What is a 1968 Irwin made of

[Delightfuldream]

I have a 1968 24 foot Irwin and just bought a depth finder for it. I can use it for thru the hull, but need to know if its solid fiberglass or not. Lowrance suggested that I carve layers into the bottom of the hull to see if there is flotation material or not ie plywood etc.., before I do that I thought I would see if anyone on here would know.
Thanks
Frank and Laura

[Joseph Shirley]

I don't know your boat specifically but most cored hulls are cored only higher up; and the earlier Irwins like yours, are normally solid all the way. At least my 1973 Competition 30 was.

Good Luck

Joe S

[Pater]

My 1969 Irwin 27 has a solid glass/resin hull.