Now that I have both a 10' and 12' Jon boat,I am looking at possibly retiring the 10' boat ,but before I do that I want to "pimp" the 12' boat to my liking. (Actual length according to the paperwork is 11.6') liking.

I was thinking of building a deck for the front of it so I can stand up and fish. I currently have to sit down to fish in my 10" boat and im missing opportunities to pitch and flip,and sitting down,I believe may hinder my casting distance,hookset and bait presentation in some occasions.

So I guess what im really trying to ask is,Is this 12' Jon large enough of a boat to put a deck on,and has anyone else "decked" a 12' Jon boat with success?

Have you tried the search function lately ?

Before you get all geared up to do that, go by Lowes or HomeDepot and get you a 1/4 sheet of 3/4" plywood, then get on old cane pole or something that will float.  Don't have anything in the boat but the plywood, pole and wood paddle and put the plywhere you think you would like a deck.  Take your billfold, cell phone and anything else out of your pockets that you don't want to get wet.  Ease out into the lake and try to stand and use the cane pole like you're flipping.

I would recommend a life jacket also if you do this in water over your head because in that small of a boat, you're probably going to get wet.

I wouldn't fully deck a 12' unless it's 48" or wider.  I put a floor in my 12' and a mini deck up front for storage and a TM mount.  I sure as hell wouldn't want to stand on a full deck in it.

You could try standing on the bench tops and walk around.  It'll give you somewhat of an idea how tippy the boat is.  But the boat will be more tippy once you deck it due to it being top heavy.  Decking a jon can be quite expensive, so you definitely do not want to spend money on an inadequate sized vessel.  Bottom width is the key to your answer. 

I agree with SoFlaBass on this one... Tinboats.net (hint hint) suggests decking anything over 38" wide. You're going to get too tippy with anything smaller. Now, personally, I wouldn't deck anything under 42" wide, but I have the balance of a drunk middle aged woman at a wedding reception...

I added a floor, slightly raised approx 3-4" off the old floor on an aluminum 12 footer I had, mounted a pedestal seat and it was still a bit too tippy. Decking a 12 footer, unless it's 4' wide at the bottom, is a recipe for a unexpected swim the first time on the water. As W2S said, wear a life vest at all times if you do it.

You should PM Speedbead.  He did some nice work on his boat.