@ Bodif,

i uset white spirit to thin the silicone

yes , it’s the problem , i did those test last week with spirit and i had the same prob,

cheers,

i found it hard to get toluene or xylol in Ireland
but i’ll keep looking
or is there anything else I can use ?

i tried with Aceton but it’s hard to dilue the silicon with .
for now the best result i had is : straight silicon.

yes, but isn’t that harder to put on a uniform layer

my table is quite big 1200x1600 mm so i’m not sure I can get a even layer of silicon on it if i don’t roll it

you can roll the straight silicone, just a bit harder but it works,
put some silicone lines (like a grid ) on the sheet of Rosco and roll it .
Make sure the Rosco is well attached ( since you apply quite some force to spread it ).

oh, you applied the silicon straight on the rosco?
does it work well?

i used rolled it on tracing paper.
so i had: acrylic
silicon on tracing paper (silicon side down)
rosco

Hi,

we had also big trouble with our Compliant Surface. After reading this post I tried the roll-On method with tracing paper. I used regular Silicone and mixed it with “Nitro-thinner” (Nitroverdünner in german, there is Xylol inside). It needed a long time to cure (4 days).  The blobs were nice and it didn’t stick to the acrylic (that was the main problem we had before) but the paper was not perfectly even anymore.

Finally I tried the Roll-on method directly on Rosco Grey (80 x 60 cm). I didn’t even thin the Silicone. I used regular Silicone from the hardware-store and rolled it onto the Rosco. Without thinning you have to push harder, but it works since the silicone can be better distributed due to the plastic material of the Rosco. The result is the best we got so far. The blobs are bright and since the Silicone is with a fine bumpy texture it doesn’t stick to the acrylic. The Projection is as you would expect it with Rosco. For us this is the best solution we achieved so far.

hi

silicon on rosco it is then (I have not used rosco gray again, does it matter what side you use)
one layer only, yes?

cheers

i applied two layers , and i will today apply one more .
i finally get xylol , so i will try it also to compare

I applied one layer on the coarse side (so you touch the smooth/glossy side).
@Jimihertz: Did it get better with more layers?

right , the 3rd layer gives good result , brighter blobs .

Humidity can increase the time, compare the white stuff to the xylol ingredients and see if they match or they differ greatly. One ingredient off can cause a completely different effect.

The three betholyicols (or whatever there called) oxidise with oxygen and completely remove themselves from the silicone over time, so after you roll it on, its just silicone.

i just did a layer of silicon on rosco, no thiner
i’ts been two hours, no change of curing
i try the second one in the morning

thanks guys
bodif

Tinkerman couple of questions.

I am using the drafting vellum from OfficeMax a friend of mine had a roll and I snagged a 5 foot piece.

One problem I am having is even after thinning the silicon (same brand/kind you use) with acetone it rolls on ok, but causes my paper to crease or bow up in some areas, is there a way around this or am I just doing it wrong?

Also is it okay to ‘touchup’ one spot on my vellum hickuped and was uneven with the rest of the surface I tried to remove it and took a huge blob out :(

Sure it’s OK to add a touch up spot. Just blend it in with the roller.

I masking taped the edges of the vellum down to a smooth surface, rolled on the silicone, and after it cured I cut the tape away and lifted out the coated sheet.
It didn’t curl or wrinkle doing it this way.

Here’s the how-to vid I did for anyone that missed it earlier in the thread.