what size should i go with for my primaries and my log... .045 or .065 ?? or other???

im using a 1 3/4 primaries and a 3'' log...



please help im wanting to order my steel parts tonight

 

.045 wow thats thin. I use .109 wall. Thinner mild steel will be more forgiving, thinner stainless is more prone to cracking. If you design it decently to be structually supportive (brackets, overall design) thin stuff can work fine. You just have to keep in mind this stuff expands and contracts through every heat cycle.