Dear Sir,
I have tried to make the 28.5 litres of JWA with five litres of sunflower oil.
Ingridients: KOH - 0.888 kgs
Initial Water - 0.69 litres
Sunflower Oil - 5 litres
Step I - 0.69 litres of distilled water + 0.888 kgs of Potassium Hydroxide
After the KOH was dissolved
Step II - Added 5 Litres of Sunflower Oil
mixed the solution of water + KOH + Oil with electric paint mixer for 15 minutes.
It is still not hardering even after 2 hours.
Previously I made 20L of JWA then the mixture solidified in no time.
Your proportions are pretty much right. For now, the alternative is to keep mixing longer. If there is a slight error in the amount of water, the mixing period may increase significantly.