Hello!

I am joining this Forum for one Week and can’t stop reading. I am about to build a Multitouch with 60*45cm Screensize, have allready some SFH485.

Right now I am planning the Surface (Tracing Paper) and how to combine this with the 8mm Acrylic. Yesterday I went to “Hornbach” and bought some silicone rubber, but its impossible to build a 1mm thick layer cause of the viscosity. In fact, I am searching for a cheaper Solution as the “great Sorta Clear 40”. Perhaps someone else did this and can help me: Do you know anything to change the viscosity of the One-Component-Silicone Rubber? Here is a Pic:

Another Question: As far as I know, you use the Silicone layer to make a better transission from acryllic to Tracing Paper. (Less Pressure --> Better/Brighter Bloobs). If thats the fact, can’t I use a silicone foil like this:

Or will I have Problems with Air Bubbles ?

Greets and Thanks for your Time!!!!

I am sorry for my bad english…

Try reading this thread on using GE Silicone 1 from a tube, applied to drafting vellum as a compliant surface for projecting onto:
http://nuigroup.com/forums/viewthread/2197/

That silicone baking sheet in the picture is probably not translucent enough. They have those at the restaurant I work for.

Hi Jan,

I got some silicone from Obi (another German hardware store) simply named “Sanitärsilikon” for 6 Euros. It seems to work fine as a compliant surface, but I’m still experimenting to find the best combination of thickness and texture/fabric. Like Tinkerman said, look at the thread he posted. You don’t make the surface 1 mm thick with this technique, but only a fraction of a mm.

My silicone layer is .012” or .304 mm.
VERY thin.

Hi!

Your Thread is very nice, thanks for that!

The Silicon baking sheet was only an example of the thing I thought at. I see that it’s not very transparent but there are other Supplieres here, please have a look at this auction:
Klick me

He sells silicone Layers from 0,3 mm on, perhaps its a nice one. I gonna contact him for more Photos.

By the Way, this product is made of normal silicon, is there a big difference to silicone rubber? I think silicone rubber is more, yeah like a rubber (more soft). But perhaps it will work!?

Greets

I wonder if there is some material that does not stick to silicone. If so, shouldn’t it be possible to create thin layers?

I currently do some experiments with different foils, also textured ones (normally used to put documents in there for protection).

I think this is getting into material research

@jan: I had the exact same problem with the viscosity of the silicone. It tends to cure very fast in the beginning and is quite sticky in the moment it’s released from
the tube. Tinkermans silicone maight have just the right viscosity during release from the tube, and after that he has only a few minutes to work with it.

As i found out, i just got the wrong one, cause it was “extra” fast curing stuff for isolation :-(

Also, i think the working process is very important. One has to be very precise and handy with the tools avoiding wrinkles, do the right movements, etc.
So it just takes some training i guess.

@tinkerman: i suppose you didn’t get the the best result with your first try, did you?

As it’s not so easy to get GE 1 round here (it may be there, but with other labeling and stuff), i also look around for other silicones.
So far, i just got some very cheap 1,99 euros silicone from the hardwarestore ( bauhaus ), it has some more viscosity, but still not the best.

Currently i still try to create separate textured silicone sheets. Any results and i’ll post it on the forum.

chris.in.touch you should try PVA. Poly Vinyl Alcohol. It’s a clear liquid used as a mold release agent.
It can be brush or spray applied. It’s available in spray cans which I like. I’ve used it to do fibergalss molding
and it’s great. Nothing sticks to it. It cleans up with water too.

I’m thinking that you could spray this onto a sheet of cloth or other textured material, let it dry,
apply a layer of silicone using your method of choice and when it cures peel it off!

I’m curious… why is it that you want to make individual sheets of silicone rather than have it bonded to a substrate?

Hi Tinkerman,

first of all, many thanks for tip. Your knowledge is really helpful. It’s good to have experienced people to talk to

the thing about the sheet is, that more of an accident, i already ordered two large sheets of rosco. That drove me to that idea of a separate layer.
Cause i don’t want to mess it up.

The second thought was about the design. I really like the thought of having a black surface on the very top.
Actually the black rosco should cover the whole table, also the rim, where no projection is visible.

And third, i just liked the idea of having those layers i could easily remove or optimize individually.
And since the first tries where quite promising, i just don’t want to let that approach go

So forth: I just like the idea and i’d really like to get this working
If this approach would work, that would be great. I don’t have to mess up with the acryl, nor the projection screen. Everything would be nice and modular.

If i have some rosco leftovers, i’ll go and try do bond some of the silicone to the rosco + a texture to the acryl side.
I already got some silicone-polyester(=fabric) sheets as a result of your approach, and i wonder if i could modify it a little and bond the silicone
to the rosco. I wonder if somebody already tried that.

We’ll see

Hi Tinkerman,

i just have another question about silicone
Since now, i only produced very thin layers, that are very transparent (as long as the layer is really thin), using transparent silicone from the store.
I just wonder if GE 1, when you make it a thick layer (like 1 mm or so) gets opaque.

I am just curious if i could get a silicone that is more transparent than mine, or if it might be similar in behaviour to GE 1.

I am also looking forward to try your painting technique to get nice thin layers, also i am a little unsure to use xylol, cause
it’s not very healthy, though (well not many chemicals are ). Might try ethyl acetate to thin it.

As far as thickness and opacity, it stays somewhat clear up to about 1mm thick, then it gets a little hazy. Even at 5mm thick light will still pass through but it will get very diffused.

So that matches with my type of silicone. It’s 1,99 from the hardwarestore. So i guess that will do. Thin sheats have a good transparency.
So i’ll go with that one