If you are fairly new to Titanium, you might want to watch my Biggest Mistakes Titanium video ...you can see it right here 

A 3g test on titanium involves a few key things to increase your chances of passing.

Since most tests like these are x ray tested, cleaning the metal properly is a key factor in preventing porosity.

There are many ways to clean titanium prior to welding but here is what I have found to be effective.

• wipe test plates with acetone and clean lint free cloth to remove any oils or debris
• next use a clean new file to smooth the edges to be welded. Often times, this edge is a sheared edge and can trap contaminants.  When you think you have filed enough, file a little bit more.
• use a fine bristle stainless wire wheel with a drill or low rpm grinder and light pressure to remove surface oxides
• make sure fixture is clean
• wipe the plates one final time and install in fixture
• also wipe filler metal with acetone prior to welding
• snip end of wire before every restart

Fixtures are all slightly different so if possible, run a practice plate to determine the right argon flow rate for both fixture and cup used.