i use CMC or gum tragacanth to make it harden quickly
Short answer no. Royal icing is a better medium to attach the handle with. If you put fondant in the fridge or freezer condensation forms on it when you bring it out and it will soften the outside of the fondant. This means that any fine work will 'melt' and it won't hold.
CMC, tylose and gum tragacanth are all powdered gums that can be kneaded into fondant to make them stiffer and harden quickly. CMC and tylose are less expensive than gum trag and you can use the paste immediately; whereas gum trag needs to 'mature' overnight.
I use my first impresssions molds all the time in the freezer and have no problems with them. The gumpaste gets a little tacky when you first bring them out but as long as you allow them to air dry without handling them they work just fine. And I have accidently left them in the freezer over night and had no problems with them. I made one of the babies with the baby mold and forgot it last week unmolded it the next day and it held all the details just fine.
I am not sure about attaching a handle to something with this method though. I have just used the molds in the freezer.
I do the same when i have to use an intricate mould, but I don't think it would work for what Renee is talking about. I mean when you take the piece out of the mould it's tacky and has to dry. The fondant stiffens enough to unmould without losing the detail, and then you leave it to dry. It' doesn't dry just freezes. I would think that once it thaws it's still going to be too soft to hold a handle.
You got some great answer....I just wanted to say Hi....Hopefully will be back on FB soon...long story....
I think a blob of royal icing would be the best option. It dries quickly and dries really hard.
Jerri's right about placing the fondant in the freezer when you use intricate molds though, especially ones with lots of undercuts. If you try to un mold the icing without freezing to firm it, these pieces will distort when you try to get it out. Once it's out you leave it to dry and just DON"T touch it for a while. In my case I also have to put it into a sealed container with some dessicate because of the humidity here - I don't want to add MORE condensation than absolutely necessary. If I leave it out to dry it melts the details! I can tell you that it's really disturbing to see the baby with melted features, although if I ever have to make a cake with pod people as the theme this will be the technique that I'll use. ROFL :D
So what is the best method to attach the handle to the umbrella? Royal icing?
I've found that if you put them in the oven but only turn on the light, DONT turn on the oven. It works awesome for me. I've found that if I put them in the freezer they sweat and I don't particularly like that so the oven works great :)
Humidity is something I don't worry much about. Once something comes out of the freezer it dries nicely... If there is enough solid area on the umbrella, you could use a half of a toothpick to run into the handle then into the umbrella... if not the royal might be your best bet.