I want to begin finishing in my own shop. I have outsourced in the past, but for small jobs I often can't afford the cost or the lead times. I am usually doing small cabinets or pieces of furniture. I have been finishing by brush, but I really want to begin spraying to take my quality and productivity to the next level. Before I take the plunge and purchase new equipment, I have some questions.
First off, I have been looking at HVLP or LVLP guns to run off my existing compressor. It's a medium size compressor supplying 6.3CFM at 40psi and 5.3CFM at 90psi. Do you think this compressor is big enough or should I upgrade? Do I need to add any filters/dryers to this compressor? It is an oil-free compressor and I'm spraying almost all waterborne products
Regarding the gun choice, I will be spraying mostly waterborne topcoats and dyes with the occasional shellac job. My local finishing supplier carries Graco and Kremlin. Can anyone recommend a specific model and price estimate? I'm looking for a gravity feed gun that I can use the 3m PPS system with.
Is there anything else I should be thinking about? I'm open to making the investment, but I also don't intend on using this every day. I'll probably only use this a few times a month, but I want good results when I do use it!
From contributor G:
6.3CFM might provide enough air with the right LVLP gun. It won't supply a HVLP. I have a Kremlin and it cost me about $1850 with the MXV gun. I changes the way you spray. If you want to spray in house this is where you need to go. Mine paid for itself one the first kitchen job in time savings alone. Your compressor will supply enough air to run a Kremlin.
Guns are generally rated for use in an automotive finishing environment, where typically one or more large pieces must be sprayed in a single session, so continuous airflow requirements are a bit higher than what a solo woodworker would typically use (production woodworking setups are a bit different). That means you can usually get away with a gun rated 1 to 2 CFM more than what your compressor can deliver - you may just have to pause occasionally to let the compressor catch up. So, look for a gun rated 8 CFM or less.
You will probably want a selection of needle/nozzle setups that matches the range of fluids you are spraying. Waterbornes can usually be sprayed with a 1.4 mm n/n set in a gravity gun, although specific products might be a bit higher or lower. Stains and dyes usually work best with smaller n/n sets - 0.8mm or 1.0mm. Shellac - depends on how heavy a cut you spray. So, whatever gun you pick, make sure you order it with an appropriate range, or at least know that you can get sets in the appropriate range at a later date.
I'd suggest paying a visit to SprayGunWorld.com to do some research on gun models. They carry a wide variety, and with a bit of poking around, you can find out CFM requirements, N/N ranges, suitability for particular fluids, etc. They also have a "Wood Wizard" section where you can get some gun recommendations based on your compressor, budget and type of coating being sprayed. I'm not affiliated with them nor have I ever done business with them, but their website is a free source for some basic info on guns, accessories and spraying requirements for various coatings.
You will need to factor in some kind of filter, even if your compressor is oil-less. You can get disposable desiccant filters that work reasonably well, but over the long run, they are costly if you spray much. A better option is to have a wall-mounted filter setup, probably starting around $100, including fittings, etc.
You might want to think about a turbine unit, although good ones are a bit more than the figure you indicate. Pros: don't have to worry about filters, compressor size isn't an issue and they are also portable. Cons: noisy, less flexibility in gun options, and if you do longer spraying sessions, they tend to heat up the air supply which can cause issues. Personally, I use an Iwata LPH-400. I have a large compressor, so can't comment on how it works with a small one, but it is sold as an LVLP gun, so is probably suitable. I spray shellac (1.5 lb) using a 1.2 n/n set and waterbornes using a 1.4 n/n set, and both work very well.
I also have an HVLP gun that came with a 1.4 n/n setup, and it sprays waterbornes almost as well as the Iwata. No n/n options, so it is lousy at spraying the shellac. Those two guns are pretty much at the opposite ends of the price spectrum, yet both deliver a high finish quality for most of my topcoats. The Iwata is more versatile due to the availability of different air caps and n/n sets, and is definitely better made. But keep in mind that the customer isn't really interested in the gun you use, just the end result.