Trending at $19.89 ebay determines this price through a machine learned model of the product's sale prices within the last 90 days. $21.85 shipping. or best offer. 38 new & refurbished from $11.82. ... borax 1 kg sodium tetraborate decahydrateboraks. $2.99. our earth's secrets borax powder multi-purpose cleaner 2 lb. bag. High solubility for higher concentrations. 20 mule team ® borax sodium metaborate, available in 4 mol or 8 mol, is an alkaline salt with excellent buffering capacity. its high solubility enables sodium metaborate to provide a much higher concentration of borate ions in solution than either neobor ® or 20 mule team borax decahydrate at the same temperature. Search results for borax at sigma-aldrich. compare products: select up to 4 products. *please select more than one item to compare Alkali borate without sodium salts potassium tetraborate results from the controlled reaction of potassium hydroxide, water, and boric acid. this alkaline salt has excellent buffering capacity and replaces borax where an alkali borate is needed but sodium salts cannot be used.