Acrylic Vs 2 Pak

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Submission by Streetneat Aug 1st 2005:

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Acrylic vs 2 Pak:

Firstly the old Holdens were painted in NC (Nitro -Cellulose)lacquer - a type of acrylic - This was a good paint but had very limited life due to its bad UV properties- it was pretty high maintenance - requiring a good level of polishing - which of course just wore it away - some of these factory NC jobs still exist on the old girls today - and owners are not game to touch them- or the paint will just disappear.

FB Range:

The FB range in 1960 saw the factory switch to low bake acrylics - which were pretty durable - but also pretty peely - (the texture of an orange peel). Some original cars still wear this paint today also- as it was a little better in durability- due the the fact it was baked. The problem here once again - was the cars were given minimal coats - and the surface rust soon began to override the paint finish on a lot of cars...

The Early Nineties:

Right up until the early Nineties Holden still used low bake acrylics - but due to environmental and cost concerns the paints became thinner and the technology was switching to the far superior two packs. The VR series two saw the whole range using two packs for the first time. Ive painted more VN/VP Commodores than any other car so I personally can vouch for the crap acrylics the factory used - very minimal paint film and no UV properties in most of the metallics.

Chemically Cured:

Some of the comments posted by others here are incorrect- obviously not made by painters - Paint is measured in microns- and to say it will fail under moderate stress is also incorrect-Two pack is chemically cured and gives the gloss chemically - instead of mechanically (buffing) as with acrylics.
Two pack should never be applied heavily over acrylics- especially 57 layers of clear - the result is two fold - one is the the gloss is sucked out of it by the underlying acrylic (actually making it more desirable for undetectable blends of two pack on existing/sound acrylic) and two is eventually there will be delamination issues.
Two pack is far from watery - acrylics are quite watery due to the amount of thinner used.
One comment is true - two packs are glorified enamels- but rest assured its a very high refinement that makes it so!

Factory Paint Jobs:

The factory paint jobs used today are still kept well under 50 microns - which means the number of coats is about two at best of top coat - Resprays in two pack are measured in the hundreds of microns however to say that two coats or two pack are the same as the old acrylic coats is ludicrous- Two pack is applied entirely differently using different equipment and technique to acrylics- its thicker - so less coats are required and it only contains up to 10% reducer (thinner)- Acrylics contain up to 75% thinner so more coats are required- and modern acrylics are now devoid of lead and other heavy materials so they are now super thin and have nearly no UV properties at all. Due to acrylics using so much thinner to carry the paint to the car when spraying - it continues drying out over time and always remains porous. The normal fate is to see humidity blisters appear and eventually the paint will dry out entirely and part company with the car - IE; look at the VN/VP Commodores.(but not VQ Statesman and some VN/VP Calais - Holden started to use two pack on the upmarket models a little earlier).

Advances in Technology:

The technology has marched on and there will always be some who want to cling to old technologies - I'm one of 'em - but no point with paint... the new two packs are far superior, longer lasting - far better finish (if applied properly) and extremely durable, cost effective and a lot simpler these days(for the professionals) to use - Unfortunately for most of you lot - this means that you are stuck with the choice of crap acrylics or getting a shop to do your car for you in two pack. Beware of painting anything at home with the stringent EPA laws - especially acrylics- as the EPA has finally woken up to the fact that acrylics are extremely high in VOC (volatile organic compounds)- The amount of thinner used means there is a lot that gets out in the atmosphere. Acrylics- for this very reason -were banned in the seventies in California! The EPA/Councils has made spray painting and other forms of coatings the new target so beware...

Cheaper is not Necessarily Better:

Cheap fast good- pick two...If its cheap  and fast it wont be  good . If its good and cheap - it wont be fast. If its fast and good - it wont be cheap.
You will always find someone cheaper to do the jobs for you - sometimes - but rarely with quite acceptable results. 5-15 grand is normal for 2pack paint jobs - and this is due to the cost of materials and the extra effort/labour/running cost required in getting the job right.
I often get scoffed at for the cost of paint jobs by many doubting customers - so we will let them do some of the prep work - and soon they change their tune- it doesnt take them long to see the effort that is required and the cost of materials involved. Shop around and ask guys with finished cars as to whats their job was worth - were they happy and so on.


Best and Cheapest:

Consider the fact that manufacturers want the better and cheapest way to paint cars at the same time as giving extended warranties and this is why they switched to two pack. Five year warranties are now normal - many cars when painted in acrylics years ago excluded paint from the warranty altogether - paint is now included- so it has to be durable and still look like new in five years- Most paint companies give ten years warranty on two packs - show me an acrylic paint job that's on an everyday driver that can make the claim its still as shiny as the day it was applied. As I said technology has moved on - for good reason.

Old Holden Look:

The argument that two pack looks out of place on old holdens is wearing as thin as the acrylics are superior claim. Done correctly the two pack job should be a pretty close match when using original colours- but without the plastic look that really is a product of orange peel finish of a badly applied job. Award winning show cars with acrylic jobs are super rare these days - they are very high maintenance (constant polishing)and rarely exposed to our harsh sun. A handful of guys that have these cars - like Adam LeBreese (EH Delivery)& Darren from Superformance( Model A Pick Up) to name a few - say they will be using two pack (sprayed by someone else) on future cars and only used acrylics because that's all they could spray at home.
Our own FC collection wears standard colours and never had we had feedback saying that they look wrong.- We use the cars as proof that when done right they can look right at home.

Cuttable Clears:

The new HOK (House of Kolour) two packs now have cuttable clears- so the peel can be eliminated altogether - although peel in modern two packs tightens right out altogether after a few weeks - as long as its been applied properly. The cuttable clears will become common place and the chemical gloss will still remain- this is due to the fact they are softer - making them more elastic and less prone to chipping. The draw back currently is they take 3 weeks to harden properly so cant be handled roughly for a while. Cheap two packs have this same soft properties and therefore can be buffed a lot easier- but dont hold the gloss for ten years like the leading two packs.


This has been a rather lengthy fact straightening that needs to be added to the Holdenpaedia (you reading this QUTE?. [Yes, Andrew, I did and have done...] All the above is based on solid fact and many years of being in the panel trade- (and still in the panel trade unfortunately... lol .

When I started in this trade over twenty years ago - we used to hear similar arguments that baked enamels and NC lacquer jobs were far better than these new acrylics... so now the argument has just shifted a little with time....
Cheers streetneat
[For more on panel and paint visit www.streetneat.com and check out the many albums on vehicle restoration and modification]

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