| Stainless steel pipe welding is gravy work. Always has | | | | way. |
| been. Always will be. | | | | Here are a few tips that will help you get a good |
| If you can do it and do it well, you are the man and | | | | purge on the stainless steel pipe you weld. |
| you will never go hungry. But it takes some attention | | | | - Make sure there is no water inside the pipe...not |
| to detail to do it right. | | | | even a drop. One single drop of water will throw a |
| The main thing that separates the men from the | | | | monkey wrench in your purging until it evaporates. |
| boys or should I say, the real welders from the rod | | | | Remember what is in water? Hydrogen and oxygen. |
| burners is the willingness to follow procedures for | | | | - Poke a vent hole in the uppermost place you can |
| welding stainless steel. Procedures like waiting for the | | | | find. Think of argon as if it was water. Because it is |
| pipe to cool in between passes, keeping the hot tip | | | | heavier than air, it will fill up any space like water, |
| of the rod shielded with argon, snipping the tip of the | | | | displacing the air as it fills every nook and cranny. |
| tig welding rod when it gets crapped up, keeping | | | | - More purge gas flow is not always better. A high |
| your tungsten sharp. | | | | and turbulent flow of argon will not necessarily purge |
| One of the main procedures I am talking about is | | | | a pipe quicker than a lower flow rate. And a diffuser |
| PURGE. Stainless steel absolutely has to be purged | | | | on the end of the end of your argon hose usually |
| with argon gas in order to prevent sugaring. Sugaring | | | | allows you to use a higher flow rate. A homemade |
| is also called granulation but it is severe oxidation no | | | | diffuser can be made with some stainless steel wool |
| matter what you call it. | | | | , some perforated stainless sheet, and a bit of sheet |
| You cant even get away with tack welding without | | | | metal. |
| an argon purge that shield the back side or inside of | | | | Once you verify a good purge, you are ready to |
| the pipe. So how do you do it? How do you protect | | | | tack. Peel the tape back just enough to tack and let |
| the back side with argon? | | | | cool a bit and re tape. Then tack again 180 degrees |
| Usually it is done with aluminum duct tape. The ends | | | | apart. Continue until all tacks are in place. |
| of a stainless steel pipe are taped shut and the | | | | More tips for welding stainless pipe... |
| whole inside is purged with argon gas. Even the | | | | - Laying an 1/8 inch wire in the root works better |
| opening in the pipe joint itself is taped so that argon | | | | than dipping a 3/32 inch rod. |
| can fill the entire pipe and push out any oxygen. The | | | | - Use a feather edge bevel. No land needed |
| tape is peeled back just enough to get a tack once | | | | - You can fix areas that do not penetrate by re |
| the pipe is purge enough. | | | | welding |
| What is enough? The only way to tell for sure is with | | | | - Use only stainless steel wire brushes and only use |
| an oxygen analyzer. A bic lighter will not do the trick. | | | | files that have only been used on stainless steel. |
| Even 2% oxygen content will blow out a bic lighter. | | | | - Use just enough amperage. Using too much |
| And 2% oxygen will result in a black root pass. | | | | amperage will overheat the stainless steel and make |
| There are some other down and dirty ways to | | | | things go south quick. |
| check the purge but an oxygen analyzer is the sure | | | | |