NC vs Acrylic Lacquer

[silentC]

What's the go? My local paint shop can get acrylic lacquers from his supplier but not NC. I've read a little bit about it and acrylic seems to be the go if you want a water-clear finish. But other people on here seem to be into nitro-cellulose.

[durwood]

silentC,
Nitrocellulose lacquer is a very inferior product compared to acrylic lacquer.

Its main problem is its bad performance if subject to sunlight. The resin goes brown and cracks making the whole finish breakdown in less than 6 months in our climate. Think sticky tape.

Its been used for interior use for a long time after the introduction of acrylic lacquer (1960) as it had been used since the 1920's and a lot of people were used to it. Don't get me wrong it is better than A/L in a lot of ways. It dries a lot faster ( rock hard in about 24 hours) where A/L takes at least a month to get to the same state. that makes it extremely easy to use especially if you mess it up ( get a run etc). The solvent used to thin it is not as strong as A/L also and it is less prone to act up.

Acrylic lacquer can be a real pain to work with compared to N/C the strong thinners attacks the finish and any problems can blow up into major catastrophies. You have to use very fine paper to rub it back as the thinner attacks the scratches. N/C is so easy to use you can spray straight thinner on it after scratching it with coarse paper and it will just melt the scratches into a glossy finish.

With the advent of polyurethanes, precat lacquers etc it is not being asked for as much and is therefore less likely the manufactures are prepared to keep producing the stuff.

All lacquers produce a lot of pollution due to the amount of solvent they give off because they have to be thinned down so much. Overseas they have been banned. Even A/L is banned you must now use a far better material. Even though 2 packs have a problem because the hardener is so poisonous making wearing air fed hoods compulsory they put out only a tiny amount of solvent into the air in comparison.

Luckily acrylic is still available here and it will give you a good finish but you have to be careful in applying it as the solvent attacks most things it is applied over and the solvent tends to dry out the moisture from the timber more. Having said that you probably won't have much trouble using it if you have used N/C. The main things to remember are thin it at least 60% thinner 40% clear and don't be in a hurry to apply coats. The longer you leave between coats the better ( at least 20 min - an hour is better) and only use about 5 coats.

If you put on 3 coats let it dry overnight, cut it back with 1200 wet then thin the mixture to 80-30 and spray the last couple of coats and leave it about a week in this weather you will get a better result.

Make sure the temperature is over twenty and stop if it blushes (goes milky) till the weather is better ( no rain)

It will buff up nicely after a week as it will be fairly dry and hard, if you find it a bit peely rub it wwith 2000 wet to flatten it and then buff.

[Lignum]

Fantastic run down Durwood your advice on this subject is always terrific. (the same as your advice on me coloring the desk) Thanks

[silentC]

Yep OK, thanks for all the info.

I haven't sprayed lacquer at all before. Only ever sprayed poly U for furniture.

At the moment I'm tossing up whether to go for a shellac/oil/wax finish on this present project or to spray lacquer and I was in the paint shop to get some metho and thought I'd ask.

Getting a temp above 20 at the moment will be problematic. It has not been getting past the teens for the last couple of weeks. The other problem is that they seem to want to sell the stuff in 20 litre tins. Maybe the lacquer experiment can wait for the next job.

Even A/L is banned you must now use a far better material.

So what would that be?

[silentC]

you have to be careful in applying it as the solvent attacks most things it is applied over

I suppose that means that using shellac as a sealer isn't the best idea? The same company that does the lacquer (Concept Paints) has a sanding sealer that might be better if I went down that path.

[durwood]

Shellac would be ok as a sealer but as has been mentioned before you then have the durability problem ( especially with heat coffee cups etc if thats applicable)

The better materials are the 2 pack acrylic urethanes

you can buy acrylic lacquer in 4 litre tins go to a store that sells automotive paint. The best one is PPG Dulon AAA clear. Though any brand auto one will be as good or better than the Concept Paints.

If you can spray poly you can spray A/L.

[echnidna]

Don't use auto lacquer its not made for timber.
Use a pre-cat furniture lacquer which is available in various gloss levels
Theres a few brands available, eg Mirotone, Haymes, Wattyl (from their industrial division not from a hardware/paint shop Croda (I think they were taken over a few years ago)

It's quite safe over shellac which incidentally is a good intermediate coat over a base that is incompatible with lacquer such as normal oil stains.

But try out lacquer based sanding sealer,
leaves other sanding sealers for dead.
its the best thing since deep fried bacon.

[silentC]

The problem I have here is that the local hardware and paint shops don't stock this sort of stuff because there's no demand for it. This one paint shop is trying to expand his services a bit - he's around the corner from a panel beater, so he's getting into automotive paints hence the connection with Concept Paints. They have recently released this range for timbers. They have 3 gloss levels in clear and then a range of coloured finishes - all in 1 or 2 pack.

If I go into Mitre 10 or somewhere and ask about Mirotone for example, they wont want to know me because there will be a minimum order quantity (if they can even get it). Wattyl might be an option.

But I just thought of something. A mate of mine runs a joinery, so he will probably either have some, or will be able to get it.

[durwood]

Echnidna,

I would be interested to know why you think auto lacquer would not be suitable for timber. Having done numerous tests comparing the two it stands up far better than N/C on timber.

[Lignum]

Don't use auto lacquer its not made for timber.
.

Bob i have been using the auto lacquer from super cheap auto for around 15 months now (i stock up when they have there sales) and its the simplest thing i have used to spray and have never had a problem or a complaint. Lots of dining tables have been done and they all have stood up well.

Im sure i could do better than super cheap with the $$$ and quality, but it suits me fine

[echnidna]

I NEVER use NC - I use precat furniture (acrylic) lacquer

I have used auto lacquer when I've been out of furniture lacquer.
and when a full gloss finish is acceptable
Yes it gives as good a finished product appearnace as furniture lacquer.

But is it as durable in the long term as furniture lacquer?

I note that if it was durable in the long term on wood the manufacturers wouldn't bother making a separate furniture finish

AFAIK Its not available in various gloss levels

[echnidna]

Lig,
try Paintmobile in Preston or Dandenong, you'll get clear precat furniture lacquer (wattyl) at a very good price if you buy 20 litre drums

The sanding sealers much the same low price in 20 litre drums

[durwood]

acrylic lacquer (auto) is far better than furnature grade. It costs more to make the automotive stuff. It has to take a far greater beating outside in the sun. No need to add all the expensive UV filters etc in furniture no need for it. Even shellac lasts inside and it will only last a matter of days outside. Same rule applies as to all paints being equal there are lots of levels of quality, paint companies make cheap versions of all sorts of things solvents included.

I started in the paint trade in the late 50's before acrylic In those days NC was the only lacquer available A/L first became available here in 1962-63.

A lot of our customers owned Rovers, Jaguars, Rolls Royces which had NC as the finish on their wood dashs. We could refinish them with NC but it only lasted a short time so our old painter used a marine varnish which was a bit better but a problem in a dirty shop as booths were virtually unknown.

When Acrylic clear hit the market the problem was solved.

I ended up working for TAFE during this period, we taught clear finishing due to the Rovers etc./ At the college were had a rack on the roof and every year we got the students to put all types of finishes on the rack to see the results. A piece of timber with masked sections for NC, A/L and enamel soon showed which was the superior. The acrylic beat them hands down.

You can govern the gloss as the acrylic lacquer has a flatting agent you can purchase that allows you to change the gloss level to anything you want from full gloss to dead flat.

I must admit coming from an auto background I am a bit biased but as the house painters from our college always came to us for material when they had a particularly tough job and being able to not only paint all metals, plastics, timbers, glass, vinyls, leather with the products available to us I find it hard to use basically inferior materials.

Obviously if I'm working on a house then house paints are usually the go but when it comes to some things like the aluminium windows I quickly head for the auto paint it gives me years of extra service

[silentC]

Well, I think that Brisol up the road has the Concept Paints auto lacquer in stock in small tins, so maybe I'll buy a tin of that and some flattening agent (rings a bell, possibly from the catalogue) and see how it goes.

[echnidna]

Must have a look for the flatting agent as I would just about bet auto clear is probably much cheaper than furniture clear