When is it too cold to weld?

[Glenn]

What is considered cold, and when is it too cold to weld?

Do you preheat, weld, and post heat to let it have a controlled cooling? What is the procedure to welding when the steel is cold.

[fat pete]

funny thing, today I was with my teacherand he showed me how to do a faggot weld....he took about a 10x.125 x1.25 piece of rusty old left over mild steel, curfed the ends, bent it around to a circle and got the spot he wanted to weld aligned and clear of slag....then he heated it to a orange and sprinkled borax on it stuck it in his busted up forge...left it get yellow and shiny brought it out and hammered medium to light and repeated the process 2x ...it welded ...we then stuck it in the slack tub which was froze and hoped it didnt "pop"
it was maybe 25 degrees outside...he said "its welded but I wouldnt hang from it"....so my conclusion is it dont matter what the temp is except in the forge...it was a propane forgethat is in need of a repair desperatly so also confirms anything I heard from guys "you cant do it with propane" wrong!

[mike-hr]

When I'm making something and I'm concerned about sticky welds, I preheat the steel to 300F (temp crayon) and stick weld 7018, welding with the piece between 300 and 400F (another temp crayon). When done, I post heat back to 400F and let cool down slow. I was breaking a lot of clapper die springs before I started using this method, they last a long time now.

[Hillbillysmith]

It all depends on the steel. Mild steel, you can weld it when it is ice cold. If you have tool steel, it needs to be preheated to what ever the manufacturer says and welded and then post heat treated to the manufacturer's specs. If you have cast iron, then you have to preheat it between 500 and 600 degrees F and welded with a nickel rod or "special" cast iron rods and cooled as slow as you can get it to. As for preheating mild steel, it just aids in penetration but is not advantages. You get sufficient penetration in stick welding mild steel if you do it properly.

[Dan OHare]

Hmmm, Hadn't noticed this section of the forum before, is it something new?
Anyway, "when is it too cold to weld"? Never actually, if you're making a living day in and day out as a welder.
Business is business, deadlines are deadlines so the show must go on.
I worked as a mig welder on several jobs for about seven years in the nineties. Most of it indoors but for two years I worked in a railyard doing repairs and modifications on rolling stock. The roundhouse was not heated, a huge old building with 28 bays, each with doors some twenty feet high.
most of the time there would be more than one car in each bay, two would just fit, three meant open doors. Also cars being moved from bay to bay all the time... always open doors. No matter how cold the weather, more often than not most doors were open. Just the wind played havoc blowing the gas away from the mig tip, apart from the discomfort of being cold for hours on end. Lake Erie was less than five miles due east. The wind always howled from west to east and the roundhouse doors faced right into it. Work on a car for a few hours, go to lunch then come back and shovel a two foot drift of lake effect away from the trucks so you can resume. Hah! Lots of fun.
The only difference I noticed due to cold was a marked increase in tacks breaking. Work on one car for a while, fitting up new sheets of steel, tacking them into place. Then go to the next car and BANG! like gunshots tacks would pop, only during really cold weather though, like below 20 deg F or so.
Frustrating.
More than once I observed guys welding or torching on scrap, just to get a big hunk glowing red for some heat to work near inside a boxcar, etc.
Buffalo New York aint a fun place to work outside during the winter months.Dan

[Finnr]

According to my Dad who would fix anything that broke in any way he could. It was too cold to weld if you couldn't put down the stinger. That is if it froze to your hand.
Finnr

[irnsrgn]

When you can't stand the cold. I have had all my fingers and toes, the left side of my face,( laying under a combine on yon knoll welding when it was way below zero and wind blowing thru helmet) and both ears frostbitten. I remember a goose neck trailer that broke going over a rough RR track when it was -15 and I was called out to repair it. had to use electric starter and hand crank to get welder started. Of all things the many full 55 gallon drums on the trailer were filled with Mosquito repellant headed for Minnesota. Wind was blowing about 35 mph, that was one miserable stinking job.

[Dodge]

Another factor to consider is the thickness of the two pieces being joined. When I worked manufacturing light poles, we welded .11" - .23" thick tapered shafts to 1" thick and above base plates. These were all mild steel. Anything over 1.5" base plates had to be preheated due to the different cooling times of the different thicknesses. This was in a heated shop although the materials were stored outside even in the winter and rarely had time to warm up before the final welding further requiring the preheating. Typically, the 1.5" - 2.25" plate got preheated to at least 150º. 2.5" and up was 300º I think. These were DOT standards if I remember right. All welding was either MIG or SMAW

[irnsrgn]

General Rule of Thumb is, 400° preheat and keep interpass temperature 800° or below. Different metals and different applications vary according to expansion/contraction rates of parent/base metal.

[Dan OHare]

Originally Posted by irnsrgn

When you can't stand the cold. I have had all my fingers and toes, the left side of my face,( laying under a combine on yon knoll welding when it was way below zero and wind blowing thru helmet) and both ears frostbitten. I remember a goose neck trailer that broke going over a rough RR track when it was -15 and I was called out to repair it. had to use electric starter and hand crank to get welder started. Of all things the many full 55 gallon drums on the trailer were filled with Mosquito repellant headed for Minnesota. Wind was blowing about 35 mph, that was one miserable stinking job.

Irn you have certainly earned your Jack Frost battle badge!