HVLP painting doors white

shartman · 02-15-2009, 08:06 PM

I am pretty new to HVLP cup painting. Trying to paint interior doors white. The doors look good when not under direct light. However when I shine a spotlight on them you can definitely see the "stroke marks".

I am using latex paint with Flotrol and thinned down with water. Not sure what I am doing wrong.

Ideas?

Bob Mariani · 02-16-2009, 08:20 AM

using a latex paint is what is wrong. It will never spray well with a cup gun. Use acrylic latex at least, but oil is much friendlier with spray guns. These marks are from the paint "flashing" like drying to fast before coating the next pass. Seems like you have too much pressure for the viscosity of the paint.

shartman · 02-16-2009, 09:37 AM

Actually I believe that it is acrylic latex. What is a good pressure to set at the input side of the gun (trigger off)?

thanks

Bob Mariani · 02-16-2009, 10:36 AM

you want the pressure as low as possible and still allowing atomization. Usually use about 50-55 PSI with cup guns. Overlap by 1/3 with each pass. Be sure to maintain a wet flow. Put on at least 2 mil wet thickness with each coat. Oil will always yield a better spray with HVLP. I use an airless for latex.

DGideon · 02-17-2009, 10:18 PM

HVLP, I have three of them. Stains and oils are perfect. You just can't get enough material on the door unless you 2 coat with latex. Use an airless.with a 413-415 tip. Don't thin your paint. your doors will come out awesome.

waynech · 02-25-2009, 09:09 AM

Dgideon is right. Rent an airless. Its easy to use and you can spray the paint with-out diluting. Good luck.

slickshift · 02-25-2009, 06:32 PM

Well, sorry, HVLPs are not the best tool for this job (latex) by any means
In fact, it's a poor choice by a large margin
An airless is by far the best way to go if you want to spray this stuff
So first off, it's the wrong tool for the job

But...to answer your question with anything other than guessing, you'd need to post up exactly what product and tool you are using

Then, there's a quality issue
(which may not apply to you but I'd like to mention it here for other readers who may look for info but not post, and as it has popped up here numerous times)

By no means are most cup sprayers labeled as HVLP, and sold at HD, W*M, and some Hardware Chains, that attach to your compressor, true HVLPs
They are not the same tools your cabinet finisher, auto painter, or trim painter, are referring to (these come with their own turbine or compressor, and cost hundreds to thousands of dollars)

Most W*M/HD "HVLPs" are (cheap) cup sprayers that attach to your compressor, and have input/output controls- not the same thing

Don't get me wrong, they have their uses (I own more than one myself)
But this is not one of them