AS193
TDPRI Member
or a guitar string.
Spray gun issue please help! (Resolved)
- Thread starter samueldixon
- Start date
duaneo
TDPRI Member
I saw the 30psi also and had the same conclusion, I looked up his gun and the specifications say: 30 PSI inlet pressure delivers 10 PSI air cap pressure at 13 CFM air volume.
His compressor is lacking a bit, it is rated at 3scfm @ 90psi. Scfm is inversely proportional to psi so: 90psi / 30psi x 3scfm = 9scfm (rough approximation). Actual cfm depends on temperature, altitude / bar, and humidity.
I'm also curious to know how well this setup is working for him.
Agreed. Even with variations in temp & humidity it's nor going to be able to spray a clean, controllable fan - unless spraying heavy like paint (which may seen contradictory, but it's not) - i.e. trying to get coverage and flow in a single coat - which is a disaster recipe.
It may LOOK great when completed, but the solvent entrapment with results in a soft, easily damaged film; blisters, alligatoring; honeycomb structure inside the soft film and so on., a full coverage fan done in a single coat is NOT good; a clear, non-flowing fan without tails on one coat is *good* - each coat melts the previous coat, creating a single coat of lacquer. Multiple (10-12 coats of half color and/or toner and half clear, all applied VERY thin and after the previous coat has FULLY dried) is what gives a good professional looking project with a finish that has "depth" - asnd one that goes straight to the buffer.
Wet sanding is ONLY for problems - excessive orange peel, small runs, dry spray (working from the bottom-up creates a sandy, dry pebbly finish over what was previously applied - always work top-down).
I have had folks breing me projects or send pictures of ones sprayed with an HVLP gun using an underpowered compressor. They often look good "now" but not a year later.
duaneo
TDPRI Member
I have a small HVLP gun, an Iwata LPH80, which works great with my compressor (5.3cfm @ 90psi, 10 gal), But I'm considering going with a bigger gun. Do you think I would see much benefit going bigger? If so, what guns would you recommend?
I have read that as a rule of thumb that you should have a compressor that has 2x the cfm your gun requires, what do you think?
Should I start a new thread? Thanks for your input!
I recently got an Airless, after 2 medium sized jobs that took
me about 2 hours to lay down a coat on a double garage size space, primer monday 2 coats wednesday & thursday..
It took me more time... to thoroughly clean the airless, than it did to paint the coats on the wall..
me about 2 hours to lay down a coat on a double garage size space, primer monday 2 coats wednesday & thursday..
It took me more time... to thoroughly clean the airless, than it did to paint the coats on the wall..
Lindsay Wells
TDPRI Member
Hey guys, you have to make sure the breathing hole at the top of the paint tank is not blocked I have many USA DeVilbis guns and it's important to clean them immediately after spraying and clean the top tank breathing hole. Sometimes it's good to run some laquer thinners through and leave it for ten minutes then do it again, the thinners should dissolve any minor blockage, but first check the breathing hole, Number six acoustic string does a good job, Cheers Lindsay
Yes - and I'm honestly the wrong guy to ask.
I spent years testing experimental compressor-based HVLP systems, and the only ones that worked were 1) for heavier-viscosity 2-component epoxies and polyurethanes (tested with various needle/cap combinations and lacquer at package consistency to virtually water-thin and NONE were satisfactory without very long dry times between coats and normally-unecessary wet sanding of the final surface prior to buffing), and 2) based around cart-mounted 60-80 gallon, 5-10 bhp compressors.
I've tested smaller systems with several well-trained applicators, and the results were - at best - "rough".
For pinpoint-control HVLP spraying of conventional lacquer my opinion is that faster, cleaner and smoother application of lacquer with excellent transfer ratio is still achievable only through of a turbine-based system, with all components from the same manufacturer.
I still believe turbine systems spraying at true HVLP pressure of 4-10 psi yields superior results - and at a lower price (assuming high quality equipment).
So respectfully, I just can't recommend compressor-based systems. High quality gear involves gun/needle/cap sets at $300-500 - and that's before a compressor, properly rated hoses and ancillary equipment.
The only airless sytems that can spray even higher-viscosity specialty industrial lacquers are air-assisted airless. Standard airless operates at excessively-high pressure for lacquer application.
Airless is great for most paint applications because of the speed and labor cost reduction. A day of airless spraying by a pro is worth the 30-45 minute cleanup time. But they are not well-suited for limited surface coverage, small material consumption and cleaning between coats of lacquer application.
samueldixon
TDPRI Member
I was told by someone to spray until it looks wet, that too thin coats would dry too fast and give me orange peel. I couldn't tell you how thick they are but probably thicker than you are describing without running or dripping.
Using this and thinning with an extender. Was around 22 seconds with my cup.
Not sure guessing its not a bleeder.
Only with the GF extender
No not measuring, wasn't even aware there was a way to do this. I am very new to this as you can probably tell haha.
Been going about 50 mins between coats. I try to make each coat the same thickness.
The data sheet for the lacquer says 21 days to cure.
This is only my second go with this setup. I honestly think the gun and compressor work just fine considering the surface area of a solid body guitar is so small I don't have to pull on the trigger for very long and tax the compressor. I think I get pretty good atomization but I am a novice so maybe I'm totally wrong. Everything I've read says shoot paint at around 35 psi and lacquer at around 28 psi.
My technique could use A LOT of help haha. It's really tough to find much good info about spraying acrylic lacquer, most everything is on solvent based stuff which isn't an option for me.
I posted another thread recently asking about a good schedule for acrylic lacquers for a little more background on where I'm at/process: https://www.tdpri.com/threads/water-based-lacquer-schedule.1103361/#post-11439544
samueldixon
TDPRI Member
I think the setup works just fine. I think I am pretty terrible at using it lol.
"Told by someone" is not a good way to go. Research and verify - find out if most applicators of the SAME material on the same type of surface using thew same equipment do it that way.
ONE persons' comment isnot good advice. Any one person could tell you to sprinkle water on the surface first. Would a beginner know that's wrong?
And (I can't repeat this enough times) - go through the ENTIRE system prep and application process on scrap until you get it right. DO NOT move to the guitar until you know what results you will get-consistently.
Practice until you get the desired results. Otherwise, you have to get lucky - and the odds of that really suck.
That changes the entire scenario. If is not a conventional lacquer - it is a WATER BASED LACQUER with a chemical crosslinker - i.e. a "curing ageny. It does not dry by evaporation like conventional lacquers, or even oddball lacquer/enamel blends.
Virtually ALL conventional lacquers and lacquer enamels dry by evaporation of the volatile components - solvents, wetting (flow) agents (aka surfactants), which is one of the major reasons for thin coat application - to prevent the surface from drying, trapping solvents in the film.
But this product dries by a combination of evaporation AND a chemical reaction once the film is exposed to oxygen - at least most do. Some start the checical curing process by exposure to and reaction with other elements in the atmosphere.
What you are using is different from products referenced in 99% of other threads on this forum. It's not unusual as an instrument coating - but in controlled environments like production facilities. Also used in wood furniture and end-products.
But very rarely seen in DIY instrument application. I'd have to spend a couple of hours - at least - researching the product, what other products (sealers, stains, dyes, thinners, viscosity adjusters, gloss reducers and other accessory products are used with it or compatible with it, what the pencil hardness is, mil thickness standards, abrasion resistance, solvent resistance...it's a LONG list...to be able to advise you from ny position of even basic knowledge.
Others advising you need to have used the exact product or be experienced enough (i.e. be professionals in the field, or retired ones) to give you GOOD advice.
Anyone else is GUESSING.
Point of clarification" "water based lacquer" is NOT the same thing as "acrylic lacquer". It MAY be - but most are not.
Conventional acrylic lacquers are NOT water-based. they use many of the same highly flammable solvents as nitrocellulose lacquers, and "acrylic" and "nitro" lacquers (ps - many "nitro" lacquers ALSO contain acrylic resin!) can be used on top of each other - you can alternate coats and they melt right into each other.
This is NOT usually true with water-based lacquers, which use completely different solvent blends - and again, cure CHEMICALLY - not by EVAPORATION.
It's like gas and electric cars - they may "look" the same, but they get to the destination via methods that are NOT interchangeable.
If someone told you "acrylic lacquers" are "water based" you were steered in an odd direction from the start. and you didn't just buy a "water based" lacquer - you bought a water based lacquer that dries by a chemical curing process...not evaporation, like the9 stuff virtually everyone uses in DIY guitar finishing (with a very few unique exceptions).
You need to be sure. You need to know what equipment you are using.
A "bleeder" gun has the air running all the time and the trigger controls ONLY the release of coating. They are generally much cheaper than "non bleeders" - which trigger both at the same time - and require extreme care in where the gun is triggered, released, and pointed after each pass; they blow dust and dirt around, and if the air is run across a fresh pass it can create waves and thin spots.
Bleeders usually hav much cheaper brass needles as well - it's important to pull the trigger before making ANY air cap adjustment, but critically important with bleeders, as a single turn of the cap can often cut a groove in the needle - destroying it, as the fan will be uneven and in some cases leak coating when the trigger is released.
There is no way you can determine "same thickness" - you are dealing with a few thousandths of an inch thick when wet. Nobody can "eyeball" that. Experience can teach you how fast to make each pass at a given pressure and distance - but it takes a $5-10 "wet film thickness gage" to measure the actual thickness as applied.
At what thickness, temperature and relative humidity?
It may be right. I'd have to research it to be sure - and the moisture content of the wood was measured by every applicator of waterbased precatalyzed lacquer I knew to ensure moisture would nbot be trapped in the wood.
Your terms are mixed up - every common acrylic lacquer IS a solvent based lacquer similar to nitrocellulose lacquer, and some "nitrocellulose lacquers" have some amount of acrylic resin added for increased flexibility, better impact resistance and resistance to yellowing.
Either you were confused or someone gave you bad information (or did not understand your needs), and you ended up using "water based, pre-catalyzed acrylic lacquer" - which is NOT the same acrylic lacquer generally used as a guitar finish.
I don't know of anyone on the forum who is an expert in that product. And I have not kept track of changes in formulations due to air quality regulations as I have with conventional lacquers - so I'm afraid all I can do is explain what you have and how different it is from the usual materials seen here.
samueldixon
TDPRI Member
Thanks?
Last edited:
Sorry - that was probably both hard and confusing to read.
In short - somehow you ended up thinking "acrylic lacquer" = "waterbased acrylic lacquer."
But that's not always the case. There are waterbased acrylic lacquers, waterbased nitrocellulose lacquers - and solvent based types of each as well - which are FAR more common and what virtually all first-time guitar finishers (and most long-time finishers) use.
The aerosol lacquer that really got the ball rolling as far as ANY lacquer for beginners is ReRanch, who also publishes complete methods on their site.. They sell solvent nitro lacquer.
Stewmac is a common source - they have some unusual products, which are solvent-based nitrocellulose lacquer blended with oil based enamel; they (and similar Deft aerosols) take much longer o dry than conventional nitro and acrylic solvent-based lacquers.
And those who want auto colors or metallics often use Duplicolor - aerosol solvent based acrylic lacquer.
Woodworking tool stores often sell lacquer - usually the Behlens or Mohawk lines - solvent based nitro lacquers (and although different labels, made by the same factory as RustOleum's aerosols...which are solvent-based acrylic lacquers.
And paint stores that cater to the commercial coatings contractor trade - selling "bulk" lacquer (quarts and gallons instead of or in addition to aerosols) either sell their own brands - such as Sherwin Williams - or Valspar, Mohawk, Cardinal and several others.
Notice I haven't once mentioned "water based" in that list?
That's because they are far less common and generally cater to the furniture and millwork (wood trim, shutters, blinds etc) trades.
Virtually none of the classic guitar colors of the 50's and 60's were water-based acrylic lacquers.
Water-based lacquers were not available commercially until the 1980's - and then only sold to shop finishers inthe furniture and millwork trades.
None of the 1970's application equipment worked with the initial versions of water-based lacquers, and Binks, DeVilbiss, Graco, Wagner/Titan - the major spray equipment manufacturers at the time - had to "reinvent the wheel", going through years os in-shop, lab and field testing of different designs (trying to NOT stray too far from familiar gear), go through the UL testing/approval process, write/print parts and use/maintenance manuals, training seminar guides...
To 1980's lacquer users, the terms "lacquer" and "water" were diametrically opposed - so extensive sales training and marketing materials were also developed.
So you really didn't see water-based lacquers and application equipment on industrial supply company shelves until this century.
Your lack of understanding "bleeder" guns was key, and it was a trick question (no offense meant - but it was important to figure out exactly what you do and don't know). The answer was an indicator that someone sold you a system or gun for the type of "acrylic" lacquer you mistakenly bought (thinking it was the common type used on guitars), but you did little research about types, brands or capabilities of equipment first.
This isn't meant to be insulting - but "someone told you" a spray method and you used it - but you don't even know what type of equipment you have, and it makes a BIG difference!
At this point, I suggest either 1) you go back to whoever sold you the DeVilbiss gun (with your compressor and lacquer & extender in tow) and ask that they show you how to use the gun, make proper adjustments, maintain it - everything about using it with the product you are using.
Every commercial paint store that sells spray equipment either provides free training as part of the sale, has manufacturers put on training seminars on a regular basis, or will set you up with a paid series of training sessions. And you'll need it for EVERY product in the system.
If you bought the gun online - well, you'll probably need to pay some DeVilbiss dealer for training - one that carries those guns in stock AND understands waterbased acrylic lacquer,
(Note - my recommendation is to NEVER buy a spray gun...unless it's a replacement for the same thing...or a full rig online. Buy them from commercial paint dealers that offer training. They are NOT "plug and play" tools - you can destroy a needle just by turning the cap ONCE if you don't pull the trigger first and hold it, and that can be a $50-75 "oops")
You are using a very unusual system, and asking questions about it on a guitar website is like betting on one number on a roulette wheel - you could be talking to a long-time coatings professional that you can look up on the web to verify qualifications; a very experienced amateur you can also check on; another beginner tossing out guesses based on something they think they heard on a podcast somewhere; a self-proclaimed expert (VERY common on YouTube) who posts utter *&$%#@ but gets away with it because there's no recourse for his/her/their mistakes; or a 13 year old kid who has never painted anything but his role-playing game characters, has a keyboard yellowed with with Cheetos crumbs - but likes to type.
It wasn't until post 28 - unless I missed something, and that's possible - that you clearly said what you are using, and even then, only in a one-word link - which is easy to miss. I had to point out it was a WATER BASED product.
Post 10 asked if you had a water filter in-line. That should have been a tip-off for you to be confused and ask "I'm using water based lacquer - why do I need a water filter?".
I'm very interested to see how this all works out. It would be more "generally helpful;" were you using a stock HVLP at normal pressure, but it's still interesting.
Where did you read that - and 2x the pressure where? At the compressor outlet, hose outlet (which can be less depending on type and length) or nozzle?
The general rule for decades has been 15-30CFM in order to spray evenly with no lag at HVLP pressure - 4-10PSI - at the air cap outlet ("nozzle"). but it can vary depending on the exact material sprayed and viscosity (after thinning).
Pancake compressors - usually 3-10 gallons - only pump out 5-7CFM at HVLP pressure. I usually recommend a 60 gallon/4HP stationary compressors for high-pressure air HVLP type guns, which are quite different from the turbine systems. A compact, name-brand turbine system - turbine, large-diameter single hose (looks like a vacuum cleaner hose) and cup (my preference) or gravity gun with all the accessories, manual and training (if bought in a commercial paint store) costs about the same or less than a good 60 gallon compressor - with NO gun, hose...just the compressor.
samueldixon
TDPRI Member
I'm good man. I have to spray what I'm spraying because I work in my basement. I make like 2 guitars a year as a hobby for myself. What I'm using works good enough.
Sorry - that was probably both hard and confusing to read.
In short - somehow you ended up thinking "acrylic lacquer" = "waterbased acrylic lacquer."
But that's not always the case. There are waterbased acrylic lacquers, waterbased nitrocellulose lacquers - and solvent based types of each as well - which are FAR more common and what virtually all first-time guitar finishers (and most long-time finishers) use.
The aerosol lacquer that really got the ball rolling as far as ANY lacquer for beginners is ReRanch, who also publishes complete methods on their site.. They sell solvent nitro lacquer.
Stewmac is a common source - they have some unusual products, which are solvent-based nitrocellulose lacquer blended with oil based enamel; they (and similar Deft aerosols) take much longer o dry than conventional nitro and acrylic solvent-based lacquers.
And those who want auto colors or metallics often use Duplicolor - aerosol solvent based acrylic lacquer.
Woodworking tool stores often sell lacquer - usually the Behlens or Mohawk lines - solvent based nitro lacquers (and although different labels, made by the same factory as RustOleum's aerosols...which are solvent-based acrylic lacquers.
And paint stores that cater to the commercial coatings contractor trade - selling "bulk" lacquer (quarts and gallons instead of or in addition to aerosols) either sell their own brands - such as Sherwin Williams - or Valspar, Mohawk, Cardinal and several others.
Notice I haven't once mentioned "water based" in that list?
That's because they are far less common and generally cater to the furniture and millwork (wood trim, shutters, blinds etc) trades.
Virtually none of the classic guitar colors of the 50's and 60's were water-based acrylic lacquers.
Water-based lacquers were not available commercially until the 1980's - and then only sold to shop finishers inthe furniture and millwork trades.
None of the 1970's application equipment worked with the initial versions of water-based lacquers, and Binks, DeVilbiss, Graco, Wagner/Titan - the major spray equipment manufacturers at the time - had to "reinvent the wheel", going through years os in-shop, lab and field testing of different designs (trying to NOT stray too far from familiar gear), go through the UL testing/approval process, write/print parts and use/maintenance manuals, training seminar guides...
To 1980's lacquer users, the terms "lacquer" and "water" were diametrically opposed - so extensive sales training and marketing materials were also developed.
So you really didn't see water-based lacquers and application equipment on industrial supply company shelves until this century.
Your lack of understanding "bleeder" guns was key, and it was a trick question (no offense meant - but it was important to figure out exactly what you do and don't know). The answer was an indicator that someone sold you a system or gun for the type of "acrylic" lacquer you mistakenly bought (thinking it was the common type used on guitars), but you did little research about types, brands or capabilities of equipment first.
This isn't meant to be insulting - but "someone told you" a spray method and you used it - but you don't even know what type of equipment you have, and it makes a BIG difference!
At this point, I suggest either 1) you go back to whoever sold you the DeVilbiss gun (with your compressor and lacquer & extender in tow) and ask that they show you how to use the gun, make proper adjustments, maintain it - everything about using it with the product you are using.
Every commercial paint store that sells spray equipment either provides free training as part of the sale, has manufacturers put on training seminars on a regular basis, or will set you up with a paid series of training sessions. And you'll need it for EVERY product in the system.
If you bought the gun online - well, you'll probably need to pay some DeVilbiss dealer for training - one that carries those guns in stock AND understands waterbased acrylic lacquer,
(Note - my recommendation is to NEVER buy a spray gun...unless it's a replacement for the same thing...or a full rig online. Buy them from commercial paint dealers that offer training. They are NOT "plug and play" tools - you can destroy a needle just by turning the cap ONCE if you don't pull the trigger first and hold it, and that can be a $50-75 "oops")
You are using a very unusual system, and asking questions about it on a guitar website is like betting on one number on a roulette wheel - you could be talking to a long-time coatings professional that you can look up on the web to verify qualifications; a very experienced amateur you can also check on; another beginner tossing out guesses based on something they think they heard on a podcast somewhere; a self-proclaimed expert (VERY common on YouTube) who posts utter *&$%#@ but gets away with it because there's no recourse for his/her/their mistakes; or a 13 year old kid who has never painted anything but his role-playing game characters, has a keyboard yellowed with with Cheetos crumbs - but likes to type.
It wasn't until post 28 - unless I missed something, and that's possible - that you clearly said what you are using, and even then, only in a one-word link - which is easy to miss. I had to point out it was a WATER BASED product.
Post 10 asked if you had a water filter in-line. That should have been a tip-off for you to be confused and ask "I'm using water based lacquer - why do I need a water filter?".
I'm very interested to see how this all works out. It would be more "generally helpful;" were you using a stock HVLP at normal pressure, but it's still interesting.
Where did you read that - and 2x the pressure where? At the compressor outlet, hose outlet (which can be less depending on type and length) or nozzle?
The general rule for decades has been 15-30CFM in order to spray evenly with no lag at HVLP pressure - 4-10PSI - at the air cap outlet ("nozzle"). but it can vary depending on the exact material sprayed and viscosity (after thinning).
Pancake compressors - usually 3-10 gallons - only pump out 5-7CFM at HVLP pressure. I usually recommend a 60 gallon/4HP stationary compressors for high-pressure air HVLP type guns, which are quite different from the turbine systems. A compact, name-brand turbine system - turbine, large-diameter single hose (looks like a vacuum cleaner hose) and cup (my preference) or gravity gun with all the accessories, manual and training (if bought in a commercial paint store) costs about the same or less than a good 60 gallon compressor - with NO gun, hose...just the compressor.
As long as you understand the differences and it works for you, great. I'm still glad you posted the thread, because once in a while someone comes along insisting "acrylic" means "water based" - and now we have some better reference points.
