seadevil26 wrote:I have a 1994 17 Montauk... I found what appears to be a missing deck plate in the anchor locker...I believe that this is where the expandable foam came out during the manufacturing.
On every Boston Whaler boat Unibond hull there is a large SPRUE HOLE located in the forward part of the boat. The hole is about 3 to 4-inches in diameter. The liquid compound that would rapidly react to form foam was introduced through the sprue hole. Typically when this was done the hull would be tilted with a bow-up angle. The foam would expand, and excess foam would come out of the interior space between the double bottom hull at the main sprue hole, as well as at some secondary vent holes.
About 24-hours after the foam was introduced and expanded, the foam would be fully cured and bonded to the laminate surfaces of the hull, which were also in the process of curing their polyester resins.
The excess foam at the sprue hole would be trimmed away to be flush with the laminate.
In some boats in some years, the exposed foam would just be given a clear sealing coat and left exposed. On some boats in some years, a circular plastic cover would be set in place to close the sprue hole and held by adhesives or perhaps by curing resin.
I cannot offer an authoritative opinion about exactly what was done to your 1994 MONTAUK 17 boat when it was made. There could have never been a plastic cover, there could have been a plastic cover and it became dislodged.
But there NEVER would be a circular pry-out deck access plate at the sprue hole, at least from what I have ever seen, heard, or read.