Guest ZPhreak Posted August 20, 2003 Share Posted August 20, 2003 I'm going to buy a paint gun so I can spray the primer. What type of gun should I be looking at? Siphon or gravity fed? Quote Link to comment Share on other sites More sharing options...
Tim240z Posted August 20, 2003 Share Posted August 20, 2003 Gravity feed HVLP. Harbor Freight has some pretty decent ones: I use this one for Primer: http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=43430 Tim Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted August 21, 2003 Share Posted August 21, 2003 While we are the topic of paint guns.....I started to undercoat some moulds I have been making the other day and my compresser doesnt seem to keep up. The gun was just a real cheep one that came with a starter pack air kit i bought years ago. Can changing the tip size make a change on the air requirement? What gun uses the least amount of air. The compresser is old but was rated above 12 cfm. It is a single cylinder howerever. I am hoping I wont need to replace it to paint the car later. Cheers Douglas Quote Link to comment Share on other sites More sharing options...
Tim240z Posted August 21, 2003 Share Posted August 21, 2003 My gun (above) is HVLP, and uses only 10psi at the gun. The older High pressure guns use a bit more pressure. The gravity feed guns seem to need much less pressure. Maybe RacerX will chime in. I do not have a large compressor, but at such low pressure it keeps up just fine. Tim Quote Link to comment Share on other sites More sharing options...
dmyntti Posted August 21, 2003 Share Posted August 21, 2003 I am having trouble with my new HVLP gun. I have a large two stage compressor and plenty of pressure. My pressure is dropping at the gun when I spray. I believe that I need to replace the regulator with a larger one. I never had this problem with my siphon feed gun but the HVLP has way less overspray. Quote Link to comment Share on other sites More sharing options...
Owen Posted August 21, 2003 Share Posted August 21, 2003 Tim is right about the newer guns only needing 10 PSI or so, the PPG paints I use say 8-10PSI. This is at the gun's tip, not inlet pressure. Changing tips won't change your air requirement. Try a gun with a lower requirement, such as the Sharpe Platinum. You can get them for less than $200 direct from the mfr. dmyntti, How do you know you're losing pressure when you spray, do you have a gauge at the gun? What I do is pull full trigger and then adjust the regulator of the compressor to give me 8PSI at the tip, I have a Sharpe gauge/regulator at the gun which shows PSI at the tip. Now if I could only paint good Owen Quote Link to comment Share on other sites More sharing options...
dmyntti Posted August 21, 2003 Share Posted August 21, 2003 I do have a guage at the gun. When I adjust the regulator to give me correct tip pressure (i think it was 15 psi) I have 70psi at the regulator. That seems like too much drop to me. I also ended up with orange peel and sagging. I am sure much of the results were my own inability to paint but this gun seemed inconsistant. My old syphon feed gun sprayed the same paint perfectly when I painted the doorjambs and under body. Quote Link to comment Share on other sites More sharing options...
zcarnut Posted August 21, 2003 Share Posted August 21, 2003 Passing note here: If you plan on doing a lot of painting, then you should be using a different gun for primer painting than the gun use use for top coats (color coats). Reason being is that primer paints have a larger precentage of solids and will wear the gun tip orfice more. Save your "best" gun for the top coats. "Primer guns" can be of a lower quality. I use one of the cheap [pressure] import guns for my primer work. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted August 21, 2003 Share Posted August 21, 2003 Passing note here: If you plan on doing a lot of painting' date=' then you should be using a different gun for primer painting than the gun use use for top coats (color coats). Reason being is that primer paints have a larger precentage of solids and will wear the gun tip orfice more. Save your "best" gun for the top coats. "Primer guns" can be of a lower quality. I use one of the cheap [pressure'] import guns for my primer work. Excellent point. That's exactly why I use the cheapy HF gun for primer. I will use the DeVillbis for color and clear. The pros actually use a different gun for each color, and one for clears.....and their guns cost in the $500+ range Tim Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted August 21, 2003 Share Posted August 21, 2003 Thanks for the replies, guys. I was always planing on a new gun for the top coats, now I have a better direction to look in. The thing is thathat you can spend so much $$$ that it would have been cheeper to pay someone else to do the final spray. Also the requirement for a air supply and its accociated gear for the sprayer to remain healthy with the better paints soon adds to the costs. Still working on a solution for converting my orchard spraying mask witha different typr of disposable filter. Might work. I just dont want to find out it didnt the hard way Douglas Quote Link to comment Share on other sites More sharing options...
Owen Posted August 22, 2003 Share Posted August 22, 2003 Oh yeah, costs add up. But once you're set to spray, you can always whip out the gun and spray something instead of taking it somewhere. I'm thinking of selling my fresh air setup (HobbyAir) if you're interested, it's only a year old. Owen Quote Link to comment Share on other sites More sharing options...
Guest freakypainter Posted August 23, 2003 Share Posted August 23, 2003 HVLP guns (high VOLUME low PRESSURE) will not perform properly under the same conditions as a conventional gun. An HVLP needs more volume of air. How do you achieve this? First use an air hose with atleast 3/8 inch INSIDE diameter, second go to your local paint supply store and tell them you want the couplers for an HVLP, a female for the hose and a male for your gun. They also have a larger INSIDE diameter than the standard fittings. You will also want a good quality air regulator attached to your air compressor not the end of your gun. Then you must practice, first make sure that your fan width is all the way open (as wide as it will go). I personally use SATA NR 2000 HVLP with a digital guage built into the handle of the gun and I use a regulator inside the paint booth to adjust pressure. As far as having 10 psi at the cap in my opinion is too much. In order to get 10 psi at the cap of my SATA the guage in my handle says 60 psi. An HVLP does not need that much pressure to properly atomize the paint. At 60 psi what you end up with a very dry spray pattern. I spray my basecoat (color) at 20 psi at the handle and my clear/primers at 30 psi at the handle. Again, using an hvlp is alot different from a conventional gun and takes alot of practice. the best advice I can give you is to buy a used hood from a salvage yard and practice with the hood both laying down and standing up. Also pay real close attention to your spray pattern, everyone recommends a 50% overlap. Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted August 23, 2003 Share Posted August 23, 2003 Thanks again, Owen I could be interested in the air set up. Shiping to New Zealand is always expensive so let me have a look into what they are worth here. Freakypainter... Practice I will get. I need to finish my race car first so I will get tonnes of practice on that. The paint quality needent be perfect on it. I also have a lot of furnature that i am building for our new house so some of that will work nicely as pratice as well. Its kind of looking like I should regulate the old compresser to runing tools and try to find a cheep three phase one. Doest any one know if you can change a compressors performance buy changing the pully wheels ratio so the pump its self works harder? Cheers Douglas Quote Link to comment Share on other sites More sharing options...
dmyntti Posted August 24, 2003 Share Posted August 24, 2003 Good information guys. I guess when I set up my new garage a will use a larger air line, fittings and regulator. This should give me more consistant painting. Thanks for the info. Quote Link to comment Share on other sites More sharing options...
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