Author Topic: A few tips on SMAW  (Read 3906 times)

Offline ieezitin

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A few tips on SMAW
« on: July 13, 2010, 01:02:57 PM »
I belong to another forum and a question was asked about SMAW, I though I would share with you my thread.

Here are some tips for the person who finds SMAW (shielded metal arc welding) or (stick welding) a little difficult. Its very easy all you need to know is whatís going on and why, with a little practice the penny will drop.

6010, 6011 etc are classified in my industry as spray arc rod with relatively low tensile strength. . Up-hill and down-hill welds very easy but you need to whip the rod, whipping is a form of dragging then hold position deposit then whip away and fall back and deposit again. It shines and was designed for filling up large gaps due to the spray and weld deposit characteristics of the flux, if you just arc and hang your rod and move forward your bead will be lumped or crowned.

Imagine it this way at the end of the rod the Filler material (rod its self) is being instantaneously made molten by the arc at the same time as the job area, the flux starts to evaporate shielding the area evacuating all oxygen, during this process the expanding gas flings the molten blob and splatters it everywhere depositing a layer on the receiver area. Itís like carpet bombing the weld bead.

Whipping then hold helps to saturate the deposit area with heat allowing for a wide layer to be laid but too much heat will explode your weld so you whip away to let is cool, as you whip away your still spraying as you travel and depositing material for future welding hence its great for filling large gaps. A little practice and you will see what I mean and your weld will get better.

Dabbing and or filling. If you have a gap between two plates example ĺ inch spray arc will do it. The two procedures are to build up the edges on either side closing the gap whipping up and down, or to stay static and dab the rod, deposit pull out let cool then do the same thing. This cannot be done with the lo-hi rods.

Now you have your root in with the spray arc its imperative you clean the slag out with a grinder. Grind away the top and remove all the black stuff leaving a smooth finish, you are removing material if you remove too much go back over it again, make sure you have a base. Why its so important to clean it is because if there is any slag left in the weld the hot fill-pass will not burn it and porosity will occur. If welding a gapped V joint A sufficient base (ie thickness) should be left as if its too thin the Lo-Hi will fall through.

7014 7018 or (Low-Hi) (Low Hydrogen) family etc are classified as a Globular arc, meaning exactly that it globulates in its molten state and the weld is made by placing each molten blob to the weld area. Itís an all position rod and produces a very nice finish, its great for filling and capping welds.

You cannot whip with it, the key to this rod is speed and amps, and you can weave slowly but be consistent in speed and width of weld. The fool proof way to know you have both amps and speed correct is presentation of the weld the tie in should be smooth with no little ridges (undercut) and the flux deposit should be peeling back on its own without the need of hitting it with a chipping hammer.

Now saying all that post heat should be applied to all welding giving you the best chance a great weld, welding on cold steel effects the results of the weld.

Rod care. Keep your rods in the tubes they came in or buy one of those plastic rod cases, the 70 style rods attract moisture very quickly due to the flux, if you find while you are welding youíre getting excessive splatter and porosity the rod is wet. Just place in a toaster oven on low heat for about 1 hour and you will be fine. If you have Lo-Hi that have been on the shelf for a while stick them in the oven before welding.

6010 6012 etc (spray arc) there not fussy. I have even pulled them out of puddles and welded with them. But keep them in the box and treat them like to lo-hi but you donít need to put them in the oven.

All of the above is for carbon steel welding, stainless is another animal. To master stainless in SMAW your skills should be honed in on carbon.

Another fundamental rule in welding is always be comfortable, do a lot of dry runs with the stinger before you start to weld, getting jammed in a spot while under the arc will ruin the result.

Rod position. Again no mystery here think about the rod as if you were holding a water hose and water is shooting out the nozzle, where ever you point the nozzle the water will flow in the linear position as the hose its self. When welding in the vertical gravity is working against you so molten pools of metal that get large will slide to earth. Speed and weaving will make your life easy here, position for vertical is about 15-20* looking up and weave side to side.

Heat. Everyone asks ďwhatís the heat (amps) for a 3/32 -7018 wire as an exampleĒ well it varies on the welder, for me I would run at 90 amps thatís excessive but I have a fast hand and prefer speed, someone who is slower needs to drop down. My point here is everyone is different, the rule is heat=speed the higher the amps the faster you go vice versa, but too low will not achieve penetration.

If your vertical welding you always need to turn the heat up too. Best example for you here is if your running flat and burning 80 amps then need to go vertical go up on amps by 3-4. It makes a big difference.

I hope this helps some people who think welding is a mystery, its not itís about knowing whatís going on then finding out there own technique.

If you cant fix it, get another hobby.

Offline Brass_Machine

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Re: A few tips on SMAW
« Reply #1 on: July 13, 2010, 09:51:42 PM »
Wow Anthony... I plan on learning to weld soon. Some great info to have,

Science is fun.

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