[zenfishbike]

I intend to spray an automotive finish on the front baffle of my Otica's and something lesser on the backsides and insides of OB subs. It will be my first time using automotive paint so consider me a novice with that. Before I get to those however I have a need to spray some bathroom cabinets with some urethane alkyd enamel. I'm looking for an HVLP gun that can do all this but there are so many considerations and choices I thought I'd reach out and see if any of you could help me cut to the chase. For these small quantities of paint I want a gun that uses a cup (1 quart?) but don't know if it should be gravity or siphon for example. I already have two compressors to choose from, one large, one small. I tend to consider tool purchases an investment so I'm not looking to cheap out here however I also don't want to pay dearly for professional duty equipment that won't get used very often in my home hobby environment. Any and all tips/suggestions to help me narrow the options greatly appreciated!

[dallaire1]

I have used a Finex automotive HVLP and like it quite well. A good model is about $350.00 the thing about the High Volume Low Pressure system is that most people don't realize just how much "volume" of air your compressor MUST be able to keep up with. You may only need a few pounds of pressure to atomize properly reduced automotive material, the thing is "keeping" the flow of material atomized. That is what requires a lot of CFM on your compressors part. Perhaps you are already aware of these issues. I have done a lot of finishing with pre-cat lacquers from Mohawk that provide an amazing finish when shot through a small airless with a double orifice reversible tip, say like a .210 or so. Anyway just some considertions. 

[zenfishbike]

I have used a Finex automotive HVLP and like it quite well. A good model is about $350.00 the thing about the High Volume Low Pressure system is that most people don't realize just how much "volume" of air your compressor MUST be able to keep up with. You may only need a few pounds of pressure to atomize properly reduced automotive material, the thing is "keeping" the flow of material atomized. That is what requires a lot of CFM on your compressors part. Perhaps you are already aware of these issues. I have done a lot of finishing with pre-cat lacquers from Mohawk that provide an amazing finish when shot through a small airless with a double orifice reversible tip, say like a .210 or so. Anyway just some considertions.

Thanks for this info. I assumed my large compressor would be sufficient but maybe not. It's 30gal, 6HP, 6.4 scfm @90psi, 8.6 scfm @40 psi. I see that "Most HVLP spray guns will use 10-14 scfm at 40 psi". Mine's a tad short of that however I see a few Finex guns that want about 7-9 scfm @29 psi. It seems that scfm rises as psi declines, if true perhaps my compressor would meet or exceed these Finex gun requirements. Jeez, I wish all this was clearer....

[Peter J]

Sometimes painting something smaller like a speaker, one can cheat buy using additional air storage, so there's more reserve before your compressor is triggered on. Although this forces you to wait for compressor to air up additional storage before cycling again...not always ideal. Air storage can be as simple a daisy chaining compressor tanks or you can run two compressors simultaneously. Perhaps borrow or rent.

I'm assuming you're looking at gravity fed guns, which are easiest to take care of. I've had decent results from Devilbiss Starting Line stuff. It's not a Sata, but the tool is only part of the equation. Especially if you intend to cut and buff final clear coats. They have some kits with different tips which you're going to need. 1.3-1.4 tip for the automotive color and clear, but I doubt you'd be able to spray the alkyd very well. For that I think you'd want something intended for goopy primers...around 1.8 or so. Airless tips are numbered differently than gravity feed HVLP. It can be confusing.

Homestead might be worth a look too, I believe they have some guns for smaller compressors.

https://homesteadfinishingproducts.com/products-we-offer/hvlp-spray-equipment/qualspray-hvlp-guns/

And just so you know, I doubt your compressor is actually 6HP if it plugs into a 120v wall plug. Just not electrically possible. But it is possible to speed a compressor's motor up to where it specs higher. There's no agency to prevent it and it sells compressors. It's clever but not honest.  Forget those HP specs and look at scfm which is a better indicator. For comparison I have a huge old compressor with a 5HP motor. I imagine it puts out 12-14 cfm but runs on a 40 amp 220v dedicated circuit.

[nlitworld]

Now we're talking, somebody actually painting up some speakers properly! So you've had some good advice so far with people recommending the Finex FX3000 or the Devilbiss Starting Line. Ideal would be a 1.3mm nozzle (not a fan of 1.4s as they put out too much material and don't atomize as nicely as they should). Both options should be had around the $200ish area. Both of those operate best around 27-30psi at the gun. For these, ideal compressor would be 60 gal 5hp to properly keep up. As mentioned previously it is possible to let a smaller compressor pump back up, just not ideal.

Next order of business is your liquid materials. You will definitely want to spray your speakers in a base/clear rather than a single-stage that comes out directly glossy. Think of single stage like whistling, juggling and doing taxes all at the same time. Base/clear makes it to where you can simplify steps of first focusing on coverage and metallic orientation if doing a metallic color. Then later focusing on smooth passes of clearcoat to make it shiny. Plus if you need to wetsand and polish it is a hell of a lot more forgiving for that too. Just curious, what part of the country are you in? Certain states and counties have some tighter voc limitations on their paints so I could walk you through your options if that's the case.

Last piece of advice is that prep is everything. Take way more than enough time to set up your garage space to be a clean room with good low air velocity ventilation. In a pinch, a lot of box fans turned on low can do the trick, two at the back pushing air across the project, and the rest at the garage opening to pull out exhausted fumes. Plastic sheeting taped to the walls to keep the dust down is a huge help as well.



Also discussing prep, make sure to use wax and grease remover to wipe down your project, lint free spunlace towels to do the wiping (one wet and one dry in a wax-on wax-off scenario) and use a tack rag to get any last contaminants off the surface.

And finally, be careful with your safety making sure to wear a cartridge respirator and have some freakin fun. Message me if you have any questions along the way and I'll walk you through the process.

-Lloyd

[zenfishbike]

Great replies guys, thank you very much. Homestead makes an reduced pressure model for lower capacity compressors which sits between their HVLP and LVLP models. They say it's their best for automotive paint....interesting. While it may not be ideal for that it may be a good compromise for my level of home hobby performance. I may give it a go.

I don't go into this with professional result expectations. I've scoured this forum and watched endless videos on automotive painting. I will do a two part base/clear application. I'm easily paralyzed by too much information and analysis so I'll jump in, swim and flounder, and be satisfied with the outcome. I listen in a dark room most of the time anyway!

[nlitworld]

I always joke with the customers at work, worst case scenario is you sand it down and try it again. 

Looking at their gun lineup, their QS600WB in a 1.3 would be an OK compromise. Just take your time and have some fun. You'll get a feel for it all on your cabinet project so that way you can be prepared when it comes to the real project.

[zenfishbike]

Looking at their gun lineup, their QS600WB in a 1.3 would be an OK compromise. Just take your time and have some fun. You'll get a feel for it all on your cabinet project so that way you can be prepared when it comes to the real project.

That QS600WB looks like the ticket to ride but currently out of stock unfortunately    I guess I'll look at other manufacturers that have guns in stock. The LVLP guns seem like they would be fine since I'm not concerned about high volume production work, agree?

[zenfishbike]

So the plot thickens. The deeper I look into this I now find that moisture in the line from the compressor is a thing but I'm not finding (surprise) a clear solution in the case of using a small 30 gallon compressor with a LVLP gun. For small jobs like a few cabinet doors and the front baffle of the NX-Otica do I really need to be concerned about this and, if so, can you guide me to (hopefully) a simple solution? I'm not going to install 30 feet of black pipe to cool the air for example! I do have 50-70ft of hose however.

[Peter J]

Yep, it's a thing. Especially if you live in humid climate or are running the peewaden out of your compressor. But not to hard to deal with for small jobs. Google "inline desiccant filter" and Bob's yer uncle. Essentially, you can have a baby one at or near the gun or a mama sized one at the other end of your hose. Beyond that, you can get papa bear desiccant ones, refrigerated dryers or this is a kinda unique one I have on CNC.

https://www.laman.com/products/extractor-dryers

For what you're doing,  the inline at the gun kinda thing would be fine.

[jdoyle]

Mount one of these at the base of the gun:

https://www.tptools.com/Economy-Spray-Gun-Filters,2504.html?b=s*Disposable+moisture+filter

[zenfishbike]

Thanks guys, I'll look into a simple (thank heaven) inline filter. Fortunately I live in a relatively dry climate high in the southern Colorado Rockies where humidity hovers around the low to mid 20% range. (Now please don't tell me that 7500ft of altitude is a thing now )

[zenfishbike]

Just to keep this thread informative for others the latest is that the QS-600WB LVLP is not in stock so I went with the slightly more expensive (and better built I presume) AM-5008/P LVLP kit which comes with 1.3mm, 1.8mm, 2.5mm tips. Hoping the 2.5 works for latex/alkyd and expect the 1.3 to be the ticket for 2 part automotive based on your recommendations. I'll provide updates to how this setup works after I've used it, alkyd in a month or two, automotive next spring/summer.

https://homesteadfinishingproducts.com/products-we-offer/hvlp-spray-equipment/qualspray-hvlp-guns/