el-cheapo- tig / arc welder at HF

[Dargo]

Since I don't have the luxury of being able to X-Ray my welds, I've very often cut a practice piece of the material I'm going to weld in half (after a test weld) to check the penetration. Generally with the BFH treatment, it breaks somewhere other than at the weld. The weld itself almost always has a greater tensile strength than the material being welded.

With the really cheap welders, if you can get past the duty cycle issue, try cutting one of the welds in half in a few places. The power coming out of their cheap transformer is very unstable and will result in inconsistant weld penetration. That is what you get when you use cheap components in your welder. So, even for the most minor repair, I wouldn't advise using one of those cheap welders unless the repair is very non-vital. Then, if it is of that little importance, throw it away. If you really need it, buy another one!

By the way, my MillerMatic 210 is foreign made in a foreign country that starts with a "C". Canada. /forums/images/graemlins/smirk.gif

 

[ScottV]

Here is a much better unit,
It only puts out 85 amps but runs one 120 input power.
It's made by Sanrex and they know how to make
real high quality circuits and welders.

I would like to have it because it's cute and
I know what I am getting. Add a tig torch/ flowmeter later,
and it will weld with that great thermal type dc arc.




http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=57039&item=7527800089&rd=1

 

[have_blue]

</font><font color="blue" class="small">( This is not a tig weld but a mig weld done with a Miller
passport. If anybody can post a picture of a better
weld made with a Chi-com wire feed, I will sell my Miller
and buy it!!! You get what you pay for and generally way less if you are looking for a bargin.
/forums/images/graemlins/grin.gif )</font>

It's a beautiful weld alright. I'm sure it is easier to get a cosmetically pleasing weld or a truly effective weld with a high dollar welder. But how much easier? Over $1000 worth?

Back when I was up to my neck in welding quality, I would have raised a flag about that weld. Depending on the thickness of the parent metal, it looks a bit cold from looking at the picture. I like to see the edges stitched in a little deeper. If it's just sheet metal and lightly stressed, it's a great weld. If it is applied to heavy metal and is heavily stressed, I would "have it sectioned and sent to the lab". /forums/images/graemlins/smile.gif

AK! Now you've got me using my old work jargon. I think I need to go rinse out my mouth... /forums/images/graemlins/smile.gif

 

[ScottV]

So you like a little undercut??

To tell you the truth the passport is a 120/230 volt mig and that
is where the value is in that unit. Portable with a internal CO2
paint ball bottle for gas. I was just cheacking to see if it had
enough power to get into a spray-arc. The edges are wetted out good with no undercut. It was a low level spray and I would not
use that gas (C-3 stainless mix) or process for anything critical. It was a test and that is it. I use a hot short-arc for .250 with that machine but I really like using something that runs bigger wire with 90/10 spray-gas. A good quality gas shielded .045 flux-core for the thickness I weld is a better pick most of the time. This weld was done by my friend with the new/old improved esab 717. It was a horizontal fillet joint and he
turned it upright and went vertical on the hot plate with the exact same settings. /forums/images/graemlins/cool.gif

 

[Soundguy]

</font><font color="blue" class="small">( The power coming out of their cheap transformer is very unstable and will result in inconsistant weld penetration. That is what you get when you use cheap components in your welder. )</font>

Um... a small arc welder.. ac type.. is going to be pretty simple on the inside.. pretty much a transformer primary, secondary, and a thermal breaker...

I don't see this as indicative of producing intermittant power.

Power will be a function of voltage and current, based on circuit resistance. as the copper in the windings heat up.. ressitance will incrementally rise.. perhaps power will drop off slightly over a long 'hot' weld.. but I would not expect to see wild fluctuations based on the transformer ( main component ). I'd guess surface prep o fthe metals being joined would be the biggest determining factor of weld structure, followed next by skill of operator, and choice of rod/suitability of type of welding polarity used, and orientation of the work piece.

Now.. on some of the fancier machines.. inverters.. dc stuff.. high freq stuff.. I could see problems possibly.. but the simply ac arc stuff seems like it is fairly bullet proof in design...

Soundguy