Pre-heat for stick weld?

[AHNC]

I run 6010 & 7018 rod. I don't weld that often and I store the rod in the metal screw top container inb my basement. When I'm going to be burning some rod I take the probable amount of rod I will need and stick it in the wifes oven on a cookie sheet. Gets rid of any moisture in the flux and makes the cookies taste great

 

[Mace Canute]

When you pre-heat steel with a propane torch, what you will initially see is water vapor from the burning propane condensing on the steel surface.... :laughing::laughing::laughing::laughing:
When condensation will no longer form on the steel, it is probably hot enough.

The higher the carbon content, the more prone to cracking on cooling, this obviously includes cast iron.

X 2! grin

 

[slowzuki]

x3, not much water in steel, its condensing out of the exhaust vapour of your torch. Once its above the dew point it stops depositing, once over 100 C it boils off whats there quickly.

X 2! grin

 

[jake98]

This will make you guys feel better about your welds. First pic: older 6013 rod with no pre-heat; #2: switched to new 6011 with p/h; #3 more big-bugger welds; #4 I think it will pull two 14" bedder disks.
Maybe Shieldarc was pulling my leg about the water. Wait till he sees my trim and tile work.

 

[Shield Arc]

Yeah that pre-heating is a wife's tale. Nobody really does it! :laughing:

 

[jake98]

This was what I was trying to do.
Thanks to all for the input.

 

[Willl]

The crane boys at work do it when welding up cracks in the container crane legs.
They use a temp crayon and draw a circle around the area and heat with a rose bud till the crayon melts.

But that's them. Here at home welding up tractor implements it just ain't going to happen.

 

[SPYDERLK]

[[[When you pre-heat steel with a propane torch, what you will initially see is water vapor from the burning propane condensing on the steel surface.... :laughing::laughing::laughing::laughing:
When condensation will no longer form on the steel, it is probably hot enough. ]]]

The higher the carbon content, the more prone to cracking on cooling, this obviously includes cast iron.

Yay! ... saved me reading all the way through before posting to clarify that! :thumbsup:
larry

 

[JB4310]

well I 'm a hack welder, been welding for 30 years in support of my contracting business, trucks, tractors, trailers, snow plows etc. Nothings ever broke that I welded, though I've seen individual beads fail on something I've welded, it's backed up by so much extra weld and support that it's not coming apart.

Until fairly recently, I never had a clue that there was so much science behind welding, I'd plug in my buzz box, connect a ground, grab a rod, and I mean any rod I could find anywhere, didn't even know they had numbers on them. then proceed melting rod and making alot of sparks.

Now I have a small mig, an AC/DC box in the shop, and a portable DC for remote or jobsite use. when I want to weld now I have to refer to manuals and rod and steel specs. it was simpler being a dumb-butt.

I've never preheated, and I'm often welding in cold temps and heavier metal, no 5x5 but up to 1 inch plate or bar. the preheating makes sense and I will try it next time I have heavy cold steel to weld, maybe it will help me to not struggle so much.

Thanks for the thread,

JB.

 

[k0ua]

I've never preheated, and I'm often welding in cold temps and heavier metal, no 5x5 but up to 1 inch plate or bar. the preheating makes sense and I will try it next time I have heavy cold steel to weld, maybe it will help me to not struggle so much.
Thanks for the thread,

Same here, I seldom weld cold metal, and usually it is 1/4 or 3/8, but still good to know, thanks
James K0UA

 

[Soundguy]

i never preheat on mild steel.. but do on picky stuff like cast iron. have had great results with that. must have at least 4 CI welds here recently with no ill results..

one of em was a repair cleaning up someone else's hack welding job where they really mauled a loader bracket.. spider webbed it everywhere..

soundguy

 

[R W]

Certain machinery manufactures used steel of a higher carbon content, this could sometimes be prone to cracking, preheat may be advisable in this situation although I have seen a great amount of this steel welded with a
7014 rod, the only preheat would have been from the goughing/grinding in the joint preparation.
Welded worn slip down chisel plough points together to make one a great many times, the only preheat was from grinding the V joint (they were 1/2"
thick), used a 7016 rod.

 

[jake98]

Is there no practical way to determine the carbon amount? You know, other than asking old carbon-credit-Al to take a look at it?

 

[Shield Arc]

You can send in your material to a lab and pay for a Spectro Analysis.
Or you can read this.

Guide to Buying Steel Online | Online Metals Guide to Selecting Metals for Your Project

 

[spo307]

being a welder, I never preheat steel, unless it is cover with snow, ice, or rain, most important is that the area 2 b welded is clean, and your welding rods are not stored where they can get moisture in them, when stick welding aluminum I do pre heat with a torch 2 get moisture out.

 

[Jstpssng]

Yeah that pre-heating is a wife's tale. Nobody really does it! :laughing:

Dumb question; in the second (right hand) pic is he preheating because of the difference in steel thicknesses?

 

[NC tractor driver]

For most of the stuff we do it's not necessary to preheat. I used to work in a power plant and sometimes doing repair on big drums and headers we required a significant amount of preheat followed up with UT and X-ray inspections.

 

[Shield Arc]

Jstpssng I really don't know the reason why he is pre-heating, I stole that picture off the AWS site. According to the thread he was getting ready to take a 6-G open root, test w/ restriction ring, with dual shield and SMAW. There could be a multitude of reasons for the pre-heat. I don't remember him mentioning why either, could be as simple as too take the chill off the pipe. Some guys like to pre-heat before a test, especially a bend test. Depending on the type of material the WPS may specify a certain degree of pre-heat. Like I said a multitude of reasons.

 

[Jstpssng]

Jstpssng I really don't know the reason why he is pre-heating, I stole that picture off the AWS site. According to the thread he was getting ready to take a 6-G open root, test w/ restriction ring, with dual shield and SMAW. There could be a multitude of reasons for the pre-heat. I don't remember him mentioning why either, could be as simple as too take the chill off the pipe. Some guys like to pre-heat before a test, especially a bend test. Depending on the type of material the WPS may specify a certain degree of pre-heat. Like I said a multitude of reasons.

Thanks, I was just curious.