I have myself a Millermatic 135 running Argon. I usually use .35 70(something) Silicone 6 wire. I also run .30 of the same stats.

I am a totally self taught welder and I do darn good (have not had a weld fail). I understand how to control the amperage and I understand the need for penetration and what it looks like. I feel comfortuable doing almost all in position welds, and have out of necessity done severel out of position (severe not the normal laying down, I am talking about having to hang with one arm and weld up toward yourelf with the other, lol)

Now given a little of what I am and how far along I am in my self made progress I have a question. What makes the 60 wires and rods penetrate better than the 70? I mean I understand the tensile streangth thing but I just am not getting what it has to do with penetration. Why does preheating make for better penetration? I usually use a figure 8 pattern is this acceptable or am I going through to much work (or not enough).

I am thinking about starting in on a suspension so I want to make sure I understand a few more things before I move ahead. Let me know if there is anything else I should research or look up and where to find it.

I have done severel winch bumpers and hitches and even a rollcage, but this suspension stuff is serious. (3 link is what it will be)

you need to go to one one the welded sites and look up rods, every welding rod has a code as in 6011 the 60 stands for the strenght the 1 is all position and i can't remember the what the last one stands for[been out of school to long]. 7018 is 70,000 psi [1 ]all position,[8 ] low hydrogen. it is the flux[sheilding gas when burned] on the rod that makes for differance in penetration. not the psi rating. co2 will give better penetration than a 75/25 mix.

When you are talking about 60 WIRES vs 70 I am going to guess that you realize you are ONLY really meaning 60XX vs. 70XX electrodes , and not wires (as in mig er70s-6 etc).
60xx series do not have more penetration than 70xx (dont bash yet READ this carefully)
example 6013 low penetration
7018 med penetration.
NOW 6010 or 7010 or 6011 (common) will be very deep penetration electrodes WHY? this has to do with coating composition only not the core wire. The number that denotes this is the Exxx0 for the 6010 (0 means cellulose sodium), and Exxx1 for the 6011 (1 means cellulose potassium)
Notes for you# Do not use a .035 wire with a MM135 only use .023 - .030 (amps are not there for .035)
Do not use a figure 8 this takes your wire out of the forward edge of the puddle which WILL lead to LOF (lack of fusion) if you must manipulate the torch use a small cresent moon type pattern( beast bet is to try to use stringer beads if you can ie no weave).

PREHEATING-------------
Just the other day a post concerning "what do my weldes look like" or whatever. I read someone give the advise --------preheat to red hot ???? WTF ever I wonder if that person knows how hot red hot is??? well its about 1050 to 1375F WHOA that breaks to cardinal rule of INTERPASS temperature which is NEVER weld on a assembly which is over 500F I adhere to 350F which is a good safe number.
While this person could argue that they haven't had anything break thats probably true also mild steel can generally take this kind of abuse IT IS a Bad idea & habit .
You really dont need to worry about pre heat unless your welding thick 1/2 to 3/4 ++++ steel which I know you're not or are dealing with 4130 or some other special alloy.
Howvwer since you are in AK if its below 70F in the shop you're working in you COULD heat the joints to be welded to 150F to sweat of moisture , and ensure no cold starts (LOF @ start of weld)
hope this helps.
weldpro

What's a stringer bead? (pull triger and move in a straight line or move in a zig-zag)

-------------------------------
or
/\/\/\/\/\/\/\/\/\/\/\/\/\\/\/\/


Why is that better than a cresent weave?
((((((((((((((((((((((((((((((((

Is there a better use for each situation?

I have always used a cresent weave for making 90* welds, and no weave for flat welds (butt weld?)

weldpro, i mentioned in another thread to preheat, but i dont think i said to redhot.... i usually watch the moisture leave, then weld.... i must admit i didnt know it was bad to weld with temps above 500............. always good to learn a few things....

It wasn't you badassjeppguy!
I wont name names but Since I replied to this I thought I would set it striaght.
weldpro

Eric its like this-----------------------------------

Thanks weldpro, that helped out A LOT!!

Lots of stuff to learn yet but with info like that from a pro I will be there in time.

I will post back if I have anymore ?? cause you da man in this area! Let me know if you need help with dogs in anyway cause that is sort of my area. LOL