70s vs 80s hull construction

We're there construction changes from 1970s era hulls and 1980s era hulls (weight). We have 2 mid 80s boats and have seen some 70s boats on the market to add to our beach's armada.

Outside of the sails being softer due to age, are the older hulls heavier due to more conservative / thicker fiberglass layup & construction? Looking to comapre those hulls to a non-red line boat of the 80s. I'm familiar with the benefits/disadvantages of redline....

1984... Class rule weights went from 340 to 320. You cen tell by the color of the glue seam. We used red starting with the lighter boats.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

I believe the red line boats were built using a vacuum bagging process which pulled excess resin out of the hulls to make them lighter.

sm

Vacuum bagging is primarily for the foam core layer. This forces the stiff panel of foam to adhere to the concave inner hull shape. We went away from Vacuum bagging the second glass layup due to excess resin and shifting fiberglass issues. The second layer is hand squeegeed to remove excess resin. In addition we changed the glue seam process to force excess resin out of the hull during deck to hull lamination. Better processes... more care makes a boat lighter.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

I can concur that. My 1985 red line H18 has some serious pleats in the inner glass layer and resin puckers all on the inside surface. The later boats have a much nicer interior finish.

sm

I was working with my brother on his collection of 18s. We combined an 84 and 94 hull to complete a boat. Both of these years are noticeable lighter than the 1980 hulls he also has. We had a junk 94 hull to cut up, it would seem the only good thing about the newer years is the daggerboard well.
The 94 hull had a side impact, and the inner glass was flapping loose as if it had no resin in it at all. Seemed to be extreme as it probably only had enough resin to stick to the foam, without much absorbing into the glass itself.
As far as 16s go, I believe the very early ones were built like tanks. I have a pair of pre 73 hulls that are solid, I don't know what year they are exactly. I have cut up a 74 and a couple of 78s because of delam. Alot depends on how the boat is used, if it's continually pushed to the limits there's more chance for hull failure. I've seen delam from bow tip to transom on the deck.

"White" color of the glass is fractured resin... not likely dry when laminated.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Has Hobie been using the same type of foam core material to construct the fiberglass/foam sandwich in the deck and sides of a H16 hull since the early 1970's?

_________________
Tim
84 H16
82 H16
87 H14T
Tortola Sails: 115222
Blue Prism Sails: 88863
Clearwater, FL