Sam

First off welcome.

Secondly... You were ok posting in the technical section..  The same guys pretty much read all sections  :)

Allan really said the important things you need to hear. 

Short circuiting transfer even with .045 electrodes is a process truely designed for thinner materials and not heavy plate.  What your trying to accomplish (short circuit on thick plate) is an unwise production practice period.

Your gas and wire as described are apropriate for spray transfer with 90/10 gas and something around 27 volts.  However getting spray transfer to run vertical uphill travel is a very difficult thing to do... and just as unwise in production as short circuiting transfer.

I could be wrong but reading between the lines it sounds like you are already into production and are trying to qualify your welders behind schedule. And all this without even a WPS in place..  (tough spot to be in)

I think your best options all include biting the bullet.

  #1  invest what it takes to rotate your parts into the horizontal position and use spray transfer

  #2   FCAW

Those .045 short circuit welds run vertically may look nice on that heavy plate... But I would bet a paycheck that they have lack of fusion issues both at the root and the sidewalls.

Can some golden arm pass an unlimited all position set of test plates in short circuit mode and .045 wire?   Yes..    Could a PQR including tensiles be run the same way and pass?   Yes.         That does not make it a wise production practice.

Trying to back qualify your welders and procedures to the *WRONG* process is going to be nothing but trouble.

Sam... What Allan told you  (no)    Really was all the help you needed.  It may not feel like help but it really is.

Our shop has used GMAW-SS for 10+ years now for 3G welds on 6 x 6 x 1/2 square tubing. Full penetration from one side. You could go 0.45 and the 90/10 mix, we use 0.35 and 75/25.  You are correct, you will have to qualify short circuiting transfer under section 4, no way around it. If you can do it, you would be better advised to use pulse. In our case we often have to go through a lot of preproject gyrations with customers due to the selection of process on our part. Many of our customers have metallurgists/welding engineers in their employ that are highly suspicious of SS on heavy plate. Our company has never had an issue with a failure in the field, and its hard to imagine a failure producing a life threatening situation with our equipment, but we still encounter a lot of resistance on this point. For the most adamantly opposed, we often have to specify 100% UT in order to satisfy their objections to the process. At one point we did try FCAW, but the distortion during welding was at an unacceptable level.

the way I look at it, is that if you're running a welder qual, it doesn't matter if it's a preapproved process.  run it in SS and qualify the weld procedure and welder at the same time.  A lot of combinations of materials and such would make it impossible to do a welder qualification with a preapproved procedure. switching to 85/15 or 90/10 in my opinion would be the right thing to do, but running parameters into spray transfer for an out of position weld usually isn't  advisable.

just my 2 cents.