HVLP setup suggestions

[jinjuku]

While I redid my Statement baffles with a Wagner Control Spray (Turbine HVLP) and I am really, really happy with the results. Well the output was slow. Very thin and small pattern. Granted this was with minimally thinned latex paints.

Just not well versed in this and asking for some general opinions/options that won't break the bank or is a turbine sprayer 'good enough' and am I not going to gain that much with a Harbor Freight HVLP and 21 gallon compressor (with oil lubed air regulator / moisture trap).

I know there are some paint experts here. Thx.

Wondering what I could have done with Automotive paints etc... also.

 

[Alex2507]

Granted this was with minimally thinned latex paints.

When I used a similar sprayer I found that I had to thin the paint out to the point that it started dripping of a paint stir stick after about 8 seconds and dripped at a rate of 1 drop per second. That's pretty thin as far as paint goes but pretty thick for the sprayer to shoot so I had the air turned all the way up to atomize the paint and the fluid control knob was turned way down. Also I used Flotrol to give the paint more time to level out the orange peel effect from being under atomized. Having the paint thinned beyond that produced runs. The good thing is that you can wipe off all the paint you just shot and start again if you find the results unacceptable. I found that primer is much more forgiving and easier to shoot.

Harbor Freight HVLP and 21 gallon compressor (with oil lubed air regulator / moisture trap).

If you bought a Rolls Royce from those people it would run like a Yugo.

I know there are some paint experts here.

I know you didn't mean me but I did just get through shooting latex out of one of those sprayers.

 

[highfigh]

HVLP isn't made for house paint, or anything with that voscosity- they're made for paints that are thin enough for overspray to be a problem. This causes two issues- one is that it wastes finishing material and the second is that it gets all over everything when used in a non-production environment. In a real, industrial spray booth, some of the overspray can be collected in the filters but it still wastes material. An airless sprayer for house paint has a small piston that opens and closes at high speed to allow the pressurized paint to atomize. The surface tension and droplet size keeps overspray to a minimum.

The great thing about automotive finishes is that most can be wet-sanded and polished to a high sheen. That alone is worth their use. Go to a music store and look at the guitars- they may have had some lumps and blemishes after the initial spraying but they don't when they're done. Pre-catalyzed lacquer is pretty standard in cabinet making- the results are beautiful, if the facility is clean and good technique is used.

 

[highfigh]

If you bought a Rolls Royce from those people it would run like a Yugo.

I really don't think anyone expects Rolls Royce products from Harbor Freight but I used one of their HVLP conversion guns when I shot the upper cabinets in my kitchen. I used MinWax satin polyurethane and the finish is flawless. I thinned it with naptha (50:50). It was pretty inexpensive and I bought it to see if it would do a decent job. After testing it, I decided to go ahead and use it- if the finish had looked bad, I would have done them the same way I did the lower cabinets- by hand. I have a lot of their stuff but none if it needs to be highly precise. I don't think I would buy a torque wrench from them- that needs to be calibrated and theirs don't come with any kind of proof that they were tested. Snap-On would probably tell me to go away if I asked them to check one out. My dust collector works very well, though. The power switch was pretty cheesy, though. It looked fine, but it melted.

 

[Alex2507]

My dust collector works very well, though.
The power switch was pretty cheesy, though.
It looked fine,

but it melted.

The persecution rests.

 

[jinjuku]

When I used a similar sprayer I found that I had to thin the paint out to the point that it started dripping of a paint stir stick after about 8 seconds and dripped at a rate of 1 drop per second. That's pretty thin as far as paint goes but pretty thick for the sprayer to shoot so I had the air turned all the way up to atomize the paint and the fluid control knob was turned way down. Also I used Flotrol to give the paint more time to level out the orange peel effect from being under atomized. Having the paint thinned beyond that produced runs. The good thing is that you can wipe off all the paint you just shot and start again if you find the results

I had to do that the first time due to thin paint. Thing sprayed like a porn star...

Wiped everything down and thickened the paint. The Turbine will get it going but you aren't doing a large project like that. Just real thin and real narrow pattern.

 

[jinjuku]

HVLP isn't made for house paint, or anything with that voscosity- they're made for paints that are thin enough for overspray to be a problem. This causes two issues- one is that it wastes finishing material and the second is that it gets all over everything when used in a non-production environment. In a real, industrial spray booth, some of the overspray can be collected in the filters but it still wastes material. An airless sprayer for house paint has a small piston that opens and closes at high speed to allow the pressurized paint to atomize. The surface tension and droplet size keeps overspray to a minimum.

The great thing about automotive finishes is that most can be wet-sanded and polished to a high sheen. That alone is worth their use. Go to a music store and look at the guitars- they may have had some lumps and blemishes after the initial spraying but they don't when they're done. Pre-catalyzed lacquer is pretty standard in cabinet making- the results are beautiful, if the facility is clean and good technique is used.

Well, I don't have a production environment. The first time on my baffles I had roller marks. Didn't even matter how light a touch and the microfiber roller I used. You could still pick out the roller marks.

So I sanded back down.

2nd time was thinned paint. That just splattered everywhere.

So I sanded back down and resealed the cut MDF edge (50:50 water:glue).

3rd time I wised up and grabbed a bunch of scrap card board and used straight up paint and started thinning until it laid down properly. It was still slow.

I think next time I will try automotive paint. I have been reading (last night) where one guy really sat down and figured the Harbor Freight HVLP. Also with their compressors you have to be choosy (no surprise there). The 2.5 hp 21 gallon is a oil lubed model and supposedly is reliable for medium around the house usage.

 

[highfigh]

Well, I don't have a production environment. The first time on my baffles I had roller marks. Didn't even matter how light a touch and the microfiber roller I used. You could still pick out the roller marks.

So I sanded back down.

2nd time was thinned paint. That just splattered everywhere.

So I sanded back down and resealed the cut MDF edge (50:50 water:glue).

3rd time I wised up and grabbed a bunch of scrap card board and used straight up paint and started thinning until it laid down properly. It was still slow.

I think next time I will try automotive paint. I have been reading (last night) where one guy really sat down and figured the Harbor Freight HVLP. Also with their compressors you have to be choosy (no surprise there). The 2.5 hp 21 gallon is a oil lubed model and supposedly is reliable for medium around the house usage.

One thing about spraying paint is that the air needs to be totally clean- that means no moisture or oil. This also means that small compressor tanks will produce more moisture in the pressurized air because of the sudden drop in absolute pressure in the tank- reducing the volume of air in a tank by any amount is a higher percentage when a small tank is used, so the condensation will be greater, too. I have a 60 gallon tank and when I use my blow gun, I always see water vapor coming out the nozzle if I open it for more than a few seconds. Industrial/commercial shops have air dryers and all kinds of efficient filters to remove the moisture and oil but that's not practical for a DIY application and that's why a turbine works better for HVLP. Fortunately, Harbor Freight, Rockler and other stores sell low priced versions that work well enough. With the right tip, they'll even spray house paint.

Automotive paints are very easy to sand and polish, in most cases. They'll polish to a much higher sheen than latex/acrylic and if you want the finish to look more like custom cabinetry, look into Sherwin-Williams pre-catalyzed lacquer. It has a decent shelf life and looks great.

The gun I bought is the 43430.

Look for a book on finishing by Jeff Jewitt.

 

[jinjuku]

One thing about spraying paint is that the air needs to be totally clean- that means no moisture or oil. This also means that small compressor tanks will produce more moisture in the pressurized air because of the sudden drop in absolute pressure in the tank- reducing the volume of air in a tank by any amount is a higher percentage when a small tank is used, so the condensation will be greater, too. I have a 60 gallon tank and when I use my blow gun, I always see water vapor coming out the nozzle if I open it for more than a few seconds. Industrial/commercial shops have air dryers and all kinds of efficient filters to remove the moisture and oil but that's not practical for a DIY application and that's why a turbine works better for HVLP. Fortunately, Harbor Freight, Rockler and other stores sell low priced versions that work well enough. With the right tip, they'll even spray house paint.

Automotive paints are very easy to sand and polish, in most cases. They'll polish to a much higher sheen than latex/acrylic and if you want the finish to look more like custom cabinetry, look into Sherwin-Williams pre-catalyzed lacquer. It has a decent shelf life and looks great.

The gun I bought is the 43430.

Look for a book on finishing by Jeff Jewitt.

I thought you could get decent filters/water trap for run of the mill compressors?

How well does a turbine HVLP do with automotive paint? I might as well purchase a pint or quart and test out.

 

[jinjuku]

Look for a book on finishing by Jeff Jewitt.

Just requested a spray finish book by him from the Library. Thx!

 

[Swerd]

If you've already spent money and time on HVLP, it might be worth $25 for this book & DVD.

Spray Finishing Made Simple by Jeff Jewitt

 

[jinjuku]

If you've already spent money and time on HVLP, it might be worth $25 for this book & DVD.

Spray Finishing Made Simple by Jeff Jewitt

I have the book on order at the library...

 

[highfigh]

I thought you could get decent filters/water trap for run of the mill compressors?

How well does a turbine HVLP do with automotive paint? I might as well purchase a pint or quart and test out.

Auto paint shops use an air dryer, which heats the air and then it passes through a large chamber filled with desicant and that works so much better than the little inline filters it's not even possible to describe, other than thinking of it as desert air that has been dried.

HVLP doesn't really care what kind of paint it's spraying- as long as the tip/needle are correct for the viscosity and air flow, it will work better than a compressor (from the standpoint of overspray and making the EPA happy) and since compressors have been used for close to 100 years, the fact that painters didn't change jobs tells me that they work well.

When you go for the paint, buy a viscosity cup and ask a lot of questions. Masterfinish is a national chain and they have everything you will need, including a wide range of thinners.

 

[highfigh]

If it's not too late for someone to save a few bucks, here's a link with sale prices on a group of finishing books-
http://ebm.e.taunton.com/c/tag/hBOFbyXAri9kwB8cHd$At6AMb.Ari9kw9n/doc.html?t_params=EMAIL%3Dhighfigh%2540yahoo.com%26PASSWORD%3DAri9kwAt6AMbBOFbyXBrkusFl%2524BMIv%26SOURCE%3DWI

 

[jinjuku]

Just finished reading Spray Finishing Made Simple. That is a killer resource and very straight forward.

I love the cleaning agent tables...

 

[TLS Guy]

Before a paint job, I empty the compressor tank and drain it of water.

I have a 60 gallon tank. I have a dry line for spraying. This has a Dixon water filter a long way from the tank, in the line. You should not put the filter close to the tank.

I use two inline filters back to back at the sprayer as well.

I have found that works very well.