Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Hello there, today we will see a build about Blitzcrank on support.
So to introduce Blitz, it's a init/support/tank and in this optic we will stuff Blitz to be useful & resist.
So first we need to begin with a Saphire Cristal  to obtain Trinity Force Asap.
After getting the Saphire  get  boots of switness, you can also get Mercury's Tread to be more resistant against Magic damage.
After getting this boots you need to continue your Trinity Force by getting Sheen after Phage and finish by Zele. 1st Step done, If the game's great you can reach the Trinity for 15/20 minutes depend how the game is turning.
In this 2nd step there is two choices, you can take the Frozen Heart  or Force Of Nature depend how the against team is, but to be honnest i prefer the Frozen Heart for cooldown reduction could be very useful.
If the game is during and there's lot of stun get the Banshee's Veil or if it doesn't take Sunfire Cap, very useful in team fight causing damage for all are near of you.
I will edit this "build" to be more precise and try to get all of the options for Blitzcranck.
I would apologize for my bad english, i think there's a lot of correction needed.
On this, Keep rockin'