The GILA “heat control window film” stuff you can get at any homedepot or lowes. It can also be found online and on ebay pretty easily. I bought the “Light” heat control window film. I decided not to use it as it dims my projection too much. I’m sure the one that blocks more than the “light” version would be even worse. Maybe for others it’ll be ok. It’s worth trying as it does block a decent amount of IR (although probably wouldn’t make your table usable in 70-100% daylight still).

Tinkerman, did you adhere the film to anything or did you just lay it on flat?

Thanks very much for taking time to share your info.
Soon I’ll be attempting an MT unit and having people like you lead the way and share knowledge will benifit all.

cerupcat - 29 June 2008 05:20 PM

Tinkerman, did you adhere the film to anything or did you just lay it on flat?

I applied it to the clear laminate just like you would on a window. Peel the backing, a little spray with water, squeegie it on and work out the bubbles.

Tinkerman - 27 June 2008 08:59 PM

@ Emiel:
It’s a beautiful projection surface. It’s translucent. It helps diffuse the image as does the drafting vellum. They both work together to produce a nice clean image.
If you use a fabric that is too course to apply the texture, it start’s to blur the image somewhat.
It doesn’t add noise to the background on my FTIR rig. With DI it may add some noise, but as mentioned, that may be a benefit due to the added sensitivity.

Great, thanks a lot. I’ll go try this out and let you know.

Hi Everyone,

i just started to produce a layer of silicone. My first result was not as expected, cause from the silicone i used, i was not able to produce an even and flat surface. I was not able to make it all even cause it looked like it dried rapidly on the very top.
I used clear silicone from the hardwarestore, i cannot get the recommended GE-1 silicone (won’t get it round here in germany, i guess).
So.. I messed up my first result.
There is still one thing i am curious about. As i am looking forward to use rosco as my compliant surface, i try to produce a sepearate silicone layer.
Silicone sticks to almost everything, but i found out from the specs it won’t stick to PET ( Polyethylene terephthalate ). So i got PET foil from the hardwarestore.
I am pretty sure it can be removed from the foil quite easily, but haven’t tested it yet. As soon as i get some results, i’ll post it here (it’ll take 3-4 days to dry ? )
Well, thats another point, the recommended curing time of the silicone i used is actually 3-4 days. i wonder why the the GE-1 has such a short time of curing?

I just recognized i have the same problems getting the layer even like GFantini.
As soon as the the silicone got to thin as i thinned it out the first time, there was not way to close any “leaks” in the layer, cause it dried very fast and
trying to correct it made it all sticky and caused parts of the already applied silicone to torn when trying to thin it all out.

I guess thats a matter of craftsmanship, which tinkerman certainly knows about a lot

Ok, my results are:

The PET thing does NOT work. The silicone DOES stick to the PET foil, well, not as good as to other materials, but since the layer is very thin, it tore apart easily when removed from the foil (to be precise at this point, the foil is almost 1mm thick, so it’s not what you would use to wrap things).
I just tried to get some very thin sheets, but this aproach does not work, apparently.

So far, using tinkermans approach, this certainly the best way to do it using velum.

But maybe there is a process to create a very thin, separate, clear and textured silicone layer?

Update: As the curing progresses, the silicone sticks more and more to the pet foil and gets hard to separate.

No luck with this approach

I think it’s best to bond the silicone to the projection material. A sheet of RTV silicone less than 1mm thick is going to be tricky to handle and keep from creeping around. If it’s bonded to the projection surface it eliminates the air gap that would otherwise be there causing light refraction and most likely a distorted image.

Before applying a second layer of silicone, you should wait at least an hour or more for the first one to get some cure time.

GE Silicone also takes days to FULLY cure, but it’s about 90% cured in just a few hours. It helps if it’s exposed to a good air flow. I hang the sheets I make on the wall, silicone side out, for a day or two before using them.

As far as alternatives go, here’s a link I found to purchase silicone sheets.
A .031” x 36.00” x 36.00” Sheet will cost you $161.

http://www.rubbersheetroll.com/silicone-rubber-clear.html

Can I put this silicone on Acrylic directly for use with LCD/FTIR setup?

@tinkerman:

I think the making of a separate layer is indeed quite tricky unless there is a way to easily separate it from the underlying surface.
I was thinking of a surface you find with glued foil that is attached to some paper and you can tear it off when using it.

Thanks for the link, but i guess without the texture it’ll not have the desired effect.

I’ll just need to have some more tries and do more experiments. Thats most of the fun, isn’t it ?

@ Geoman:
I’m sure you could get it on there, but how well it would work is another issue. I’m not so sure it would behave the same way Sorta Clear 40 does.

@ chris:

Yep.. fun and cheap!

@tinkerman
makes sense… will destroy one acrylic regardless; for kicks

Hi everyone,

i did some experiments and.... yepp i was able to create a skinlike piece of silicone sheet! Well this is just a testing. I don’t know if it works like expected,
but i managed to find some process to create this skin.

I used two sheets of polypropylen foil to trap the silicone inbetween. i separated the two sheets immediately (if the the silicone remains between the sheets there is no
moisture to help the curing process -> silicone stays liquid). And after curing, i was able to simply remove the “skin” from the foil.

The problem i have in this step: When separating the two sheets, the silicone gets ripples from moving the two sheets apart.

If the silicone was able to cure completly between the sheets, i would be able to create a perfect flat sheet, and amazingly thin as well…

The polypropylen allows the easy removal of the cured silicone. That’s what i was looking for

Thanks again to tinkerman, whose approach gave me the inspiration

Well, still to be experimenting around, but things are in progress…

@Tinkerman:

when i use fabric to give the silicone sheet a texture, i get a lot of ripples when i start to pull back the fabric from the silicone.
Not everywhere, but i can’t figure out why.

Did you have this effect as well? And, if so, how did you avoid that and have only the fine texture from the fabric on the silicone?

It’s rather difficult to say without watching your technique. Any chance you can post a video of what you’re doing?
I’d like to see the squeegie and how your dragging the silicone with it.

I wasted about 2 tubes and a several sheets of vellum and fabric before I tried it the way I ended up doing it.
Some of my experiments did not work at all, some gave me results I didn’t expect.

Your biggest asset at his point is your drive to create and experiment.
Like me, you see “failure” as an opportunity to improve and try again!
Keep up the good science.

I just got some other foils from the hardwarestore today and also some of the foil i used before.
It’s actually PP (Polypropylen) foil that is used to cover books. The thing is, i could not get a wider foil than 40 cm (the screen should measure 60 cm)
Well, i created some testsheets, as soon as i have my setup running again (always have to take it apart, not to much space in the flat, to leave it all for days )
I got some larger sheets today and improved a little of my technique to produce them.

If the new foil i got is working, that would be great. I must say at this point, i did not try it out yet with the FTIR effect, but i’ll try it in the next few days when i got
some larger testing sheets.

@tinkerman: I’ll also post a video and some detailed images then, with the technique i used to create the silicone skin.

So we’ll see if this has a chance of working.

Thanks for the motivation I’ll keep on working with that. No result is also a result