3 of 13
3
Tinkermans method - Casting Textured Silcone
Posted: 10 July 2008 04:59 PM   [ Ignore ]   [ # 31 ]
Avatar
RankRankRank
Joined  2008-06-01
Total Posts:  338
Sr. Member

Huh huh umm yeah… three GIGA bytes. wink

 Signature 

Blobs the likes of which even the Gods have not seen!

Profile
 
 
Posted: 15 July 2008 06:57 AM   [ Ignore ]   [ # 32 ]
Avatar
Rank
Joined  2008-05-28
Total Posts:  42
New Member

I rolled on two layers of thinned silicone onto a clear foil (100% transparent) to find out how strong the diffusion will be.
So i got this result. I could not find out from the video, cause you put it directly onto the vellum, so i tried this.

Furthermore, i wonder if you’ll probably have the same diffusion on your layer on the vellum and if your silicone
is probably more transparent than mine (also i think the silicone i got from the store is clear, cause my sqeezed layers are almost 100% transparent)

So i wonder what effect this will have on the image (Don’t have a projector yet).

Hope i am on the right track.

Image Attachments
two_layers_silicone_rolled_on.jpg
Profile
 
 
Posted: 15 July 2008 10:58 AM   [ Ignore ]   [ # 33 ]
Avatar
RankRankRankRank
Joined  2008-02-12
Total Posts:  1120
Member

It looks like you have microbubbles… also what was the brand of silicone you used, I’ve had better results with DAP Draft Attack Clear Silicone.

Taha

 Signature 

Company Website - Knode Research and Development
My Youtube

Profile
 
 
Posted: 15 July 2008 11:16 AM   [ Ignore ]   [ # 34 ]
Avatar
RankRankRank
Joined  2008-06-01
Total Posts:  338
Sr. Member

Those are micro bumps I’d bet. wink

The bumps help the silicone spring back after touching so the roll-on method works well if it’s on the top layer facing down.

It will be interesting to see how your’s works applied to the acrylic. It may diffuse the light nicely and you’ll get a nice image. I don’t think it will degrade the image very much.

 Signature 

Blobs the likes of which even the Gods have not seen!

Profile
 
 
Posted: 23 July 2008 10:50 PM   [ Ignore ]   [ # 35 ]
Rank
Joined  2007-10-07
Total Posts:  7
New Member

thanks tinkerman for all the tutes!  i used your roll-on technique and it’s working great.  how many rolled layers of silicone did you end up using?  i used 3, but haven’t experimented yet with different numbers of layers.

again, MANY THANKS!

Profile
 
 
Posted: 24 July 2008 10:33 AM   [ Ignore ]   [ # 36 ]
Avatar
RankRankRank
Joined  2008-06-01
Total Posts:  338
Sr. Member
beeduul - 23 July 2008 10:50 PM

thanks tinkerman for all the tutes!  i used your roll-on technique and it’s working great.  how many rolled layers of silicone did you end up using?  i used 3, but haven’t experimented yet with different numbers of layers.

again, MANY THANKS!

I tried up to four layers but three seems to be fine.

 Signature 

Blobs the likes of which even the Gods have not seen!

Profile
 
 
Posted: 05 August 2008 01:21 PM   [ Ignore ]   [ # 37 ]
Rank
Joined  2008-08-05
Total Posts:  25
New Member

I tried two coats of roll on silicone, I cut it off when dry, but the vellum stayed attached, is that the way its supposed to work, or is there a way to get the silicone layer off the vellum? (I could not pry it off)

Do you think I made it to thin or thick? Im going to try 4 or 8 more measured experiments tomorrow, my first one wasnt measured.

It did, however, work touch sensetive wise, but I do not think the vellum will make a good projection surface.

Awesome find though tinkerman, and thanks for sharing.

Profile
 
 
Posted: 06 August 2008 07:13 AM   [ Ignore ]   [ # 38 ]
Rank
Joined  2008-08-01
Total Posts:  9
New Member

Thanks Tinkerman for the roll-on idea,
I tried the the xylene-roll-on mix, but it took ages to dry (probably because of the humid british weather). So I thought why is everyone so crazy about the xylene / toluene stuff, let’s try without it - and my first test piece works fine. All you need is a long ruler/board/spread-thing to smudge the silicone evenly over the tracing paper. After having done that, roll it, to give it the micro structure. The more you roll the more equal the distribution will be. That’s it - no xylene - and damn cheap: tracing-paper(~1£) + small paint roller(~1£) + silicone(~2£)

Profile
 
 
Posted: 06 August 2008 08:21 AM   [ Ignore ]   [ # 39 ]
Rank
Joined  2008-08-05
Total Posts:  25
New Member

Because tinkerman already did that too, with a squeegie thingi. This thread was for a different setup he was trying. You can do it either way

Profile
 
 
Posted: 06 August 2008 10:16 AM   [ Ignore ]   [ # 40 ]
Rank
Joined  2008-08-01
Total Posts:  9
New Member

What is actually the advantage in using the xylene then? Will the surface be smoother? A comparison might be good. I have the slight feeling that a lot of multi-touch building starters read around this board and come to the conclusion they have to order a bottle of toluene/xylene to get a working touch surface. That could give them a headache because this stuff is not so easy to get (in some countries - because of its use in drug production), and it’s an expense that might be not necessary.

In any case, the roll-on stuff is top - easy, cheap, works! Maybe someone could update the section in the wiki (it still says: Compliant surface overlay (material yet unknown) ) I could do it, but Tinkerman seems to be our expert here wink

Profile
 
 
Posted: 06 August 2008 11:14 AM   [ Ignore ]   [ # 41 ]
Rank
Joined  2008-08-06
Total Posts:  1
New Member

Thanks tinkerman for all the info. What grade (or translucents) of vellum works best? I need to build a 36"x 48” rear projection table. Here is one website with all the options. Matt on 1 or 2 sides? Thickness?

http://www.grafixplastics.com/drafting_film.asp

Profile
 
 
Posted: 06 August 2008 11:26 PM   [ Ignore ]   [ # 42 ]
Rank
Joined  2008-08-05
Total Posts:  25
New Member

Cool just tested a few more combinations. You can roll the silicone on the paper just one layer and it works pretty good, but it must be tough paper as its very sticky (i used one of the newer rollers, the foam ones, not the mop ones). The xylol helps to thin out the mixture for easier rolling, then evaporates pretty much completely when its dry, leaving just the silicone, so this is a better approach.

I think if you use enough xylol ( 2:1 ratio maybe ) you might not even have to roll it, just pour it on, as long as theres something there stopping the flow ( couple layers of tape, wood, exc )

The result of one layer of pure silicone or two layers 1:1 xylol/silicone is about the same, good points, tapping, or dragging.

I do NOT however have the drafting vellum required. Will try tracing paper, also do not have projector, so dunno what these things look like with picture on them, sorry =(

Profile
 
 
Posted: 19 August 2008 11:39 AM   [ Ignore ]   [ # 43 ]
Rank
Joined  2008-06-27
Total Posts:  42
New Member

Hi
getting ready to do my compliant surface
I have already bought the Rosco Gray so I better use it

just wandering which is the best option from the bottom up:

1 - acrylic, textured silicone on tracing paper and Rosco or
2 - acrylic , texture silicone straight on the Rosco
cheers

Profile
 
 
Posted: 19 August 2008 11:47 AM   [ Ignore ]   [ # 44 ]
Rank
Joined  2008-08-05
Total Posts:  25
New Member

Probably the silicone on the rosco, but i’ve heard that that leads to streaking, or whatever its called, trailing, thats it.

If you put tracing paper down, it will eat the projection, the rosco might still get some of the projection, but not as much as without the tracing paper.

Profile
 
 
Posted: 28 August 2008 03:37 PM   [ Ignore ]   [ # 45 ]
Rank
Joined  2008-06-27
Total Posts:  42
New Member

hi

i went on to do the silicon on tracing paper 112 gms
a have 2 coats os silicon and it is taken forever to cure
I rolled it on tuesdau evening, that is Aug 26 and now it is Aug 28 and it still leaves traces.
the humid weather in ireland
i uset white spirit to thin the silicone
maybe that is the cause?

thanks

Profile
 
 
   
3 of 13
3