CRMA/MM Superplex Formula - Page 50

Advice needed,(hey back to making this better). I've sprayed my second coat of Silver on my board but even with the 2.2 nozzle and floetrol, 4 ounces in a cup, water 3 ounces in a couple I still have a problem with the coat. Seems I get big droplets that when they hit they cause tiny craters. Now maybe this isn't even and Issue. Since it craters it has a different shinyness to it than the surrounding area. Will this cause variations in my output or is it so tiny (smaller than 1/8" diameter) and because it's behind the Mississippi Mud it won't be seen. Whats everyone Else's experience. (PS I tried all variations of spray settings, and I am an experienced spray painter.

Any ideas accepted

Big droplets = poor atomization = not enough air or to big of a needle/cap combo. My guess would be that the 2.2 needle/cap combo is too big for the amount of thinning that you ellude to. These paints really can't be thinned by any more than 25% without suffering problems (not the least of which is adhesion).

I have great luck with a 1.3 in my Sharpe Platinum HVLP gun thining 20% from the can. With this combo, I get great atomization with about 7 psi (measured at the tip - works out to about 35-40 psi at the feed for my particular gun).

I'd try reducing the amount of thinnng or switching to a smaller needle/cap. If you're getting 'cratering' then no amount of extra air will help.

Orginally I had the 1.4mm nozzel and didn't thin it, and still had the big droplet problem. But I could try small nozzel and floetrol, I have not tried that combo.

Hope everyone reads this thread. Get the real skinny from a man in the know. Thanks, rfehr

Here's what worked for me: (surprise, surprise...it's right in line with the above information)

MissMud diluted with distilled water. 14 oz of mud and 6 oz of water. Mix very well.
HVLP gravity fed gun with 1.4mm nozzle. 60PSI in. Out unmeasured.

Excellent atomization. No craters or uglies.

Thanks CMRA, I'll do that when I get to MM. How did your silver come out on boards. (not the back of plexy glass. Do you think I can leave it. If that doesn't work I just happen to have enough silver automotive paint left over from a Christmas job. It's brighter and more reflective than the behr but less than a mirror. (also this is a temp screen for me as I have to move on to a roll down.

Chuck

That goes back aways. My silver solution started here. The subsequent posts detail my efforts and results complete with screen shots.

http://www.avsforum.com/avs-vb/showt...93#post2987893

Well I used about 50% water and some floetrol. I also used the 1.4mm nozzle and the air cap from the 2.2 nozzle so I could get more air for atomization. By far the smallest droplet size and resulting "craters" but I still would not call this production process. I think my cup gun could feed this reduce thickness material. If my cup gun can feed the liquid it will atomize the best (but you loose allot more material) Next is the MM. I'm hoping the smaller size of craters is not a problem and plan to move on to the next stage. Unlike others this will not be my permanent screen.

Now given that I have years of experience shooting lacquers and acrylics I have one recommendation for anyone considering saving money by not going with the mirror and buying the silver paint. Don't, I bought a second behr metallic at $20 so I've got forty dollars in silver paint. But worse is the time and reduced quality. Spend the ~$80 bucks and buy an acrylic mirror and be done in half the time. MTC

Is it possible you are experiencing contamination issues? Have you used your equipment with oil based paints before? Is your rig filtered? Lastly, I used gravity fed. Is yours siphon fed?
I know for an experienced painter these should not be issues but something sounds out of whack. Just some thoughts. Best wishes.

Hello rfehr,


170 degrees is all you can ever hope for, and that just to say, "See, it does it." It'd not really an enjoyable watch past 140 degrees.

But from the start, everyone of my screens, be them painted Drywall, Hardboard, or Plastic, all have demonstrated "as good as it gets" viewing cones.

The real trick, and what's being delved into at this very moment, it that same attribute, but accompanied by at least 50% better ambient light reduction as well.

Harken ye unto the image below, and aspire to achieve.

Here's looking at you sideways BYW, this is MMud only on Drywall w/1/96 pz. red oxide per gal.

I was going to mention contamination as well cmra i do not know what gun chuck is using or if he is using a true hvlp gun or a hybrid type with a compressor. But when using a compressor instead of a true clean air turbine there are oil considerations as well as moisture from the tanks which can sometimes get contaminated with oil . What chuck sounds like he is experiencing is fisheye from an oil or silicone contamination. It could also be from the surface before he started with a wax. i once had a problem similar and it was caused from silicone from the shrink wrap that they wrapped all my woodwork in.I had to end up cleaning all the wax or silicone off with laquer thinner . Atomization problems can cause something like this but given that it was thinned 50% and then floetrol that even if it was an atomization problem it would have flowed out but the craters are staying so it sounds like surface tension from contamination .
I am not sure if this has been covered but not using a filter with an oil lubricated compressor or water in the tank can cause problems with these compressor gun combinations they should have water traps and oil filters, the true hvlp units with turbines produce a clean dry airsupply . just something to consider i know that most of these projects are one time only so a 50 dollar gun with a a compressor is the more economical way to go unless you are buying compressor and guns new then there might be a consideration to use a turbine powered unit .i am not sure if this is what you are experiencing as i cannot see it , but thought this might be a good time to consider these potential problems .
Bruce

PS I agree with rfehr that this amount of thinning is excessive 50% water plus floetrol must be so runny i can just imagine what it looks like even with the thick mm let alone just the sm ,and as the problems with seperation in the mix and adhesion he mentions as well .

I really worry about this cratering (poor atomization) problem. While this may not cause a noticable problem for applying the silver side, it is pretty much a non-starter for a top coat (which really needs to be not far from perfect).

Do you have a viscosity guage? If so, I'd try to match the viscosity of the laquer that you shoot sucessfully and use the same needle/cap combo. I shoot Becker Facett with about 25% Beneryl reducer with the same gun and needle/cap combo as above. MM thinned with 20% water yeilds pretty much the same viscosity hence similar atomization results.

The problem is that a good quality, high solids lacquer is VERY forgiving to spray and Facett in particular has wonderful flow out properties. Second, the gun I use is a pricey little thing and I bought it specificly because it can get really good atomization with very little air (hence very little material waste and bounce back).

Many people on this thread is thining above 40% with apparently good results. I personally think this is to much - general rule with HVLP is to use as little reducer and as little air as you can to get good atomization. Problem is that the industry who created this rule is well incented to sell you much more expensive equipment that can shoot molasis with 5 lbs of air.

Given the number of people that have had sucess at your level of thinning, I still have to believe that it's one of the other variables - gun/needle/cap combo or the flow enhancer.

BTW, I completely second the comment on 'screw the silver side spray operation'. I'm buying acrylic mirror (plaskolite) for under US$85 a sheet - that's $30 more than the plain acryilic sheet that I had used before. If the silver side finish yeilded superior results (it doesn't), then I'd still be spraying both sides. The superior results of acrylic mirror, and the speed and simplicity of only having to deal with one side is worth FAR

WOW again MM. Thanks for the 'sideways' post - I'll skip the experiment.

p.s. my test area is extremly narrow (therefore I can't really get a feel for viewing angle) but it does afford me the luxury of spraying in-place right on the screen.

Thanks for the ideas, I'm using a compressor but it's and oil-less, The air is clean and dry, (I had a bad experience with turbine based HVLPs as they heated the air causing over spray) the craters are definatly large droplets. Easy to see them as they hit Also if I do a very fast pass (for experiment) I can see that individuel drops are too big. I'm going to try the cup gun on the MM. I think I have the same gun MM has, harbor freight, purple in color, But it's not your normal tawian crap. It's at least as good as my Devibliss cup gun which is a standard in the automotive industry.

CMRA, when you thinned as much as you did how many passes are you up to, to get the right layer thickness?

chuck i am curious as to what model you have i just looked at their hvlp line up and they seem to have a few purple guns is yours one of the 39.00 ones . There are only a few reasons for shiny craters and i think most have been covered , but good luck on the mm what type or size of compressor are you using do you know the gallon size of the tank ,or the cfm out .
bruce
i am curious because a buddy wants to buy one of these little guns to see what they are like and i haven't used one of those for a while it looks like the quality has come up quit a bit

!0 gallon, I get the large droplets at full or reduce pressure, Higher pressure and more air helps, again pointing to atomization. I think the finish is okay but not as good as it should be.

Hey if I make the screen to good I'll be disappointed with my electric roll down :-)

chuckvb,

It sounds like you've covered all the bases (lots of clean dry air, properly reduced material, flow enhancer, various needle cap combos, well prepared surface, ...).

So... If you've got piles of air going in, have the fluid flow way down, and are still not getting proper atomization, then the air is not getting where it's supposed to go.

My last idea is that something is restricting the air passage within the gun or you have a leaking seal (the seal behind the needle or the one behind the trigger). On my gun, a leaking seal behind the needle is very obvioius as air and whatever you're spraying start to ooze/spray backward onto my fingers. The other potentially suspect seal is behind the trigger. There's no fluid at this point but you should be able to hear and feel leaking in this seal as it's still on the high presure side. I'm not familiar with your gun but these are the ones that are most frequently replaced on mine.

The manufacture of your conversion gun should have a table of input v.s. output presures - if you measure the presure at the tip and it's way off the chart, then you know the air is not getting where it supposed to go.

Also, I find that shooting any sort of water based finish tends to 'gum up the guts' whether you think you've thoroughly cleaned it or not.

In either case, maybe it's time for a long disassembled soak in gun wash and a new seal kit.

Well it's done and we had the first movie party tonight. Thanks to all the picture was great! The MM went on better than the silver. I think one of the big differences is the metal particles in the silver really multiply the crater effect. Seems the particles line up and loose the randomness where a large droplet hits. We I couldn't see any diffference in the picture. (last coat of silver was the best) I may add more MM to the screen as it looks a little streaky and I can percive the silver in the thinner spots (but not during the movie and that's what counts) Never did find my cup gun I think it may have grown legs.

Anyhow our friends were wow'ed and that's just a sign that taking the different road was best road. I didn't get everything in place. I didn't finish my install so I just put the projecter on a cat post. So I have a lot of work left but I can enjoy what I've waited over a year for.

Thanks to all, I'll still be asking many questions.

Well it's done and we had the first movie party tonight. Thanks to all the picture was great! The MM went on better than the silver. I think one of the big differences is the metal particles in the silver really multiply the crater effect. Seems the particles line up and loose the randomness where a large droplet hits. We I couldn't see any difference in the picture. (last coat of silver was the best) I may add more MM to the screen as it looks a little streaky and I can perceive the silver in the thinner spots (but not during the movie and that's what counts) Never did find my cup gun I think it may have grown legs.

Anyhow our friends were wow'ed and that's just a sign that taking the different road was best road. I didn't get everything in place. I didn't finish my install so I just put the projectors on a cat post. So I have a lot of work left but I can enjoy what I've waited over a year for.

Thanks to all, I'll still be asking many questions.

Chuck,
you said "I may add more MM to the screen as it looks a little streaky and I can perceive the silver in the thinner spots."

I say, you need a 'duster' coat.
BTW, do you get the 'plasma glow' from yours?

Hum, Not sure about the plasma glow, I can't compare it to anything but I'd say not. The silver is really quite dark compared to a mirror. I would bet that the amount of light returned with a mirror is factors more than the silver.

I may be helping a friend, who first let me preview his Z2, build a superplex screen. The I can do a side by side comparision.

Chuck

thanks for the input chuck do you find the screen darker at this point that an upw ? and are you still going to put any more coats of mm on ?
Bruce

UPW? ultra pure white? It's had to keep up with a the short hand. If that's what the acronym stands for, I'll have to paint a board and put it up for comparison. I can do that. I would have gone with the mirror but since I have to go to a roll up because my room is multipurpose and the layout limits choices I went the cheep route.

I'm not sure your question is fair but I think I know where your going. I think your trying to ask, Does the silver provide a real benefit. I think the only fair way to answer that question to compare MM with silver verses MM without. And I think that was the start of this whole thread. MM adds colors to improve the picture but all additives work by removing colors from the reflection. So MM/silver may be dimmer than UPW but it still looks better. (Maybe I'm way off course from your question)

Yep Bruce, my Z2 is on the way, should have it by Wednesday darn I'm excited, hopefully I'll be able to get some sample pics posted in the near future...

Hot Dog,

AOTC-on HBO HDTV tonight. Shrek looked great, but tonight it's SW on LFS! If only I could pause my HDTV for some sceenies. And, don't kid yourself, HDTV on a Z1 can look delightfully good.

And, oh how I wish the decision makers for the new HDTV standard would have opted for 2.35 to 1.

High Def and movies go hand in hand. Unfortunately, at 16x9 you still get cropped movies. Not near as bad as 4x3 but so much is still lost. At 4x3 you enjoy 56% of the original image and at 16x9 you enjoy 78% of the image.

Hurry up Blue Ray...I want my lost 22%!

How does this go with a crt projector? Any hotspotting?

UPW is Behr's Ultra Pure White. Others have substituted pigmented white primer, however. It's an AVS standard for color purity.

It would appear the CRT camp hasn't rallied around LFS. I suspect because they look so good on just about anything.
Clarence, however, did some testing. Here's what he came up with:

http://www.avsforum.com/avs-vb/showt...22#post3340422

chuck i was just asking if you had a screen previous to your sm with mm top coat? And what difference you saw in comparison to a upw screen . I'm glad your screen turned out , So you were just blasting the metal particals into the paint and the craters were pretty small i guess ,and not what we were imagining when you mentioned craters .
Bruce

This was my first time running the projector and/or screen. So I don't have any comparison. I also still need to run the calibration but who of us could wait to just watch that first movie right after taking the projector out of the box. I didn't even have my ceiling mount installed so I just used the cat post. :-)