Hi
I am researching the topic....
I have seen many “screen protector” on the market. Some are clear and some are matte, I have seen even some think silicone sheet that is available to protect your computer keyboard (flat). I was wondering if anyone has tried them both as a compliant surface and projection screen for the LCD projector?

Any thoughts?
Thx

ccuuhhkk - 16 June 2008 03:45 AM

I have seen many “screen protector” on the market. Some are clear and some are matte, I have seen even some think silicone sheet that is available to protect your computer keyboard (flat).

I tried several such products while having problems with my toluene solution but not a single one produced ANY results.  I even found a thin layer of rubber with an adhesive back that I applied with a squeegee but had no luck. 

After my failure with toluene I thought working with chemicals would be too difficult but I gave in and ordered the Sorta-Clear 40 and found out it wasn’t.  I followed the video tutorial and advise I found in the forums.  Learning from other people’s mistakes made it easy and in a few hours I had the perfect compliant surface.  The sorta clear has no smell, it wasn’t too runny, and it dried overnight.

Unless there is some reason to avoid the product, like it not being available in your area, I would definitely suggest that you use it.  It’s not just sorta clear… at the thicknesses we’re using it is perfectly clear.

Of course you may find the holly grail but my quest keeps bringing me back to the tried and true sorta clear.

I’ve had this idea for a few days. I’d like to try it later today. I’ll post results in this thread.

First, I have to find a fabric for rear projection that is durable and can be kept clean by wiping it with a cloth. Something like nylon or dacron in a straight fine weave.
Then, coat one side with a thin layer of silicone. It could be squeegied evenly across the entire surface. Once dry, use it as the screen and compliant material on top of the acrylic. Just might work!

http://www.invisibleshield.com.hk/en/what-is-the-invisibleSHIELD/p12

Paul - 16 June 2008 08:18 AM

ccuuhhkk - 16 June 2008 03:45 AM

I have seen many “screen protector” on the market. Some are clear and some are matte, I have seen even some think silicone sheet that is available to protect your computer keyboard (flat).

After my failure with toluene I thought working with chemicals would be too difficult but I gave in and ordered the Sorta-Clear 40 and found out it wasn’t.  I followed the video tutorial and advise I found in the forums.  Learning from other people’s mistakes made it easy and in a few hours I had the perfect compliant surface.  The sorta clear has no smell, it wasn’t too runny, and it dried overnight.

I really need to look for this… normally I would avoid any chemicals....
Would you need to put the acrylic perfectly horizontal for the liquid silicone to set in? I guess the thickness wouldn’t be too even no matter how carefully u are… but I guess the thickness and smoothness would not be too critical as far as the blob tracking is concerned...?

Yes. A perfectly horizontal surface is extremely important.
Yes, it’s hard to get it super even, but anything close to 1 mm is good enough.
And yes, a little unevenness is not much of an issue as far as blob tracking is concerned, but it could affect the feeling of the surface in terms of tactile feedback.

this video is what convinced me to give it a try…

http://www.youtube.com/watch?v=bnjeWbvVCCo&eurl=http://ssandler.wordpress.com/2007/10/12/pouring-the-silicone/

then i found this blog post showing me how to use tape to make 1mm rails

http://ssandler.wordpress.com/2007/10/12/pouring-the-silicone/

easy…

two hints i picked up by reading about people’s troubles…

1: use the entire sample kit.  even though there seems to be enough silicone to cover more surface than you have use the entire package because the amounts have been measured for you and your much less likely to screw it up.

2: be sure to stir!  i set a timer for 10 minutes and had no problems.

Thx for your responses.
I will look for this wonderful liquid silicone thing here!

I hope BlaXwan’s project using LCD instead of projector would be successful (http://www.diniro.net) as I have a 18” (yes) old LCD monitor lying around and a 14” super old LCD monitor too (backlight is an issue).

Hey this idea works really well!!

I tried my silicone cloth test and it’s a success!

I used some really cheap cotton cloth, cut an 8” x 10” piece and taped it to some glass (nice and flat) with masking tape on all sides. I pulled it nice and tight. Then I used a metal straight edge to spread a goodly amount of clear silicone across it. I just used a caulking gun to lay a couple pencil sized beads on the leading edge of the cloth, then made two passes, let it dry and did two more. Perfect!

It works great. This could be done to any suitable fabric suited for rear projection.
You could even lay a sheet of clear mylar over it to keep it clean and protected from fluids.