| Before beginning I do want to say there are not | | | | filed before every pass except the root pass. Even |
| many places that will give you the chance to learn | | | | the bevel needs to be filed on the hot pass and all |
| how to TIG weld thin wall stainless steel pipe. I was | | | | color changes need to be filed to pure metal at all |
| lucky enough to have Fluor train me and am very | | | | times. Failure to file all heat affected areas will result |
| thankful for being able to attend their training | | | | in the filler wire not being able to flow into the joint |
| program! Fluor is the only reason I got to learn this | | | | smoothly. |
| skill! | | | | Moving your tungsten quickly is very important when |
| What I can share is that TIG welding stainless steel | | | | TIG welding stainless steel pipe. The trick to avoid |
| pipe is not much harder than carbon steel pipe. There | | | | melt through and overheating the pipe is to move |
| are a few rules to follow and you should be able to | | | | quickly. From the moment you strike the arc that |
| pick it up quickly! The rules are as follows: | | | | tungsten needs to be moving. Don't start and wait |
| - Purge your pipe well. | | | | for the metal to heat up before moving. Ideally you |
| - Everything must be clean. | | | | want to start 3/4 of an inch before the area you will |
| - Keep your tungsten moving at all times. | | | | start adding filler wire too. This will allow enough |
| - Allow the pipe to cool before the next weld. | | | | preheat for the filler wire to flow properly. Ideally |
| Stainless steel pipe must always be purged. The | | | | when the weld is finished it should have a copper |
| result from a less than perfect purge will cause the | | | | color to it. If it is gray or dark in nature you are using |
| root to get contaminated. The slang term used in the | | | | too much heat or moving too slow! |
| field for root contamination or oxidization is "sugar". | | | | When it comes to stainless steel the heat this metal |
| Sugar is caused from the weld being exposed to | | | | absorbs and holds is unbelievable. Now add thin wall |
| oxygen in the atmosphere. The weld joint must be | | | | pipe to the picture and you have a radiator that is |
| taped off and only untapped when you are ready to | | | | always ready to overheat! You need to allow the |
| weld that part if the pipe. | | | | pipe to cool enough that you are able to touch it |
| In general TIG welding requires a very clean weld | | | | with your bare hand. TIG welding stainless steel pipe |
| joint but with stainless steel this is an absolute must! | | | | requires a lot of waiting for the pipe to cool. It only |
| The tungsten must be clean. That means cleaning it | | | | takes an extra inch of weld too soon to ruin the |
| after every restart and pass. The weld joint must be | | | | weld joint! |