Talk to me about HVLP

[Phillip Mitchell]

I've got an upcoming job that requires more painted wood than I want to do with a brush and am considering tooling up to be set up to spray. Materials to spray for this job includes nickel gap (interior shiplap boards), built-in plywood boxes, and interior wood trim which will all be white. I'm considering Target Coatings waterborne pigmented laquer with a custom tint, but I have no practical experience doing this method of painting. I've simply read and heard about this being a good option for spraying.

I've worked as a carpenter for years and generally always pre-finish (both stain and paint grade) the interior trim off site, then install carefully on site. What will it be like trying to fill any small nail holes after installation in pre-finished, sprayed (with pigmented laquer or similar) and then spot painting the filled holes? Should I expect / budget for having to go in at the end and mask off and respray the trim after filling nail holes or is there a better way. This is less of an issue with stain grain or brushed on paint, but its still a small detail that has always bothered me with trim work. It can come out sloppy if you're not anal about it, but I've never done it with sprayed trim. I'm trying to avoid on site finishing as much as possible, both for my own inconvenience as well as the clients' sensitivity, but a small amount of "touch up" could be accounted for it absolutely necessary.

There will also be a large amount of naturally finished Cherry. Considering a seal coat of shellac with Waterlox of something similar as a top coat. Is HVLP a good setup for spraying shellac?

I have no experience using HVLP, and have read some threads and begun to do some research, but just thought I'd post a thread as well for hopefully some more specific answers and advice from those more experienced. Thanks in advance for any info.

I have access to a large capacity / CFM compressor as well as plenty of space to set up my own temporary spray booth, so do I just need a HVLP conversion gun to get started? What do I really need (in terms of accessories, etc) to get started?

I started my own business last year (has been mostly part time up to this point) doing custom woodworking, but am opening up the gates a bit to include more custom interior trim / built in / etc to broaden my opportunities beyond custom furniture / strict "woodworking" and make my living and reputation based on the work I put out. It appears that I'm getting busier than simply part time and it makes sense to invest properly in tools that I can depend on and will last. In the future, I could see me spraying a lot of shellac and other clear coatings for furniture / built ins / more of the same type of work as described above.

I'm fairly picky in regards to tool quality and don't like dealing with poorly made tools, so what guns would be on your short list?

I'm sure I'm missing some details, but hopefully this is enough to start the conversation.

Thanks!

[David Eisenhauer]

I used an Apollo HVLP setup with Target Coatings clear products for many years during my similar one-man commercial venture and had no issues or regrets that I can remember. Target has their own water based dewaxed shellac that I tended to use as a primer coat, then top coat with one of their own clear coats depending on the level of protection I was looking for. I never used a conversion gun setup, so no help there. The knock against older Apollo setups was that they were a "bleed-through" type (air constantly blowing through the gun), but newer setups eliminated that issue (if it ever was one at any rate). I never received any bad finish that needed replacement, but tended to not order during hard core winter weather months for the supplier. The shellac needs to be laid on in a very light, quick coat(s) because it will run in a heartbeat if the gun lingers at all. I tended to prefer two quick, dryish cross-hatch patterns to avoid problems. Their top coats were easier to lay on and flowed out well. I typically recoated in an hour or less during optimum weather conditions and never encountered any fisheye or orange peel issues. Note that with Target products that no scuffing between coats was necessary if the re coat schedule was adhered to. You can add some Transtint dye to the clear products to mimic lacquer or shellac ambering effects (or toning) as desired. They also had a clear stain base (without any dye added) that could be used to bring out the grain before topping with other finish. I never used any of the pigmented products, but was always provided with good technical advice from Target when I had questions and their user forums were active with usually already discussing any questions I had at the time. The equipment was not inexpensive, but it has worked for me many years and has paid for itself in a similar situation that you describe for yourself. best of luck.

[liam c murphy]

I’m in a similar place in terms of career progression. I anticipate doing more work outside of the shop in the future. I spray everything in my shop. I wouldn’t spot finish anything that has been sprayed. I think it is hard to manually touch up sprayed surfaces without having it look bad. Wax pencils will work for small nail holes. If you must face nail, and have to fill nail holes, consider skipping pre-finishing and just spray on site if possible. Otherwise, you’re practically finishing everything twice.

I use a compressor and the $75 chrome guns from Harbor Freight. I like the ability to obtain replacements quickly from a local source. I tried a Fuji 5 stage over the summer, and I was disappointed with its performance. I returned it. I respect the opinions of many folks who endorse turbine systems. In the future, I’ll have to explore turbine systems again. I see their benefits for finishing in a finished home. However, I’m not sure I prefer their use in a shop.

I’d argue that you should be able to put together a decent system for around $500. I use a compressor that cost less than $300. You can get decent guns for less than $100. I have 3 versions of the same model that I use for finishes with various solvents. I use a cheap inline desiccant dryer for non water based finishes.

In the future, I’d like to upgrade to a larger (quieter) compressor from California Air Tools.

[John TenEyck]

If you want to spray everything from shellac to paint you will either need multiple guns or a gun with several different needle/nozzle sets and preferably a pressurized cup. And I know this won't sound correct but the cheap HF guns spray some products just as well as guns costing hundreds of $'s. For example, the purple HF gun that goes on sale for $10 sprays shellac, dyes, and other low viscosity products as well as anyone would want. So don't think you automatically have to spend a lot to get excellent results.

You will get more bang for your dollar with a conversion gun, since you already have a large compressor. Unless you need portability there is no advantage I know of for a turbine unit. I would get a couple of the HF gravity HVLP guns to start with and learn how to use them to spray shellac and dyes. The purple ones have a 1.4 mm N/N and can spray anything up to about 30 seconds viscosity. All you need is the gun, a secondary or mini regulator to control the pressure at the gun, and a cheap in-line filter. $50. Most WB clearcoats have a viscosity in the 40 - 60 second range (through a Ford #4 cup. Buy a cheap plastic one of those, too.) To spray them you will need a gun with a 1.8 mm N/N, or thereabouts, assuming it also is gravity feed. You actually can spray WB through any gun as long as you clean and dry it soon after use, but it's best to buy one with all SS internals. So you could get another low cost gun from HF, TCP Global, etc. I started with this kit and used it w/o issues for several years: https://tcpglobal.com/collections/spray-guns-tcp-global/products/tcpg7000. (https://tcpglobal.com/collections/spray-guns-tcp-global/products/tcpg7000)

If you want to spray paint, and probably even the TC pigmented lacquer, however, you will need a gun with a 2.0 or even larger N/N if you stick with a gravity feed gun, unless you thin it and that's not a good thing with WB products, or you could go with a pressure feed gun. That's the route I took when I had the need to spray pigmented products like paint and lacquer. I ended up buying a Qualspray gun from Homestead Finishing that comes with 1.0, 1.3, and 1.5 mm N/N sets (and more available) and a pressurized cup. It sprays everything from dyes to BM Advance (450 seconds) very well. It's middle of the road price and quality wise, I'm talking around $375 if you go with the 3M PPS option, which I highly recommend. If you are unfamiliar with the PPS system, go to 3M's website and read up because it has several advantages over conventional cups. So rather than buying 2 or 3 guns to cover the range of products (viscosities) you want to spray you could just buy one. And of course you can spend more and Iwata, Sata, Devilbiss, CA Technologies, and others are there if you want to.

Some guys like to have several guns; others one gun that does it all. No right or wrong.

As for spraying on site, nope, wouldn't do it. Finish in house, touch up nail holes with wax sticks or putty and paint with an artist's brush. Then again, I don't install miles of trim either. Maybe others know how to use detail guns to do on site touch ups. I'll be interested to read how they do it.

John

One more comment. A temporary spray booth works fine; that's what I use, just plastic sheeting hung from the floor joists and Kraft paper on the floor. But you need exhaust even with a temp. spray booth and even with WB products, for two reasons. Exhaust helps carry away the overspray so it doesn't settle on what you just sprayed and make it feel rough. More importantly, exhaust removes chemicals you don't want to breath. Of course, you also need to wear a respirator with organics cartridges. And you don't need fancy filters, just exhaust. The nice part about WB products is you don't need explosion proof fans or lights, any type that does the job will do. Some folks use cheap box fans; I use my DC fan. Depending upon your source of makeup air you may need to filter that. My makeup air comes from a window far enough away that any dust particles large enough to cause a problem in the finish fall to the floor before getting there. Your situation may be different.

John

[liam c murphy]

As for spraying on site, nope, wouldn't do it. Finish in house, touch up nail holes with wax sticks or putty and paint with an artist's brush. Then again, I don't install miles of trim either. Maybe others know how to use detail guns to do on site touch ups. I'll be interested to read how they do it

John

I certainly agree with the idea that it’s better to avoid it if possible. Most of the people that I have seen spraying on site spend a lot of time masking things off. They also appear to be using WB products. Check out #sprayfinishing on Instagram . There are a decent amount of people spraying wainscoting, wall paneling, built ins and doors on site.

[Jim Becker]

I recently purchased the Qualspray setup from Homestead that John mentions to replace an older, now worn HPLV conversion gun I've used for years. I'm looking forward to using it on an upcoming commission as it will kick things up a few notches for me in material handling. Quite frankly, even with the PPS cup system, I found it to be very reasonably priced given the extent of the kit and capabilities.

[Wayne Lomman]

I agree with John and Liam. Don't spray on site. It is not cost effective for anyone. It is best to touch up with a good quality artist brush and matching filler of your choice. Do it right and it is invisible.

[Phillip Mitchell]

Thanks for all the info, guys. This is most helpful.

Ive got some research ahead of me before I make any decisions, but now have a more focused view on the matter thanks to this thread.

[Phillip Mitchell]

Thanks a ton for all the details, John!

Is the Qualspray you have this one (https://www.ebay.com/itm/QualSpray-AM-6008-HVLP-SPRAY-Package-for-Woodworking-with-PPS-w-Bonus-Cup/253788471933?hash=item3b16f8c27d:g:hQ4AAOSwMfhaVM-~:rk:2:pf:0) (AM-6008 HVLP) ? What compressor / how many CFM do you have?


If you want to spray everything from shellac to paint you will either need multiple guns or a gun with several different needle/nozzle sets and preferably a pressurized cup. And I know this won't sound correct but the cheap HF guns spray some products just as well as guns costing hundreds of $'s. For example, the purple HF gun that goes on sale for $10 sprays shellac, dyes, and other low viscosity products as well as anyone would want. So don't think you automatically have to spend a lot to get excellent results.

You will get more bang for your dollar with a conversion gun, since you already have a large compressor. Unless you need portability there is no advantage I know of for a turbine unit. I would get a couple of the HF gravity HVLP guns to start with and learn how to use them to spray shellac and dyes. The purple ones have a 1.4 mm N/N and can spray anything up to about 30 seconds viscosity. All you need is the gun, a secondary or mini regulator to control the pressure at the gun, and a cheap in-line filter. $50. Most WB clearcoats have a viscosity in the 40 - 60 second range (through a Ford #4 cup. Buy a cheap plastic one of those, too.) To spray them you will need a gun with a 1.8 mm N/N, or thereabouts, assuming it also is gravity feed. You actually can spray WB through any gun as long as you clean and dry it soon after use, but it's best to buy one with all SS internals. So you could get another low cost gun from HF, TCP Global, etc. I started with this kit and used it w/o issues for several years: https://tcpglobal.com/collections/spray-guns-tcp-global/products/tcpg7000. (https://tcpglobal.com/collections/spray-guns-tcp-global/products/tcpg7000)

If you want to spray paint, and probably even the TC pigmented lacquer, however, you will need a gun with a 2.0 or even larger N/N if you stick with a gravity feed gun, unless you thin it and that's not a good thing with WB products, or you could go with a pressure feed gun. That's the route I took when I had the need to spray pigmented products like paint and lacquer. I ended up buying a Qualspray gun from Homestead Finishing that comes with 1.0, 1.3, and 1.5 mm N/N sets (and more available) and a pressurized cup. It sprays everything from dyes to BM Advance (450 seconds) very well. It's middle of the road price and quality wise, I'm talking around $375 if you go with the 3M PPS option, which I highly recommend. If you are unfamiliar with the PPS system, go to 3M's website and read up because it has several advantages over conventional cups. So rather than buying 2 or 3 guns to cover the range of products (viscosities) you want to spray you could just buy one. And of course you can spend more and Iwata, Sata, Devilbiss, CA Technologies, and others are there if you want to.

Some guys like to have several guns; others one gun that does it all. No right or wrong.

As for spraying on site, nope, wouldn't do it. Finish in house, touch up nail holes with wax sticks or putty and paint with an artist's brush. Then again, I don't install miles of trim either. Maybe others know how to use detail guns to do on site touch ups. I'll be interested to read how they do it.

John

One more comment. A temporary spray booth works fine; that's what I use, just plastic sheeting hung from the floor joists and Kraft paper on the floor. But you need exhaust even with a temp. spray booth and even with WB products, for two reasons. Exhaust helps carry away the overspray so it doesn't settle on what you just sprayed and make it feel rough. More importantly, exhaust removes chemicals you don't want to breath. Of course, you also need to wear a respirator with organics cartridges. And you don't need fancy filters, just exhaust. The nice part about WB products is you don't need explosion proof fans or lights, any type that does the job will do. Some folks use cheap box fans; I use my DC fan. Depending upon your source of makeup air you may need to filter that. My makeup air comes from a window far enough away that any dust particles large enough to cause a problem in the finish fall to the floor before getting there. Your situation may be different.

John

[John TenEyck]

Yes, the Qualspray AM-6008 HVLP SmartPak with the 3M PPS H/O cup. My 60 gal single stage compressor makes about 10 CFM at 40 psi, more than enough for the HVLP version.

John

[Chris Parks]

What size air lines to the gun John?

[Jim Becker]

Thanks a ton for all the details, John!

Is the Qualspray you have this one (https://www.ebay.com/itm/QualSpray-AM-6008-HVLP-SPRAY-Package-for-Woodworking-with-PPS-w-Bonus-Cup/253788471933?hash=item3b16f8c27d:g:hQ4AAOSwMfhaVM-~:rk:2:pf:0) (AM-6008 HVLP) ? What compressor / how many CFM do you have?

I can confirm that's the same kit I bought from Jeff at the suggestion of John not long ago. It's a quality setup for sure.

[John TenEyck]

What size air lines to the gun John?

It's 70 ft from my compressor to the spray gun. I'm using 3/8" hose the whole way and haven't had any issues. I have the regulator at the compressor set at 90 psi. From there a 50' hose takes it to a step down regulator. That normally is set at 29 psi. From there I use a 20' hose to the gun.

John

[Malcolm Schweizer]

Ironic- I came here to post a similar question, so forgive me if I piggy-back on this thread. I'm an old-school hotrodder who has a lot of experience with spraying lacquer and enamel. I have tons of pressure spray gear. Is it really worth it to go to the expense of buying a HVLP setup when I already own and am familiar with pressure spray guns?

[John TenEyck]

Ironic- I came here to post a similar question, so forgive me if I piggy-back on this thread. I'm an old-school hotrodder who has a lot of experience with spraying lacquer and enamel. I have tons of pressure spray gear. Is it really worth it to go to the expense of buying a HVLP setup when I already own and am familiar with pressure spray guns?

I guess the answer is "yes" and "no", Malcolm. Going to an HVLP gun won't improve the quality of the finish you get from a high pressure gun, except maybe if you need to spray the insides of a cabinet because it will have less bounce back. But an HVLP gun has much higher transfer efficiency, like 65%, compared to a high pressure gun which might be only 40%. Whether or not that's important might depend upon how expensive the products you spray are. Some of the WB clearcoats I use are over $100/gal so I'd like to put as much of them on the work as possible.

Learning wise I have no clue. My guess is an HVLP gun is a little harder to use in that it's less forgiving if you don't have the viscosity matched properly with the N/N, or maybe better said the other way around, but I've never used a high pressure gun so I have no actual basis of comparison. But even if it is, with all the experience you have with high pressure guns I would expect it would be an easy transition. You could buy a budget level HVLP gun, like the $10 HF purple gun, and give it try. It sprays shellac and low viscosity products beautifully. Go from there.

John

[Tom M King]

Answering Malcolm, I still use my old Binks 18, and 15 guns sometimes. They use a higher pressure, and there is a lot more overspray, but there is no loss of quality in the surface. You wouldn't have any trouble switching to a conversion gun, but if you are used to using a pro gun, you might not be satisfied with some of the cheaper guns. If your guns are doing what you need, there would be no real reason to change unless you wanted to cut down on the overspray.

The pro conversion guns give you a lot better atomization, and have great control. I have a little Iwata (Japanese) LPH80 that can atomize so nicely that you can overlap 75% in complete control, and never get a sag, or spit. It does great on small square footage areas, like a piece of furniture, but if you are painting a boat hull, you would want a full sized gun. I think that gun is around 300 bucks with a PPS adapter.

For a full sized conversion gun, the 3M gun is pretty good, and was made for the PPS system. The cap is plastic, and disposable for around 5 bucks if you don't want to clean it, or you change sizes much, for different finishes, a set of caps costs about 25 bucks for a package of several. The only thing you really have to clean is the end of the needle, but the caps can be cleaned out with just a couple of ounces of solvent. That gun, with several sizes of caps is less than 200, and comes ready for the PPS cups. The cups just slip into the top of the disposable caps. That gun is capable of spraying a top quality finish, but not as good on small parts as the LPH80. The LPH80 gun uses almost no air either.

For painting like Phillip was asking about to start with, I'd use a FFLP airless rig (Fine Finish Low Pressure). FFLP changed airless to something that users of the old rigs would hardly recognize now. An airless rig is not worth cranking up unless you have a whole set of cabinets to spray though. It's more work to clean than a conversion gun.

I had an Apollo turbine unit, that did a good job, but didn't need it any more, so I sold it. A turbine rig is good for a hobbyist that doesn't have a good source of dry, compressed air, but I don't know of any pros using them any more.

[Malcolm Schweizer]

Thanks for the detailed replies and to the OP for letting me join in.

[Tom M King]

Malcolm, the one detail I left out about using my old Binks guns is that I only use them for spraying gelcoat these days. The reasons are: They have leather gaskets, and I figured styrene, used to thin gelcoat for spraying, would either not harm the leather, or it would be easy enough to make new gaskets. Also, I didn't want to risk the newer guns with something that might kick before I could get the gun cleaned out, and I wasn't sure about synthetic seals, or plastic 3M caps interaction with styrene.

When doing fiberglass work, it's much easier to get the surface smooth, and error free before the final coat is put on. Spraying leaves little sanding to do before polishing.