HELLO, WHAT DO THE PRO'S ADVISE ABOUT SOLDERING JOINTS ON TRACK LAYOUT'S, I HAVE ALWAYS HAD A COUPLE OF HESITATION AREA'S ON MY LAYOUT, THAT NO MATTER HOW MUCH CLEANING OF THE TRACK AND LOCOMOTIVES, I STILL HAVE THOSE SLIGHT HESITATION AREAS. I AM WONDERING IF SOLDERING IS RECOMMENDED BY THOSE WHO HAVE HAD MUCH EXPERIENCE WITH MODELING. ANY ADVISE WOULD BE MUCH APPRECIATED AS ALWAYS, THANK'S IN ADVANCE Y'ALL