Benefits of transparent silicone
Posted 05-16-2008 at 04:52 AM by twigling
Much excitement as I demolded those first pieces today that have two-part molds. I've just mixed up a batch of resin and poured into the new molds. The Shore A 40 silicone is a little firmer, but I think I really like working with it. Nothing wrong with the softer stuff, but it feels very solid.
The awesome thing about transparent silicone is that you can see the mold filling up and know when to cut off the stream of resin. Previously I would just pour (being in a hurry before the resin started setting up) and suddenly the mold would be full and overflowing and dribbling down the side of the mother mold. Not any more.
The other huge benefit is of course that you can SEE if there is any air getting trapped at the top.. and I did see some, but I think I'll be able to make some small mods to the molds using a scalpel to fix that up. Anyways will have a cuppa while I wait for the resin to set, then demold and snap a few shots of the results.
The awesome thing about transparent silicone is that you can see the mold filling up and know when to cut off the stream of resin. Previously I would just pour (being in a hurry before the resin started setting up) and suddenly the mold would be full and overflowing and dribbling down the side of the mother mold. Not any more.
The other huge benefit is of course that you can SEE if there is any air getting trapped at the top.. and I did see some, but I think I'll be able to make some small mods to the molds using a scalpel to fix that up. Anyways will have a cuppa while I wait for the resin to set, then demold and snap a few shots of the results.
Total Comments 8
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You would make an excellent salesperson for Polytek.
 You should be making commissions from them! Seriously, you're making this clear silicon sound so wonderful, I'm having to resist the urge to not kick myself for not having any to use. |
Posted 05-16-2008 at 02:38 PM by KitsuneUdon
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The stuff from SmoothOn is pretty much the same, just has a shorter curing time (4 hrs instead of 24) and mixes by weight instead of volume; also the part A and B of the Platsil are different consistencies so it's easier to know when it's properly mixed.
If I was going to collect commissions from anyone, it would have to be Aves, the makers of Apoxie.. I've touted their stuff for the last 6-7 years I think  |
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Posted 05-16-2008 at 09:31 PM by twigling
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oooh Therese, the clear molds sound delicious! What an absolutely fabulous thing for beginners to have as well. How does the cost compare to the blue or green stuff from Smooth on? Just thinking it might be really nice to have for the artist event if we can afford a few barrels of it.
And Aves! Thanks to you, they have made me a dealer : - ) Come and get your free samples here! |
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Posted 05-17-2008 at 01:28 AM by Catrina
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$166 for a gallon of SmoothSil 920 (cures in 4 hrs), but I paid more than that from the Australian distributor. It's definitely more expensive, but also more durable. A gallon of Moldmax is between $80 and $90.
Platsil 71-40 is $156 for 9.8 lb, but takes 24 hrs to cure... again high quality stuff, very durable.. Probably the best thing to teach people is how to vent and prepare properly with cheaper materials and move on to the good stuff when they have something for bigger production planned. I'd love to get a sample of the Aves Apoxie Sculpt Super White, but no hurry. |
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Posted 05-17-2008 at 02:27 AM by twigling
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I'm going to look into those. Seems the tear strength is lower than the Moldmax 20 and 30.. do you feel they are as strong as those?
Here are data from Smooth-On's site: Smooth-Sil™ 910 10 1:1 pbw, pbv Translucent 45 Min. 7 Hours 25.8 1.07 23,000 cps 102 pli 475 psi Negligible Smooth-Sil™ 920 20 1:1 pbw, pbv Translucent 25 Min. 4 Hours 25.6 1.08 20,000 cps 120 pli 550 psi Negligible Smooth-Sil™ 930 30 100:10 pbw Blue 45 Min. 24 Hours 24.0 1.15 40,000 cps 110 pli 575 psi Negligible Smooth-Sil™ 935 35 100:10 pbw Blue 45 Min. 24 Hours 23.5 1.18 40,000 cps 115 pli 650 psi Negligible Smooth-Sil™ 940 40 100:10 pbw Pink 30 Min. 24 Hours 23.4 1.18 35,000 cps 100 pli 600 psi Negligible Smooth-Sil™ 950 50 100:10 pbw Blue 45 Min. 24 Hours 22.3 1.24 35,000 cps 155 pli 725 psi Negligible C |
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Posted 05-17-2008 at 04:09 PM by Catrina
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I haven't used Moldmax so I couldn't tell you. But looking at the numbers, Smoothsil 920 has 120 pli/tear strength, only beaten by Moldmax 30 at 125, and 5 points difference I can live with. Also.. transparent!!
And Smoothsil sets up 20 hrs faster than moldmax. |
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Posted 05-17-2008 at 09:07 PM by twigling
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It's interesting that SORTA-Clear™ 40 appears to have a better tear strength and is cheaper per gallon than the Smooth-Sil™ 920. When I come into some money for more equipment/supplies, I feel like I should go that route.. Any suggestions or warnings that I may not be seeing? It's a 10 to 1 volume mix, maybe that's harder to mix accurately?
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Posted 05-19-2008 at 02:10 PM by KitsuneUdon
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If I was deciding between smoothsil 920 and platsil 71-40, I'd get the platsil.. I like the harder durometer.. plus its clearer. Platsil 71-40 is 5 to 1 mix, and it's easy because the two different parts are a different consistency, so it's easier to know when it's mixed.
What I do is I listen to the radio while I work, and spend at least ONE song mixing.. maybe more. Oww my arm!! |
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Posted 05-19-2008 at 10:25 PM by twigling
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Recent Blog Entries by twigling
- F-i-n-i-s-h-e-d!!!!!!!!!!!!!! (05-24-2008)
- Coming to a close (05-22-2008)
- Benefits of transparent silicone (05-16-2008)
- And [finally] we're away!!! (05-13-2008)
- Stupid or just ignorant... (05-10-2008)
