Safe HVLP finishes?

[tiroth]

I've had good results wiping shellac, and I'm interested in upgrading to a HVLP (conversion) setup. My rationale is that this will be a lot faster to apply and a little easier to get even coats with no missed areas.

1. Does shellac spray well?

One of the reasons that I like shellac is that it seems like it is probably one of the safest possible finishes. It is also fairly reworkable, which is nice for a novice.

2. Are there any safe laquer finishes? (no respirator needed)

3. If I can't afford a $$ gun, am I better off just wiping finish?

I know there are a few people that are experts on finishing; I'd really appreciate your input.

[mwmkravchenko]

1. Shellac does spray well. It makes a very good base coat in some situations.
2. All finishes have components in the mix that are not good to inhale. Including shellac. Think about inhaling alcohol that is not fit for ingestion.
3. A wiped or brushed finish can be as good as a sprayed finish if you are willing to expend the time needed to flatten the brush marks. Then bring the surface back up to a polish.

Most of this can be done with a good finish and a good hand at spraying. A really good gun does not a really good finish make.
So don't spend megabucks on a gun. Learn how to do it right and you will be laughing at most jobs in no time at all.

Mark Cabinet maker at large ( no longer in graphic design )

[oaktsh]

Mark,
Could you comment more on point #3 (i.e. your method on flattening out the brush lines and bringing the surface back to a polish). I work with laquer and have been having suboptimal results with brushing. Thanks for your reply

[paulhfx]

Lacquer is extremely difficult to brush, as it simply dries before the brush lines have a chance to run together.

The flattening he was referring to is sanding down the finish, to remove brush marks, dust on the surface, orange peel (when spraying), etc.

The is sometimes referred to as "finishing the finish". Typically you'd start with about 400 grit sandpaper, go to 600, 1000 and 1500. Follow that with polishing compounds to get a perfectly smooth finish.

Check this site - it's talking about paint, but the method applies also to lacquers and other clear coats.
http://www.pc-workshop.net/articles/...int101-3.shtml


Paul

[mwmkravchenko]

One thing that I may add. Laquer may be brushed if you either thin it with laquer thinner or if you are more sophisticated thin it with reducer. It will dry more slowly but the brush marks will be minimised. The down side is that it will take longer to produce a decent build up of finish.

One note on the sanding and rubbing out of a finish. You have to have something down to actually sand and flatten. There needs to be at least thre or four good coats of laquer to do this on. My only addition to pauls advice is that if you are working on larger flat areas is to make yourself a glass backed sanding block. It will be dead flat and will create a dead flat finish.

THe steps are usually sand you surface to 220 grit. Seal, first coat sand with 400 wet with a bit of soap and water. One or two drops of dish soap per 1/2 liter of water. Clean and apply second coat. If it looks good go to three or four. Sand with 600, 1000,1500 or pumice or coarse rubbing compound. Then rotten stone or fine rubbing compound. If you are a pro or just plain crazy you can follow the coats three and four step. ( of course ley it dry a day or two ) [forgot to mention that part in the beginning]
THen get out your power buffer and cream compond and go for it. Beautifull when done by the right person.

Mark

[tiroth]

Thank you finishing gurus! I really appreciate the info.

I'm guessing from the silence that you don't know of any "safe" sprayable lacquers? I guess a basic respirator is a good idea in general but I know that that really bad chemicals aren't fazed by the regular Organic Vapor/N95 style masks.

[mwmkravchenko]

There are no really safe sprayed finishes. They all contain chemicals that are best left outside of your body! Even the water borne stuff has some ingredients that are harmfull. Just think about your respiratory system and the way it works. Much to easy access to your blood stream through your lungs. Some of the stuff in finishes is pretty nasty. Get the WHIMIS sheets and the MSDS sheets if you don't believe me.

The whole problem lies in the fact that the best performing coatings are usually the most dangerous to spray!!

Mark

[botrytis]

That is why no black laquer finishes are done in the US anymore. OSHA shut most of them down because they use really nasty chemicals to create that nice finish.

Spraying would cause other problems, like getting it on other things and getting dust in the finish. You really need a spraybooth.

dave

[Cheap Shot]

Black laquer no problem just break up pieces of old 78 records
(must be old ) and soak in laquer thinner. the thinner will melt
and bingo bango black laquer.works great, BTW there are all types of additives to keep your finishes from drying to fast
(brush marks ) laquer thinner only thins and helps dry faster
check your local paint dealer or old timer hardware store!

[Greg B]

1. Does shellac spray well?

I dunno, but I've heard of people having problems. I've only ever used spray can shellac, which is basically a joke.


Here's my quick and dirty shellac technique:

1. prep wood by sanding and filling with a burn in stick. Wet it, let dry, and sand some more.

2. Brush on about 5 coats fresh shellac a couple hours apart.

3. Let it dry a day or two, and wet sand flat with 400 wet or dry around a felt block.

4. Rub with 0000 steel wool dipped in paste wax.

5. polish with a dry clean cloth.

The End. Comes out medium gloss if done well.

2. Are there any safe laquer finishes? (no respirator needed)

Try one of the new waterbased acrylic/urethane fake lacquers. They've gotten much better. They can be wiped, sprayed, or applied with a foam brush.
Maybe try KTM9

You will need to learn to do an abrasive rubout by hand at some point anyway, if you want a pro finish. There's nothing I know of that you spray on that comes out perfect.

GB

PS. Old 78's are made from shellac.