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I started rolling the 1x4 foot test panel at 8PM tonight; that was a mistake, I'm too used to spraying. It turns out I have to wait several hours between coats to roll when I am used to around 10 minutes between coats when spraying!

I chose to use a 3 inch trim roller for several reasons; since I'm only painting a small test panel I didn't want to use a full size roller, this conserved both paint and mimicked using a larger roller on a larger panel thereby letting me see if roller marks would be a problem. The roller seems to be a smaller version of larger "fuzzy" rollers and is not a foam roller.

I have two coats on for tonight and I can tell it would take me ALL DAY to put the whole 5.5 ounces of mix on the panel! I would loosely estimate that one rolled coat is equal to perhaps 2 sprayed coats. The thing is, I don't have to wait so long between sprayed coats because I don't have to worry about lifting the previous coat of paint by it sticking to the roller.

I have already learned a few things. If bubbles are in the rolled coat that do not pop and flow out before the paint dries, the crater formed doesn't have a bright ring around it like mech had with AAA-F, but rather the whole center of the collapsed bubble looks like a mirror! And as above, I can put down a LOT more paint in a given time by spraying.

The mix is BWN8 8:1 using Valspar Ultra Premium Enamel tinted to a N7.9 neutral gray. For this panel I mixed 4 oz. gray with .5 oz. AAA-M and then added 1 oz. distilled water (that's about a 20% dilution). I wish I had thinned it more! I'm getting bubbles! After two coats I still have most of the mix left!



Addendum:
I forget to mention that when I normaly spray a 1x4 foot test panel I use anywhere from 5 to 6 ounces of paint mix (which includes the water I dilute with).
 

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the thinning of the paint for rolling...

when i painted my UKBW wall i found i was struggling to remove roller marks after 2 coats so for the third coat i thinned out the mix by about 25%. what effect this had on the functionality of BW i dont know... it did make it much easier to eradicate roller marks but the splatter of paint was increased.

the addition of the water extended the working time enough so that i was able to reroller the the screen horizontally without any extra addition of paint after the initial vertical roll.

i know that thinning was not advised for the original US BW but there was a thought that the paint in the uk was thicker...
 

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I usually thin a mix even more with water for spraying, but I thought that would be too thin for rolling. I thinned the mix just so it would go on smoother and flow better, which I thought would be better at letting any bubbles come to the surface and pop before the paint dried. Do you think thinning the paint caused bubbles?

I'll look at the panel tonight and see what's what. If it seems covered enough I'll probably use it for initial testing, but it will have way less paint on it than my usual sprayed test panels. I do plan on putting more coats on, so we'll see how much difference they make.
 

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I usually thin a mix even more with water for spraying, but I thought that would be too thin for rolling. I thinned the mix just so it would go on smoother and flow better, which I thought would be better at letting any bubbles come to the surface and pop before the paint dried. Do you think thinning the paint caused bubbles?

i have seen more bubbles with thinner mixes. i dont know what size they are for you but they are only a mm or 2 in size and they dont seem to have any adverse effect.
saying that i only thinned my testing panel mixes by 5-10%.
the problem was worse when i used a partially wet roller on the panels.

i think i eradicated the bubbles by rerollering as the the conventional size roller allowed me to while the panel was still wet.
of course this method may be too difficult with a large screen ......'KISS'

I'll look at the panel tonight and see what's what. If it seems covered enough I'll probably use it for initial testing, but it will have way less paint on it than my usual sprayed test panels. I do plan on putting more coats on, so we'll see how much difference they make.
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My rolling exercise was pretty much a failure because of bubbles, but I think it will do to see if rolling gives the same results under the PJ. If not, I'll roll on some more paint with a different roller.

Custy, I forgot to address your question about spatter with the thinned mix. I didn't have any. Most of the time I barely put any pressure on the roller at all and rolled slowly.

The bubbles make the surface look horrible, but there are no roller marks.

Something I'm going to TRY and remember to do is to roll some of the mix on a piece of clear glass or plastic to see what it looks like from behind.
 

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Discussion Starter #6
Wow, I can't believe it's been 10 days since I last updated this. The injury to my foot hasn't responded as I had hoped. Nothing super-serious, but I do need to stay off it as much as possible for awhile to allow it to heal, thus not much work is being done on DIY paints.

One new wrinkle I have discovered is that the BWN8/AAA-M 8:1 mix is responding differently when 100% Valspar Ultra Premium Enamel is used than when a combination of that paint and Behr #1850 is used. That is rather surprising to me and totally unexpected.

I'm not sure who is reading this so I will explain this a bit since most of the work on the lighter BW mixes has been done in PM's. Thanks again to Sonnie for making this special forum for development purposes.

I had a quart of the Behr #1850 flat latex enamel paint tinted "Reference Gray"; this is a VERY neutral gray of N7.6. I found that mixing this paint with Valspar Ultra Premium Enamel (which we are calling VUPE for short) in Ultra White in various ratios proved to produce neutral gray mixes ranging from the N7.6 of the pure Behr paint to almost N9. Since I didn't have any Behr #1850 in white, I used the VUPE as both are latex enamel flat paints. I used these Behr/Valspar mixes to find the correct shades of gray needed to produce N8 and N8.5 mixes when adding AAA-M (Auto Aluminum Air (medium)) to produce a BW mix. I had assumed that since the Behr paints in white are VERY similar in color to the Valspar paints that mixes using either pure Behr or pure Valspar paints of the required shade would make the same N shade when AAA-M was added. That seems to have been a bad assumption.

I have not had the ability, because of my injury, to prepare a proper test panel using the pure Valspar paint and AAA-M, but I did mix it and test it's shade. While the Behr/Valspar/AAA-M mix resulted in a shade of N8.1, the exact same ratio of AAA-M to pure VUPE tinted the same as the base of the other mix produced a paint of N7.8. It is a visible difference and can be traced to using a pure base of tinted VUPE instead of a base from the combined Behr/VUPE.

To make matters even more strange, when AAA-M was added to the combined base it makes the total mix LIGHTER in shade. When AAA-M was added to the tinted pure VUPE base the total mix DARKENED in shade.:wits-end:

The tinted VUPE base and the combined base are almost EXACTLY the same shade of gray.

Once again paint chemistry throws a monkey wrench into the works!

I will test the Behr #1850 that has been tinted to the same N shade as the tinted VUPE and see if the AAA-M brightens or darkens the mix; but I'm not sure when I can do that; I'm hoping this weekend.

I know the above may be clear as mud to those not following along in the PM's.
 

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Don I'm still reading the full thread...

With that said, yes rolling is a different animal than spraying.

I personally don't use those small 3 or 4" trim rollers (whatever thier size is). I use a regular roller since that's what I use on my full size screens. I have used the larger 6" trim rollers, but again I prefer regular rollers myself. (I also prefer larger test panels after the initial tests show merit).

Bubbles... Yeah I've run into that when thinning and having a 'soupy' consistancy. Most bubbles will take care of themself. With aluminum added though the worse thing to do is pop the bubbles. You'll get a bright 'crater' that definitely will stand out. What I do is to carefully reroll the area where the bubble is before the paint has a chance to start to set. With a little care you can eliminate all of the bubbles.

If you're having problems with bubbles then the mix is probably too thin for rolling.
 

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Discussion Starter #9
Does this mean that a mix like Black Widow should not be thinned if I plan on rolling it?
That's my take on things at the moment. but I'm not a roller. I also think I need to point out that I was not using a "real" roller for the test above, but rather a trim roller which is a different animal.

When rolling, go with the best (usually the most expensive) roller cover you can get - save money elsewhere in the project. While I'm not a roller, I have heard this advice from enough people and enough places to believe it.
 

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I have added small amounts of water before when rolling. Too much though and you may have trouble. Bubbles are the curse of thinned aluminum and, more than likely, mica mixes. Avoid the bubbles by not thinning at all. And use a 9"+ size roller. Also set up a light off to one side so that you can see and eliminate any roller lines. Using Valspar Ultra Premium Flat Enamel, ther should be no trouble at all.
 
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