but you can do so for a better finish. Can be used in industry, esp. poly's like Imron. Usually used to paint trucks, airplanes, etc. Urethane clears lead to the use of basecoat/clearcoat systems. Base is usually a different chemistry, air dry, while the uro clear is chemically cured/hardened, for a tough finish. All uros, polys, and acrylics with hardeners are very toxic to spray, but that is what makes them tough.