Experienced tig welders please chime in!
12-10-2010, 12:10 AM
#61
Also I've found I get the best results for mild steel when i grind the electrode all the way pointy then just barely zip the end to give it a tiny flat. With it incredibly sharp the arc is almost too focus and have to move the torch around a lot to direct the arc between the two pieces being joined, as well as sometimes a little arc will jump off the side to a random part of the parent pieces.
12-10-2010, 07:14 AM
#62
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How does stuff like brake cleaner work for removing oil like residue from aluminum? I have some nice size scrap aluminum that when through the punch press. Its greasy with whatever is used so i need to clean that up.
Im going to sharpen it down a little at a time, till i get to a point that i feel comfortable with. The only thing is i won't have a comparison point since it will be my first time. My dad is going to ask one of the welders at his work if he has time to teach me a little some weekend when the shop is empty. They make jet engine parts and such, so im sure he's better than the functioning alcoholic that welds at my work.
Im going to sharpen it down a little at a time, till i get to a point that i feel comfortable with. The only thing is i won't have a comparison point since it will be my first time. My dad is going to ask one of the welders at his work if he has time to teach me a little some weekend when the shop is empty. They make jet engine parts and such, so im sure he's better than the functioning alcoholic that welds at my work.
12-10-2010, 10:20 AM
#63
Also I've found I get the best results for mild steel when i grind the electrode all the way pointy then just barely zip the end to give it a tiny flat. With it incredibly sharp the arc is almost too focus and have to move the torch around a lot to direct the arc between the two pieces being joined, as well as sometimes a little arc will jump off the side to a random part of the parent pieces.
To sharpen the tungsten I use a drill and a belt sander, just put the tungsten in the drill, sharpen it to a point making sure the grind marks go lengthwise, then put a small blunt on the tip. you should also try to use a belt sander that hasnt been grinding alot of different metals to prevent contamination of your tungsten. Also, if you havent done alot of tig, your going to dip the tungsten...alot. after you dip it you should grind off the metal from the tungsten or you will get some baaad looking welds. also make sure you have good post/pre flow, or your tungsten will turn blue.
12-10-2010, 11:03 AM
#64
What gas flowrates as well as pre/post flow do you use? I use 10-15cfh for steel and been told a bit less for aluminum, and have fiddled with 3-5 seconds pre/post flow time, but my machine came setup with 10seconds pre/post time...
Last edited by frojoe; 12-10-2010 at 02:22 PM.
12-10-2010, 01:38 PM
#65
yea, post flow should be about 8-10 sec, flow rate about 20 CFH, make sure and use the proper cup size too, should be fine with what they send with the machine. oh, and find out what kind of rod to use, 4043 or 5356 are the most common for aluminum.
12-10-2010, 03:29 PM
#67
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doesn't really matter, you just need it to flow long enough to keep the tungsten from discoloring when it shuts off. on small diameter electrodes and low aperages, you won't need much. if you're running 1/8" tungsten and 250 amps, you'll need more. If the gas shuts off while the tungsten is still orange, you run a risk of contaminating the tungsten with gases/particles around it, usually oxygen contamination is the biggest issue.
What you really need to do is set the postflow for 8-10 seconds like suggested and never touch it again. you'll never need more than that, less would probably suffice, but there's no harm in having some extra.
What you really need to do is set the postflow for 8-10 seconds like suggested and never touch it again. you'll never need more than that, less would probably suffice, but there's no harm in having some extra.
12-12-2010, 11:26 AM
#68
There is an account going around on the net, and I have heard it from other sources as well, about kidney damage resulting from burning the residue of brake cleaner. Use acetone or alcohol that will entirely evaporate before you begin welding.
01-24-2011, 02:29 PM
#69
Couple thoughts (learned on an old union carbide, have used the 165, as well as a couple nice synchrowaves, if you have a little more money the Thermal Arc 185 gets great reviews, understanding that advice is too late for the OP)
For sharpening tungstens, there are specialty sharpeners that you can use, or dips, but I personally just dedicated a small grit grinding stone to sharpening tungstens (you can even use one of those green stone disc bits in a dremel tool, put the tool in a bench and move the tungsten), and it works great. Make sure that you are grinding it so that the grind lines run down the cone (as opposed to around the cone.)
For balling a tungsten, it doesn't really have much to do with waveform (AC modes) it has to do with how much heat you are dumping in to the electrode vs. the workpiece (time in DCEN vs. DCEP.) A good way to ball a tungsten is to sharpen it, and then turn it on to AC mode (the 165 has one preset non-adjustable AC waveform) crank up the amperage, and just zap a large piece of metal, the tip of the tungsten will melt a bit and you will get your ball. That being said, generally the ball is an after effect, you can weld using AC just fine with a sharp tungsten, only the tungsten will not be able to take the heat and will ball a little anyway.
Some random advice for welding aluminum, you need the current up a little higher (don't be shy), the workpiece will absorb a lot of heat, and if you don't have it high enough your weld pool will cool too quickly, and you will get poor penetration of the weld. Also, at a slightly higher amperage you will get a more stable arc. If you are trying to weld something that is a bit thicker than your welder should be able to handle, preheat it with a torch, and insulate it as best as possible.
Finally, you want your aluminum really clean. Aluminum quickly forms an oxide layer that melts at a substantially higher temperature than the rest of the aluminum, this oxide layer causes a lot of problems if it is not cleaned off first, and it reforms rather quickly. There are fancy etching solutions that do a great job, but generally at least acetone wipe and a SS brush on the surface you are going to weld (don't use the SS brush for other things like steel, it will deposit impurities on the aluminum and then mess up your weld.)
For welding in general, make sure everything is as clean as you can get it, and tight joints. The biggest key to welding really is in setting up the parts. The rest is just practice practice practice.
Oh, and you can look up/ask stuff on weldingweb forum, sometimes that are a bit cantankerous, but they know what they are doing.
Good luck!
For sharpening tungstens, there are specialty sharpeners that you can use, or dips, but I personally just dedicated a small grit grinding stone to sharpening tungstens (you can even use one of those green stone disc bits in a dremel tool, put the tool in a bench and move the tungsten), and it works great. Make sure that you are grinding it so that the grind lines run down the cone (as opposed to around the cone.)
For balling a tungsten, it doesn't really have much to do with waveform (AC modes) it has to do with how much heat you are dumping in to the electrode vs. the workpiece (time in DCEN vs. DCEP.) A good way to ball a tungsten is to sharpen it, and then turn it on to AC mode (the 165 has one preset non-adjustable AC waveform) crank up the amperage, and just zap a large piece of metal, the tip of the tungsten will melt a bit and you will get your ball. That being said, generally the ball is an after effect, you can weld using AC just fine with a sharp tungsten, only the tungsten will not be able to take the heat and will ball a little anyway.
Some random advice for welding aluminum, you need the current up a little higher (don't be shy), the workpiece will absorb a lot of heat, and if you don't have it high enough your weld pool will cool too quickly, and you will get poor penetration of the weld. Also, at a slightly higher amperage you will get a more stable arc. If you are trying to weld something that is a bit thicker than your welder should be able to handle, preheat it with a torch, and insulate it as best as possible.
Finally, you want your aluminum really clean. Aluminum quickly forms an oxide layer that melts at a substantially higher temperature than the rest of the aluminum, this oxide layer causes a lot of problems if it is not cleaned off first, and it reforms rather quickly. There are fancy etching solutions that do a great job, but generally at least acetone wipe and a SS brush on the surface you are going to weld (don't use the SS brush for other things like steel, it will deposit impurities on the aluminum and then mess up your weld.)
For welding in general, make sure everything is as clean as you can get it, and tight joints. The biggest key to welding really is in setting up the parts. The rest is just practice practice practice.
Oh, and you can look up/ask stuff on weldingweb forum, sometimes that are a bit cantankerous, but they know what they are doing.
Good luck!
