Difficulty soldering gold to argentium

I have recently made the switch to argentium and in general I am
very pleased.

However, I have been having difficulty soldering gold to argentium.
I have only tried 14k yellow. Would I have better success with 18k?
Or using a different solder? Any suggestions/comment will be greatly
appreciated.

Thanks.
L.J.
L.J. Smole
W.Fox Studio in Eureka Springs, Arkansas
www.wfoxstudio.com