I've searched the group, but I still have a couple of questions that I didn't see answers to.
I've got the Rockler single turbine sprayer and some nitrocellulose lacker primer and lacquer. When I tried spraying straight primer on some test pieces of plywood last night, the finish was clumpy. After further research, I decided that the primer needed to be thinned with lacquer thinner. This did produce a much smoother finish.
However, I'm still confused about how much of the primer to apply. How much is enough? If I put on one thin coat of primer, you can still see some of the wood color and it isn't particularly smooth. Should I put on a second thin coat of primer, or will the smoothness and solid color come from 2 or more coats of lacquer?
Is one thin coat of primer enough for the lacquer to bond to?
Also, I'm assuming that I need to sand the primer after it has dried. Is that correct?
Primer is typically used to lay down heavy and sand smooth. Lacquer doesn't typically have adhesion problems unless you are spraying on something very smooth so any amount of primer will be fine.
I never prime clear finishes that are the only finish on a piece. They are their own best primer, and adhere best to themselves. Unless there are surface problems that would cause adhesion or finish issues (fisheyes, craters, etc.) there isn't any need. Especially with lacquer your first coat will make a great primer.
Lacquer will build nicely if applied properly. Add another coat to your regimen as the primer.
something very smooth so >any amount of primer will be fine.
Even then you might have to do something really wrong to keep the finish from adhering. Lacquer has been used in fine finishing for many, many decades and most furniture makers have certainly sanded smooth before application o finish.
lacker primer and lacquer. When I tried > > spraying straight primer on some test pieces of > >plywood last night, the finish was clumpy.
With a single stage turbine, who knows. I know a lot have had great success with these machines and their brothers and sisters, but I would sure think that your mixtures would need to be almost perfect ot get the gun with that little output to work well.
As far as clumping, my first suspect would be to look at thinning and pressure adjustments. Check out this thread:
formatting link
can be caused by a lot of other things so if you are going t be serious about finishing you should keep a notebook with temps, humidity, product lines, thinners, etc. as well as your mixing formulas and pressure setups.
thinned with lacquer thinner. This did > >produce a much smoother finish.
Thinner product with allow a lower pressure gun to push more material out and distribute it more evenly. Since an HVLP gun doesn't atomize a finishing agent the way a high pressure gun does, the material must be thinner to accomodate the "Low Pressure" part of HVLP. Lower pressure of the HVLP setup doesn't atomize the finishes it sprays, making all the more important to thin properly.
How much is enough? If I put on one > >thin coat of primer, you can still see
Just because you see some of the original wood color doesn't mean it isn't sealed. However, it does speak to your technique of application. Unless you are using some very highly figured woods, or some soft woods with a lot of grain challenges, your primer should be applied at the same rate and the same thickness on the overall piece in order to preserve the integrity of the final finish.
Many times the prime coat isn't smooth. However, if you are sanding off more than nibs or a little bit of dust after you prime, you probably should 1) sand more before you start finishing, and 2) make sure you are finishing in a clean area.
In your case though, I am thinking the culprit is that you didn't apply the primer evenly or at the right viscosity.
A second coat probably won't hurt anything at all. I am hoping that when you say "solid color" you are meaning "consistent" color. If you are spraying piano black, red or white colored lacquer, you have changed the game.
Assuming "solid" to be "consistent", you should consult the product manufacturer for proper application thickness. They can help you with your thinning procedures, and also tell you how thick to apply their product when spraying. You final taget will probably be around 3 - 4 mil or so, maybe a little more.
You build that one coat at a time. Example: My favorite lacquer is applied at a 4 mil coat with 10 - 15% thinning in moderate weather. This dried down to only 1 mil thickness. So to get the manufacturer's recommended final thickness, I spray another 2 - 3 coats.
Usually.
Depends. If my "off the gun" is good and I don't raise any grain, I don't sand. Sanding raises dust, introduces particulates to the surface of the work, and suspends dust in the air. Also, incorrect sanding methods or just a sanding accident can introduce scratches and swirls into the primer which will reflect into subsequent coats of finish.
Additionally, there is no reason to sand lacquer for he purpose of adhesion. It will build fine without any further surface prep.
If you do not want the wood grain to telegraph through the finish, then you must at least prime it with severl coats sanded flat. Even the smoothest birch (or any) ply will show the grain through the paint. This is what primer can do for you and it's main purpose.
There might have been some better choices for a paintable surface than a wood venred ply but no matter. Prime and sand if you want it really flat or just spray on the wood if you want to or if it is OK to see the grain.
(PS I figured out you must be us> Sorry, I thought I was giving enough information, but apparently I > didn't. >
on something very smooth so >any amount of primer will be fine.
lacker primer and lacquer. When I tried > > spraying straight primer on some test pieces of > >plywood last night, the finish was clumpy.
thinned with lacquer thinner. This did > >produce a much smoother finish.
apply. How much is enough? If I put on one > >thin coat of primer, you can still see
you must at least prime it with severl >coats sanded flat. Even the smoothest birch (or any) ply >will show the grain through the paint. This is what primer
Are you saying that the main purpose of primer is as a pore filler to hide grain?
it's main purpose.
Now if you are switching to paint, I could see some benefit. I know that a couple of good coats of Bull's Eye under a hard enamel will really make a beautiful finish as it will mitigate the grain quite a bit.
Primer can be used for several reasons such as making an even colored under coat or lighter or darker undercoat for translucent or light colored paints. Or to prevent the telegraphing of stains or sap or mold into the paint. Or to provide a good adhesion where the paint alone might not have the best properties to adhere.
However, in this case and in many cases primer is a thicker consistencany than the paint an is used to smooth the surface.
This gent did use the word "lacquer" (although mispelled). Everyone (or many) people here assumed it was clear lacquer like is most common in wood projects. However, as was proven by his subsequent post, he is using colored lacquer paint, as I assumed in my first post. He also mentioned that he is using white. So I again assumed that 1. You don't need a primer to help with color if you have Birch ply. White paint will look fine over the nearly white Birch. 2. There is no adhesion problem with wood. Therefore, the main (or only) reason a person might want to use primer in this case is to smooth, fill pores, but more than just fill pores in this case, primer is almost like a skim coat of plaster or other similar material.
In automotive and motrocycles we used to use lacquer quite a bit. In that case the primer was better at adhering to bare metal and it was also totally used to flatten.
you must at least prime it with severl >coats sanded flat. Even the smoothest birch (or any) ply >will show the grain through the paint. This is what primer
(or many) people here assumed it was clear lacquer >like is most common in wood projects. However, as was proven >by his subsequent post, he is using colored lacquer paint, as I >assumed in my first post.
You're right. I sure missed it. Most of the finishers I know have abandon colored lacquer and actually moved to modified paints. So I automatically went to the clear stuff and said so in my post. And for me when I shoot lacquer it is clear.
Thinking about it, I think the last black lacquer finish I applied was for a guy that had me build his water bed furniture in tehhe 80s! It was mirror black with gold plastic piping I had to groove and tap into place. It was really cool then, but it has to look pretty cheesy by today's design standards.
But I just finished some interior work for a client that had a baby grand piano refinished due to roof leaks damaging the top. It was not finished with the traditional black lacquer, but with a super hard industrial black paint that was coated with a clear coats of a modified lacquer of some sort. The top coats were then cut down and buffed out as normal for a lacquer type of finish.
He laughed when I told him I thought everyone was using Pianolac. He informed me almost no one was. What?!? Am I always the last to know?
Anyway, sounds like we are on the same page on the application of primer and its use. I appreciate the well thought out answer as it made it easier for me to understand what you were saying.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.