The powders which are a part of many of our DIY kits or dealer packages are not an absolutely necessary item, so the answer would be “not usually”. They are provided for 3 primary reasons: 1 – to allow you to control consistency and provide a thicker product for vertical build on the sides 2 – to allow you to control texture by varying the amount of the coarser product (lp40) and make either a smoother finished product, or a more slip proof product 3 – to keep your costs down since the powder product is less expensive per volume than the liquids.
We also usually provide more powder than the kit amounts dictate so you can vary the lp80 to lp40 ratio to suit your individual needs. It is not unusual to have left over powder products. If you end up with significant amounts of powder products left over, you may want to give us a call now or for future orders so we can custom quote a kit without powder and provide the best price for your specific needs.