I'm going to use Mold Builder to create the mold but don't understand why I need to remove the bottle cap and replace it with a cork. Can someone tell me why? Or can I make it with the cap on?

I left my cap on, not sure why your not suppose to. You might want to check out makeyourownmolds.com, they have a tutorial on bottles

I saw that tutorial, that's why I'm asking. I don't understand why the mold builder tutorial has the cap taken off and replaced with a cork. I wasn't sure if it had something to do with Mold Builder. I also like the idea of filling up the mold and then pouring out to get an even coat.

Ren15 did you make your mold with the cap on it? I am going to make a mold tonight and was wondering if I really needed to remove the cap. Thanks

I think they are removing the cap because you run the risk of tearing the mold when you pull it off. Plus I think it would dry faster than having the mold builder in the grooves of the cap. I removed the cap when I made mine. Saved it to make the gumpaste one for the bottle. There is a photo in my pics.

Well I tried it with the cap on and it didn't tear the mold (yea!). As for the mold builder...this stuff took me almost a week to make.

lol....I made my mold with the cap on as well and it did not tear. took me about three day with drying and several coats to make the mold thick and sturdy enough... it helped give a little insulation when pouring the hot sugar....that stuff is hot!!!!!!