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Tegmark
13th September 2016, 06:08 PM
My understanding is this stuff is non reversible only after a few days, & because the coats dry so fast when spraying,
if you spray 5 coats in a day they will all melt together forming one single thick layer without any issues with witness lines like poly.

Is this correct?

Further no sanding is needed in between coats as the spray gives a fine result, & it dries rock hard very quickly so dust & debris cant ruin the finish compared to poly which although flashes quickly takes alot longer to resist dust.
Is this correct?

For a typical desk or something how does Cat Lacquer's chemical & scratch resistance compare to poly? Does it sit somewhere in between oil based & 2pack?
For example oil base poly can take countless times being cleaned with feather dusters & isopropylalcohol/water on a fine cloth without getting any scratches or being attacked by mild cleaners.

Thanks

Arron
16th September 2016, 08:30 PM
My understanding is this stuff is non reversible only after a few days, & because the coats dry so fast when spraying,
if you spray 5 coats in a day they will all melt together forming one single thick layer without any issues with witness lines like poly.


It is sort of reversible after a few days. If you get an object sprayed a few weeks before and rub it with thinners then yes, it does melt somewhat. Like a thin, sticky surface. I do this from time to time to eliminate scratches - rub over with thinners, leave to dry, sand, polish. I seem to recall doing it with objects sprayed a month or so before, but have never tried anything much older then that.

Well I've never noticed any witness lines so I guess its true.

Precatalyzed lacquers don't meld together quite as thoroughly as old-fashioned un-modified nitrocellulose lacquer, but still largely true.



Further no sanding is needed in between coats as the spray gives a fine result, & it dries rock hard very quickly so dust & debris cant ruin the finish compared to poly which although flashes quickly takes alot longer to resist dust.


What I do is spray two coats of sealer then sand well. In fact I sand just about all of it off. Sealer is made to be sanded and it sands like a dream - down to a silky smooth surface. Its easy effortless sanding with no clogging of sandpaper. 400 grit. Then I spray 2 or three coats of finish lacquer - without sanding between unless I screw up somehow. If I must sand, its usually just a quick once over to knock off a few dust nibs. I find sanding the finish lacquer just tears the surface.

Generally
Sealer - is made to be covered so need no abrasion resistance, so its made to be sanded (sanding is abrasion)
Finish lacquer - is made to resist abrasion to give you a good service life, so its a pig to sand.

In my opinion the sealer is a must for a high quality job. If you have done your prepping/sealing well then the lacquer should be dead smooth straight off the gun. If not you are using the product wrong.

The product I use (Wattyl Stylwood) dries in about 10 mins. Any dust that lands on it after about 5 mins can usually be brushed off. I find using it outside a spray booth there is no great problem keeping the dust off something for 5 mins.

Generally I ignore any dust and leave it till the final buffing stage. A very, very light sand with 1500 grit, then hand buff with Meguiars fine compound is enough to deal with it.


cheers
Arron

soundman
19th September 2016, 12:17 AM
If ya talking stuff like Mirrotone precat laquers ........ you can scrub the stuff of with a bowl of thinners and a rag any time you like ...... if it has been on for some time it may take a while for the solvent to do it's job ....... but it will.

This is why it's a bad choice for dressing tables unless you are putting glass over the top ...... nail polish remover with take it right off.

cheers

Tegmark
19th September 2016, 06:14 PM
Generally I ignore any dust and leave it till the final buffing stage. A very, very light sand with 1500 grit, then hand buff with Meguiars fine compound is enough to deal with it.


cheers
Arron

Compare that to poly 2pack, after 5 hard hand polishes still couldn't get the sand marks out.

Thanks for your help Arron.