Yes aluminum can be welded.
I hear it may actually weaken the surrounding aluminum though. It should definatly repair the problem for a while at least. Probably worth doing vs replaceing.... (a lot cheaper) and should last for years.
BUT FIND A GOOD WELDER! i had a bad welder "repair" my TheMightyHobie18 rear beam.... (cracks underside at the beam bolts)
i gave him spacific instructions and when i wasn't looking.. he grinded off the rivets that held internal part in place
I stupidly gave him another try and have him an upper casting to handle some small stress cracks.. and he ended up breaking the casting completely.. then added about 4lb of metal to it to "fix" it... and he didn't even get it back on straight... (nor did he even remove the hard edges... it was razor sharp).
$350 later i purchased new castings.
Where in FL are you?
I HIGHLY recommend Brian, the welder at JSI in st pete (he is a good friend and does stellar work)