Spraying Lacquer

[Richardwoodhead]

Had an interesting experience today which I thought I'd share with other lacquer spraying novices (experts can stop reading now...)

I'm embarassed to say I've been trying for years to get really good (OK, I mean great) lacquer spray finishes. It's been a long (LONG) journey through lots of equipment ugrades, spray booths, trips to Perth to speak with Becker Acroma re lacquer hassles, and LOTS of reading and still more phone calls to Beckers, etc etc. (I think they got sick of hearing from me..) Up to now I've managed just "OK" finishes, but always seem to not get it right, with some minor orange peel problems, runs, or other hassles. And it seemed such a struggle regarding correct gun settings. How much fluid, how much air, etc etc.

This afternoon the furniture finisher for a local furniture gallery came by and we sprayed 3 pieces of furniture I'd prepared for the occasion. I was doing it all wrong.

Here's how this guy did it..... LOTS of air from the gun (almost wide open). Fair amount of fluid (say about half open or more at the gun setting). And full cone of spray regardless of workpiece shape / configuration. When he set the gun up that way I was like, whoa, this'll be good (expecting too much air, fluid and cone to cause problems). What he did next was the real eye opener. Whereas I always dawdle my way down workpieces to get full coverage (I've had to as I was throttling down the air & fluid) this guy FLEW down. I mean he was spraying like picasso. Very steady and very carefully positioned (about 150 - 250 mm above the workpiece). But quite fast!! First one complete coat, then immediately back over the whole piece again. Repeating the same sequence. I was gob smacked.

Along the way he was explaining the logic behind which surfaces he sprayed in what order, from what direction and what angle (differs for edges, tops, sides, corners, legs, rails, etc etc.).

I then sprayed the last piece under his guidance. Best spray job I've done so far. His work was perfection.

Another thing I learned.... he mixes his lacquer in the ratio 10:1:6

10 parts lacquer (Becker Acroma DM 307, 30% gloss)
1 part hardener (acid catalysing hardener)
6 parts thinners

This is about 2 parts thinners more than I'd been using. He normally applies 3 coats for the gallery work. But 2 is OK - with the double application per coat.

It would be very difficult to learn this technique without getting hands-on teaching - to get an appreciation for speed of application, sequence of spraying, etc. So if anyone out there is having lacquer spraying hassles, I'd highly recommend, FWIW, to find someone experienced to give you some live teaching. Maybe other furniture finishers spray differently to this guy, or have mastered a different technique that works for them. But at least you'll learn something that really works. (If you're in West Aust and want to see the results of his spraying, drop into Boranup Gallery south of Margaret River...)

Hope this info is of some interest / help to others...

Richard

[la Huerta]

mate you just got me all exited...i was just thinking of a faster way of applying my finishes, french polish and varnish (or maybe lacquer would be better} i don't need a piano finish as i use recycled timber, but still a low sheen/semi gloss...what would you reccomend , and what would it roughly cost to set up???

[Richardwoodhead]

Huerta, lacquer finishes offer the quickest method I'm aware of to finish large and / or complicated pieces. Maybe there are other quicker ways, but I don't know about them. I've been through a steep learning curve since I started finishing in 1999. I started with organoil which darkened and flattened my finishes. I later learned I was not "working" it properly. It takes LOTS of work and time to get a good oil finish. And even then it's not going to give a good satin finish, IMHO. So I went to oil / varnish combinations (Danish, Floorseal and my own mixes). These worked very well, gave great finishes, especially when sprayed on with a little turps added as thinners. But again it was a fairly time consuming exercise with an overnight wait between coats. Then I discovered lacquers. Using 30% or 40% gloss lacquer gives a really fast & beautiful, hard wearing and waterproof satin finish. It's worth looking into. But learning how to spray properly has been a struggle for me..

Good luck with it,

Richard

[Pops]

Hi Richard,

Well, here I am with a gun and compressor too scared to use them on lacquer for the same reasons you mention. Have had much and varied advise from casual users all of which still had me very hesitant to try it and maybe ruin a job but your post has given me the confidence now to give it a go. Mind you I know little about lacquer. So thanks for the information, much appreciated. Next time I go down south I will drop in to the gallery. By the way, I ony have a cheap gun, works OK for painting the house. Is it worth the expense to buy a professional gun specifically for lacquer or is it an actual necessity to have pro gear, and if so, could you recommend one.

Many thanks
Pops

[Richardwoodhead]

Pops,

My hunch is that someone who's an experienced spraying "expert" could probably do a good job with a "garden hose" and tin can. You could spend lots on a full pro set-up and still do a lousy job if you don't learn to operate the gun correctly - and learn a technique that provides good even coverage. There are probably different techniques by different experts, but each one enables the pro to use a particular gun setting "style" (amount of air / fluid / cone of spray, method of application across the workpece - i.e. speed, direction, sequence, angles, distance of gun from workpiece, etc) to get a perfect result. I had invested in a full pro set-up but was still not getting consistently good results. And was starting to "dread" the finishing part of my woodworking. So the main intention of my post was to encourage others who might be having spraying hassles to get some "expert" hands-on teaching. Once you actually see how it can be done right (and there are probably more ways than one), then you can start to get success and develop your own "expertise". I wouldn't say I'm now an "expert" - but I can see what I was doing wrong and think I'm now "on my way".

But, all that said, good equipment is a bonus. And it has to be maintained - kept clean, particularly the fine pin hole size nozzle openings. (First thing this guy did when he arrived at my shed was take the nozzle off my gun, look carefully at all the fine openings and tell me 6 holes were blocked. I always "clean" my gun & spraying apparatus religiously after using it -by spraying through some thinners etc. So I thought I was OK. But there are 6 VERY small atomising holes on my nozzle and I hadn't noticed they were blocked. It doesn't take much for lacquer to block them. So he very patiently got all the holes clear with a piece of very fine wire. I now know I need to keep the nozzle clean by brushing and "wiring" as well as solvent flushing)

My set-up is a 10 litre pressure pot on rollers with a feed line to a hand gun with in-line filter. Plus wall mounted pressure regulator with water trap. Set up runs about $700. The gun is an Iwata 200 which seems to be the standard pro gun around here. But you can get an Iwata gun and pressure pot set-up (gun & pot attached to each other) which is top quality and MUCH cheaper. I bought all my stuff from Twenty Two Services in Perth. Their factory & offices are in Turnbull St, Neerabup. The technical guru I deal with is Paul Daley (9206 0220). If you're interested give him a call (don't mention the name Richard, he'll probably run off screaming into the distance ... only kidding). They sell all the range of equipment from simpler hand held pots to top of the range 20 litre pressure pots with feed lines, to industrial spraying equipment. They are also the agents for Becker Acroma lacquer. Which is the finish of choice for most of the furniture galleries in the Margaret River area, as well as others I'm familiar with (JahRoc, etc).

But again..... see if you can find someone who is experienced at spraying to give you a quick demo. If you're ever down this way, give a holler.

Richard

[Gazza]

I am about to try my hand at spraying my first piece ever with laquer.
New spray gun & compressor, never sprayed before so should be interesting :rolleyes:


Along the way he was explaining the logic behind which surfaces he sprayed in what order, from what direction and what angle (differs for edges, tops, sides, corners, legs, rails, etc etc.).
If you could expand on the above at all it would be greatly appreciated and educational, especially edges & corners as I am spraying a TV cabinet.

Also if you have any information on pressure settings that would be very helpfull.

Thanks
Gary

[Richardwoodhead]

Gary, not sure I can do your query justice. Bit like trying to teach someone to ride a bike over the phone. Which is the point I've been trying to get across about lacquer spraying for novices. TRY to get someone experienced to give you a demo of their technique - what works for them (assuming they achieve good results). You CAN learn a fair amount by simple trial & error and reading up on spraying techniques & trouble shooting (there are lots of threads on spraying in this Finishing Forum), but 10 minutes with someone who really knows what they're doing could save you lots of time, money and effort. And frustration and heartache.

But to try to answer your questions (and remember I'm NOT an expert at this. Maybe Neil or Shane or someone who really is experienced can jump in??)...

For tops, do the edges first, moving the gun fairly quickly and probably a little further out ( 250 mm) than for horizontal surfaces (150 - 200 mm). This helps prevent runs. Do one edge then look carefully at the coverage. Good even full coverage with no runs? If yes, you've got enough fluid & air at the speed at which you moved. On to the next edge. If it's splotchy you've gone too fast or not enough fluid. Repeat with fluid dial opened more. (If fluid is running & dripping down the edges you either went too slow or your fluid dial was turned too high). Finish the edges. Then do the top progressing from one side to the other (ie - don't start in the middle & work out to each side). When you've finished one coat, hit it again immediately, exactly the same sequence (ie, dont start where you ended - go back to you're intial surface and go in the same sequence)

For vertical panels, inside the cabinet, do the corner join areas first, then the panel areas between, being carefull not to re-spray immediately right into the corners. Just go slightly into the area already covered when you did your initial vertical corner sprays. This helps prevent too much fluid & hence runs in the corners. Outside - do the same. Swipe down the corners first (pointing the gun so the cone of spray bisects at the corner, then fill in the panels, from one edge to the other, but again allowing for an overlap at the corner so you're not putting too much fluid right onto the corner area from both sides.

This is the same technique for post & rail table leg / base construction.

My air compressor is pre-set at about 110 psi. But the air then goes through a regulator which drops it to about 50 psi for spraying. However, the most important "setting" is the amount of air you allow through your gun. That's controlled by the air valve (usually on the bottom of the gun handle). I'd been throttling my air WAY down. Which resulted in too little air for my fluid setting. Which (along with blocked nozzle holes) created a splotchy orange peel problem. This guru opened the air at the gun way up. Opened the fluid dial about half way. AND MOVED FAST. With that much air and fluid, you need to move fast enough not to get too much fluid in one area. As a guess I'd say he moved at between 1/2 - 1 meters per sec. Faster on the edges and vertical surfaces. We were spraying big surfaces - table tops & bases. For smaller surface areas and confined areas, I'm sure you'd need to dial down the air & fluid. It's all about getting full even coats with no runs (too much fluid) or splotchy dry areas (too little fluid).

Good luck with it.

Richard

[la Huerta]

i think i will quit while i;m ahead, and stick to french polish , that's easy and looks great, and i just discovered hard shallac, if it's as easy to apply as the normal shallac then that will be what i will use from now on, no equipment required.

[Pops]

Hi Richard,

Firstly, thanks for taking the time to reply in such detail, much appreciated, including the reply to la Huerta, that was also very helpful. When I finish off my next job I will take your advice and then give laquer a go. The finish is worth it I reckon.

Thanks again, and if I get down your way I will buy you a beer.
Cheers
Pops

[treefrog]

Hello I will share some of my skill in spraying which I used when I was building kitchens and furniture. This technique was used on a professional level by a few Business' I worked for and I adapted these myself.

Firstly you need at least a 10 cmf Compressor.

The standard spray gun used in the cabinet making industry is the Iwata w77 or wa 77. This spray gun is awesome.

The air out take is set at 60 PSI

I would not use laquer but a thinners based poly utherane which is touch dry in about 5-10 minutes. You will need to try a few brands to see what you like.

Firstly you will need to spray 2 coats of qaulity sealer to suit, sand back and then use the poly ontop.


Always use anti silicone drops in your poly as if there is any silicone tubes opened in your workshop or outside it will cause fish eyes on your work. Before spraying the poly empty the filter from water and at the start of the hose line apply half a bottle cap of metho spray it out of your gun without releasing the poly utherane. This will get rid of any water. Stay about 6-8" away from your work and thats it. Make sure its not cold so you might need to warm the room a little.

I am learning to use oils and waxes as this is not healthy for you or the earth but if I don't get the finishes I seek then I might need to resort to my old method.

I hope this helps.

Joe

[Gazza]

Had my first go at spraying Lacquer today, just on some plain'd & sanded boards as this was my first try at spraying anything at all.

60psi at the compressor, 20psi at the gun, Porter Cable HVLP1.

First tried spraying with water to check out the settings on the gun and found I could get good atomisation as low as 8psi at the gun.

Onto the Lacquer....
First tried it straight out of the can, I think it was a bit thick as it left an orange peel type pattern on the wood and did not give even coverage, some areas did not have any lacquer at all.

Thinned @ 10%
A bit better but still seemed to splatter a bit and was not as fine an atomisation as the water.

Thinned @ 25%
Seemed to have good atomisation, played with the spray pattern a bit, left the pattern at where it just gave a narrow oval shape. Not to sure about fluid adjustment, screwed it all the way in and with the trigger pressed in started to back it out, stopped where it seemed to give good atomisation.

Now I tried on some prepared timber:
First coat you could hardly see where it was sprayed. Left 20 min. Felt rough. Sanded lightly with 320.

Second coat you could just start to see a bit of a build of finish but was not even or consistent across the width or length of the board. Left 20 min. Did not feel anywhere near as rough as the first coat. Sanded lightly with 320.

Third coat I applied a bit heavier, moved the gun a bit slower, I moved it too slow on some boards and got quite a heavy wet coat, thought it might run or sag as I was spraying them all upright. Left 20 min. Felt quite smooth. Sanded lightly with 1200.

Last coat I applied normal speed but went back and forth over the boards until it looked wet all over when held up to the light at an angle. left 20 min. Felt quite smooth.

Conclusion:
Even though I applied the lacquer quite heavily in places I never got any runs or sags. On top of some knots the lacquer seemed to pool around it and not cover the knot itself, I applied several extra coats to these spots and eventually covered them, very wet coats but still did not run or sag.

I think I will do some more test spraying next weekend before attempting my first real project that is built and ready for staining finishing.

Happy spraying.

[Richardwoodhead]

Gazza, you're on your way. Good to hear.

Were you spraying onto flat / horizontal test pieces? I've found you can go pretty slowly and get a very wet finish, without runs. Unfortunately, with vertical surfaces & edges, you'll get runs if you go too slowly or have too much fluid. Or spray too close. I usually back off a little on edges as opposed to horizontal surfaces. And go a little faster. Another trick with edges is to give them a couple of hits, allowing a little time (30 - 60 seconds) between hits.

Regarding orange peel / incomplete coverage, in my case I learned I wasn't getting a good even full coat because I was airing down my gun too much. The guru I had give me a demo turned the air way up, increased the fluid a little, and got a perfectly even coat. But he did move faster across the workpiece.

Let us know how the next spray goes,

Richard

[Gazza]

Well, finally got the courage up yesterday to have a go at spraying the completed centrepiece of the unit.

In summary:
Not as good a finish as I would have liked, BUT I am happy with my first attempt at spraying something for real. A bit of "Orange Peel" here and there, not consistent coverage, but I guess you get all that with experience. I think I was to scared of getting runs and didn't thin the Lacquer enough, which in hindsite did not give full coverage so I opened the material flow a little without increasing the air flow or fan spread which I think added to the "Orange Peel" problem.

It is easy to sit back after the fact and think I should have done this or that but at the time without experience it is hard to know what to do while in the act of spraying.

I have started to compile a "Common problems" chart that I can have handy while spraying and refer to that.

For instance I have searched the net and found out that I could have tried the following:
1. Thinned lacquer more
2. Reduced the flow of material
3. Increased the Fan spread without touching anything else.

I actually increased the material flow and reduced the fan spread, the exact opposite !!!

Well, still got the two side units to spray so more practice I suppose.

I sprayed a couple of drawers and found I got a LOT of blowback when spraying into the corners, I am glad I left the back off of the centre unit.

Equipment:
Porta Cable HVLP gun
Carbatec Belt driven Compressor
Lacquer thinnned 25%
75psi at compressor, 20psi at gun

[Richardwoodhead]

Gazza, I'm wondering if you had enough air through the gun? My orange peel was caused by too little air for the fluid, so I was not getting good atomisation, but rather a "droplet" effect. Also, my guru kept a full fan cone going. Even on edges. So for him it was lots of air, a fair amount of fluid. And confident fast spraying.

If you're not happy with the finish, just lightly sand with 320 and hit it again. That's the nice part about lacquer. It's not a huge drama to do a light sand and another coat.

Richard

[joez]

Gazza,


One thing I have noticed when spraying lacquers is that the finish can change over the first week or so.

I have had orange peel type finishes flatten out over 3-7 days. Just becuase it feels dry doesnt means its really dry.

Someone told me once if you can smell the lacquer it hasnt fully cured becuase its still off-gasing and setting up, not sure how true that is though.

Joe

[Gazza]

Gazza, I'm wondering if you had enough air through the gun? My orange peel was caused by too little air for the fluid, so I was not getting good atomisation, but rather a "droplet" effect.Richard

Yes, from my list of Spraying Fixes I am compiling Orange Peel can be corrected by:

Increasing pressure OR Thinning material OR Increase spray pattern OR Decrease fluid flow.

I di dnot want to increase pressure as I was using a HVLP gun at 20psi and wanted as little overspray as possible, I did not know about the other fixes at the time.

Next spray job, in a few weeks I will thin an extra 10% and use decrease the fluid flow a bit.

[Richardwoodhead]

Gazza, just an idea, but I'd be really interested in the result if you experimented on a test piece doing the following.... increase the air (the guru used my HVLP at 50 psi) and increase the air at the gun. Use a full cone. And move quickly. I think you'd find you get a full even coverage and no orange peel. But it helped me tremendously to SEE it done. You've got to be a little "aggressive" and move confidently over the workpiece.

Good luck,

Richard

[echnidna]

Gazza, Mix the lacquer with the same amount of thinners.

[mailee]

Excuse me for butting in guys but I am a paint sprayer by trade and think I can help here. Mix the laquer as per manufacturers instructions and use around 60psi at the gun. Dont worry too much about the orange peel finish as once dry and hard this substrate can be flatted and polished. Use 1200 or finer wet and dry paper on a block and flat the whole area. Dry it and then burnish it with a mild cutting compound. I don't know what makes of compound you have over there in Oz but we use G3 here and then polish to a high shine. If you have a machine polisher it works wonders with a lambswool mop head. Be careful not to burn through by applying too much pressure or not moving the head enough. I would suggest leaving the sprayed article until the next day though to make sure it is completely hard. Also the technique with the spray gun is to fully trigger the gun before the spray hits the surface and move onto the surface and off the other side before releasing the trigger, this avoids build up of the paint/laquer on the edges where it can run. Hope this is of some help to you.

[Gazza]

Richard, I will give it a try on a test piece in a few weeks and post here how it went.

Mailee, I am using a HVLP gun and the instructions say use between 20 - 45 psi, I have seen some posts that people are effectiveely spraying with as little as 8psi ??? This is my first spray job so I know nothing other than the million or so posts I have read on the subject.

One of my reasons for buying the HVLP was to use low pressure and avoid a lot of overspray as I don't have a spray booth or anything.

Joe, I think you may be onto something there, I checked this morning (day 4) and the finish is DEFINATELY MUCH FLATTER & SMOOTHER then it was on Sunday. Still can see the orange peel by using a light at a low angle but the feel is quite smooth.

I don't think I have enough material coverage though, it is very hard to tell when applying clear, I have brushed on Poly before and this finish is only a fraction of the thickness of the finished Poly.

Thanks everyone for your input and suggestions.

Gary

[mailee]

Sorry Gazza I didn't realise you were using a HVLP setup. Yes you are right in that it should be around 40 psi. Should get good coverage from this setup. Best of luck.

[soundman]

Thin to manufacturers recomendations.????
Most manufacturers seem to recomend thinning 10%, the manufacturer of the laquer I'm using says " thin up to 30%. ????
I know a number of people who use tha same brand of laquer ant routinely thin 50/50.
It depends greatly on what you are trying to achieve and who's product you are using.
Spraying solid colours as in auto spray painting is an absolute doddle compared to spraying clears & tinted clears on timber.

With timber laquers you should be able to get a smooooooooth coat on the last coat, dust & bugs permitting.
With enough thinners nitro seems to self level quite well with the right amount & type of thinner.

[durwood]

Hi,
I have just joined the forum but have been looking for the last couple of weeks.
My background in in spraying, you guys are on the right track but have missed a few points.
to spray lacquer ( which by the way means its a low solid paint which drys fast but must be applied in several thin coats) as compared to enamels which are high solids which dry slowly and only need about two coats) you have to first of all have these conditions.

1) you must have a gun set up to spray lacquer. The trade term used by gun manufactures is (set up) refering to the air cap, fluid tip and its needle. If you just go to a shop and buy a gun these days most will be set for 2 pack enamels as used by the smash trade. If you use lacquer in them there will be too little paint for ther air coming out of the gun. A lacquer gun has a fluid hole neally twice the size. As lacquer drys so fast most of the solvent is used getting it onto the surface. If you hold the gun too far away the air will dry the paint completely into dust. Each gun manufacturer has a list of set-ups and the paints they are suitable for , a lacquer one usually has a flid hole about 1.8 -2.00 mm an enamel one about 1.2mm.

2) Always thin the lacquer at least 50/50 with thinner and increase the thinner up to 80/20 of thinner to finish. Apply about 5 coats. Usually a sanding sealer is applied first especially to open grain timbers (2-3) coats sand with fine paper then apply the clear lacquer.

3) Leave about 10 minutes between coats or longer, if the temp is below 20 degrees C get the air warm with a heater or sunlight if it looks like rain give it a miss. If the clear goes white stop and wait till the weather improves. You are getting moisture from the air on on the lacquer if you spray over it you will have water under the clear. Don't place a heater especially an infra red one at the timber at it will draw the moisture and air out of the timber and make bubbles in the lacquer.

4) Don't forget air hits the timber before the lacquer gets there so if the grain shows holes when you spray you will be hard pressed to fill them. One of the reasons lacquer was so popular is because of its ability to be "pulled" or treated like french polishing. If you cut with wet paper like a car painted does you get white sludge which is hard to clean away. If you make a pad using a piece of fair dinkum chammois with cotton wool inside to rub the lacquer after its final coat (let it dry completely -24 hrs) you can soften any dry spray or orange peel and move it into the grain holes. As the lacquer drys so fast you just work your way over the area when its gets too soft move on and come back later.

To do this mix 50% thinner and 50% metho adjust the mixture up or down to suit your needs metho weakens the action ot the thinner making it possible to rub the surface and move around the lacquer. Add the mix from the back of the pad wetting the cotton wool and squeezing it through to the front of the chammois. don't have it dripping but the chammios must be wet. Rub in circles, then in figure eights and then straight lines. If you ever wondered how they get grand piano's so good this is how.

You should be able to get a mirror finish, but some people like to pull the lacquer and then spray a flow coat of thinner/clear -90/10 to finish. Pulling over is really good on odd surfaces such as turned legs and other odd shapes.

About actually spraying, wide open fan ( long thin oval) thats like a wide paint brush. less chance of runs. If you close the fan all that paint gets stuffed into a smaller area so you will get runs. Hold the gun about a hand span away and at 90Degree to the surface move at a rate of about a metre in four seconds if you move faster you need to open the fluid control for more, if you go slower close it. you won't get a run if you keep the gun moving and keep the didstance the same. always pull the trigger before surface and don't stop till you get pass the other end. start at the top of vertical surfaces and work down.

Over lap about a quarter of the fan width each time you do the next pass,
On edges spray moving the gun just as you would on a big surface, every second you are onto a dry area, if you go vertically you have to cover the length of the fan to hit dry surface, turn the air cap across ways to do vertical painting of tilt the gun at an angle to you use the narrow part of the fan.

If you still need more info let me know.

[Gazza]

Durwood, welcome to the forum,

I will certainly give your ideas a go next spray job in 2 or 3 weeks.
I am realy kean to get it right.
I did find that laquer does not fill any gaps at all (such as poly will).
I also found that you could spot spray in a small area and get quite a built up of laquer and not have it run, seems quite forgiving in that area.

My main proble is Orange Peel finish and uneven application of the laquer.

I have a Porter Cable HVLP Conversion Gun with a 1.8mm nozzle I think.
I kept on thinning until the laquer seems to spray OK (25%), but I think now that more thiners would have been better.

I really have no idea how to set the gun up, I am trying to work it out from what I have read but everyone just says it is different for every job ???

Thanks for your input and guidance.

Regards
Gary

[echnidna]

The metho tip sounds interesting.

[durwood]

Hi Gazza,

There isn't any real variation for each job, just each person. depending on who is spraying and how fast they move the gun and how far away from the surface they hold the gun the adjustment is the same. It is supposed to go on as a full wet coat.

Open the fan, turn the material down until hardly anything comes out then keep turning out until you get a full wet coat when you hold and move the gun as you want to. Try it on a test piece and keep opening the gun until you find that it wants to run. Either cut the amount back or move the gun slightly further away.

Lacquer drys by evaporation, which means all the thinner has to leave the coating. Nitrocellulose (duco as its known by its common name) drys within seconds to be dust free and is pretty much hard dry in 24 hours.

If you put on lots all at once, the top drys out and seals off the ones put on before, so do one at a time and let it dry out you can't leave it too long the solvent melts into the previous one to get adhesion. Anytime even years after if you hit it with more the thinner will soften the previous lacquer and melt into it.

If the paint has orange peel its too thick or there is too little or too much air,
you are moving too fast along the panel or you are holding the gun too far away.

If you get a run or the gun drips onto the surface leaving a big blob, quickly wipe it with your finger while its still wet. with a bit of practice you can get it so smooth you can keep spraying and not have to rub the runs.

If you want to see how rubbing the lacquer works. mix some thinner and metho and rub some on to dry lacquer with your finger. do it on a piece of timber with deep grain holes to see how easily you can fill them in.

Let me know how you get on with the spraying, writing instructions is a lot harder than having someone with you to see exactly what you are doing.

[Richardwoodhead]

Durwood,

Sounds like you have a lot of experience with lacquer spraying. Do you work as a furniture finisher? Reading your advice, I think you operate pretty much the same as the guy who gave me some hands-on help. Enough air and fluid to get full coverage. Full cone of spray. I think this guy used more fluid but moved faster. Probably each operator develops a specific technique within general "boundaries".

It was immensely helpful for me to watch him work. Sounds like watching you in action would be hugely helpful to us spraying novices. I started this thread mainly to encourage other novices to try to get some hands-on teaching with lacquer spraying from guys like you. Spraying produces a beautiful finish quickly. But can also be very tricky if you don't know the pitfalls. Pity we can't arrange spraying seminars and hire guys like you to give lessons.

Anyway, WELCOME and thanks for your advice and tips.

Richard

[Richardwoodhead]

Durwood, I meant to ask if you sand between coats? You mentioned 5 coats with the 50/50 thinner mix - including a final coat at 80/20 (80% thinner). Do you do a fine sand between coats or just allow the thinner to melt into the previous coat?

Thanks,

Richard

[durwood]

Hi Guys,

No need to sand that just makes dust. the gloss level will go up as you rub. If you want add some retarder to your spray mix especially in the cold weather or hot weather as this help the paint flow out reducing orange peel. Retarder is very slow drying only use a tea spoon per about a litre or it will take days to dry. Its a bit strong to use in the pad for rubbing the lacquer.

I taught at a tafe college for over thirty years these paints were all we had in those days.

[JB]

2) Always thin the lacquer at least 50/50 with thinner and increase the thinner up to 80/20 of thinner to finish.


Thanks for this helpful post Durwood. A couple of questions...

Regarding 2) above, do you do this with pre-cat lacquer? And do the other points also apply to pre-cat?

[echnidna]

I disagree that its undesirable to sand (de-nib) between coats of lacquer.
I used to manage a commercial furniture factory with 50 employees. The polishers always de-nibbed between coats. All spraying was done in a large fully enclosed heated booth so airborne dust was not an issue.

We also found when using sanding sealer it was best left to cure overnight before top coating. (As it tended to outgass for a few hours after it was dry).

[gmrepp]

I am a beginning lacquer sprayer, having not sprayed since high school shop class. I read Richard's story about turning up the air and the liquid, and gave it a try last night, on my project, the body for an electric guitar. It was great! Come to find out, I was using so little air and so little liquid, I must have been dispensing only single atoms of lacquer. The old way would have taken me years to build up good coats. Thanks!

[China]

Pops and others
Quality of the spray is important when using lacquer, most finishers use hp guns (high presure) runing about 60 psi, this allows you to move quickly and achive top quality results. To give you an idea the gun I will not give you mutch change from $600, so buy the best gun you can afford

[Gazza]

Well, this thread has been going for quite a while but keeps getting resurected, and as I have gathered so much information from it (some conflicting) that as I have just completed spraying my second piece of furniture (2nd spray ever) I would give my conclusions.

I am using Protec NC Lacquer.

Try 1. (settings as first spray job)
a. Thinned 25%
b. Pressure at Compressor 60psi
c. Pressure at gun 20psi
d. Material flow open till a flow was achieved.
e. Fan was about 1/2 openned
d. Moving the gun at a medium/slow pace
The above produced barely adequate results, uneven coverage and orange peel.

I then went to the notes that I made after reading this forum.

Try 2. (settings gathered from forum)
a. Thinned 35%
b. Pressure at Compressor 70psi
c. Pressure at gun 50psi
d. Material flow openned wide up.
e. Fan was about fully opened
d. Moving the gun at a fast pace
The above produced very patchy results with the fan being split into 2 separate circles with a gap in the middle.

Try 3. (modified from above after experimentation on scrap)
a. Thinned 50%
b. Pressure at Compressor 100psi
c. Pressure at gun 30psi
d. Material flow openned till flow achieved and then 1/2 turn more.
e. Fan was fully opened then closed 1 turn
d. Moving the gun at a medium fast/fast pace
The above produced the best results I have ever had to date. I am not saying it was perfect, just the best for me.

A wet even coat was applied to both horizontal & vertical surfaces and the only runs experienced was on vertical end grain. A quick wipe of the finger over the run and the next coat blended it in.

The above settings/application method was achieved by combining bits from a lot of posts in this thread, so thank you to all those who have contributed as without your input I would still be sitting here looking at the spray gun wondering what to adjust next, your input at least gave me the knowledge to have a go.

[legin]

Gday guys.

I know many automotive spray painters.

2 of my best friends are spraypainters.

So, after reading all of the posts in this thread I decided to get both of them around and help me with my spraypainting. (I'm not too bad at it)

Anyway Russell (My first mate) had the style of really bombing on material. We sprayed paint and poly. He said that the poly was virtually like automotive 2 pack paint. Wide open material and air. He was pretty picky about how his fan was. Moved quite quick and very skillfully over the piece. Excellent finish. Made my work look ordinary.

Then the next day Adrian came around. He sprayed with the air pressure slightly lower with the material nearly wide open too. He set his fan after he had his material and air setting right. (Just as Russell did too) Moved accross the piece quite quick too. Looked great.

Both guys said to me that if you thin the material down too much you have more chance of getting runs. Yet they both really bombed the stuff on.

Both guys were spraying cupboards with a backing board attached. But they both said it would be easier if the backing board was not there. Didnt look that way to me the way they were spraying!!

[Johan]

Gentlemen,

I use a simple technique but it works for me to ensure the spray is evenly applied. It came about by spraying a coca cola red onto a car some years ago. Firstly, the mix ratio was about 10:6:1 (pant:thinners:harner) When spraying, I noticed that where the paint is applied, it is wet and therefore shines. This was particularly noticeable because of the red colour. So one could easily see where you have already applied enough, therefore avoiding spraying over the shining wet areas as this would cause paint to run. At the same token, the dull areas had too little paint and one would apply more paint there until it ebvenly shines and merges with the rest of the paint. When the car was finished, it looked like a pro's job, and I took pride in my first spray job. The next time I sprayed a car, the colour was white, and guess what, it's most probably the most difficult of all colours to spray because the glare from the white paint tends to blind you somewhat, That's when I developded my technique.

The techniques is to hold a lead light in one hand and spray gun in the other and use the light to reflect off the wet paint to see where is enough and where too little. But all the time you must act fairly quickly as to avoid paint sections to dry while you're still busy spraying.