Spraying lacquer

[Brian Kent]

I have been trying rattle can lacquer on chalices. How do you keep it from sagging?

I have read that I can smooth it out with a brush and/or sand to level.

Any better ideas?

Curly Maple, blue and red transtints, gold spray paint on the inside for color experiments so I don't waste the metal leaf.

[Prashun Patel]

How thick a coat are you spraying? In my experience it's best to spray multiple, thin coats. It dries so fast, I can recoat every 10-15 minutes. Which brand are you using? Deft? Minwax? I get good results with Minwax. I get even better results with Deft.

[Bob Vavricka]

Brian spray can lacquer has a low level of solids to solvent so will sag or run if the coat is put on too heavy. It dries fast so use light coats to prevent the sags. Sanding sags is tough. You will tend to burn through the finish on the sides of the sag. On flat work I usually use a scraper to scrape down the high spots and then feather it with careful sanding. It will be more difficult on turned work. I would probably spray several more coats to build up more finish before working on the sags to give you more finish thickness. The brushing idea will work if it is done before the finish dries. It will leave brush marks which will be easier to smooth. You might pose this question in the finishing forum for other ideas.

[Brice Rogers]

Brian, you have got good advice.

I also live in Escondido, and - - as you are aware - - the weather has been cool here. So, if you are spraying in a non-heated area and the spray is also cool, it will be slower to set up and will be more inclined to run. If you sprayed on a low-humidity 80 degree day, it probably wouldn't have run. Scraping a run helps. Also, I have used a star-bucks wooden stirrer with a piece of 320 grit sand paper attached to spot-sand runs.

Right now, I have a seasonally-repurposed (home made) food drier that I've repurposed as a heater. It is a wooden box about 1.5 x 2 x 2 box with two 60 watt bulbs, an auto air filter and a small exhaust fan. I'm keeping my turned stock inside along with the rattle can. It keeps everything warm - - about 95 degrees. I'm not getting runs. Also, after I spray, I try to put the turned pieces inside the heater box as soon as I can safely do so. I think that a high-wattage flood light/heat lamp might work just as well.

BTW, your chalice looks very nice.

When I spray, I try to arrange lights so that I can watch the reflections and can see when the spray goes from looking dull to looking wet. Once it just begins to be wet - - stop!

[Brian Kent]

Thank you everyone. I am trying to just get it wet, but I am probably using too much. If I spray so lightly that it looks like a frosty window rather than a consistent surface, will it level out?

[john taliaferro]

2.3 rpm on the spendel with a gear motor . I saw it on the morthorup video multi shaft finishing machine . Matt was brushing on heavy globs and it would flow out smooth . Ive tried it on large turnings it works great and cut my finishing time .

[robert baccus]

Like Bryan says-he says. Rattle cans have high solvents and low solids but the purpose is small orfices and low spray pressure. If you can get a real spray setup--even the co2 and glass jugs you will get better results. I use Mohawh precat laq, and heavy bodies SS and I can vary the amt. of retarder. (prevents blushing and increases flow out. I usually use 2 coats of each, with a bit of 220 sponge sanding--this would take 6-8 coats of each from a rattlecan. A RC of retarder is priceless for runs and fogging. But doing things in a different method is great too. It's called inovation. I used many cases of rattlecan in my misspent youth before I discovered the easy way is often better.

[Glenn Barber]

A couple of tips I got about using rattle-can anything that helped greatly.

1) Make sure the can is at appropriate temperature. Might need to sit can in warm water for a few minutes.
2) Shake the can twice as long as the directions state.
3) When spraying, follow the 8-12 inches and spray like you are "throwing it on the surface". You want the misted spray to land lightly.
4) Shake can often while using. After every 2-3 sprays, re-shake can for 5-10 seconds.

Hope these help.

[Russell Neyman]

Comments about rattle can lacquer:
1. Warming the lacquer really helps.
2. My preference is a brand made near Seattle, Rudd. It has more nitrocellulose and builds quickly.
3. A very light pass followed ten seconds later with a coat that flows smooth helps avoid sag. The second pass grabs onto the irregular droplets of that initial spray.
4. If you choose Deft, use the lacquer sanding sealer as a first coat.
5. Lacquer can be (and probably should be) sanded and polished, so don't sweat the imperfections. I wet-sand with 600 grit, but sometimes hit it with a fine 3M pad, then hit it with the Beall system.

[Faust M. Ruggiero]

Brian,
Hand a piece of cardboard on a wall and practice spraying. Spray too far from the piece and you will just get grain. Spray a bit too close and you will get sags. You must keep a consistent distance from the work piece. That's difficult on a circular subject like a chalice but it can be done. Turn a bunch of cylinders and practice. Many light coats will work best. keep the can back far just far enough and move just quickly enough to spray a wet but not runny film. Probably best to spray the length not the circumference. Overlap 50% with each pass. Let it try enough to sand lightly with 320 grit paper and do it again. Repeat the process for up to 10 coats to get good results. Each coat will be better. Your lacquer, your work piece and your room must be 70% or so.

[ALAN HOLLAR]

Stay 8-12 inches away. For a round vertical piece, sprasy one pass top to bottom, turn 90 degrees and repeat, then do that twice more till all 4 quarters are sprayed. Stop for a few minutes, spray a second coat and a third before sanding if you have color work on the piece. Sanding sealer sands easier, and fills surface irregularities slightly faster, but otherwise is not necessary.

[Barry Richardson]

Hi Robert, a couple of questions from a rookie, what do you mean by "heavy bodies SS" a sanding sealer I assume, any particular brand? And what do you mean by a "RC of retarder"? Thanks in advance for sharing your knowledge...

[Brian Kent]

Thank you, Barry. Those were my questions too.

[Prashun Patel]

It will level out, yes. If - even after the surface is sealed - you are getting a frosty window after drying, then it means the lacquer is drying before it lands. This can happen if you are spraying too far. What's your distance? 8-12 is right.

(forgive me if I am stating things you probably already know: )

Also, how fast are you moving. you want to move in a slow sweep once, maybe twice. MAYBE 3 times. No more before you let it dry.

There may be better lacquers out there, but you can certainly get professional, good looking results with the lacquers available @ big box if that's what you have right now.

[Russell Neyman]

Stay 8-12 inches away. For a round vertical piece, sprasy one pass top to bottom, turn 90 degrees and repeat, then....

Be aware, however, that many spray tips have a vertical/horizontal tip that "fans" the spray in one direction or the other.

[Bob Bergstrom]

Hi Robert, a couple of questions from a rookie, what do you mean by "heavy bodies SS" a sanding sealer I assume, any particular brand? And what do you mean by a "RC of retarder"? Thanks in advance for sharing your knowledge...

I believe "RC" stands for recoat. Spraying retarder and some better lacquer thinners will allow the moisture to escape from the finish. Cheap thinners will dry very quickly. Retarder added to a cheap thinner will slow the drying time.
From the looks of the chalices, spraying the inside is more liable to run. Heavy bodied sanding sealer fills pores more readily with less coats. I stopped using sanding sealers years ago. For rattle can lacquers I use Mohawk. It is used by refinishers across the nation and comes in a number of types. Those chalices should be done with at least cat-lacquer. Mohawk makes lacquers for guitars, brass, and furniture. They also have a vinyl sanding sealers for bathrooms and kitchens.

[Prashun Patel]

The other issue with spraying the insides is the bounce-back. I bet it'll be much harder to get a smooth, non-dusty finish inside that narrow cylinder than on the outside.

[Geoff Whaling]

Sagging can be caused by a number of things, too much thinner (not shaking can properly before use); too much product applied in one coat; too many coats applied before the product has a chance to dry between coats; cold surface on the sprayed item; even a poor nozzle on the can.

When using rattle cans, a frosty fuzzy rough appearance in lacquer can be from over-spray or bounce-back or from spraying to far away from the target surface. It is really lacquer that has pre-dried before it has a chance to properly adhere to the surface.

Frosting / blooming / blush (milky appearance) can also mean that moisture is being trapped in the finish as it is drying, either picked up from humidity in the atmosphere or even coming from the wood if it is not sufficiently dry. Aerosols from a can or a dedicated spray setup will cool as they leave the nozzle potentially condensing any/some of the moisture in the atmosphere. That is why many use the tip to warm the cans before spraying.

The other thing to be mindful of when using rattle can (and bulk products) nitro-cellulose & other lacquers is the propellant / thinners used in the product. Some NC lacquers use acetone as the thinner others use Toluene and a mix of VOC's in various proportions but the thinner component of the product can be up to 70%.

Acetone (propanone) & Toluene etc take up moisture from the atmosphere differently which may explain why one brand of product may appear superior in some areas / environments. Some products contain other thinners etc such as Xylene, propanol's, butanol's, MEK (methyl ethyl ketone) etc in various proportions. Acetone is becoming a thinner of choice in some areas (i.e. CARB) because it is not considered a VOC but it is miscible i.e. will mix with water (and many other products) which can create problems when spraying in high humidity..

Generally the thinners & propellants are also flammable / highly flammable so users should be aware of potential fire hazards, ignition sources and the hazards of using such products in small work spaces or without appropriate ventilation.

[Brice Rogers]

I've got one can of spray lacquer that sprays large droplets. Perhaps it is the nossle or perhaps it is the thickness of the lacquer. But it is impossible to get a decent coating. It doesn't flow. But I have a few cans of Deft lacquer that sprays very nicely. So perhaps Brian's issue might be with the manufacturer of the rattle can.

[Brian Kent]

By frosty, I just mean when the micro-droplets are not connected to each other. It is not milky. Does each coat need to have a connected layer? Particles against each other?

[robert baccus]

Backing up to spray is an old car painters trick when in a hurry. called a dry coat. you can do several dry coats followed by a wet coat with a generous amy of retarder and poof. It all melts into one nice coat. The fogging is caused only by high relative humidity and standard fast drying lac. thinner. An addition of retarder(a slow drying thinner allows the condensation of water caused by cold drying to work out. It can be applied straight if done quickly when fogging occurs. It is very dificult to spray laq. in humid areas without blushing. Straight retarder will also flatten out orange peel if done carrectly. SAnding sealer, women and cars come in various quality's. The worst are thinned out lacquer--yuk. The best is like heavy cream which fills pores ect. It sands like chalk and leaves a flat surface for the laq. overcoat. RC is rattle can--sorry. The idea is to fill and level the wood pores with SS and 220 before you even look at the lacquer can. This is nothing new--this is exactly how we put show finishes on hotrods in the good old days. Most guitars are finished this way. Today we have better finishes and materials. Refrain from buying film finishes from big box stores. Also factory stores have an unbelieveable selection of product to fix any finishing problems. I have the flu or it was a great new years party.

[Bruce Lewane]

Having used Deft spray since they put it out a bazillion years ago I won't even use it this time of year. Temps and humidity are everything. Below 70 degrees
you won't be pleased. 80 is good. 90 better. I also use Deft spray sanding sealer,2 coats, before the lacquer. Having a unheated shop, I either wait till spring or switch to other finishes. Their are so many choices, there is always at least one for whatever conditions you're faced with.

[Bob Bergstrom]

Having used Deft spray since they put it out a bazillion years ago I won't even use it this time of year. Temps and humidity are everything. Below 70 degrees
you won't be pleased. 80 is good. 90 better. I also use Deft spray sanding sealer,2 coats, before the lacquer. Having a unheated shop, I either wait till spring or switch to other finishes. Their are so many choices, there is always at least one for whatever conditions you're faced with.
I spray with Rattle can Mohawk lacquer on my front porch below freezing, let the bowl stay outside, but bring the can back inside. Lacquer flows out to a smooth finish. I do use Forby's Tung oil under the lacquer. I steel wool the dried oil first, then blow compressed air over the bowl to clean off the fibers. This provides a very smooth subsurface for the lacquer. I've done probably 100 bowls this way with no failures.