HVLP Help

[dancam]

Hey Guys,

Getting awfully confused :BangHead: with so many options for HVLP. I'm looking to get into spraying some finishes (hobby furniture) but don't know what to get.

I think a HVLP Conversion is probably the way to go but I'm unsure as to what size compressor I would need. I currently have an Emglo twin tank 1 1/2 HP that works well for general use (nail guns, staplers etc.) but is this enough AP for the PC conversion gun that a lot of folks have purchased.

Any help adice would be greatly appreciated.

Thanks,
Dancam

 

[Gofor]

With HVLP, you are as much concerned about volume of air (cfm - cubic feet per minute) as pressure (psi). For HVLP (High Volume, Low Pressure) you will need 7 - 8 cfm at 40 - 50 psi for a full sized gun, like a Binks Mach 1. I doubt a 1 1/2 hp compressor will give you that (probably closer to 3 cfm). Check the specs your compressor and match them against the requirements for the spray gun.
May want to do a search on the forum on HVLP and another for LVLP. LVLP is rather new, but may be more suited for your other equipment.

Hope this helps

Go

 

[junquecol]

I have an Apollo gun and a home made turbine. The turbine uses an Ametek vacumm cleaner motor that I bought from Grainger. Turbines systems are the way to go. You can pack turbine and gun up and spray at jobsite if necessary. Motors are almost always 110volt. I build cubbies for local YMCA. They are basically a set of 16" nomiinal size boxes. An eight foot unit contains 24 openings. Went I changed from regular air gun to HVLP gun, I cut my varnish requirements by over 50%. When you are talking about $50 per gallon, that is a lot more money IN MY POCKET.

 

[Redfish]

I occasionally use an HVLP gun in our cabinet shop for small items (we use the air-assisted airless pump for the big stuff).

Couple of tidbits for you.

1) I wouldn't use a compressor smaller than *roughly* a 5 horsepower with a 20-gallon tank. I use, and know SEVERAL finishers that use the Craftsman 5 hp with the 25-gallon tank version, it's a good compressor (noisy as heck but tough). I believe ours is rated at 9-10 cfm, which runs our HVLP just fine.

2) Get a GRAVITY FEED gun. There are some siphon-feed (ie, cup on the bottom) types. The siphons are a VERY, VERY slow painting gun--- that 15 psi that HVLP's run off just doesn't have much suction to it. The gravity feed, cup-on-top models have gravity on your side.

3) Get to know your thinners well. If you spray any lacquer-types, have some standard thinner and some retarder handy. If you spray polyurethane, thin it with Naptha, which flashes off a good bit quicker than mineral spirits--- leaving you less prone to runs and sags versus thinning with mineral spirits.


Lastly, for the price, the Harbor Freight gravity-feed HVLP isn't a bad gun. For hobby use, that is what I'd use.

 

[jmauldin]

I agree about the size of the air compressor. A l 1/2 hp just can keep up with the air demand. I would opt for a 5 hp with a 60 gal. tank. Run your air lines out of 1" copper and you double the size of your resevior. I have both air and turbine and prefer the turbine 2 to 1 over the air compressor. As was said, it can be portable if need be. A turbine "warms" the air and aids in drying the finish quicker. (BTW, in addition to thinning with naptha, add a small amount of Japan Drier to your finish. All things considered, it will make varnish dry in a couple of hours or less. Not quite as fast as lacquer, but a whole lot better that waiting 6 hrs. or overnight.) Now, as to the gun. Yes, a lot of folks use gravity fed and love it. Mostg body shops use them. However, if you are spraying furniture, try to imagine spraying the inside of chair legs with a gravity gun. It can't be done!
I use suction cup and have never had a problem.
Jim in Mayberry

 

[dozer]

Just go to harbor freight and buy a $20 paint pressure pot and hook that to the compressor then your gun to the pressure pot. I had and Accu-Spray set up like that with a 1 1/2 hp compressor and sprayed cabinets and trim everyday for over 8 years and never once had a problem with the compressor.

Just seems to me like buying a $20 pressure pot is a whole lot easier and cheaper. If you need help getting it set up and using it shoot me a pm and I'll be glad to help you out.

 

[mkepke]

Well, I am definitely an amateur at spraying (maybe somebody could conduct a spraying workshop :eusa_thin ) but here's my $0.02 after a couple years of HVLP use.

A turbine-based HVLP is your simplest option. It's self-contained and pretty cheap compared to the cost of a new compressor.

On the other hand, I have found the performance of my HVLP (CH 2500 with siphon gun) variable, especially since I need to do my spraying outside. The combination of variable ambient temperatures and temperature rise in the turbine's air-stream makes consistent spraying challenging. A conversion gun would eliminate the heating issue, but at the cost of mobility.

-Mark