Effects of too-big HVLP nozzle?

[Scott Gardner]

What are the expected symptoms of using a too-big nozzle with an HVLP gun? I just finished my first practice project, and everthing went great except for some orange peel in the clearcoat.</cr>
I was using a 1.6mm nozzle, since my Sears HVLP gravity-feed gun only came with 1.6 and 2.2mm nozzles, and according to Sears, no other sizes are available. Most of the people I see on this board are using 1.3 or 1.4mm nozzles for their BC/CC paint jobs. What's the difference in the end result between using a smaller versus a larger nozzle?</cr>
Also, what's the most common cause of moderate, uniform orange peel over an entire paint job? The troubleshooting charts I've seen are either too vague, or in some cases, even give conflicting causes.</cr>
Thanks,</cr>
Scott

 

[rex]

I don't know HVLPs but it sounds like the tip's too big or you need a little more pressure.You need air volume for these too so if you're using 1/4" air line you might want to go to 3/8.A lot of things cause peel but it sounds like you're not getting enough atomization.Fisheye eliminator will add a little peel to it too.

 

[shaunboy]

The fact is that hvlp is trickier than conventional .
You need to spray closer and faster.
Ive used hvlp for years now and was using 1.4tip untill about a year ago.
Now i use 1.6tip
This definately blows alot more paint out and will create peel if not carefull.
Is a sears gun topline or cheap?
My devilbiss GTI cost me $650 and i tried some cheaper $200 copies and they were 3times cheaper and 3times not as good.
For me I eliminate as much orange peel from the gun finish as possible by using a slow hardener and almost no reducer at all and bump the pressure up a bit and spray the clear on like theres no tomorrow

and give plenty of flash off in between coats.
This method can be risky if you arent used to it because when it runs it @#$$$% runs

Also most of the show bikes and cars that you might see have been flattened ,cut and polished to eliminate any peel.

 

[Mitchb71]

You are gonna get peal no matter what. They chemical makeup of the clears now a days makes everything evaporate. Every now and then you get one that can fly but, ive never seen one leave without getting sanded and buffed. The orange peel is meant to be there truthfully. It gives the paint job dexterity and strength. Look at the vehicles on the lot at your local car dealer. They are orange peely as hell.