I used “seasonal removable” silicone caulk selant. Its ment to be used in the winter outside and can be removed in the summer The guy at the hardware store suggested it when I showed him the DAP brand Christopher used. Don’t know if the removable part is the key.
i don’t have much options here in my city .... the only silicone i have access to is the aquarium tank sealant ..... it can be removed easily if things go wrong ... so thts not a problem ... the FTIR effect is also good ... trasparency is good ..... just tht the layer which gets formed comes out to be uneven (my mistake) ... and some left out bubbles .....
wats the solution for the bubbles u said ?? ... can u plz elaborate on tht .....
1. Poured the solution into a second paint can through a paint filter (which also makes it a slow pour).
2. When pouring onto the acrylic I also poured through a second paint filter. I did this standing up . as Adam pointed out, the longer the pour distance, the less bubbles you will get, because the bubbles can escape while the silicone drops. When I used metal rods for the scrapping, I also got much better results that with the wood i used the first time around. You can see the materials I used in the video I posted here: http://nuigroup.com/forums/viewthread/1069/P45/#8248
**Don’t use baby powder*** I said that in another post, but I’ll say it again.
When I used Lexel, it poured with a consistency of warm honey. Adding more toluene was like adding warm water to warm honey. Eventually the bubbles will all surface (thus making them easy to pop). The 100% silicone caulk I tried smelled awful and was harder to mix, difficult to pour and spread, but I did try it first, so you learn better by the second attempt, which for me was the Lexel. But the Lexel is very fluid when thinned properly and doesn’t need to be “spread” by a tool as it will evenly cover a perfectly even and level surface.
@Christopher
am not moving the acrylic at all .... the silicone dries quickly ... and over the last passes of the strip .... it sticks to the strip and forms waves and lines ..... so i shud stop after 2-3 passes ... and in those 2-3passes .... a few bubbles remain over the surface......
I have a couple of small bubbles in one spot and about 4-5 larger bubbles over all that do not show show up on the camera image at all. So i dont think a few bubbles create much of a problem, you just dont want bubbles everywhere to keep it as transparent as possible. The Lexel might also work well. If there is an online retailer, I can send it to India for you if you are willing to pay for it and the shipping. I can also send you the stuff I used which I can get at any hardware store around here (Iowa City, IA, USA) I have one tube left I dont need anyway. You can PM me if you want me to send you some of the stuff.
thnx thomas for all tht support ... will let ya knw if i need lexel .. or the stuff u used .... in tht case ill bear the total cost of stuff + shipping ...
Ok i understand thats to much solvent or a to big layer… Theres retarder sold for this kind of purpose its really easy to find by here but i dont know in india.... It allow the product to dry slower and this way it cure egal without the ripplng effect your are describing… Maybe you could try to fill those wave with the product like Adam does....
I never tried it, but I think its more of a oily substance like W40 since its called lubricant. Sounds messy if it doesn’t dry. On the other hand it seems easy to test and if it would work might be cool.
Adding more materials is only going to increase the refraction of all lightwaves as they pass through each different material. If you were using electromagnetically identical materials it wouldn’t matter because of evanescent wave coupling. I have tried reproducing Jeff Han’s TED demo setup based on some close-up photography and I suspect that he is using (top down) transparent mylar, Rosco Grey, silicone (or possibly Lexel), then acrylic. My tests using this ordering were better than the transparent mylar, compliant surface, acrylic, Rosco Grey ordering, though that did work too. The only way I know to completely remove air gaps or “bubbles” that occur when you put something over the compliant surface is to apply it while the compliant surface is still wet and curing. I know this is dangerously irreversible, but if that is _the last_ issue you are trying to resolve, then that’s the solution. Otherwise, see if a better camera works. Believe it or not, spending $300 (US) on a high fps IR camera like the FireFly MV with the proper filters will make all the difference in the world. You wouldn’t believe how totally sloppy you can be with your setup (and still have it work!) if you have a good camera.
