Preheating question

[camshawn]

I am about to weld some ears for mounting a hydraulic cylinder on my back blade. The welder at work recommender to preheat them before welding (1" thick onto 1/2" backing plate). I did not think to ask him how hot to get them before welding.
Thanks, Cam

 

[Shield Arc]

That can be a loaded question, but most of us here welding mild steel anything over 50-degrees is enough. But here is a good article on pre-heating.
What is Preheat?

 

[camshawn]

Thanks for the quick reply. One of the things I love about this site.
I will read the article. Everything I am using is mild steel. I think that preheating gives better penetration on the thicker pieces. Is that correct?
Cam

 

[Shield Arc]

I think that preheating gives better penetration on the thicker pieces. Is that correct?

If your welding machine is under powered, it sure can't hurt! Proper joint prep is key also!

 

[camshawn]

If I manage to stop procrastinating, I will grind off the mill scale, preheat until warm (100 deg F) weld 3 passes (t joint), with 035 wire, about 430 inches, 23 volts, 85/15 gas.
It is. Hard to get moving when it is raining out and the coveralls are going to be damp. Inside is warm and dry and has the internet. Thanks for the preheating link Shield Arc
Cam

 

[Shield Arc]

Oh wow! Is .035 the biggest wire your machine will run? The 85/15 gas is a big help. Any chance your welder can produce more volts so you can get into spray?
Put your numbers into the this calculator, and you'll see my concerns!
Miller - Welding Calculators

 

[camshawn]

I see what you mean. I would be better to use stick and 7018 for this heavy material. My thermal arc 211i maxes out at 210amps
Cam

 

[Shield Arc]

The .035 wire sends up red flags to me! I wouldn't think twice about 1/8-inch 7018, 5/32-inch would be better.

Here is some spray I did with my V350-Pro with .035 wire, and C/10 gas.

 

[camshawn]

I will use the 7018. 1/8 is what I have here. With the cold coming next week in southern BC, snow may come with the warming and I need to get this back blade finished. Off to clean and weld, Cam

 

[Shield Arc]

OK, now we'll need pictures!

 

[camshawn]

There are some pictures under the u-built forum. No pictures taken today. The ears are welded on, only a little undercutting. Dc stick is another learning curve for me. I had some trouble getting the heat into the right area. I finally found a use for that old toaster oven I have been keeping in the shop. It worked great to pre and post heat these small pieces.
Cam

 

[Shield Arc]

I went over there and looked. You do some nice work! :thumbsup::thumbsup:

 

[camshawn]

Thank you.
My wife bought me a new welder and a cut master 52 plasma cutter for Christmas in July. It has been an enjoyable learning curve. I was able to borrow the mag drill from work to do most of the hole drilling. I have since bought an adapter and the first of many annular cutters to use in my drill press. Some of the smaller parts I was able to get cut on the plasma table at work.
Cam

 

[Shield Arc]

Yeah those annular cutter are the only way to go.

 

[camshawn]

Now I have annular cutter envy, the down side of tractors by net
Cam

 

[Shield Arc]

They come in handy when you want to saddle pipe too.

 

[weldermike]

I looked all over, and cant find the thread for the pics. Any help buds?

 

[jack707]

I would say up to 300 for that thickness

 

[camshawn]

I looked all over, and cant find the thread for the pics. Any help buds?

http://www.tractorbynet.com/forums/build-yourself/294874-back-blade-build-started.html

 

[camshawn]

I was not real happy with the way the ears came out, the 1/8 rod was only 3/32 and there was just not enough weld material. I got a few 1/8 rods dorm the rod oven at work and did 2 more passes. Everything looks better. I was a little hot with the smaller rod.
Cam