learning to spray lacquer

[gpj1136]

Jim

At the risk of sounding political, Which I hope this not.

In California just south of San Francisco in the 70's when I was a boy. We had what were called smog alerts. During these times at fifty yards you could not see branches or definition in the trees, only silhouettes of the trees. They would close the schools and some people would become ill. Then they required smogging or filtering the exhaust of the auto's. To this day we can see the trees.

This is one of the reasons people here have concern for the environment. There are others, but this is one that I am very familiar with.

[Jim.S]

I only have the conventional set up Louie, so am assuming from what you say I suppose that's why I thin more. I do use a booth which filters all solids out but I don't reckon those paper filters stop the gas.

I certainly have concerns for the environment GPJ, I have three kids who have to live here a lot longer than me hopefully. I practice varying methods of restraint that I believe reduce my impact on the environment, I am just not concerned with the extra litre or so I may use per year with my spray set up to make a change though I have recently bought some Shines "hard shellac" which when I get around to using it I will FP the stuff. My next guitar I think I will use a satin lacquer which will use less solvent but its not for environmental reasons its cause I want that look, though the environment may benefit ever so slightly.

On a political aside ( maybe just outside the forum rules) I live in the Northern Territory of Australia and the powers that be want to start "Fracking" as well a dumping world nuclear waste in our state. I hope that with enough political opposition this will never happen cause all I see in that is disaster. The nuclear waste will come through Darwins port and then town which is a frightening prospect for me. Lets hope Fukushima is a last of its kind, though I don't have much faith in hope.

Jim

[B. Howard]

Originally Posted by Jim.S

Well don't tell them then Brian (assuming EPA means Environmental Protection Agency) just treat them like you treat the tax department. Anyway I guess the environment would be politics and if we want to adhere strictly to rules (not that I have read the forum rules) we should either take the discussion to the open section or off forum altogether.

Jim

Edit. When I said "you" I don't mean you Brian I mean all those other people who don't tell the tax man everything.

Except in certain parts of this country they set up air portable air monitoring stations and they do track down folks from the fumes.....

[Jim.S]

Originally Posted by B. Howard

Except in certain parts of this country they set up air portable air monitoring stations and they do track down folks from the fumes.....

Oh no! I just had the thought of a couple of teenagers chroming cans of spray paint in their garage and having the tilt-a-door kicked in by S.W.A.T. team. Bummer, mum and dad won't be impressed.

So if they turn up and you are just a hobbyist with a couple of cans of spray paint you are fine? If you have a sets of books that show receipts of payment for spray painting services you're buggered? How does that work?

Jim

[LouieAtienza]

Originally Posted by Jim.S

I only have the conventional set up Louie, so am assuming from what you say I suppose that's why I thin more. I do use a booth which filters all solids out but I don't reckon those paper filters stop the gas.

I certainly have concerns for the environment GPJ, I have three kids who have to live here a lot longer than me hopefully. I practice varying methods of restraint that I believe reduce my impact on the environment, I am just not concerned with the extra litre or so I may use per year with my spray set up to make a change though I have recently bought some Shines "hard shellac" which when I get around to using it I will FP the stuff. My next guitar I think I will use a satin lacquer which will use less solvent but its not for environmental reasons its cause I want that look, though the environment may benefit ever so slightly.

Jim

It's likely so. Every brand finish is different so you really need to look at the material data sheet to see what the recommended ratios are. You finish supplier should have mixing cups with the ratios printed on the side; that removes the guesswork.

I still say all the prep work beforehand is what makes the difference in how much you actually spray. The finer your surface is prior to spraying, the less finish you need to get a perfect surface. Which just happens to be more beneficial for something like a guitar. The trick is to find the lowest air pressure necessary to get your finish out of the gun and still level out nicely, and learning when to pull and release the trigger on the gun. This way you use the least amount of finish necessary. Sometimes I'll put the cup of the gun in warm water to warm the lacquer a little.

You can also try an HVLP gun. They lay finish down a little differently. I have one setup; it comes with a combination turbine/air warmer and compressor to pressurize the tank/cup. I have a couple nice Binks conventional guns that I don't really use anymore unless I need to use a siphon cup. I use two cheap HVLP conversion guns one Porter Cable and one Finex, but they're gravity feed and can be a pain depending on what I'm spraying. I have a cheap touch up gun that I use for bursting and some color-shifting mica stuff.

For conventional guns DeVilbiss has a really nice gun called Tekna that comes with three different nozzles and needles and fully coated inside and out so you can spray waterborne finishes, and it's priced reasonably.

[gpj1136]

Louie,

How would the HF conversion gun compare to a cheap HVLP ?
I can control over spray well but the flow is not as fine as I would like unless I thin it more than I like.

I have thought about replacing the gun to a higher quality HVLP but keeping the low cost unit.

Just curious about the conversion guns. I have never used one.

[LouieAtienza]

Originally Posted by gpj1136

Louie,

How would the HF conversion gun compare to a cheap HVLP ?
I can control over spray well but the flow is not as fine as I would like unless I thin it more than I like.

I have thought about replacing the gun to a higher quality HVLP but keeping the low cost unit.

Just curious about the conversion guns. I have never used one.

I buy lots of clamps from HF, but I won't even consider buying something like a spray gun from them! The Porter-Cable cost me around $120. The Finex maybe $15 more. I can't see how spending less saves in the long run if it equates to headaches later.

[Jim.S]

Thanks Louie, that devilbiss gun is around $400 without the cup in Australia, maybe cheaper if I search more. The Star I use cost $100 and like I said I get the finish I want with the set up I have.

The paint makers mixing recommendations are for the furniture guys and they don't spray like we do as they don't like to spend time leveling, just an off the gun finish is good enough for them (I should add that I would be surprised if anyone can get that mirror finish in lacquer off the gun with out any leveling in the process). I thin and look at the way it drips off a stick so it is not really guesswork its methodical. I get 6 instruments out of a 4 litre tin of paint (so around 600-700ml or a pint per instrument) and 4 litres of thinners (about $100 all up) with some left over so am not unhappy with the amount of product I use. I guess a fair bit comes off with leveling so I end up with a thin finish for a gloss. I am certain I will use less for a satin.

You mob are right, I could probably get away with less thinning if I mess with my technique but for me things are fine the way they are.

Here is a pic of my gloss taken almost square on (no cheating with a low angle shot)



Jim

[gpj1136]

I was actually meaning the porter cable not sure where the HF came from.
I do like their clamps though and shamefully use their diamond polishing hones for my chisels . I bought 4 of their grinders one day for cutting stone because my guys kept burning up my Bosch grinders. They lasted about 2 hours and all 4 were toast.

Jim, beautiful finish

[B. Howard]

Originally Posted by Jim.S

Oh no! I just had the thought of a couple of teenagers chroming cans of spray paint in their garage and having the tilt-a-door kicked in by S.W.A.T. team. Bummer, mum and dad won't be impressed.

So if they turn up and you are just a hobbyist with a couple of cans of spray paint you are fine? If you have a sets of books that show receipts of payment for spray painting services you're buggered? How does that work?
Jim

Not sure as I have never experienced it first hand and have always worked at places with all their permits in order. Most folks seem to run afoul after a complaint is made....IE one of your neighbors is tired of smelling paint fumes. They are a Federal agency and will show up with warrants and take anything they want and yes if they find records indicating you are being paid then your hopes of claiming hobby use are gone. There are thresholds for types of industrial use and some of those are determined by geography and zoning regs. Even if they can't make a case stick for air pollution they will be happy to forward what they find to the IRS, your local fire marshall and other government entities that will generally make your life a nightmare. Some years back when the state I live in made consumer sales of oil based paints all but illegal ( only able to buy in qts with quite a premium on price...) someone I know got caught trying to bring 100 gallons of the stuff in from a neighboring state. Started with a speeding ticket...ended with a $10,000 fine.

[Jim.S]

Thanks Brian, your response is almost the S.W.A.T scenario, does seem like a bit of a nightmare. I doubt you would last long in the suburbs here spraying day in day out, we do have some rules and even in a industrial area Work Health and Safety would come sniffing up your back door if you were blowing great clouds of wet paint plus gas all over the place. Certainly if I was spraying even one guitar a week I would go use a mates industrial booth (one that complies to industry standards) as I could not subject my neighbours to that. Australia is generally behind some states in the USA when it comes to banning the use of hazardous chemicals for example we were a decade or longer behind some of your states in stopping the use of organochlorides like DDT.

Jim

[LouieAtienza]

Originally Posted by Jim.S

Thanks Louie, that devilbiss gun is around $400 without the cup in Australia, maybe cheaper if I search more. The Star I use cost $100 and like I said I get the finish I want with the set up I have.

The paint makers mixing recommendations are for the furniture guys and they don't spray like we do as they don't like to spend time leveling, just an off the gun finish is good enough for them (I should add that I would be surprised if anyone can get that mirror finish in lacquer off the gun with out any leveling in the process). I thin and look at the way it drips off a stick so it is not really guesswork its methodical. I get 6 instruments out of a 4 litre tin of paint (so around 600-700ml or a pint per instrument) and 4 litres of thinners (about $100 all up) with some left over so am not unhappy with the amount of product I use. I guess a fair bit comes off with leveling so I end up with a thin finish for a gloss. I am certain I will use less for a satin.

You mob are right, I could probably get away with less thinning if I mess with my technique but for me things are fine the way they are.

Here is a pic of my gloss taken almost square on (no cheating with a low angle shot)



Jim

The finish looks great, but to me is an extraordinary amount of finsh. In comparison, I sprayed one full acoustic (and resprayed the neck) and three electric gutar bodies, with a pint of 2-part urethane.... and I still have over half the can left! And that's one thin seal coat and two finish coats!

[Jim.S]

Impressive quantities Louie (to a mug painter like me), is that a leveled finish? How is your opinion on the look compared to lacquer?

A lot of my paint ends up in the paper filter and then as a whiteish liquid on the floor.

Jim

[LouieAtienza]

That's leveled and polished out. The finish doean't require thinning though the hardener does cut it down some. Looks like glass after hitting it with Perfect It microfine compound and 3M foam wheel. If you check my build thread below I go up to 5000 grit Trizact and no polish, since it gives a softer "glow" so to speak.

The way I do it is spray one coat, and level that off starting with 800 minimum and going to 1500. This is not aggresive sanding, but I do sand wet always using pads, and I can sand after 24 hours. Then I'll wipe down with degreaser, air dry, wipe dry. I spray one nice wet coat, let it sit 5-10 minutes, then spray a second coat over that. Done. The finish is level enough to start with 1000 grit, and as mentioned before I work to 5000, in lieu of using rough compounds. I go straight to the Perfect-It microfine if I want deep gloss.

[gpj1136]

Louie, Your saying just one coat, then level, then two wet coats making a total of three coats ?
I'm not sure I could pull that off with my gun, but if that is correct it seems obvious I'm leveling with to course of mesh from the start.
My goal is an even thin finish with as few coats as possible.
Maybe instead of three to start. I could try two and then 800 grit then a few thinner coats to finish