Finishing With Laquer?

[agoetz2005]

Hello All -

I am finishing a small piece with Deft Rattlecan Laquer in semi-gloss. I am also using their branded sanding sealer as well.

My procedure so far has been to sand the piece to 220, apply 3 coats of sealer, and then sand with 320. On top of this I am adding a fine coat of laquer every 30 minutes as per can instructions to a total of 3 coats sealer, and 4 coats Laquer.

My question lies in the final finishing. Will 4 coats be sufficient to wet sand to say 1,000 grit without any problems, or should I go to 5 or 6 coats? I plan to go with 400 - 600 - 800 - 1,000 grits.

thanks
Andrew

 

[DeanGThomas]

Thoughts on "proper" lacquer finishing.

Multiple coats are better if you're going to do sanding, especially if you're going through any number of grits.

I don't know the project, but when furniture makers "do" lacquer, they don't do that much sanding. They sand to flat, maybe 600 grit wet sanded or wax sanded, and then they use several grits of pumice and final rub with rottenstone and abrading oil. Thick felt pad is used to do the rubbing, different pad for each grit.

Ever felt a newly finished grand piano? Big mama concert grand? Lovely silken look and feel?? Lacquer and rottenstone. It's also very theraputic. I've done more than a few pianos that way. Look great, feel great, doesn't matter a lick to the sound! Causes marvelous oooohing and aaaaahing sounds to come from a grateful owner.

Oh, almost forgot: Don't forget to read the lacquer instructions for maximum grit prior to recoating and don't forget to allow the lacquer plenty of time to cure prior to the final, final rub out. Not drying, CURing.

 

[agoetz2005]

I have the directions stating a light 320 between coats which is what I am doing.

The piece is a 9" diameter walnut burl bowl, I am re coating every 1/2hr as the can states.

I believe I have some rottenstone left from when I was finishing gunstocks, but I'll have to get some felt

thanks a bunch
Andrew

 

[robert davis]

next time try one coat of sanding sealer,one coat of lacquer,then buff with the beall three step system. you will ba amazed..

 

[Mark Mandell]

Andrew,

The great advantage to lacquer (and shellac) is that, being solvent finishes, they partially re-dissolve the prior coat making the the coating into a single layer and doing away with witness lines between applied coats. Finishers refer to this property as "burn in."

The mistake that is often made with lacquer and shellac is that people think that once the film is dry, that that's it. In actuality, these solvent finishes can take up to a month to fully "outgas" the solvent. While that slow drying process is going on, the film is very slightly shrinking and compacting down toward the wood surface. This is why finishes rubbed out to a high gloss too soon wind up showing texture and grain pits several moths after they were supposedly "finished."

Solvent finishes don't "cure" like polymerizing oil/resin finishes do, but they can take almost as long to get rid of the carrier solvents and reach their final equilibrium. Same goes for the newer acrylic resin lacquers, pre-cat materials, and even some 2-part epoxy finishes.

Key here is to take your time, and allow the material to reach equilibrium. You'll have a lot less call-backs that way.

 

[pyrocasto]

Without using sanding sealer, and sticking with a spray on laquer I've been getting the right result after about 5 coats. Between each coat is sanded with 320 by hand.

I think laquer doesnt show scratches as bad as some oils too, which means I dont sand past 320 ever for a laquer finish.

 

[Mark Mandell]

Without using sanding sealer, and sticking with a spray on laquer I've been getting the right result after about 5 coats. Between each coat is sanded with 320 by hand.

I think laquer doesnt show scratches as bad as some oils too, which means I dont sand past 320 ever for a laquer finish.

Chris,

You want to be carefull about those scratches when using lacquer. One drawback with the "single layer" created by lacquer's 100% burn-in, is that it serves to optically transmit any defect underneath it up to the surface. When you couple this with the curved shape of a turning, the clear resin coating can act like a magnifying glass and visually enlarge small scratches and blemishes all out of proportion. I've spoken to several people who don't use lacquer on curved surfaces for just this reason, because they have to sand the wood to much higher grits (i.e. 1000-2000) to complete the piece and not have telltale makers' marks showing through the coating even though the surface itself is clear and smooth.

BTW if you're using NC lacquer, you don't have to sand between coats at all. That's a method used to improve adhesion of follow-on coats for other finishes which don't burn in like oils, polys, and varnishes. You can still use a bit of sandpaper the remove or flatten dust nubbies between lacquer coats, but be careful to vacuum off the surface well to prevent abrasive grit and dust being locked into the finish film.

m

 

[Bill Boehme]

......My procedure so far has been to sand the piece to 220, apply 3 coats of sealer, and then sand with 320. On top of this I am adding a fine coat of laquer every 30 minutes as per can instructions to a total of 3 coats sealer, and 4 coats Laquer......

My thought is that 220 grit is about where you should begin sanding the bare wood and not the stopping point. I would go to 400 or 600 before applying any finish. And multiple coats of sealer aren't necessary as far as the finishing goes. The sealer is meant to penetrate the bare wood -- once that is done, additional coats of sealer are only obscuring the grain. My opinion is that you could do much better by thinning lacquer with 3 parts reducer to one part lacquer as a sealer. I also don't like to build up a bunch of coats of lacquer. To me, it makes the wood look like it has a thick layer of plastic covering it. The first thing that I want to see when I look at a turned object is the wood and not a plastic shield. Reminds me too much of vinyl seat covers. You should avoid sanding a lacquer finish altogether if you want a high gloss. Sanding to 1000 grit is not going to give a glossier finish that the unsanded lacquer topcoat. If you want to knock down the gloss then use steel wool or rottenstone.

Bill

 

[Jeff Jilg]

Hi guys - I haven't used lacquer yet on my pieces, mostly because of procrastination. Currently using Tung Oil.

Mark - you indicated you don't have to sand between the lacquer coats. My "shop" is pretty dusty and there are typically a bunch of dust nibs in the finish. If lacquer is used, does the fast drying time reduce the amount of dust that gets embedded in the surface. Sometimes in my shop it seems like the pieces are magnetically attracting all spare dust particles within 1 square mile.

 

[Bill Boehme]

Hi guys - I haven't used lacquer yet on my pieces, mostly because of procrastination. Currently using Tung Oil.......Sometimes in my shop it seems like the pieces are magnetically attracting all spare dust particles within 1 square mile.

Jeff,

I do not think that you are missing any great opportunity. I do not use lacquer very much -- I just prefer other finishes such as tung oil, BLO, CA (for small items), or friction finishes (because they fill the grain and give a nice smooth finish).

Bill

 

[Jeff Jilg]

Hi Bill - I agree with you on the "plastic coating" comment. But I seem to spend a lot of time either with steel wool or fine sandpaper between tung oil coats. Other that that, the final finish using that media turns out well. Maybe there are no free rides in life!

 

[Mark Mandell]

Hi guys - I haven't used lacquer yet on my pieces, mostly because of procrastination. Currently using Tung Oil.

Mark - you indicated you don't have to sand between the lacquer coats. My "shop" is pretty dusty and there are typically a bunch of dust nibs in the finish. If lacquer is used, does the fast drying time reduce the amount of dust that gets embedded in the surface. Sometimes in my shop it seems like the pieces are magnetically attracting all spare dust particles within 1 square mile.

Jeff, Sprayed lacquer goes dust free almost immediately, but you can still get nubbies dust on the surface which will be soft for a little while. Lacquer is not, however, a good choice to use in a dusty environment. Of course, I'm not sure that any finish is good that way. That's why I use a KD finishing booth for all my spray and solvent finish applications. Nothing more that 4 walls of Visqueen over firring strip stock with 2 box fans and filters to exhaust at one end and a pair of 25x25 furnace filters on the other. Creates a kind of instant Clean Room and makes a big difference in the quality of the finishes. Sets up as 10' by 10' in my garage with the fans out the door, but stores away in a corner.

Of course you could clean up your shop . . . . .

m

ps Before anybody jumps on my case about "explosion-proof fans", these box fans are induction motors (no brushes - no sparks) with their switches removed and mounted well outside the vapor stream. They are fine for occassional use like mine, but would not pass OSHA and fire code for structures subject to regulation.

 

[john lucas]

I spray my lacquer. It's thinned a little less than 50 percent with lacquer thinner. I sand the wood to at least 400 grit. I'm still experimenting with how far to sand what woods before I start spraying. I sand in between with 400 grit at first. Once I get everything level I sand with 600 grit. I have a very dusty shop and almost always have to sand some defect out even with the lacquer this thin it still takes long enough to dry that I have a dust nib.
I finish it off one of 2 ways. I will use 4/0 steel wool to make sure every last dust nib is gone. Then I'll rub it down with white polishing compound I get from the automotive store. Then I rub it with Johnsons paste wax. it gives a really nice gloss without looking plastic.
My other finishing method is to wait a week or so and then buff with the Beal System. This is a little glossier.

 

[PapaDoc]

Mark, you mentioned a KD booth. What does that refer to? Is there a link? One of the things I am most excited about the new woodturning studio at John C. Campbell is a dedicated finishing area with vent et al. I have been trying to improve my finishes and have been experimenting with a variety of Russ's recommendations. I am very dissatisfied at present b ut commited to finding something that works well for me.

 

[Mark Mandell]

Mark, you mentioned a KD booth. What does that refer to? Is there a link? One of the things I am most excited about the new woodturning studio at John C. Campbell is a dedicated finishing area with vent et al. I have been trying to improve my finishes and have been experimenting with a variety of Russ's recommendations. I am very dissatisfied at present b ut commited to finding something that works well for me.

KD = Knock Down

Sorry Doc. It's a 1x2 firring strip frame built in 5'x7' sections. Then 8 mil visqueen, plastic construction film that comes in a 12'x150' rolls, is stapled to the frames. Panels and corners go together with mending plates and a couple of screws. Single piece of plastic makes the top tarp-style secured with some tape, and the two back panels are hinged so one makes a 5' wide entry door. Whole thing goes together in about 15 minutes with one guy. Box fans are $12 from Costco and the filters are 25x25 spun-glass furnaces filters for both inlet and exhaust. I have an old modeling stand that serves as a turntable. Use 2 20" box fans set at floor level and then the filters in the rear are set up high. That way the air in the booth stays clear so I'm not working in a fog of overspray. Three 500 watt work lights on poles outside the plastic "walls" and it's "Show Time". Whole thing stows in a corner and takes up a couple of feet of space.

I built this for furniture finishing. Rarely use it for turnings unless I've got a bowl to do when working other stuff, but if I were going to shoot lacquer, whether NC or waterborne, I'd have it out all the time.

 

[PapaDoc]

Mark, thanks...that is very helpful. I am just beginning to spray with lacquer. A little daunting for me. Your detail in construction is great. Thanks for taking the time.

 

[Mark Mandell]

Mark, thanks...that is very helpful. I am just beginning to spray with lacquer. A little daunting for me. Your detail in construction is great. Thanks for taking the time.

Few small details: Panels will need gusseted corners and at least one stretcher. The filters on the fans are placed inside the booth so they catch the overspray and mist to keep the fans clean. Plastic surface should be on the interior. You can seal the joints between panels with tape, but it's not necessary. The "door" will need a stretcher over it to hold the box together. If the "roof" sags too much, you can keep it up and tight with some light bungi cord and a few hooks around the outside of the frame. Fans and filters are NOT a substitute for a good organic vapor mask to protect your brain cells which is still REQUIRED EQUIPMENT.

 

[john lucas]

I guess I'm the neanderthal of spraying. I have a fan at my back. I put my turning on a stool with a lazy susan. I set that in the door to my shop and spray toward the outside. On windy days that can be a problem because it wants to blow the spray back in. I try to avoid those days when possible.
I have 2 problems with this. One is dust. No matter what i do I still get that errant piece but I do a final clean up with 4/0 steel wool to get rid of that and then buff with the beal.
My other problem is heat and cold. When it get in the mid to high 90's I have orange peel problems. When it gets below 40 it's just too cold to open the door. During those periods I finish with minwax wipe on poly. Different look and different technique but it still looks nice enough for my clients and friends.

 

[Mark Mandell]

I guess I'm the neanderthal of spraying. I have a fan at my back. I put my turning on a stool with a lazy susan. I set that in the door to my shop and spray toward the outside. On windy days that can be a problem because it wants to blow the spray back in. I try to avoid those days when possible.
I have 2 problems with this. One is dust. No matter what i do I still get that errant piece but I do a final clean up with 4/0 steel wool to get rid of that and then buff with the beal.
My other problem is heat and cold. When it get in the mid to high 90's I have orange peel problems. When it gets below 40 it's just too cold to open the door. During those periods I finish with minwax wipe on poly. Different look and different technique but it still looks nice enough for my clients and friends.

Not so; you're just practical

I did the booth thing for furniture. Way overkill for spraying a bowl. You still should be wearing a mask, John. Reducers and thinners will do strange and all-bad things to your head, not to mention your lungs.

m

 

[john lucas]

You may be right Mark. They obviously made me old because I used to be young and I'm sure I still am.

 

[Bill Boehme]

I use a permanent spray booth -- called the Great Outdoors. Works great except if a dust devil happens by at the wrong time (unless I want a sandpaper finish). This year, it has been too hot to spray during the daytime.

Bill

 

[woodwish]

I used to do a lot of model building before I got my lathe (I used to do a lot of other stuff before I got into woodturning, but that is another thread) and built a small spray booth to spray enamels and a lot of laquer. Didn't build one in when I built the new shop because it was too small for furniture usually. Now that I do more and more turning that would fit in a smaller spray booth I may go ahead a build one.

Basically my old one was a plywood box on it's side the same size as a large AC air filter. I stacked two filters with a few inches of space behind them. I used a large bathroom exhaust fan and 3" hose to vent outside. Before someone jumps on me for not using an explosion proof fan- I did use a fan with an external motor, much like a smaller version of the ones on DC's. The vapors don't really get to the motor like it would on a fan. I installed a flourescent light in the box and also had two floodlights, never too much light for finishing. I used an airbrush to spray but the same thing would work with spray cans.

Just an idea that may help some others spray small pieces, doesn't really take up much space and sure works great. Think it's about time to build another one

 

[David Somers]

Shellac ?

I am a bit curious why I don't hear folks using shellac more? Mark mentioned it early in the post but that was the only mention. It has become a favorite finish of mine, though I never try to bring the piece to a full on gloss with it. I usually apply it with the piece spinning lightly on the lathe, using a lint free cloth to apply it. 15 minutes between coats, usually 2 coats max. Then I let it dry for a few days and buff it with Beal until I have the effect I want for that piece; usually a soft satiny finish. I agree with Bill in that I usually don't care much for heavy lacquer use because of the plastic, heavily sealed effect it gives. 2 coats of shellac seem to meet my need if I want a bit of protection.

So....having said all that....how come folks don't seem to be playing with it much?

Dave