Thanks Mike! :)

Neil.

On Sun, Mar 16, 2008 at 8:53 AM, Mike <mbucchino@charter.net> wrote:
> It's definitely a good idea to cut one cross-sectionally to demonstrate
>  penetration.  You do need 100% penetration; this can be achieved by
>  V-notching the thickest parts before welding, even if it means laying down
>  more than one bead to fill the gap completely.  This is how the thickest
>  metals are commonly joined by welding professionals.
>   One way to judge if you've achieved 100% weld penetration, is to look at
>  the backside of the joint; if you can clearly see an even, 'heated' stripe
>  of discoloration in backside of the base metal, you've got it.
>   If you have thick, rounded 'mountains' of filler metal standing above the
>  base metal, there's not enough penetration, and the joint will be weak and
>  will crack.
>   If you have thin 'valleys' of melted base metal, there's too much heat and
>  not enough filler; possibly undercutting and weakening, even to the point of
>  'blowing-through' in spots.   This too will be weak and will crack.
>   It's this delicate balance of proper heat, filler and penetration that
>  takes lots of practice to achieve, and the procedure differs for
>  butt-welding, lap-welding, corner-welding, vertical-welding, tube-on-tube,
>  tube-on-plate, different thickness materials, thick -to-thin metals, TIG,
>  MIG, oxy-acetylene, etc.
>   Have fun and get lots of practice, and some critiqueing from experienced
>  welders.
>
>  Mike B.
>
>
>
>  ----- Original Message -----
>  From: "neil N" <musomuso@GMAIL.COM>
>  To: <vanagon@GERRY.VANAGON.COM>
>  Sent: Sunday, March 16, 2008 11:07 AM
>  Subject: Re: WAS: building carrier bar..... NOW: Test Weld PIC
>
>
>  > Thanks again Gary.
>  >
>  > I've been pushing my welds. Was considering pulling so I could see the
>  > puddle better, but I'll stick with the programme. Good tip on pre
>  > heating. As for wiring etc., I don't use an extension, but I did find
>  > that with the welder set to max. and my big fan on max, that the
>  > circuit will overload! (can a guy weld in the dark? --- ;^)
>  >
>  > I can sort of "see" that the penetration on 1/4", even if welding
>  > optimally, would be limited. I'll bet that at best, it's only going in
>  > about a 1/3 of the way. I should cut open a 1/4" weld and see.
>  >
>  > Appreciate the help. And nice lookin' Vanagon bike racks!
>  >
>  > Cheers,
>  >
>  > Neil.
>  >
>  > On Sat, Mar 15, 2008 at 11:14 PM, Gary Lee   www.vwrack.com
>  > <gary2a@telus.net> wrote:
>  >> Well gas will be cleaner than flux, but not necessarily stronger.  If you
>  >>  only weld occasionally, I would not bother with renting or buying a gas
>  >>  bottle.
>  >>  Good you got lots of amps available.  That makes a big difference.
>  >>
>  >>  120 volt welders can't produce enough heat to weld 1/4" 'properly'.
>  >>
>  >>  To maximize the amount of heat a small welder will produce:
>  >>  - Heavy gauge extension cord
>  >>  - Hold tip as close to work as possible
>  >>  - Push the bead, as opposed to pull.  Push = like driving forward.  Pull
>  >> =
>  >>  like driving in reverse
>  >>  - Preheat the piece with a propane or acetylene torch
>  >>  - Move torch slow, steady and smoothly.  In a controlled motion.
>  >>
>  >>  fwiw, I wouldn't be welding any trailer hitches with a 120 volt welder.
>  >>
>  >>  If anybody in Calgary needs simple welding jobs like that done, I do it
>  >> for
>  >>  free for local vanagon owners.
>  >>
>  >>
>  >>  Gary Lee
>  >>  www.vwrack.com
>  >>
>  >>
>  >>
>  >> ----- Original Message -----
>  >>  From: "neil N" <musomuso@gmail.com>
>  >>  To: "Gary Lee www.vwrack.com" <gary2a@telus.net>
>  >>  Cc: <vanagon@gerry.vanagon.com>
>  >>  Sent: Saturday, March 15, 2008 11:44 PM
>  >>  Subject: Re: WAS: building carrier bar..... NOW: Test Weld PIC
>  >>
>  >>
>  >>  > Thanks for the pointers Gary.
>  >>  >
>  >>  > Yup. 120, MIG with flux but am running 12 gauge from a 20 amp breaker.
>  >>  > I found I could go quite slow on the 1/4" plate and will slow it down
>  >>  > more. Quite a contrast to the practice welds I tried on the scrap
>  >>  > exhaust tube.
>  >>  >
>  >>  > I may end up using 1/8" plate and angle instead of the 1/4". Those
>  >>  > were free scrap pieces so I gave it a whirl.
>  >>  >
>  >>  > I'm learning pretty fast, but there's lots to learn even with just
>  >>  > setting up correctly. Proper lighting, material and work position etc.
>  >>  >
>  >>  > It'll be nice to get set up with gas. The flux puts out too much smoke
>  >>  > and spatter.
>  >>  >
>  >>  > Thanks,
>  >>  >
>  >>  > Neil.
>  >>  >
>  >>  > On Sat, Mar 15, 2008 at 10:30 PM, Gary Lee www.vwrack.com
>  >>  > <gary2a@telus.net> wrote:
>  >>  >>  >Now I KNOW I'll get this load bar done. Too bad I can't get
>  >> material
>  >>  >>   >til Tuesday!
>  >>  >>
>  >>  >>   > http://tubaneil.googlepages.com/1stlargeweld
>  >>  >>
>  >>  >>   >Thanks guys,
>  >>  >>   >Neil.
>  >>  >>
>  >>  >>  Neil,
>  >>  >>  Looking at your picture, I'd say you are using a 120 volt MIG.
>  >>  >>  Fluxcore?
>  >>  >>  That would give you marginal penetration on material as thick as in
>  >>  >>  your picture.  Go slowly and weave back and forth.  I hold the torch
>  >>  >>  with two hands, one on the trigger and the other near the tip. Hold
>  >>  >>  the torch close in to the material, as little 'stick out' and
>  >>  >>  possible.  Plug your welder in as close to the breaker box as
>  >>  >>  possible.  Avoid using extension cords.
>  >>  >>
>  >>  >>  Gary Lee
>  >>  >>  www.vwrack.com
>  >>  >>
>  >>  >
>  >>  >
>  >>  >
>  >>  > --
>  >>  > Neil Nicholson. 1981 Air Cooled Westfalia - "Jaco"
>  >>  >
>  >>  > http://web.mac.com/tubaneil
>  >>  > http://tubaneil.googlepages.com/
>  >>  >
>  >>  >
>  >>  > --
>  >>  > No virus found in this incoming message.
>  >>  > Checked by AVG.
>  >>  > Version: 7.5.519 / Virus Database: 269.21.7/1329 - Release Date:
>  >>  > 14/03/2008 12:33 PM
>  >>  >
>  >>  >
>  >>
>  >>
>  >
>  >
>  >
>  > --
>  > Neil Nicholson. 1981 Air Cooled Westfalia - "Jaco"
>  >
>  > http://web.mac.com/tubaneil
>  > http://tubaneil.googlepages.com/
>  >
>
>

--
Neil Nicholson. 1981 Air Cooled Westfalia - "Jaco"

http://web.mac.com/tubaneil
http://tubaneil.googlepages.com/