I am not a professional by any means, simpy a mom making her kiddos birthday cake.

I have my daughter's birthday party coming up and she has requested a petal cake which isn't a problem. I am trying to find a recipe that won't melt in about 70/75 degree weather outside. I have tried making the buttercream with soley butter and it wasn't pleasant. It also started to look curdled, if that is the correct term. Last night I tried half butter and half Crisco, and it turned out much better. It didn't seem to hold it's texture very well. I have looked online and found recipes that are completely Crisco without any butter. Anyone have any luck with this?

Also, as I mentioned before the first buttercream I tried looked curdled after an hour or so, as if it the butter seperated. Am I not supposed to chill buttercream? The last cake I made in March I chilled in the fridge with the crumb coat, then after I decorated it with store bought frosting I chilled it again until time for the party. Can I not do the same thing with buttercream? Any tips would be greatly appreicated!!!

What buttercream and recipe are you using?  I use American buttercream, all butter, but have never had it curdle.  I have heard about the meringue buttercreams curdling, but you just need to whip it until it comes back together. Advice is dependent upon what you are using.  As far as temp, crisco will hold up better in the heat, but butter tastes better (to me). Regardless of type of BC, you can chill between coats and after it is done.

Anything 35 to  50% or so fat will melt in heat.

The party is outside so cant the cake stay  in an air conditioned space?

Many of our seasoned wedding cake pro's will not allow buttercream (of whatever sort) to sit outside even for wedding cakes.

They either refuse point blank to make it or make the customer sign a disclaimer for the melting hot mess it will be.

Its physics babygirl x

Thanks everyone! For whatever reason my account won't open, so I had to create a second. I ended up doing my buttercream with 1/2 butter & 1/2 shortening. Turned out great!!! I'll post a pic! 

After 7 months CC has finally let me access my original account. Yay! The half butter/half shortening has been my go to buttercream since April. I've done two outside weddings since and they both held up fantastic to the heat. Granted it was about 75/80, so it wasn't crazy hot!