Welding

https://www.youtube.com/watch?v=FEJDqJrZyOQ

http://www.mig-welding.co.uk/tutorial.htm app for calculating amp setting.

https://www.millerwelds.com/resources/article-library/mig-aluminum-diy-selecting-the-right-welder-spool-gun-and-filler-wire-for-success-at-home

weldingtipsandtricks
http://www.weldingtipsandtricks.com/

https://www.youtube.com/watch?v=sZuq4XQTHVs part 3 wire speed, voltage amp settings.
 * 2mm steel at 78amps, 126IMP or 1.25 on 10 dial wirespeed setting.

https://www.youtube.com/watch?v=VLCpg_qjkjU stick welding tube with start stop.

mig https://www.youtube.com/watch?v=26Mfs_nViC0 anti spatter spray with flux core welding, MIG without gas. Use smaller thin tip,not the larger copper tip, allows seeing the welding. Blue nozzle gel,place on tip before welding, prevents crud on nozzle. use silver streak white pen instead of white stone.

mig https://www.youtube.com/watch?v=L737AuJF7zs n3rdbear I always push a puddle. dragging it is just like welding down hand it's not as strong. push and make little circles you will see the difference in the flux it will peel itself off

mig https://www.youtube.com/watch?v=kI7GOVrB33c flux core welding use ribbed(spur gear) wire feeding gears. Attache to negative polarity,positive is for gas welding.

https://www.youtube.com/watch?v=lO8OYPry6qU but weld two pipes with this diy device

welding table
https://www.youtube.com/watch?v=35VPGz2Ge00 leveling a welding table.

sqr tube welding
https://www.youtube.com/watch?v=8NUFYGE4Lug weld opposite tip ends so tube doesn't arc up.

warping
http://www.pirate4x4.com/forum/shop-tools/1949354-avoid-metal-warping-shop-table-top-legs.html  Build the frame. Weld, drill and tap some solid bar flush with the top of the legs and bolt the top down with countersunk hardware. Or another problem folks have is they full weld all the way around the legs to the top when a few 1" long welds will do the trick AND be easier to cut off if something goes wrong

Angle iron supporting the sheet in the middle helps out a ton. You need to tack it heavy every 2 inches and stagger those tacks and you shouldn't have any problems. Every thickness CAN warp with enough heat though.

I came across this table a few years ago and always thought it would be a decent way ensure a flat top, or at least as flat as you can get with the tools most of us have in the shop. Thread here: New welding table. - OFN Forums. http://www.offroadfabnet.com/forums/showthread.php?t=5289 Essentially what he did was weld all-thread to the plate that attached to stringers. Once it was all together, he could adjust those studs and push or pull the plate flat.

gas bottles
http://www.yellowpages.co.za/business/SA_6319328_BUS 0118184845  6 north phoenix  rd, springs. Air liquid, Air products refils at R580. Will refill without insisting on monthly bottle rental, but bottle must have some brand logo. Any Logo can be copied.

Rymar hardware, terril gas bottle R1895. cnr of baviaans poort and badenhorst street. R2020 outright purchase of argon gas bottle with argon gas. Only supplier willing to sell gas bottles direct to public, does not require a monthly rental.

http://www.ewns.co.za/contacts.htm