Originally Posted by Ftoast
Because SF is also 31-33% water, do its 6th,7th and 8th+ coats require 1/2-1hours+ drying time as well?
I'm guessing this is an across-the-board aspect of spraying?
This also sounds like thoroughly cleaning the gun between every coat after the 4th/5th becomes mandatory from the waiting.
No, that is not the case at all.
The properties of the Glaze are much like Polyurethane, so one must imagine diluting Poly with 1/3 water content.
SF has far more a percentage of Acrylic Latex components...it's Poly content is much lower.
Water itself does not increase drying time, in fact the opposite is true when Dusting is employed, as the high water content allows for faster evaporation of sparsely applied coats. However the more layers applied over the multiple Duster process do tend to absorb more of the water content each subsequent coat adds, making drying "a bit" more protracted.
In truth, it's the actual drying conditions that make the real difference. Cool and / or humid conditions can greatly prolong drying times. In my cases as shown, I at minimum use a clean
18" Pole Fan set on Medium / High and "centered" on the screen at a distance of 6' to 8' away. If possible I up the room's temperature to 80 degrees (...or higher...) as well. With Fan & Heat combined, I get honest initial 15 minutes drying time per coat up to the 4th-5th coats, and at most 25-30 minutes drying time per coat for the rest. And I'm talking "DRY". The benefits are many...but paramount is the rapid shrinkage of the paint droplets works to flatten and smooth texture. Prolonged drying allows for the surface of Paint to develop a "skin" that creates texture,(...think: Scab ) while the underlying paint retains moisture that also adds weight to succeeding coats, and that accumulation can cause Orange Peel as well as sagging.
Now many, if not most cannot follow both those dictates, a Fan being the easiest to oblige. The "Fan only" method, when used under normal conditions, (70 degrees - 80% humidity) allows for initial 20 minute dry times and 30 minutes dry times for later coats.
As far as Gun Cleaning......first and foremost it's the type Gun used that dictates the needed cleaning regimen. "One Piece" Wagners tend to heat up the Gun Components, and cause "baking" within the Plastic Needle / Nozzle assembly, so rinsing between coats is advisable. The separate Turbine Guns with metal Needles are different. What with the SF being such a loose, water saturated paint, and with the lack of heat at the Nozzle, cleaning is initially limited to once after the first 3 coats, and once after each of the next 2 coat cycle.
But why the sad face? I mean really! All the Gun heads disassemble in about 30 seconds...and you just rinse the parts with a strong stream of water. Sheesh! All told it takes about 3-4 minutes. I can assure you it takes FAR longer to rinse a Roller! The latter being a lot messier to do as well.
In the end, if one wants absolute maximum assured performance out of a Gun, then they'll Man-Up and rinse the thing if the time between coats exceeds 30 minutes. (..one additional tip though...wipe the outside needle tip area immediately after each coat...)
Of course repeated use and familiarization makes both spraying and cleaning seem so much easier. That is why practice makes for perfect...and when one wants perfection in a surface, to not practice only means one is either too lazy or doesn't want to bother. One thing is for certain though...no one can say I never bother to advocate practicing, nor do I gloss over potential pratfalls. Why bother when in reality there are so few to worry about that to ignore those few is simply a case of not really wanting to do the best job possible. I repeat such instructions time and again because I want everyone's screens to be everything they can be. Mostly, that's what happens....but every now and again along comes someone who just ups and does it without checking, reading, or following the oft-repeated instructions. Then............there comes along the