Easy HVLP water-based spraying of lacquer or poly

[blueman]

I am a newbie to HVLP and am looking for advice for an "easy" newbie finish that meets as many of the following criteria as possible:

1. Strong/durable clear coat
2. Easy to set up & apply
3. Forgiving to newbies with low-end equipment
4. Easy to clean-up (of course fast drying would also be nice)

I am applying to a raw birch plywood shelving system.

I been told that it is best for beginners to start with water-based since solvent-based lacquer & poly are more complicated in terms of cleanup and proper ventillation.

However, I have no idea what brands and specific finishes best fit my "wish list". Perhaps I am asking for the impossible. But it would be nice to build my confidence in spraying by having some good first results.

I really want something that will not give me to too much trouble as a beginner whether it is worrying about getting viscosity right, worrying too much about sags or drips, fume issues, and cleanup.

Thanks!

[Jim in Milwaukee]

Check out General Finishes waterbase stuff.

[l-lopez]

Spraying water borne stuff (lacquer or paint) is not as easy to spray as the solvent based finishes. It takes better equipment to do the job. It has been said that a 3 stage Fuji gun will work. However, you still need to thin the products to make it work. Too much water can affect the quality of the finish. For example, enamels don't always have that low lustre sheen when thinned too much. I bought a Fuji 4 stage gun (expensive) and can spray heavy paints with a #4 cap and minor thinning.

For products, I find that Hydrocote resistane plus (pre cat lacquer) sprays well and does not need too much thinning. For paint, I am currently spraying Benjamin Moore Impervo. BJ says it can be sprayed without thinning - if you use an airless sprayer. They give a crappy finish! The Fuji 4 stage seems to work well with the #4 cap. You do need some thinning and need to put it on lightly. Make multiple passes.

Good luck

Len

[Swingman]

3.5 out of 4:

Shellac ...

[J. Clarke]

How "low end" is the "low end HVLP" in question? I have no problem spraying precatalyzed lacquer with the Harbor Fright purple gun, however the nozzle is really too small and it needs a ton of reducer. TCP Global's G6600 with the 2.0 tip does fine Magnamax as it comes out of the can for about 30 bucks and shipping (it seems to be the same gun as the current Harbor Fright purple gun but it's not purple and TCP has a bunch of different nozzles for it--when I called Harbor Fright they didn't have any).

Of course both need a compressor.

Lacquer's not all that hard to spray--I do it in a garage with the door open--it dries so fast that dust isn't really an issue.

I've gotten good results with a "critter" sprayer with latex housepaint--it takes a huge amount of water and floetrol added though. The G6600 with the 2.0 nozzle should handle it fine as it comes.

[nailshooter41]

Yup....

Sounds like it is Deft time to me.

Or Bullseye.

What could be more forgiving than shellac? You can use it as a sanding sealer, primer, then change to the waxy stuff and put it on as a 100% compatible top coat.

And the Bullseye stuff actually does last for a couple of years in the can (as advertised) if you don't use it all.

Excellent choice.

Robert

[blueman]

And is the 0.5 deduction for strength/durable?

I didn't realize though that Shellac was sprayable. If it is, does it matter what type (waxed or not)? Premixed in the MinWax type or cut to a custom proportion from Shellac flakes?

Thanks...

[blueman]

I have the "better" quality Harbor Freight gun

surprisingly seems to get some pretty good reviews for a gun that is $39.99 on sale

Also, where does one find "precatalyzed lacquer"? Is it the same as the Minwax type stuff in local hardware or big box stores? Or do you need to go to a specialty place?

Any brands or products to recommend?

Thanks

Could I spray it in my basement as long as I wore a respirator or is the fire hazard too great?

[Swingman]

Here's the content of an old post of mine on spraying shellac ... don't have time to find the responses, but you can DAGS if you need more:

Shellac is about the only finish I use, and I always spray it.

With an HVLP system overspray is not a problem, IME.

If you are not planning on using anything but shellac, buy the three pound cut and thin it down to 1 1/2 with alcohol (I prefer to use this cut when spraying, but YMMV) ... experiment.

3 pound cut is what you get out of the can for the standard, althouugh I've seen 4 and 5 pound cut at paint stores, and the "sanding sealer", out of the can should be a 2 pound cut.

You really don't need the dewaxed if shellac is all you're using ... the dewaxed being essential for compatibility with lacquer, poly and other top coat finishes added post shellac application.

The Zinnser sealer is dewaxed and works well when sprayed and can indeed be used as the finish coat.

I just generally use the regular BullsEye amber 3 pound cut, thinned to a 1 1/2 pound cut with isopropyl alcohol (depending upon the temp/humidity) sprayed on for the final coat.

I find I have better application on extremely high humidity days with isopropyl alcohol, but the Borg denatured works fine 99% of the time.

IME, with humidity, what you're worrying about is blush.

With isopropyl alcohol so cutting you need to pay particular attention to the shellac drying before it hits the surface. If that is a problem, simply cut your material flow down a bit and spray closer to the work (with HVLP).

Spraying shellac is not that difficult, as a matter of fact, it is easy and forgiving with an off the shelf, $100 HVLP unit. A couple of minutes with a scrap piece to make sure material flow and distance is right, and spray on.

[blueman]

By denatured, I assume you mean the methanol sold in cans at the borg. And by isopropyl, do you need to find 100% pure stuff or can one use the drug store diluted stuff.

[Swingman]

It's been 40 plus years, but ... :)

Don't know about "sold as" labeling, but I am a chem major and IIRC they are similar but different alochols.

"Denatured alcohol", as I recollect, is "ethanol" (C2H5OH), with "methanol" (CH3OH) added to make it poisonous.

Any paint section should have cans clearly labeled "Denatured Alcohol".

That is what I use to cut shellac with for most spraying purposes.

I buy 99% isopropyl alcohol from the drug store.

[Puckdropper]

Swingman wrote in news:FOmdnUaES-6bhVbRnZ2dnUVZ [e-mail]:

I tried using 90% (not 99%) isopropyl to thin shellac, and did not get good results. It just did not seem to "take."

Denatured alcohol worked excellently, so I haven't tried anything else.

Puckdropper

[Swingman]

Too much water.

[blueman]

Ahhhh I vaguely remember that too from chemistry class. According to Wikipedia it is also called "methylated spirits" which is probably why I got confused with Methanol.

Thanks!