"Comtech Boat Foam" 2 Lb. Density is a new technology formula of single compontent expanding polyurthane foam for boat flotation. -It needs only mixing with 1% to 5% water to start foaming (manual mixing without drill). -It's suitable for filling gaps in all kind of boats , kayaks and other marine applications. "Comtech Boat Foam" is expanding with a high ratio to save the consumed quantity. -When it cured it makes rigid strong closed cell foam. -Reaction time : 2 minutes to start foamin , 6 minutes to complete foaming , 20 mintutes tack free. -As it has low viscosity it can penetrate through very narrow gaps. Foaming ratio up to times.