Harry
being involved in welding for 35 years I can say with confidence there are three things you need to know and understand before you pick up a rig, metals theory and chemistry, the
importance of being clean and techniques of applying the weld via all welding methods IE.. SMAW TIG MIG gas-flame etc.
Theory: metals need to be in a liquid state to be fused and mixed together to make the joint, I analogize it to baking bread, the mix (dough being pliable or fluid) has to be blended with flour, milk, salt and seasoning etc all have to be compatible with each-other and the blends need to be just right to get the desired result, a nice crusty outside while the texture on the inside, if your materials are no compatible with each-other your weld will not be successful, it may be too hard and crack, contaminated etc knowing your metals and alloys dictates your method and technique.
Being clean: I cannot stress enough about being clean, your work piece and filler material needs to be free from mill scale, surface oxidation, oils, dust etc, most people weld stuff together and it looks like pigeon snot little did they realize it was the contamination that made it fail. All metals to be welded need an oxygen free environment, oxygen is contamination, your gases or flux need to be clean and applied in a manner where they cannot be contaminated by oils or dust, just because your working in a dingy fab shop there no reason why your work station cant be clean, dust free and tidy.
One refinery i worked in paid over $1.5 million in overage charges due to welds failing inspection on a Chrome-Molly reactor, I and others were buddy welding the shell with TIG with an argon purge for 8 weeks and all welds failed repeatedly with sugar in the root, we finally figured out that the purge gas was picking up grinding dust within the shell itself, this was a case of not paying attention to proper clean purge practices.
Techniques: A little woman from Louisiana kicked my ass on one job TIG welding stainless pipe, she was quicker, she burned thicker wire than i did so that meant more heat or (Amps) and her cap looked like it was made by a submerged arc set up (machine welder) the reason for this is women are more dexterous than men with there hands, also she had small hands which allowed her better access and flexibility in hard awkward places,
Have you ever watched a old lady crochet or knit this takes dexterity and superb hand eye coordination, this applies to welding using the stinger, gun or rig. one tip from me is always watch your weld-pool or (puddle) this is your instant feed-back on what the weld is doing, how hot you are, how deep your penetrating, how clean it is.... also sound plays a role yet this, its hard to explain until you have weld time under the hood.
I am very suspect of votech schools because the teachers don't have the vast experience in all welding techniques in real word environment but its better than nothing, dont get me wrong any knowledge is power.
Jody's site is by far the best learning on the web to be found, he goes into detail visually and written like no other, this guy truly has nailed the art of welding.
If your going into the pipe welding trade hit me up on here and i will explain the legal cheats to pass a 6-G test
To sum up... Patrice, paying attention to detail, being clean, practice, don't give up, and finally practice will make you a welder, this is the only blue-collar trade where you can make more money than a lawyer
Hope this helps.... and sorry for the long thread
Anthony.
ieezitin, proud to be a member of MetalworkingFun Forum since Jan 2013.