Replies

1. 
   DonStephan | Oct 05, 2005 01:32am | #1

   Check the FWW magazine index for an article on spraying basics by Jeff Jewitt within I think the last 6-15 months. He gives very detailed info on setting up a spray gun, including how to minimize bounce back. Hope this helps.

1. 
   Quartersawn | Oct 05, 2005 02:11am | #2

   See FWW magazine, April, 2004.

2. 
   KesslerCraftsman | Oct 05, 2005 04:50am | #3

   Hi Stevo,

   I'd call Jeff Jewitt and talk to him personally.

   "Pressure" can mean many things.  I have an Asturo ECO conversion gun (which I LOVE, BTW) and the tank pressure guage (which is miles away from the gun) is 50 pounds, but the little pressure guage going into the gun (and that's the most accurate way to measure this...IMHO) WITH the trigger pulled to "spray" position is 12 pounds..and I get a sweet off-of-the-gun finish with Nitro lacquer every time...check out the furniture on my website...www.kesslercraftsman.com

   Jeff will give you a credible answer!

   lp

3. 
   TomT226 | Oct 05, 2005 02:12pm | #4

   Lot of it depends upon needle/cap size, and material being sprayed.  I've got a Asturo 9010, and use a remote pressure pot, and a screw-on pressure pot.  I usually spray WB and unthinned nitro lacquer with a 1.0 MM needlw/cap at about 25 lbs.  Outside temp, humidity, and your "fan" setting will affect the appearence of "orange peel."  Do call Jeff.  He does give good advice.

4. 
   mudman | Oct 05, 2005 06:55pm | #5

   as you will soon, or already have, discover there are many variables in spray set ups. viscosity, flash time of solvents, retarders, pressure, cap size, fluid flow and pressure, size of spray pattern, ambient air temp, gun temp (I have a turbine system and the gun heats up changing how much flashes off in the spray). And there are more. Compounding that is that the instructions from the finish manufacturers and the gun companies are never agree. It will take experimentation. For me the most importaint thing is to get the viscosity into the recomended range. After that try to find the combination of fluid flow and air pressure that gives the best compromise of surface quality and over spray.

   Good luck,

   MIke

1. 
   stevo1952 | Oct 05, 2005 09:27pm | #6

   Thanks everyone for your advice. I have had lots of spray experience with airless systems in my youth and realize that it is a complex topic.
   I will take your advice and follow up.
   My real question is: How much bounceback are people getting with HVLP if that can be answered? It sounds like to me that the product and the bounceback should be greatly reduced from a normal air driven sprayer.thanks again everyone

1. 
   mudman | Oct 09, 2005 12:03am | #8

   I have a Fuji 4 stage and the overspray and bounce back is less than it was with the standard guns I used. However I do still get overspray.

   I dont know how to quantify it though.

   Mike

2. 
   TomT226 | Oct 09, 2005 03:25pm | #9

   Generally I get much less "bounce back" with HVLP.  However, it depends on what and where you're spraying.  I generally up the pressure to spray acrylic on the outside of cabs, lower the pressure for the inside where the overspray is trapped.  The finer the atomization of the material, the less "bounce back" you'll get.

2. 
   WillGeorge | Oct 08, 2005 08:41pm | #7

   as you will soon, or already have, discover there are many variables in spray set ups. viscosity, flash time of solvents, retarders, pressure, cap size, fluid flow and pressure, size of spray pattern, ambient air temp, gun temp WHY I sent my 'GOOD' stuff out to a PRO to do the finishing!

5. 
   WillGeorge | Oct 10, 2005 04:41am | #10

   This may be WAY off base because I only spray on occasion.. Usually brush/pad finishes..

   I have a 'L'-CheepO spray gun.. I was having problems.. I put a pressure gauge After the regulator (My compressor is crap also),,

   I noticed a pressure drop as I pulled the trigger.. I added a small 5 gallon air tank after the regulator and before the gun.. Seemed to help ALOT! Not sure how this applies to HVLP though?