MIG welding stainless steel explained | step by step guide

One of the most common questions asked by newbie welder is if a MIG welder can weld stainless steel. Below we give some information about welding stainless steel with a MIG.

Can you MIG weld stainless steel?

Definitely you can. But there are some following factors to be considered before MIG welding stainless steel.

1. First of all, make sure your machine is set up correctly to weld aluminum or stainless steel.

2. before you get started welding, you must always ensure that your MIG torch is in good shape. This might also be useful to buy a torch larger than you can for ordinary steel, equivalent to welding aluminum. Because welding stainless steel produces more heat, higher amperages are better for a larger torch.

3. Make sure it is stainless steel: sometimes, steel seems like stainless steel as a coating is put over the steel. You can use a magnet to find out it is stainless steel or a coat. Pure stainless steel will not stick with a magnet, where, the coating will stick with a magnet.

4. Use the right MIG welder: our suggestion is to use an actual MIG welder that can weld mild steel. If a MIG welder can weld mild steel that can inevitably weld aluminum or stainless steel. You should not use flux core welder to weld stainless steel.

5. Use stainless MIG wire: if you use the regular mild steel MIG wire, the weld will rust. You will need to coat the weld to stop rusting. So, you should use a stainless MIG wire to avoid the rusting problem.

6. Using Spool Gun- You can carry the wire in the welder with a spool gun and move the stainless wire to the spool gun to save time on the welder. Set the machine up and run it as usual.

7. Return Purge – We recommend you check the rear of the tubing while welding to prevent contamination of the weld while welding stainless pipe. You can do this with a single tube-like tube tap and a tin film with a tube inside the tube to fill it with welding gas when you are welding.

8. You have to ensure that the workplace is free of iron, steel or ferrous oxides, as well as its susceptibility to ferrous pollution. That may sound trivial, but it is crucial. Smoothness is always necessary for the successful welding of materials and workplaces. Only the slightest particulate emission is critical with stainless steel.

Now, the step by step guide to MIG weld stainless steel is discussed below.

Protection is the first priority

we recommend you to put-on welding helmet along with a respirator mask and earmuffs. You must cover up your body as much as you can. To do so, wear a full-length shirt, pants, gloves, and boots.

Shielding gas

a 90% helium, 7.5% argon, and 2.5% carbon dioxide mixture is recommended for MIG welding stainless steel as it will not only protect your weld and but also strengthen it.

Cleaning the base metal

you will have to remove the impurities of the steel by a wire brush that is especially designed for stainless steel.

Removing the debris

use an old piece of cloth coated with acetone to wipe away the scattered fragments.

Place the metal to a welding table

use jigs and fixtures to arrange the steel pieces together. While welding, make sure your work-piece does not slip, it may cause a weak joint formation.

Setting up the filler wire

feed the filler wire through your MIG machine’s reel and let it out through the torch then turn on the gas. Now you are ready to start your work.

Moving the torch ahead

move the torch slowly and steadily at a 30-degree angle above the edge of the joint. Moving too fast will not melt the steel enough to make a healthy joint. But remember if you are welding a thin metal you have to move more quickly so that the metal cannot melt too much.

When you are done, turn off the gas. Make sure your weld and torch cool down before moving them. 

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