What do you guys use to put the carpet down to your platform?   Heard of carpet glue but i dont want to get the wrong stuff an find out the hard way

Outdoor carpet adhesive. Get it at Lowe's or Home Depot. Use a roller to apply carpet to roll out bubbles. I used a heavy wooden baker's rolling pin.

Outdoor carpet adhesive for outdoor carpet?  What a unique idea!  Gosh, I was planning on using Elmer's wood glue.   :

BTW, I really like the idea of the rolling pin. 

The heavy rolling pin works great with a heavy guy pressing down on it too.

Henry's 663 adhesive is what you're looking for for the flat surfaces. It's available at Lowes or HD. When you get to the corners and edges, you'll want to go to contact cement. I went with Weldwood available at Walmart, Lowes or HD.

thank you,  now to find time to go get it