On a tank that size I would never even chance a "field repair". I would just order a new full frame and not worry about it blowing out some day. Here's the important part to think about...it's not the mess of 180g of water, all your fish, and whatever decorations you might have ending up on the floor....it's the chance of you, or someone you care about standing in front of it admiring your fish when that front glass blows out and cuts anything in it's way in half.
JMHO