Why You Should Use Solar Flux
When welding stainless steel or one of the high nickel alloys (Inconel, Monel, etc.), the shielding gas or the flux in the electrode only protects the FRONT of the weld. You must use something on the BACK of the weld to keep the oxygen out, float out the oxides and dissipate the heat. This can be accomplished either by purging with an inert gas, usually argon, or by the use of SOLAR FLUX. Failure to protect the back of the weld by one method or the other will result in a sugary, porous weld, burn-through; and the weld will not be of x-ray quality.
SOLAR FLUX has been protecting the backs of welds, keeping the oxygen off, dissipating heat and unwanted oxides, and producing x-ray quality welds for nearly 100 years. It is often preferred over inert gas purging because it is easier, faster, simpler, less expensive to use, and yet yields the same x-ray quality weld.
Half of this test coupon was protected by Solar Flux, while the other half was left untreated.
From the front, the weld looks perfect. However, turn it over, and the difference is clear.
With Solar Flux Unprotected