Hi all, I've found there is no need to convert as you work with one or the other. If your titrating with 0.1%KOH ( 1 gram of KOH per 1 litre of distilled water) then when you find out how many grams to neutralise the fatty acids you will know in KOH terms how many grams per litre to convert wvo into biodiesel. Dont think about conversions of 1.4 or what ever. All you need to settle on is how much you are going to use as your base amount. In NaOH its 3 or 5 grams depending what school or though you come from and for KOH its 5 or 7 grams depending what boat you got out of. But its unneccessary to have to sit down and convert. Its like going OK today I'm gonna drive from a to b. It just so happens that one or the other is 5/8 in the miles/kilometes conversion but there is no need to do the conversion (unless you wated to) your car either has how any K;s or how many miles you drove on the speedo.

Just to clarify the issue with (3 or 5g) and (5 or 7g). Some say that 3 grams of NaOH and 5 grams of KOH isn't enough to achieve ASTM conversion. Whats ASTM? Its the american standard on how biodiesel is converted. ASTM purists use higher amounts of reactant to ensure ever last tri/di/mono glyceride is converted and the BD washed and dried as per the ASTM specification. Others who aren't so concerned might not even titrate their oil if its from a regular supplier and may not even wash. They just settle for a week. I spoke with a guy who uses 9 grams for every batch of oil he gets from the same shop. (Thats 7 grams as the base and 2 for the titration/neutralisation). Then he lets it settle for 2 weeks. He says he run over 50k's with no probs in his late 80's Land Cruiser. He changes a sacrificial filter every 5-7000k's. Each to their own.

So like I said pick which reactant your gonna use and stick with it. It just so happens you might use 1.4 times more of KOH over NaOH but its academic.

Hope I haven't confused anyone. To summarise stick with one or the other and work out how much as a base your gonna use. 3 or 5 for Sodium Hydroxide or 5-7 grams for Potassium Hydroxide. I've used 5 and 7 grams of KOH as a base and I have had great successes with both. When you get to the upper amount you will get no conversion, so I'm of the believe that 7 as a base is probably better.

Joe