Spraying Lacquer finishes

[Rodney Watson]

Been a woodworker/finisher for a lot of years and I've always either brushed poly or sprayed it using an HVLP Wagner unit. Lately, I've been using BullsEye Clear Shellac, brushing, with good results. But in general, I've always had pretty good luck with the poly. Delt with the dried bumps from dust, since you generally do at least 3 coats, I just sand and by the 3rd coat, usually have a pretty slick, attractive, thick finish that I know is durable. Done mostly doors and some tables. Our dining room table was initally sprayed with Satin poly about 16 years ago and its still in great shape - you can't beat the poly's durability. Spraying chairs with poly was better than brushing for sure, just have to remember to do many very light coats.

I'd like to get comfortable with spraying lacquer for that hard clear finish when desired - clear poly gives red oak a bit of a golden hue. Sometimes I want that, and sometimes, I'd like not to have it. Tried spraying lacquer from a rattle can on a small flat unsealed maple project, only to get a bunch of fish-eyes and not so slick finish. Two coats later, it looks the same, and the fish eyes stayed. I can sand it down and give it another go, but what happened there? Puzzled? My main interest is panel doors. Would like to think I can do the doors without the fish eyes and matty looking finish. From what I've been reading on SawMill, sounds like a sander sealer coat first - might be the secret to getting the lacquer to land right and stay nice. I already have a gallon (old) of Parks clear lacquer. Have read here where cheap lacquer is crap and good lacquer is good. Don't know how this gal. of Parks stacks up on that scale.

I don't mind trying the WB lacquers, for obvious reasons. When I'd do poly, I set up the shop for the overspray and was very careful, making the job quick and neat. I've gotten to feel comfortable with it even with the odors (using a mask) and cleanup - but need to work on getting comfortable with doing lacquer.

Haven't used my Wagner gun for lacquer ever, might give it a go, but would like to hear from some of you veteran sprayers for some do's and don'ts. I've got two 6-panel R.Oak doors that I rubbed a light coat of BLO on about 10 days ago. I wanted to enhance the grain before doing the finish. They're pretty dry now, but I'll wait another 2 weeks before doing anything.

Any comments? Thanks.

[Leo Graywacz]

I'm just wondering if you really had fisheyes on the oak or if the lacquer didn't span the pores. I have what I would call pinholes when I do open grain woods with lacquer. A few coats later with sanding in between and they go away. Most lacquers except nitrocellulose has mil limits, usually around 4-5 mils. So you can't just keep putting the coats on.

I have been spraying lacquer for a few years now (ML Campbell's) and it is pretty easy to work with. And dries quick which is the main benefit. Not much is tougher than oil polyurethane. The normal finish for cabinets is Conversion Varnish which is a post catalyzed product. You mix it up and spray it. This is pretty tough but poly will beat it.

You wagner might spray it, not sure, I use an HVLP 90% if the time and a pressure cup gun the rest of the time.

[Rodney Watson]

Thanks Leo, appreciate the response. My fish eyes were in Maple, haven't done the red oak yet. Thanks again.

[Mike Henderson]

In my opinion, lacquer is about the easiest finish to spray. Goes on easy, flows out well, dries quickly, burns in to the previous coat so there's no witness lines (if you rub it out), and you can rub it out to a high shine and to get rid of any nubs in the finish. May people think it looks better than poly, also.

The new water based lacquers spray as easy as the older solvent based lacquer, IMO, and are better on the environment.

The only negative I see to lacquer is that it is heat sensitive (non-catalyzed lacquer, that is) so if you use it on a table top and someone puts a really hot dish on the table, it will mar the finish.

It was the work horse finish for factory made furniture until catalyzed finishes came available.

Mike

[george wilson]

Parks lacquer is sold at Ace hardware. I don't think it is very good lacquer.

Your fish eyes are possibly because there is a trace of something like silicone polish,wax,or something on the wood. Has nothing to do with sealer.Do you polish your machine tables with silicone spray to make them slippery? Death to finishes like lacquer. Stay entirely away from it.

If you use lacquer,you should use lacquer sealer under it. it contains tiny cellulose fibers that make it easy to sand,and help seal the pores in the wood. But,sanding sealer shrinks for MANY,MANY months,re exposing the pores of the wood. Use a wood filler first.Do at least 2 coats Follow the instructions:Put on a coat,using a brush with the bristles cut off half their length.Push it into the pores of the wood with the stiff brush. When the filler turns dull,rag the filler off ACROSS the grain. Don't wait too long,or you will have a devil of a time getting the filler off. After removing any filler that is on the surface,sand the remaining filler with 220 paper. I recommend garnet paper,not the paper with the white zinc stearate in it. Do the process again next day.

If you want a cool,clear finish with NO color,use acrylic lacquer products. Acrylic has a blue resin in it,that gives a "cool" finish. Spray on 3-4 coats of sanding sealer,sanding well between coats. then,apply coats of lacquer. You should get FISHEYE REMOVER if you have any fisheye problems. Put 3-4 drops into a pint of lacquer. Some old timers would use a few drops of diesel fuel.I'd get the fisheye remover. Strain the lacquer through fine strainers into the gun. You can get everything at Sherwin Williams.

Use Nitrocelluose lacquer if you want a warm finish. It has a yellow resin in it. Use the correct thinners for each type of lacquer. Nitro for nitro,etc.

They may have to order the nitrocelluose for you. They usually seem to stock the acrylic better.

Between coats of lacquer,you can wet sand with 600 wet or dry paper. You can rub the final coat with white automotive rubbing compound for a piano finish.

There is a lot more to know about lacquer finishes,but I can't write a book here.

[Mike Henderson]

You can use dewaxed shellac as a sanding sealer under lacquer (or just about any other finish). Just make sure it's dewaxed. If you use the waxed shellac, the lacquer could peel off.

Mike

[Rodney Watson]

Mike, George, and Leo, Great advice and tips, I thank you. I'll be sure to follow your tips on a test piece of red oak before I do the doors. Think I'll look into the products you suggest and follow the directions and sequence to make it come out right. I appreciate all your time responding.

As for the fish eyes, I think you're right about a very small spec of something being on the wood. That's the only possible answer - don't use silicone anywhere in the shop, my table tops are old particleboard. Been sanded on, painted on, and sprayed over many many times. Some small spec of something had to have been on the maple.

[george wilson]

I would maybe use a washcoat of shellac to help keep the sealer from soaking in.But,lacquer does not bond to shellac,and a thin washcoat leaves enough roughness from the wood for the lacquer to get a mechanical grip on it.

[Mike Henderson]

I would maybe use a washcoat of shellac to help keep the sealer from soaking in.But,lacquer does not bond to shellac,and a thin washcoat leaves enough roughness from the wood for the lacquer to get a mechanical grip on it.

I beg to differ with you on that, George. I've used dewaxed shellac as a sealer on a lot of furniture and have yet to have a failure. It's also taught as part of the finishing class at the woodworking school I attend. The guy (Brian Miller) who teaches the finishing class has 30+ years of professional finishing experience.

I spray it on, then lightly sand to get the nubs off before shooting the lacquer. The only advantage of the specific sanding sealers is that they dry a bit faster than dewaxed shellac, which is only important in a professional shop environment where they really want to push the work out. For hobby use, dewaxed shellac is an excellent sealer.

Mike

[Let me stress again - you can only use DEWAXED shellac as a sealer. You cannot use ordinary shellac because it contains wax which will affect the adhesion of the finish applied on top of it. You can get dewaxed shellac in premixed cans - Zinsser sells it.

You can also use dewaxed shellac as an intermediate layer between two incompatible finishes. Suppose you have an oil based finish on a surface and you want to use a water based on top of it. To be safe, shoot a coat of dewaxed shellac before the water based. Since shellac is alcohol based, it seems to adhere to both finishes well.]

[Jim Becker]

Mike, de-waxed shellac must be used under water borne products and anything containing Polyurethane resins. Waxy shellac is fine under most other finishes. That said and in general, solvent based lacquers "like" themselves or their specified sealer in combination. The solvent in lacquer will dissolve shellac, too, but it shouldn't be an issue with spraying thin coats--they flash off pretty quick. You are correct that lacquer will stick just fine over shellac.

Zinsser SealCoat, however, as you say, is an excellent barrier coat.

OP, one must be really careful spraying solvent based lacquer...it can be downright dangerous if you don't have the right environment and the right safety equipment. Water borne products...which are pretty darn good these days...are much safer to use for spraying. They and shellac are the only things I'll spray, in fact.

[george wilson]

I have seen lacquer flake off of dewaxed shellac. I guess we've had different experiences. I've been using lacquer since 1955. Of course,I have been making guitars,which are thin,and the wood moves a lot more than on furniture,giving more of a chance for bonds with dissimilar finishes to fail. That might be the difference.plus,your light sanding does help the lacquer to grip better.

[Michael Pyron]

I prefer to use a vinyl sealer as I've found that to perform better than anything else...

one thing to realize is to use an air dry sealer if you are using an air dry top coat, and use a pre-cat sealer if using a pre-cat top coat...

I know of at least one brand of sealer that is air dry that states you can use it under pre-cat...I don't think so...I've seen a finish fail when done that way...while I've never read literature that actually states why I reason it out as follows: if you shoot a pre-cat top coat over an air dry sealer the sealer will be re-activated by the solvents in the top coat..being an air dry product the sealer will take longer to harden than the top coat, which means it will keep shrinking after the top coat has finally cured...this results in failure...if one shoots an air dry top coat over a pre-cat the top coat is still shrinking while the sealer has already hardened which also results in failure...

in general I shoot my sealer coat (sometimes 2 coats) using a bit more thinner than I would for the top coats so that the lacquer will tend to get into the wood a bit more...I shoot 2 coats for flat surfaces like tables so that I have a thick enough build that I can whip out the ROS w/240 grit paper and sand the heck out of it to really level things out before I shot any top coats....

[William OConnell]

I'm a big fan of Gemini coatings there ultra solids is what I spray on just about everything. Its odd that you don't here about them much on these forums as there products are superb. I'm also one who rarely rubs out a finish with any compounds . The beauty of a good post catalyzed lacquer is that when your done spraying your done, maybe just a very light buffing.
Heres what I spray alomst exclusively.
http://www.geminicoatings.com/p/12131/Default.aspx
Its absolutely awesome stuff and almost idiot proof. No critical recoat time. Serious solids content and a greta build. Again I use no sealers at all just this product with fantastic results.

[Howard Miller]

William,

Have you used the Gemini Precat lacquer?

[Ron Bontz]

Ok I am checking out the link. I was curious though. I have been using Deft Wood Finish and Watco Lacquer. I prefer the watco. I use only the lacquer for the seal coat after staining, sand lightly then re-coat. I hear a lot about "pre cat" lacquers, nitrocellose, etc. What is the difference or is there a good reference? Thanks