Mega Screen™ - Black Widow Flavor

[Quantum]

Hello friends,

I've been watching TV on front projector for over three years, and it came to the point where, um, a 10' screen wasn't enough anymore. You know how it is...

So I began looking around and quickly found that plywood, siding, masonite, sheetrock, etc never comes in widths greater than 4', so that was out. Formica comes in 5', but that would also have required a seam which I may or may not be able to disappear.

So I came across linoleum, or what the kids today call 'vinyl flooring'. 12' widths, unlimited length, and cheep as dirt. Lowes has it for 45 cents/sqft, so a screen as big as I can manage for $72! As a bonus I can take it apart and roll it up when I move.

Now; this stuff has a reputation for curling, and this is because of the different coefficients of expansion between the plastic layer and the paper backing. Of course my intention is to paint the paper with Black Widow, and so the idea would be to seal all moisture out of the paper so it stays flat.

So I got four samples from Lowes and two from Home Depot. I washed the paper back of all my samples for ten seconds under the faucet, to simulate a worst-case coating of paint. My four samples from Lowes all curled parabolicly (across the whole surface), and unacceptably, particularly at edges. This is regardless of paper thickness (factor of 3), and on samples priced from 45 cents to $1.10/sqft. However my two samples from Home Depot were much better. (66 cents/sqft each) Both are Armstrong "Metro", one with an octagonal pattern and one with a square pattern on the plastic side. The octagonal is bent a bit, evenly across the surface with no emphasis on edges, but the square one had almost no deforming at all. This is Metro Agean Mist White @ 66 cents/sqft.

These samples are all from Armstrong, but the main difference between the Lowes and HD samples is the nature of the paper. HD samples' paper is slightly darker gray, I don't know why. But it deformed far less, and there is almost no edge curling as was so evident with the Lowes samples. Once the samples were dry and results conclusive I suspended a sample full of water, to see whether the plastic side is porous... it is not. So I bought my vinyl, 130.5"x76.5", to give a 12' screen after I add my frame. Do yourself a favor and just have HD rough cut it, and you trim it to size with a sheetrock square; I had to fight with them to make them use their machine to cut it, on the theory that it will make a nice square cut, but what I ended up with wasn't particularly accurate in size.

I can't paint the wall because I'm renting, and I have dark wood panelling in the theater, so I started out intending a 16' screen, but Harpmaker showed me that my projector wouldn't be bright enough. So then I went to a 14' screen, but I found that the dimensions are so large that one person couldn't reach the top to move it around, and it is only me. Thus a 12'. Still looks like a monster.

It is important to keep moisture from the paper backing, to prevent curling from differing coefficeints of expansion between the plastic and paper, so I decided to go with a cheap semigloss primer. Years ago I managed an apartment complex, and that was all we used. Once we had a roof leak, and the semigloss paint came down in a bubble full of water, rather than letting the water through the ceiling! This tells me it's watertight. I have no reason to believe that Kilz2 or other conventional primers are water/airtight.

I bought a quart of bright white semigloss (Evermore EM6411)and as it was Base 1 I had them fill it to the top with white pigment, to try and get as much out of it as I could. I diluted it with water (1/4 can) so it will soak into the paper better, and for the same reasons Black Widow is diluted, to form a more even, thin surface when dry. The correct viscosity is described as flowing between the tines of a plastic fork. I can tell you though, that for a 12' or bigger screen, a quart of diluted primer is not enough when rolling two coats. The first coat went on well and laid down just fine as it dried; but I was so low on paint for the second coat that I pressed on the roller to spread it, and this left permanent texture on the surface. Do yourself a favor and get a gallon of primer... it costs only a little more.

I was unfortunate enough to have a paper bubble right in the center of my screen, where the paper had delaminated in manufacture, about 1.5" in diameter. I lanced one side of it and filled under with paint, smoothing it over. Looks like it's going to be fine. I am also noticing some waviness in the vinyl, as vinyl does, but I'm hoping that will flatten out as the paint dries.

Now the Black Widow. I have been a little worried about BW as my projector (Planar PD7150) is bright enough only by a small margin, so Harpmaker has been patiently working with me on an experimental formulation of BW called BW-X1:
4oz AAA-Fine
4oz AAA-Medium
1qt Valspar UPIFE Bermuda Beige cut significantly with white paint.

The idea is that the AAA-Medium is lighter than Fine, and so needs less red tint to offset. Harpmaker recommended mixing one quart BB with 1 quart white, and he tested this for me but unfortunately I can't attach the chart hereto because:
"Your file of 25.1 KB bytes exceeds the forum's limit of 20.0 KB for this filetype."

Well, take my word that it is very flat, except for a small hump at yellow-orangish and slight dropoff in deep red. 81.96 0.26 0.75 So like a smartalec I thought I'd improve on that therefore to my quart of BB I added .75qt of white, to try and increase the red push. We'll see how it tests. Mixed it up, poured off to a quart, and added my AAA_Fine and -Medium. First coat is drying now, and the second coat later today. Then I construct the screen. I'll keep you posted.

[mechman]

Excellent work Q! Did you take pictures along the way? I'd love to see them if you did. It will also be interesting to see how the AAA-M and the white work out for you.

As for lumens, you have the same as I do with my HC3000 and a 100" screen - 13fL. I wouldn't worry about the brightness. I never have.

[Quantum]

Ya I have pics of the linoleum laid out, primed, and painted with BW, but there's no hope of posting them to this forum due to filesize limitations.

I am optimistic that the semigloss primer will also help gain, as it seems some light penetrates the BW and could be reflected back.

I gotta say, this BW formulation is alot lighter in color than I'd expected. I may not even have to recal the projector.

[Harpmaker]

Boy... I'll tell ya... you give 'em books and you give 'em books and all they do is tear out the pages.

Just had to go and mess with the formula didn't ya...

Just Kidding!

I want to point out that this is an EXPERIMENTAL BW mix and is NOT APPROVED for general usage. Quantum was kind enough to test this formula (with his own added twist ).

He is also going to send me a sample for testing with a spectrophotometer. You did remember to do that, right Q?

As for not being able to attach the spectral chart, I suspect it has something to do with the gallery here at the Shack. We always use other photo hosting services, such as Photobucket or Imageshack, so we don't run into that problem.

[wbassett]

Welcome to the Shack Q!

[Quantum]

It's done!

To start with, here is the linoleum ready for painting, cut to 130.5"x76.5":


I painted as noted above, with two coats of semigloss for primer; I can tell you that 1 quart is not enough, even though I'd diluted the Evermore by 25% to soak in and lay flat. Then I painted with two coats of Black Widow-X1, as noted above. After the first coat of BW had dried (4 hours) the semigloss sheen from the primer coat was still somewhat visible in incident light; not a bad thing just yet.

40oz of BW is not enough for two coats on a screen this size, as when the first coat had dried I didn't have enough paint for the second coat, so I had to dilute it to almost watery. I recommend that at least 60oz be prepared for screens 12' and larger. But I laid down the second coat of BW and let it dry overnight. This was my final coat, and when it was dry there was virtually no sheen from the underlying semigloss primer in incident light, which was very good news indeed! This will mean no hotspotting, and yet as light penetrates the BW layer it will be reflected back by the primer, recovering that light for better gain.


The linoleum was laying flatter and flatter as time went on, thankfully, and as of today there is no apparent waviness when viewed straight-on. More on this later.

My method of hanging the screen is unheard-of, at least to me, but it works great. I bought a nice straight 1"x4" at Lowes, the length of the screen width, to run across the top and serve as a hanger-board. I put this under the linoleum across the top, and put staples in every half-foot. Then I put staggered staples in, between these across the top. Then I banged in each staple with a hammer, for good measure:


It was time to prepare the frame. I had some leftover deep blue velvet, which turned out to cover all four sides of my frame. Dark velvet is excellent at capturing stray light and eliminating it, better than anything else I know. I bought some 3.25" rounded baseboard at Lowes, two pieces of 11' each for the top and bottom. For the sides I reused my baseboard from the old screen, which I'd previously covered in black felt. Not trusting the theory, or even my tape measure, I laid each baseboard along the side of the screen where it would go, and marked it for length. I made each one 1/4" longer than the actual screen material, so the screen wouldn't show; this turned out to be perfect. Took each in the garage and used a tri-square to mark my 45 degree cut on the flat side, and made the cuts with a hacksaw for precision.

Took each outside and set it on blocks for covering. I used 3M 77 spray-glue and coated the three sides evenly (not too much glue, or it will soak through the velvet and show), then laid the velvet over it, slightly stretched. I worked along the length of the baseboard stretching the velvet and smoothing it down, first on the top surface, then on the two sides. With an operation like this, it is important to use a forgiving glue which will let you unstick/restick as needed, like the 3M 77 that I was using.


Then I flipped over the baseboard onto towels (to protect the velvet), and trimmed off the excess with scissors. Pulled away the remaining velvet and spray-glued the flat side of the baseboard, to lay down velvet and smooth for finish. I gotta say, gluing is far better than stapling for this.


Now I laid out the parts for assembly:


This frame will have four diagonal braces to hold it together, and for this I used some scrap 1"x6". I cut a 45 miter in each end, and the long side was 36". The two braces at the top will fasten to the edge of the hanger board with a screw. You MUST predrill this, or the diagonal will crack. So with the screen still laid out I put in place all four braces under the linoleum, with the edges lined up with the edge of the screen, slightly recessed. Then on the screen I laid all four baseboards comprising the frame. I adjusted these, checking all sides several times until the whole was squared and centered, and then I stapled each corner together on the front (temporarily) with 3-4 staples each to hold it all in place. Next would be fastening these to the braces.

I'd bought a small container of black sheetrock screws, 1" long, from Lowes. For the top baseboard I put in a screw about every three feet, to hold it to the hanger board. The screw heads became almost invisible against the velvet. And I put two screws through the baseboard, into each end of each brace. Everything was fastened together now, and I could stand the screen up.


I now put in the two screws fastening the top braces to the hanger board.

You'll notice some bowing of the linoleum now, as the braces are not letting it hang like it should. However the braces are necessary to hold the assembly together while it's being maneuvered and hung.

The only way one man can move around a screen this size is from the back, lifting on the hanger board. I am 5'10" and am barely tall enough. So I lifted it and turned it around, ready to be hung. I got four 3" drywall screws and started them in certain locations in the top baseboard. I measured the width of my room, and marked the center close to the ceiling. I measured the screen and marked its center with a small pencil mark, and then shifted the two marks into alignment. Then I got on a chair and lifted the screen up on the wall, about 2" from the ceiling (I could barely lift it), held it and grabbed the screw-drill from between my legs, and managed to get the first screw in. From there it was easy. I was able to take my time and get the screen level.


I expect that the linoleum will hang and stretch for a while, and it was already bowing being held by the braces. So I removed all the front screws from the braces, to let the linoleum hang freely. I'll probably leave these off for at least a week, with the frame only being held together by my corner staples.

There was some concern that the BW coats would not bond well to the semigloss, and that it may scratch off with a fingernail, but I can tell you that's no problem here. I put down the BW within 12 hours of the primer, so they apparently bonded well. Also, the texture I'd pressed into the second primer coat was all but ameliorated by the BW coats. And one note: apparent defects in the final screen picture are not on the screen, but are photo anomalies for some reason.

One important consideration I had was that I need to be able to disassemble the screen, as I am renting and may move. You can see that it is a simple thing to remove the brace screws and just roll up the screen, maybe with a protective tissue layer.

Last night I auditioned the screen, and it is wonderful! Glorious huge size, and pretty good 3D picture, although my projector needs to be recalibrated brighter.

Next I'll take some oblique pictures to give an idea of flatness, and some screenshots after I recal.

[mechman]

Looks great Q!

[Harpmaker]

And you got a "dancing banana" from mech! That means he really likes it!

I certainly hope that using the flooring material as a screen substrate works as well as it seems to be doing so far. This would really help folks that want a larger screen than can be made with a single sheet of hardboard, MDF or laminate.

Lookin' good so far!

I finally calculated how much paint I use when I spray my test panels. It works out to about 1 ounce of paint per square foot of screen surface. For Q's screen above this comes to about 62 ounces.

To calculate your screen size in square feet, simply multiply screen width by screen height if the dimensions are already in feet. If you only know your screen size in inches, multiply screen width by screen height and divide by 144; this will be the size in square feet, and also a good guess at how much paint, in fluid ounces, you should have to paint it. It's always better to have a little bit too much paint than too little.

[mechman]

I think this is the first time I've actually seen linoleum used. There's always been talk but no one ever stepped up. I like it. Not to mention Q gets an A+ for the testing of it prior to actually diving in.

[Quantum]

Thanks guys. To me it was a new idea, and my methods are definitely radical compared with what's usually done. My gift to you (especially Harpmaker) for helping me out so much.

HM I had that chip in the mail today, but it wasn't picked up. Maybe it's President's Day or something... If it turns out to not have enough BW, it won't be too hard to take down and recoat.

About to go in and calibrate.