Any advantage to pre-heating parts prior to stick welding?

markba633csi

markba633csi

Mark Silva
H-M Supporter Gold Member
Joined
Apr 30, 2015
Messages
11,255
I did a job this morning and it seemed like re-striking was easier on hot parts vs. cold- Don't know if the overall bead is
better- seemed like the bead got smoother as the parts warmed up. Used 6013, 105 Amps AC, 3/32" rods. 1/8" mild steel parts.
Mark S.
 
Hi Mark,
it generally doesn't hurt to preheat parts, but is not necessary in thin sections, due to the great amount of heat generated by the SMAW process.
some exotic metals won't weld right unless they are pre-heated. but most of those will be welded GTAW.
thicker cross sections may require preheating considerations from 300 to 400*F.

6013 is an easy to start rod and you are up there at 105 amps for a 3/32 rod, you shouldn't have much arc starting problems-
it wants to weld, and you'll get the deepest penetration at the max amps
you'll have a harder time trying to start 3/32" 6013 at 75 amps, the melting flux would try to extinguish the arc- especially if the arc length is long

now 7018 can make restarts interesting, it creates a bubble of slag over the end at the wrong times, you gotta strike the arc with hard tap instead of a drag
 
Last edited:
You're right Mike, 6013 is an easy "beginners" rod and I've had good results with it. The slag can be a bear to chip off though.
I get a lot of rod sticking at below 90 Amps so I've been keeping it up there on the current.
I have a hard time controlling a full length rod so I like to burn off about a quarter of it on a practice piece, kinda wasteful but I get better welds in
those tight 90 degree situations where you need a steady hand. I did a nice one yesterday, one of my best yet.
Mark S.
ps Do you consider 1/8" material thin?
 
Last edited:
Hi Mark,
use the technique, that you feel the most comfortable with.
if it wastes a few rods, but you get good results- you won!

1/8 would be considered thin.

my test plates in school were 3/8" thick, we didn't preheat them even when testing.
 
Depending on the material being welded and the type of rod used you may have to pre heat and even post heat. I've welded cast iron and the rod manufacture recommended pre and post heat. Other cast rods with high nickel content required no heating. As said above some exotic alloys require heating. Normally mild steel doesn't need any heat the rod will provide enough.If your welding other than mild steel, do some research on the welding methods recommended. The different rod manufactures provide a lot of good info.
If you want a real easy rod for flat work only on mild steel get some 7024 also called jet rod. Just start the arc and lay it down all most fool proof, but its only good for flat welds. 7018 is good all round rod great for all positions.For deep penetration use 6011 also known as a fast freeze rod. This rod is used a lot in the pipe welding field for the root pass and then capped with 7018. Also keep the rods warm and dry, use a rod oven if you have one. If not an insulated metal box with a 60 watt light bulb works pretty good. Because 7018 is considered a low hydrogen rod it has a tendency to suck up the moisture for the ambient air. It's a good idea to keep all your opened rods in a warm dry place. If the package is sealed don't worry about it, store it any where
Once you have the basic technique mastered it's just a matter of practice, practice, practice.
 
I've read about 7024; does it work for AC?
I have some 7018 but I need to dry it first. Another project on the list: drying box. I better stock up on 60 w bulbs, another item that might go extinct soon.
I like 6011 for deep penetration and strength, I haven't been able to get as "pretty" a bead as 6013 yet.
Mark S.
 
6011 is not made for pretty welds, it is made for deep penetration and poor fit up.
it's used for root passes and it can be used for rough cutting steels in a pinch if you turn the amps up.
in normal use, if you can make 6011 welds that look like horizontally stacked dimes, you did good.
you use a whipping technique with fast freeze rods like 6010 and 6011- 6011 is an AC rod 6010 is DC
 
Do any of you bother preheating your 6013 rods?
I seem to find the second half of a rod welds better that the first half and had put it down to the rod warming up - but it could also be that it is just shorter so I have more control over it.
 
Hi guys

I also preheat cast iron with a flame and weld it and let it cool down on its own AWAY from any breeze otherwize it cracks right on the middle of the weld.Anyhow that is my experience. All welding for me comes down to a lot of practice and a steady hand.

My 2cents
Michael
 
6011 works best on DC electrode positive, 7018 is good for AC or DC but you'l get better results with DC. All my welding is done on DC electrode positive .Best to check with the rod manufactures as to the best polarity and weather it should be AC or DC this info should be on the box the rods came in. DC is the most common. If I'm doing any critical welding I heat the rod no matter what it is. All rods will benefit from keeping them hot and dry, even SS like 316L, 309 Half an hour at 150 F in a toaster over works very well. Cast iron will crack depending on the rod an weather you post heat or not. Eutectic makes a great rod for cast, high in nickel burns with a pink arc no heating needed.
Keep a supply of the most common rods, 6011 or 6013, 7018, 316L for stainless. 309 SS for welding SS to mild steel and some cast rods. 3/32 and 1/8 dia rods is all you need. I do have some 1/16 SS for the real small jobs since I don,t have a TIG. And remember practice, practice
 
You must log in or register to reply here.
Back
Top