Swimming pool????

Discussion in 'Other metal working projects' started by Jason, Aug 1, 2018.

  1. DavidF

    DavidF Administrator Staff Member Banner Member

    With the wire screen in it to diffuse the gas.
     
  2. Jason

    Jason Gold

    you bet.
     
  3. DavidF

    DavidF Administrator Staff Member Banner Member

    Just checking. :cool:
    Know how to "walk the cup"
     
  4. DavidF

    DavidF Administrator Staff Member Banner Member

  5. Jason

    Jason Gold

    nahh.... no walking the cup here. :oops: I use stubby gas lens. I want to try a larger cup. I think I was using a 6 last night.
     
  6. DavidF

    DavidF Administrator Staff Member Banner Member

    You've probably all ready watched all these..
     
  7. Jason

    Jason Gold

    I just found that guy yesterday. I'm starting to watch his stuff now. I see he is using my invertig.
     
  8. DavidF

    DavidF Administrator Staff Member Banner Member

    When I used to weld ss pipe we ran 90 to 110 amps with a #8 cup. I rarely walked the cup unless the cuts were off leaving a gap.
    I don't miss those days one bit. Sitting in a pipe rack 100 feet in the air along the river with 40 mph winds in January... kma no more thank you. :p
     
    Jason likes this.
  9. Do you have a stainless steel wire brush to brush them? Rather than grinding, brushing them will show the weld.

    Welds look OK! Have you sectioned them?
     
  10. Jason

    Jason Gold

    cut, grind and semi polish. I hit it with naval jelly. It didn't seem to do anything to the stainless. Maybe phosphoric acid only works on mild steel. no clue.

    15350798986668576196001857321094.jpg
     
  11. Stick it in some water with salt and pass a DC current through it, don't let the bubbles that form stick on it for long or it'll mask off the surface. Maybe use a 12V battery charger and wire a 12V bulb in series for current limiting. It'll etch but may not reveal anything: metalurgical etch recipes can be nasty, in some cases they say: "do not store" but don't mention that the reason is because it becomes an unstable nitro explosive.

    http://www.metallographic.com/Etchants/Stainless steel etchants.htm
     
    Last edited: Aug 23, 2018
  12. Jason

    Jason Gold

    I can do that. Shouldn I connect the part to positive directly and leave the negative wire hanging in the water?
     
  13. I can't remember, I use a carbon rod out of a D cell and reverse polarity if it's not immediately etching. Looking at that etching stainless link, some hydrocloric acid and optionally ferric or cuprous chloride is going to work well. That's actually what I use for my generic electro etching solution anyway.
     
  14. Jason

    Jason Gold

    I saw some of the stuff on that link. For all that BS, I think I'll weld some more stuff, try not to make it look like hell and bring it to my NDI weenie down in san antonio. I've got some wheels that are coming due, he can beep beep my welds at the same time.:p
     
  15. At best etching'll show penetration and remove the sawing marks and possible smeared material obscuring voids.
     
  16. Jason

    Jason Gold

    Love the net some days......... I should have called this thread, Everything you didn't know about SS.

    The simplest way to etch Stainless Steel is to use Electricity (12 Volts DC) and plain old Table or Cooking Salt. Paint the surface of the item to etched with a quick drying but 'Sticky' paint. Off the 12 Volt Dc power supply use ANY type of piece of metal (a Stainless Steel Bolt about 1/2 inch diameter for jewellery or say a Knife ) and connect this to the NEGATIVE terminal of power supply, and the item to be etched to the POSITIVE terminal.
    Saturate TAP WATER with Table Salt and immerse bolt and item to be etched in the Salt Solution. Bubbles will form on the BOLT showing that etching is taking place. KEEP THE TWO SUBMERGED items apart or if they touch then the FULL power supply voltage will flow and the Power Supply will blow a fuse or set on fire if it is not fused. Make sure that ALL surfaces that are not to be etched are painted or the WHOLE item will be dissolved.
    Chemical etching is OK in some circumstances but ALWAYS messy and TOXIC to various degrees. I etch Copper clad PCB boards for circuitry and use the quicker and cleaner SODIUM PERSULPHATE and not the usual slower but less expensive FERRIC CHLORIDE. EXPERIMENT yourself with the Salt and Electric method and you will surprise yourself. Power Supply current? Around ONE AMP.
     
  17. Jason

    Jason Gold

    Hooked the part to positive on an old school battery charger. 12vt/6amp Diluted a bunch of salt in some hot water and stuck a cotton ball in the negative clamp. Soaked the cotton ball and here is the result. Now wtf does this mean? The fat one on the right was run with filler wire on only one side. The 2 on the left were no filler I ran on both sides.... In the corner, I ran filler on the outside and no filler on the inside. Should the dark areas touch to demonstrate full penetration? I've never gotten any complaints in the past.:p;)

    SSetch.jpg.jpg
     

    Attached Files:

    Mark's castings likes this.
  18. Woohoo, that worked much better than I expected, obviously the grain structure of the weld zone is different enough to show plain as day, any chance of a close up of a weld?. At least you can see the penetration of the weld clearly.
     
  19. Jason

    Jason Gold

    focus is a pain on edge like this, but I'll try.
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    15350930158418399985648928863409.jpg
     
  20. That has got to let you fine tune your weld settings for best performance, a good visual diagnostic tool: it never would have occurred to me to even try it. I have an eyepiece off a broken scope sight that makes a great magnifying loupe, even better it fits over my cheap Nikon digital camera's lens and lets me get extreme closeups of things.
     
    Last edited: Aug 24, 2018

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