original 60,70s seacraft cunstruction?

[hugo]

what type of wood and resine were used in the original boats back in the 60,s and 70,s? i am wondering why huge diffrences in transom building methods. didnt the original ones last better than 30 years or so? i know i am in need of one done and have been reading as much as could about the subject with no prior experiance on the matter, and its enough to make you scatter brained with all the diffrent types of materials available. i am a very handy guy and im not worried about trying to possibly take this project on, im just trying to understand which method is best and not going to keep my kids from attending a good school one day. i cant beleive the diffrences in prices for this stuff. how long is a wood and poly resin transom good for?

sorry if i am ranting a little but i just bought this boat and was told the transom was done a few years ago, i used it 7-8 times and have a crack and a flexing transom, could strangle that guy!
anyway....
thanks everyone.

[fdheld34]

Poly and wood transom replacement ..in my opinion if done correctly...good for another 20+ years...just like the factory
or get all high tech etc...and spend more money and use composites and epoxy!!!!
You choose...depends how old you are I guess???!!!

-Fred

[hugo]

thanks fred, i guess at 40 im good enough that whithin 20 years one of my kids will own a boat and take the old man out on thier boat!

[Blue_Heron]

Originally Posted by fdheld34

... if done correctly...

Exactly.

As amateurs, we don't always do it correctly. A polyester resin layup with a plywood core, done correctly, and then not compromised by incorrectly installed fasteners will last 30-40 years.

A couple sheets of plywood bonded together and then laminated with poly resin and a layer or two of 1708 on each side may not last 10 years. The laminate on these original transoms was at least 3/16" thick inside and out. IMHO, A polyester layup thinner than that isn't going to protect a wood core from moisture.

Today, you can compensate for less than perfect technique by using the high end resins and core materials. But you still need to reproduce the original inner and outer laminate thickness to get a transom as stiff and durable as the original. It's a common misconception that the strength of a transom or deck comes from the core. The strength in a cored laminate comes from the laminates.

Dave

[hugo]

someone put some patches in in my boat at one time to support the washwell, anyway these patches came loose easy like the glass was never boded properly, when doing glasswork what is the trick to getting a good bonding to existing glasswork with poly resin.

[hermco]

It's a common misconception that the strength of a transom or deck comes from the core. The strength in a cored laminate comes from the laminates.

Excellent point.

[hugo]

if i wanted to use foam rather than wood, is it lighter? is the proses the same as using wood? is the same amount of glass used or does it need more layers?and where do i get it?. thanks.