MakerGear Forum

Needed some flexible rubber lid vent plugs for some Pyrex food containers. You can't just buy the plugs, or even the lids separately. I printed a mold and stuffed it with oogoo (silicone caulk with a dash of corn starch to speed up curing). Works great.

I didn't have any corn starch; rice flour worked fine as a replacement. I think any hygroscopic fine powder will do.

From Home Depot:

GE All Purpose Silicone I 100% silicone is compliant for incidental food contact under FDA 21 CFR177.2600 "Rubber articles intended for repeated use."

You guys are just effing brilliant.

Any mold-release used? Or does it peel out fairly easily?

(Oogoo...Who knew?)

No mold release.

I had originally made a mold from the original with an epoxy resin. The first cast was less than perfect, but it released. The second would not release and the mold was unsalvageable. So I resolved to print a mold instead. Silicone doesn't stick to PLA.

As a side note, using calipers to get consistent dimensions of an object is surprisingly difficult. Measure A to B, then B to C, and the sum is often not what you get when you measure A to C.

jsc wrote:......Silicone doesn't stick to PLA.

That is great to know.....I did some mold work years ago, and the worst thing was to forget to spray it before you poured! (Wound up having to rebuild a bunch of molds.) I'd wondered about using the resins - I've still got a lot of it. But it is messy to work with, I'd much rather print them if they work that well.

Thanks!

Maybe I need to make a mold for custom soles for my shoes. I could resole my Nike Frees.

You should! I wouldn't use silicone caulk for that, though, way too soft. A sneaker sole is approximately 50A durometer (http://www.tested.com/art/makers/492594 ... k-u-shoes/, 7:30). In the comments, Frank says he used Vytaflex 60, which is a little harder than the originals; it also comes in Shore A 50 (http://www.smooth-on.com/Urethane-Rubbe ... index.html). At 9:25 in that video they talk about how to apply the sole using Barge cement. At 10:40, he talks about maybe not wanting to walk around in those, and maybe trying a glue called "Renia" (?)