I have a some cracks at the outsides of my bracket, twin 225 optis. Will it be OK to tig weld these small cracks to finish out the season before buying and installing a new bracket, they are only about a inch long, one crack on each side of bracket, and just barley bigger than a hairline crack, enough to slowly leak water in it. Biggest concern would be the electronics getting fried while welding it with the engines on it. Anyway to prevent that? Thanks

Take it to a reputable shop that repairs aluminum for the bulk of their business. You're probably gonna have to tear it apart to keep heat from burning up what is attached. A good welder will repair it well enough that you don't need to buy new (unless heat treated).

fresh water yes salt water mmmm maybe but good luck..

The boat has seen salt water, lived its first half of its life in the salt.

fixall is correct if it has been for any amount of time salt will get in there and do a good job of eating the aluinum

Unplug the electronics and ground as close to the weld area as possible.

If the cracks were present in saltwater, the area will need to be ground out to fresh aluminum and welded up. This is because the exposed aluminum will be a form of aluminum oxide which does not weld properly.

Not difficult to do, but don't let them just weld over it.

MC

Cracks became present after the boat went to fresh water, the cracked area was not there when I bought it. But I will never know the real story, it may have had fresh paint covering it? Biggest concern is the electronics on the optis when we start welding it.

I wouldn't fret too much about the electronics.
Aluminum welding, though, DOES involve high frequency current induced into the arc.

Disconnect the battery cables, clamp the positive and negative cables together, and turn the ignition keys on. Turn the breakers OFF to all accessory panels and such.

You've now got a path for spurious high frequency millivolt currents to "sink" and cannot build up in the circuits.

MC