First-timer DIY Screen

[xflapx]

Hello. First let me say I love these forums, lots of great information.

I've spent the last few days talking with Harpmaker regarding paint mixes and the general process of setting up a home theater projector. I've settled on BW and was trying to figure out what to use as a substrate. I want to have the possibility of building something larger than 100" diagonal so my original idea of using hardboard limits me to just that. I'm going to be hanging it from a wall in a rented home using a french cleat, so it can't be so heavy it requires extensive alterations. Harp suggested I look into vinyl sheet flooring so I called around town. I actually found 6'x9' precut vinyl sheets from Lowe's for $30. That's about 55 cents a sq ft, though granted with a 4" border you can only turn than into a 115" diagonal 16:9 screen. Still it's not a bad deal and about 2 dollars a sq ft cheaper than quotes I received from the flooring stores in my area. In fact most of them told me there would be a 65 dollar freight charge for such a small order, since they kept nothing in stock that wasn't intended for a job. So, with that in mind, does anyone have a better/cheaper idea for a 100-120" substrate that is sturdy and proven?

I tried to post a link but i'm not allowed to yet. It's domco 6' precut white sheet vinyl from Lowe's. Model #L90216X9

I'm going to take a look at the back side over the weekend to confirm it's quality, until then any suggestions would be greatly appreciated.

Darin

[Harpmaker]

Hi Darin!

Welcome to the Shack!

If you haven't already found the thread about the vinyl flooring screen here it is:
http://www.hometheatershack.com/forums/projector-screens-diy-screens/16799-mega-screen-black-widow-flavor.html

Quantum had better luck with flooring from Home Depot rather than Lowe's, but the test he used to determine this was a severe one. It is still something to think about if you have a Home Depot near you.

Peruse away, and don't be shy about asking questions.

[mechman]

Welcome Darin! You paint the backside of this right? I want pictures along the way!

[xflapx]

Thanks for the welcome.

I'm still going to check out the domco, as it only comes in 6x9 precut sheets. This isn't cut-to-order rolls like what Quantum tested (in fact I doubt I could even get a sample without purchasing the roll). Most likely the backside won't be the highest quality, but then again maybe I'll get lucky. I'm also going to head over to the new house (I'm moving in next week) to get the exact dimensions of the room. I remember thinking it was huge, but I'm not sure I can base screen size, viewing distance, and PJ throw distance based on "huge." Maybe it is smaller than I think and I'll be forced to build a 90" screen. this project is becoming more and more expensive...

[xflapx]

Just so this whole process makes more sense, let me first say I'm a student at UF. As such, money does not flow freely from the money tree. I had about 1000 dollars that my ex-girlfriend owed me for school and other things while we lived together, so she basically said "spend a grand on my credit card." While it's not free money by any means, it's not money lost as I never imagined she would have wanted to pay me back, so I thought I'd try to build a home theater setup for around 1000 dollars. I have the surround sound system and a HTPC, so all I have to do is focus on the visuals. I bought a Sanyo PLV-Z60 for around 750 assuming that the highest rated projector on projector central in my price range was the way to go. I didn't realize all of the mitigating factors at the time, but obviously at this point it's water under the bridge. It has a beautiful picture and I have no regrets. So with all of that in mind, I have a budget of about 250 dollars start to finish.

The room measures 18'x13'. The ceiling is 8' high. If I set one couch at 10' and one couch at 14', the suggested screen size according to SMPTE standards is 100". THX is 115", but I don't think I can pull off a decent screen that size at the budget I'm setting for the project. The domco sheet vinyl was very thin and the paper felt very chalky and weak, I'm 99% sure it would have reacted poorly to paint.

I can get very close to 100" diagonal if I use a 4x8 piece of hardboard and glue it to a frame. I can then attach a french cleat to the frame and border the hardboard substrate with velvet-wrapped mdf trim. It shouldn't be too heavy and will eliminate the concerns of a flimsy surface. As long as I'm picky about the piece of hardboard I feel confident I can make it work, and for less than 120 dollars including paint, frame, trim and velvet. I had planned on building a 10" riser to set the second couch on, but as it turns out the previous tenants are leaving a bar behind that they built. With a few alterations I can turn it into the riser at the cost of some 2x4's.

After completing screen, I would like to purchase a large quantity of black velvet to curtain off the back side of the room since it has an open doorway that leads to the kitchen and on the other side a door that leads to the garage. Also against that rear wall are windowed double doors leading to the backyard (the 18' depth was measured to the start of the kitchen opening, the room is actually 22" front to back). So the curtains would control the ambient light those doors and open areas create as well as allow a hall of sorts that would lead to any of those entrances/exits.

I'm going to be painting the ceiling a dark flat brown that matches the wood paneling on the walls, so all in all it should be a relatively light-controlled setup. Still I want the option to be able to open the curtains and throw a gameday party or whatever.

Now that I've explained my plans and situation to date I have a few questions. The bar, as it is, sits about 24" off the ground (once I lay it down to act as the riser), so I can cut it down to any height under 24", what do you recommend? Do you foresee any problems with my design? Do I need to ceiling mount my projector? What are the advantages of doing so?

Well if you made it this far thanks for reading, and if you plan on answering some questions thanks for being patient. I can't wait to start.

Darin

[mechman]

Darin,

You'd need an extra inch in height for a 100" screen - 49"X87". Or were you saying that you were attaching the linoleum to the hardboard?

I would cut the riser down to 8 or 10 inches.

As for mounting the projector, I'd try to put it on a shelf if you can. Ceiling mounts are not cheap and will put a dent into what's left of your budget.

[xflapx]

I said I could get close to 100", or I guess I should have phrased it "I can get close to the SMPTE standard for my viewing distance." I think I'm going to settle with a 90" screen. That way I can attach a 1x2 inch frame to the hardboard, screw the french cleat into it, add the velvet trim and call it a day. Then I don't have to worry about damaged corners or edges, and the cuts don't have to be perfectly clean. I found the 16oz bottle of AAA-F for 30 dollars shipped, so I went ahead and ordered it. The plush velvet is also on it's way, so all I have to do is pick up the materials from HD and Lowe's and I'll be ready to start next weekend.

There isn't a place to shelf the projector since the back of the room is open. In fact considering the dimensions of the room I have to ceiling mount it. It's either that or put it in the lap of the person sitting front center. Guess it wouldn't pay to arrive late to the theater at home either...

Oh and I called the current tenants again (how I originally go the dimensions of the room) just to make sure, and it turns out I have a terrible memory. The walls are drywall, not paneling. Looks like I'll have a lot of painting to do...

[xflapx]

Do you think there will be a difference between a single coat of BW over 2 coats of kilz prem and 2 coats of BW over 2 coats of kilz prem? Wouldn't there be a chance of the white having an effect on the projected image with only one coat? If so would a black primer have an opposite effect? What about a higher density of AAA-F in a base coat and a lower density in a topcoat? I can't seem to find much in the realm of layer testing. What about wet sanding? How does that effect the performance of a mixture? I've lapped several cpu's as well as worked with some acrylic that has given me reason to have some high grit sand paper at hand. The highest grit (can't remember number and it's packed away) gave my copper heatsink a mirror finish. Would wet sanding increase the chance for hotspotting, or is there a chance it would help to reduce any imperfections that result from rolling?

The development section has me thinking too much. I can't afford another obsession.

[Harpmaker]

xflapx wrote:

Do you think there will be a difference between a single coat of BW over 2 coats of kilz prem and 2 coats of BW over 2 coats of kilz prem? Wouldn't there be a chance of the white having an effect on the projected image with only one coat?

While no definitive tests have been done along this line, in theory, yes, there would be a difference since BW isn't a totally opaque paint; but I doubt the difference would be visible unless a LARGE amount of light was hitting the screen. A number of users have only used a single coat.

If so would a black primer have an opposite effect?

In theory, a darker base coat would provide less reflectance from the top coat, but again, BW isn't all that translucent. The two main reasons for using a white primer as a base coat are to provide a good gripping surface for the BW to stick to and to provide a neutral color base so that any effect the base color might have would not throw off the neutrality of the BW.

What about a higher density of AAA-F in a base coat and a lower density in a topcoat? I can't seem to find much in the realm of layer testing.

While others have experimented with layered mixes, I think they are more or less a solution to a non-existent problem. If a simple single mix can provide good results why make things more difficult? With layering, every layer that goes on will greatly affect the overall result; if even one layer is not correct then the whole screen will suffer. I'm not berating those that have done layered screens, or those wanting to attempt them, but so far the results haven't been good enough to sway me away from simple.

What about wet sanding? How does that effect the performance of a mixture? Would wet sanding increase the chance for hotspotting, or is there a chance it would help to reduce any imperfections that result from rolling?

The problem with sanding a screen is that screens are BIG! It is very hard to get an even sheen over such a large area by sanding. When dealing with metallics in a screen surface the problem is made worse since the metallics tend to show every single imperfection in the screen surface. The greatest problem I remember people having is having a DIFFERENCE in surface texture in a screen (usually a wall). As long as the wall was one texture, even rough, it usually worked; but texture differences pop out when metallics are used.

As for controlling sheen, there are simpler ways than sanding.

The development section has me thinking too much. I can't afford another obsession.

Be mighty careful! This stuff is addicting!!! You have been warned...

[xflapx]

Well if you can neutralize a paint mixture, surely you can neutralize, say a black gloss base and a single topcoat. As long as care is taken in the application of the single coat, it should be a fairly repeatable process, no more prone to error than mixing a solution. The only layering I've read about is silver and it goes in a completely different direction. Anyways just tossing ideas.

I'm only asking because I already know once I have BW up I'm going to have a new hobby. I read the developer's forum top to bottom, but it seems like it's a newer idea and a lot of development and discussion happened in the main forum, or elsewhere. I've read some of it, but obviously it's hard to find the information I'm looking for. Suggestions? Also, I saw somewhere a link to the tool you use to measure fL, but how do you measure the neutrality of a surface? What about grayscale?

Thanks again.

Darin