With a new boat especially make sure they do a good job of dewaxing the hull FIRST. It needs to be done before any sanding to get all the mold release wax off the hull so the paint will stick. If they start sanding first the heat from the sanding can drive the wax into the gel coat. First a wipe down with a dewaxer using the 2 rag method, one rag with solvent the second rag wipe immediately after to pick up the wax while it is in suspension in the solvent. Changing the second rag very often. Then sanding the hull to provide tooth for the barrier paint. Then the specified, per the paint manufacturer, number of coats of the barrier paint and finally the number of coats of bottom paint. The timing of all those coats of paint is critical, the paint from the last coat needs to be thumb print dry but not too dry for the next coat to chemically bond. Too dry and you have to sand and then wipe with solvent before the next coat. Thumb print dry means that if you use your thumb on the drying paint it will leave a print but paint does not transfer to your thumb. It depends on the weather, temp and humidity how long between coats. Do not let them short you on coats of the barrier paint. Make sure they use the recommended amount of paint the manufacturer specifies for your size boat. Boatyards will say a couple of coats is sufficient but probably not true. Ask the manufacturer of the paint. Last boat I did a barrier paint I did 6 coats of Interprotect and then 2 coats of bottom paint with a 3rd coat at the waterline. It took me about 4.5 days to do all the coats because some days I could do a coat early in the day and a second coat late in the same day.
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