For two years I used the same brand of flux from the hardware store and blamed my forge heat for cold shuts. Last month I mixed up a batch of borax and iron filings using a recipe from a guy in Ohio, and my welds came out cleaner on the first try. The old stuff was fine for light work, but it burned off too fast on 1/4 inch stock. Has anyone else found that homemade flux beats the commercial stuff, or am I just compensating for a bad technique?
Actually that recipe with iron filings is more about adding a little mass to the flux so it sits on the metal longer, not about the borax being better than what you bought. Borax is borax for the most part, the commercial stuff just has a lower burn point sometimes depending on what they mix in. But hey, if it works for you on the thick stock, that's what counts.