Kevin I recently bought a gallon of the primer and got 7 tubes of hardner with the gallon. I have done a search on the this forum and can’t find the mixing procedure. Only 5% by weight. I’m not sure what that means exactly. I use mixing cups and I’m sure u know the break down on them as far as the ratios. Could you please tell at what ratio to mix the primer with the hardner. Or is the hardner even really needed. Thanks in advance. Dave H.