Solar flux or Argon purge?

[YvesVT]

Hello all,

I'll be starting work on a large stainless steel "human-like sculpture".
I'll mostly be using my Maxstar 150 STH Tig, as it is pretty thin stuff, (16 gauge) but some pieces will be 3/16".

I was just wondering, is it worth it to back-purge every single weld to avoid sugaring or could I just use the "solar-flux" type paste?

N.B. - None of the welds will be visible from the outside, but I still want them to look nice, (however the importance here is that they do not sugar, because I don't want them rusting in a couple months because the chromium got out).

If anyone has experience in this field, please let me know,

thanks!

[con_fuse9]

If you are just doing fusion welds (no filler - and probably not full penetration) you will probably be O.K. The moment you put enough heat in it to add filler rod you will be in trouble. Need to keep your joints tight - more or less touching.

A dual output Smith flow meter is about $180 (on line) - comes with 60" or so hose.

You can get some benefits from pre-flow from the torch.

The Solar Flux is relatively expensive (I think a can is like $35 on E-bay and $50 everywhere else) and quite frankly not a perfect solution. In your case it is probably good enough. Mix up only what you need, follow directions and when in doubt, go heavier. In my experience on exhaust pipe (spots that I can inspect after the fact) there was still signs of sugaring. I'm not sure if I ever used it properly, but my results were acceptable, but less than inspiring.

If the piece was subject to lots of vibration, I would suggest back purge. Other than that, you could probably tack weld it together with acceptable strength.

[Wicked one]

If you are just doing fusion welds (no filler - and probably not full penetration) you will probably be O.K. The moment you put enough heat in it to add filler rod you will be in trouble. Need to keep your joints tight - more or less touching.

A dual output Smith flow meter is about $180 (on line) - comes with 60" or so hose.

You can get some benefits from pre-flow from the torch.

The Solar Flux is relatively expensive (I think a can is like $35 on E-bay and $50 everywhere else) and quite frankly not a perfect solution. In your case it is probably good enough. Mix up only what you need, follow directions and when in doubt, go heavier. In my experience on exhaust pipe (spots that I can inspect after the fact) there was still signs of sugaring. I'm not sure if I ever used it properly, but my results were acceptable, but less than inspiring.

If the piece was subject to lots of vibration, I would suggest back purge. Other than that, you could probably tack weld it together with acceptable strength.

Solar flux is entirely adequate for what you are doing. They use it in the pulp and paper industry for x-ray quality welds. As for being expensive, trying to back purge a piece of art will be extremely hard compared to solar flux. You'll have to figure out a way to hold the argon , so that may include building some sort of fixture so that it can do it's job. Or you can just paint the back of what your welding with solar flux and don't worry about it. As for welding all the chromium out of it will not cause it to rust. Sugar(Carbide percipitation) will not rust. Plus argon and the flow meter's for purging will cost a ton compared to solar flux. Jef

[YvesVT]

thanks

To con_fuse and Jef,


thanks a bunch for getting back to me, info,some ideas and costs, and for the clarifications, (I assumed it was the chromium that precipitated, but you're right, it is the carbide).

I was thinking the same thing, that backpurging many different and irregular shapes would be a hassle in general compared with the solar flux. I just wanted to see what others would say so that I could forge ahead with a little more confidence!

and, I probably will be adding filler and doing a few full penetration welds so shielding of some sort on the backside will be necessary,

thanks again,

(if others have any other options, solutions, comments, feel free to reply)
best regards,

[SundownIII]

Yves,

My vote would be for Solar Flux.

I use it quite frequently when doing SS handrails (marine repair/fabrication). Works great in areas difficult or impossible to purge.

The only complaint I've ever heard is that it can be difficult to clean up if the side protected with SF is visible. Inside a handrail, inside a figure (hidden as you describe) that's not a problem.

Solar Flux DOES NOT have to be removed except for appearance.

A small can ($35-50 depending on where it's purchased) goes a looong way. Mix only what you need for say an hour's welding. It's mixed with methanol alcohol. I use the gas antifreeze (HEET) which is mostly methanol.

[wagin]

I have purged and Solar fluxed. My personal opinion, I'm not a fan of the sflux. As stated by Sundown, it is hard to clean up, and to me does not offer that much gain for the labor required.
By acciedent, I descovered a method of tigging SS sheet metal with full penitration, producing no sugar on back side. If you layer the back of sheet metal with clay it will prevent ozone from reaching molting SS. samuri sword makers use specific clays when treating the blades.

[thunder71]

solar flux will be what you want to use for your project & it works well...if you need some i can send you a can for $20.00 + shipping costs

[YvesVT]

solar flux will be what you want to use for your project & it works well...if you need some i can send you a can for $20.00 + shipping costs

I just got a quote from my lws and its about 40$, so with shipping costs, it'd be the same to get yours.

thanks for the offer though!

[thunder71]

yea shipping is about $5.00