Replies

1. 
   RalphBarker | Jun 02, 2010 08:48pm | #1

   entry-level HVLP

   First, let me warn you that I have no actual experience (yet) with HVLP sprayers. I did, however, do a little online research before ordering an Earlex 5000 recently. The impression I got was that the lower-priced units lacked versatility in terms of different needles being available for different materials. That might not be an issue for you if you plan to spray only water-based poly, and the unit you are considering is suitable for that purpose.

   Before making a final decision, I'd suggest that you do a Google search on "HVLP sprayers" and spend some time reading the articles, reviews, and specs for different models.

1. 
   user-87215 | Jun 03, 2010 09:14pm | #2

   I have used both turbines and compressor based, and think that compressor based are more flexible, and that the lower end turbines can have some problems getting good results with water based finishes.  The main issue with either is getting enough air. - with a turbine, you want a 3 stage motor for water based - with a compressor, you want something so that you don't have to stop spraying in the middle of a panel, because that can give you poor results.  My current favorite setup is an Asturo Eco  with a Porter Cable 25 gal tank with a compressor rated at 6.8   @ 90 psi.  I am a hobbyist, not a professional, so I am not shooting large jobs, but I can handle a table with no problems - the compressor may run a few times, but I never run out of air.  I just tried the Woodriver HVLP gun that Woodcraft sells for $35 - which is a great price, but is now on sale for $25. Some minor quibbles - there is very limited selection of needles ( most good guns have needle sets every .2 m so you can select the right set to deal with the viscosity of the finish -  the gun comes with a 1.4  - the next one is a 2.0,  I like 1.7 for waterbased in general - though in the few seconds I sprayed it, it handled Enduro precat unthinned, and didn't seem to have a problem.It doesn't appear to have a packing nut - which is adjusted to keep the needle from leaking, but my other guns have them, and I haven't adjjusted them, so this may or may not be a problem in the future.  I have read that oil free compressors aren't built for the long haul, so I would suggest oiled.   I haven't used a HF compressor , but they offer a 20 gal oiled, that puts out about 5 cfm at 90 http://www.harborfreight.com/air-tools/oil-compressors/3-hp-21-gallon-115-psi-cast-iron-vertical-air-compressor-94667.html

     According to Woodcraft, the gun uses 4.2 to 7 cfm, so the gun will use air faster than the compressor can keep up - but the 20 gal tank should keep you from having to stop mid panel.  For hobby  this should work because you aren't going to be spraying all that much in a row - for me I have a small corner I spray in, so I have to carry things in and out which gives the compressor time to recharge.  Sears  has a 25 gal tank with compressor rated at just under 6 cfm, so it should keep up pretty well , though it costs $469 - it has some good reviews http://www.sears.com/shc/s/p_10153_12605_00919541000P?vName=Tools&cName=Air+Compressors+%26+Air+Tools&sName=Air+Compressors&prdNo=5&blockNo=5&blockType=G5

2. 
   zgmc | Jun 05, 2010 09:19am | #3

   I don't know if you will get good results with a cheap hvlp, especially with waterbased clear coats. I have a graco 4900, with a  pressure pot, and spray only waterbased clearcoats. It is very tricky to get it dialed in. The air and fluid mixture needs to be just right, or you will experiance air bubbles in your finish, which makes it feel fuzzy, or terrible orange peel.  I believe that there are some reasonably priced systems out there that will work. There are even some advertised to be designed specifically for waterbased.  If  you get a turbine unit, go with at least a 3 stage.

1. 
   user-87215 | Jun 05, 2010 09:14pm | #4

   Woodriver sprayer

   Andrew,  you sent me a pm and I agreed to run some tests.  I sprayed a cheap luan plywood that I used to make a torsion box some time ago.  Overall, I am pretty impressed with the Woodriver HVLP.  I first tried spraying Enduro precat  ( 30 sec in a Ford # 4 )  It was 90 degrees outside and I had no trouble getting a nice sized fan.  I shot at about 20 psi and in terms of coverage I was able to do 30 inches by 40 inches - about 8 square feet ( overlapping each pass by 1/2)  before the compressor kicked on.  I may be wildly wrong, but I have a 26 gal tank, and with the pressure stops at 120 and cuts on at 100.  I think that means that it consumed about 4.6 cubic feet of air to do that.  If you get something with a 20 gal tank ( divide by 7.4 to determine cubic feet - 2.7 cu ft)   and it pressurizes to 115 and you can run it down to say 30 psi and still be able to spray - than would equate to about 15 cubic feet -  or about 3 times the area I sprayed,  So I think either of the 20 gal tank units should power this gun, the higher the cfm of the compressor, the less you will have to wait to have it catch up, but certainly doable.  I also sprayed some Hydrocote Resithane - which was pretty thick  ( 60 sec in a Ford # 4 ) and the fan width was more in the order of 5 inch, than the wider fan I got with the thinner stuff, but it ended up fine.    I have attached a picture that shows the aircaps - you can see the Asturo ( Black ) has the finest air holes ) but the Woodriver ( bottom air cap)  is pretty fine compared to the Astro which is an okay gun.  I also attached a photo of the finish - it looks pretty crappy in spots because I didn't do the surface prep I would have it this was something other than just a test of how much an air hog the Woodriver is.    So, if you can swing a 20 gal compressor, I would go with the Woodriver.  I don't have a pancake compressor, but I think you would spend forever waiting for it to pressurize the tank and if you ran out of air in the middle of a piece the results wouldn't be pretty.  I will try tomorrow to spray some solid lumber to get a better Idea of the type of finish I can get with the Woodriver  

   
3. 
   DonStephan | Jun 06, 2010 12:01pm | #5

   For a number of years I used a pancake compressor with an HVLP gun, BUT I bought a high quality gun Homestead Finishing (Jeff Jewitt) said had a very low air consumption rate, and I added a storage tank from Grainger between the compressor and gun.

   Seems I've read in different articles that some turbine guns harder to use with WB because they heat the air and/or something about constant air flow at the tip?

   Jeff Jewitt's Spray Finishing book and video address both compressor and turbine spraying, and might be a good source of info before making a purchase.

   I've trusted Jeff implicitly for a number of years and have never had any regrets.  It's also a great comfort for me to be able to purchase all my finishing equipment and supplies from one source.  You might check the Homestead Finishing web site to see its offerings for compressor and turbine systems.  Just my two cents.

1. 
   user-87215 | Jun 06, 2010 08:01pm | #6

   Andrew,  I finished some test samples today and the Woodriver did a pretty good job of spraying a thick waterborne ( Hydrocote Restithane)  I have attached a photo of the piece right after I sprayed it, you can see some orange peel but that is pretty common with waterborne when it is wet.  I have also attached a later photo  after the finish dried and you can see the orange peel has disappeared .   The one other thing I found out is that the packing nut ( which in most guns can be adjusted so the the needle moves smoothly but fluid doesn't leak out the back ) can only be reached from inside the gun with a special adapter that comes with the gun - but unfortunately, something is the wrong size because I can't get it to turn.  I bought a second gun and it has the same problem.  Overall though I would say it is a pretty gun at $50, very good at the normal price of $35, and outstanding for the sale price of $25.

   
1. 
   andrewthecb | Jun 08, 2010 02:51pm | #7

   Thanks for the help

   With everyone’s advice I have decided to go with a compressor upgrade and the woodriver hvlp gun.  I purchased a brand new Puma 20 gal, 2 hp, 5.5 cfm @ 90 psi, and 7.1 @ 40 psi.  Its belt driven and oil lubricated.  Found this steal on craigslist for $300!  BRAND NEW!  I have not purchased the spry gun yet but will before the sale ends on the 26th.  I know this is more expensive than what my first question asked but i thought a good compressor was a smart investment.  Thanks again