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Discussion Starter #1
Should you sand between coats? I am using a one can Behr paint solution, Behr Silver Screen using 4850, and Behr White Opal Pearlescent.
 

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Welcome to HTS Capt Proton! :wave:

I'm not quite sure what you are doing so it's a bit hard to advise, but in general you shouldn't have to sand between coats of paint unless you have to repair problems like runs or other texture problems. If whatever you are painting is rough enough to require sanding, do so before beginning to paint, or sand your primer coats until the surface is smooth before applying your color coats.

I'm curious about your intended screen mix. Are you combining Silver Screen and WOP into one mix or are you using the WOP as a top coat? BTW, the more WOP you add to Silver Screen the less color neutral the mix will be; also the greater chance you will get a shimmering effect in image highlights on the completed screen.
 

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I am actually painting over a Behr 9.0 Grey. I made a big error and psinted on melamine. Paint did not stick well (there's a surprise) and it was a bit rough looking. If I tried to sand it, it made little balls and peeled off. After two weeks, I noticed that the paint was able to be sanded, but, once I did that, the screen was a mess. I came across an article about this mixture. Pictures looked good, and it seemed simple enough, so I am trying it. So far, only one coat on, but, I am pretty impressed so far. Colors are definitely better, and the whole thing has more pop.
This screen will be the one I am going to use while I figure out what is next. As I use my PJ with my computer, and like to surf the internet etc, the screen must be as true as possible so that the whole thing stays in focus. To accomplish that, I am using 5/8" melamine mounted on a frame. My new screen is going to be, probably, 3/4" fir. Right now, I am hankering to try Black Widow, but finding the Createx Auto Air Fine Aluminum is going to be the challenge. Not many places where something like this would be carried, so I may have to find someplace on line and order it in.
I find the coat that I have applied to be fairly rough in texture, so I think it may be better to sand between coats, but I wanted opinions first, in case that would adversely affect the qualities of the paint.
 

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Welcome to the Shack Capt! :wave:

How did you come up with the Silver Screen - WOP mix? I would stick with Silver Screen alone before I would add WOP to it. WOP is a mica based paint which can cause screen artifacts (I've called this noise and graininess in the past) and hot spots. My hunch is you must have gotten it from avs.

A few questions, what ratio are you adding it in? What projector are you using? What's the throw distance and screen size? Will there be ambient lighting? What color are the walls and ceiling? The answers to these questions will help us determine a more appropriate solution for you rather than something that is untested and unmeasured.

Good to have you here! :T
 

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Discussion Starter #6
Got the idea here elvis ripley dot co. Can't post a real link yet. Mixture is 70% Silver Screen and 30% Pearl.
I am using a HD65 with a throw distance of 10'9" giving me a 91" screen that I am viewing from about 9'. Room has pretty good light control, however, ceiling is quite low, and is varnished pine boards, so is quite light.
It may sound odd, but, I am looking at it right now, and the colors are far superior to the straight neutral grey.

PS. If the comment about avs is due to rivalry, just be aware that I am not looking at the posts at this site with any intent of getting into any kind of flame war.
 

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Nope, no rivalry with avs, they do their thing and we do ours; and no flame wars allowed here. Period. I'm pretty sure what prompted Mech's question is that WOP was a popular ingredient in mixes at avs a couple of years ago. In fact I remember a mix very similar to yours being advocated by a member in FL I believe; he even posted a link to a video of him mixing the paints.

My guess is that as long as you don't add something like clear polyurethane to your mix to make it more translucent, the Silver Screen will control the negative aspects of the WOP quite well. While I would guess that your mix would push a bit red, it will almost certainly be something that can be compensated for by calibrating your PJ to the screen.
 

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Avs is where I saw WOP used quite a bit in the past, as well as Silver Screen. This will be an interesting mix if you choose to do it. We pretty much stick to the SMPTE, ISF, and THX standards here. I'd like a sample of your mix for spectro measures if possible. And if you're agreeable, maybe something like a 10X10 inch sample on hardboard for gain, gray scale and gamut readings.

In the end though it's all down to what you want and what looks best for you. Most folks want everything to be according to the standards. Others don't care one way or the other. Either way, we're here to answer any questions you may have. :T
 

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Well, just watched Ice Age, The Meltdown. Fantastic looking. Now, one must remember that I have not seen a professional screen, so my point of view is just my own. I shall be sanding it and putting one more coat on tomorrow. I do seem to have a bit of glare in the middle when I have something that is mostly white on screen, but, I think this may be due to the amount of sanding I did right there to get rid of a couple of drops from my neutral gray coating. The sheen from the melamine may be pushing through. When I'm done, I shall attempt to post some pics and you can tell me if you think it's worth sending you a sample.
 

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As you have already noted, painting on melamine isn't a good idea. It can be done, but it's a delicate surface that won't take much abuse before paint starts to come off. That is why we don't advocate painting on what those at avs call TWH, which is really melamine coated hardboard. My first DIY screen was Silver Fire over TWH. I learn from my mistakes too. ;)

Glad you're liking your new screen. :T

You probably know this already, but just in case, don't sand the final coat of paint on your screen; it's almost impossible to get the whole screen back to an even sheen if you do.
 

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Adjust your white and black levels and then go and look at that scene again. How many coats do you have on it already? I doubt it would be the melamine unless the paint went on very thin. One rolled coat of paint is generally enough to stop all light from passing through. There's a translucency experiment that I conducted this last summer here. Of the 15fL of light hitting the screen, only .77fL made it through tot he back side. And that's only one coat. If you have two coats you can cut that in half.

More than likely it's one of two things, white/black levels not adjusted properly or the WOP is causing it to hot spot. My money is on guess number one. If it was something like a silver fire mix which consists of mainly polyurethane and mica mixes, my guess would be number two. But you're only using 30% WOP.

Do you have a calibration disc? If you don't you can download one at avs for adjusting your brightness and contrast.

I seen Elvis' page. He painted the whole wall. It looks pretty good in those shots that he has posted. I'm kind of wondering if I would like it though. Lately I've been brooding over the widescreen aspect ratio movies and my not so black gray bars on the top and bottom of my screen. It would be interesting to see how the whole wall looked with no velvet trim... :ponder: Unfortunately, my wall is venetian plaster and cannot be painted. :foottap:
 

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Here's my input...

I don't normally sand. Unless there is a blemish or noticeable imperfection I roll the primer coat and then two coats of the screen paint. Now, if you have multiple coats from testing dozens of mixes and OTS screen paints and there is a lot of build up (like my test screen has!) then I had to hit it with a light sanding to knock down the texture and get it back to a normal level. Keep in mind some texture is a good thing, too much isn't. There aren't many 'glass smooth' commercial screens out there, and the ones that are available are specialty screens and their 'superior performance' is questionable.

The bottom line is if you can paint your house walls you can paint a screen. Over the years this has become some sort of rocket science and it really isn't. I truly believe this happened to make things sound better, as in if it's easy it can't possibly be good mentality. The application isn't what is difficult, it's the testing and engineering to get a neutral balance in a matte finish that's difficult. Once you get to the application part of things it should be something anyone can do.

I do agree that spraying will provide a nicer finish because it does with everything, so screens are no exception. The thing is I don't agree that spraying is the only acceptable way to go.
 

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Discussion Starter #13
Well, I did sand. Something in me from my woodworking perhaps. Just can't stand a rough finish, although, in this case, rough is just textured.
Now to wait about a week to allow the paint to cure, and we shall see what I have ended up with. I know one thing for sure, this is it for a while. Pretty soon, I'll have spent enough on DIY screens to have bought a middle of the road one!
 

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I obsessed about having to spray for quite a while, then I "wimped" out and rolled my screen. Now I would say, roll if that's what you are comfortable with, because my rolled screen came out very nice and even, and I doubt I could have sprayed it better than (or even as good as) I rolled it. The surface is extremely even with no textural differences.

I used the Tiddler one roller method and simply just took my time. I believe if you have more experience rolling than spraying, then just roll.

As for your flame wars comment, I can tell you that there is a big difference of opinion in what works for a screen paint between the folks here and at AVS. I started at AVS and ended up here simply because there seemed to be a more scientific approach to the development and testing of DIY formulas here.

Mech, Harp and wbasset have been amazingly helpful and logical and patient and and and. Everything they tell you, they can back up with spectro results and science and tons of hands on experience. I think Harp may even sleep in a giant paint can... :)

I just finished rolling three coats of a new N8 formula that Harp gave me to test out and the results are amazing. I rolled directly on to drywall, so my needs may be slightly different than yours, but these guys will not steer you wrong.

Also, wrt sanding, if you are going to sand I would wait for a 3 day cure before trying it, the paint is not good for sanding after only a few hours drying time IMHO.
 

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Discussion Starter #17
Glad to hear that there is no intent to conduct flame wars. All I want to do is read, absorb, learn and have some fun.
Other DIY Screens.
I started with a 4X8 sheet of primed MDF wainscotting. That actually worked fairly well, but there were scratches and such. I went to the local hardware store and asked for the flattest, whitest paint they had. I used that, and it was not bad. Definitely a step up on the primer.
At this time, i had a data projector. Not a bad picture, but, I knew I could do better.
I got my HD65, and used the Behr N9 mixture. I liked it, and stayed with that for a while. I noticed my screen was not in focus in certain areas. This started my quest for alignment, and a flat screen.
Using a laser level, I got the PJ lined up properly, and I built a frame for the 1/4" MDF. Better, but not there.
Next, a 5/8" sheet of melamine. Used the same N9 paint. Still not what I wanted. I was able to shim out most of the faults with the melamine to make it flat. Have spent a lot of time reading to determine my next step. I find most threads very confusing. Too much OT and there are some people that just write a load of tripe to say very little.
Came across the blog Elvis Ripley put up with the paint mix I am trying this weekend. So far, I am liking it, and plan to stick with what I have for a while. I think I like the look of the Black Widow, but, shall have to find a source for the auto paint. Hopefully, it won't be that hard.

By the way, the glare I was seeing in the middle of the screen is mostly gone.
 

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Glad to hear that there is no intent to conduct flame wars. All I want to do is read, absorb, learn and have some fun.
Flame wars don't do anything but irritate people.

We don't recommend the mica-heavy mixes advocated at AVS simply because they don't work as advertised there. We have tested some of these in the same way and to the same standards as we test our DIY mixes, and even commercial screens, and caught some serious flack at AVS for doing so because it disproved their claims. Our testing procedures are the same as the commercial screen manufacturers use. That said, if someone wants to try those mixes they are certainly free to do so and they won't get any grief from us about it other than perhaps a statement such as above to let them know the documented facts.

Different people make DIY screens for different reasons. One person may need to make a screen as cheaply as possible, another may do so because they like the feeling of accomplishment that comes with building such, and yet another may want to actually get a better screen than they can buy pre-made. DIY is the answer for all of them. While we take DIY screens seriously here we realize that if it isn't fun people won't do it. We also try to make all our screen mixes easy to make and apply while maintaining performance.

I think I like the look of the Black Widow, but, shall have to find a source for the auto paint. Hopefully, it won't be that hard.
Here is the web page for Auto Air dealers (http://www.autoaircolors.com/dealer/dealer_frames.html), but also search for on-line dealers that might give a discount. The links I could give you for on-line dealers are all in the States.
 
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