My Flawed Thinking About Double Barreling

[willw9]

So basically I feel like I double barrel way too much, and it's costing me a lot of money. The following hand is a good illustration of spots where I double barrel often (probably incorrectly), and my thoughts follow.

Full Tilt Poker, $2/$4 NL Hold'em Cash Game, 6 Players
LegoPoker Hand History Converter

BB: $140
UTG: $1,022.80
MP: $534.10
Hero (CO): $400
BTN: $364.90
SB: $652.30

Pre-Flop: K[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/heart.gif[/img] dealt to Hero (CO)
UTG folds, MP calls $4, <font color="red">Hero raises to $18</font>, 3 folds, MP calls $14

Flop: ($42) 2[img]/images/graemlins/diamond.gif[/img] 8[img]/images/graemlins/club.gif[/img] 4[img]/images/graemlins/diamond.gif[/img] (2 Players)
MP checks, <font color="red">Hero bets $33</font>, MP calls $33

Turn: ($108) A[img]/images/graemlins/spade.gif[/img] (2 Players)
MP checks, <font color="red">Hero bets $80</font>

Villain here is like a 50/15 donk. Preflop, his range is obviously very wide. The flop is standard obv, but then the A hits the turn, a standard card to double barrel. However, there are many draws on board. I think, and I don't think that this is correct, but I think that double barrelling this turn is kind of merging your range. Villain folds out a lot of one pair hands like 2x, 4x, 8x, 33, 55-77, but if he calls, we are also getting value from a ton of draws that only have one card to hit.

Is my reasoning spot on, or am I just an optimistic fabricating spewbox?!!