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silverghost
02-28-2011, 07:53 PM
Just when I thought I was finished with the re-core of my "Benchseat 18" YellowJacket's deck I picked-up the engine hatch cover to check it for proper fit ~~~

As I lifted the heavy hatch a trickle of water poured from the "Donzi" hatch lock knob hole.
I cut the underside glass near this hole and the water dumped-out !
Finally I removed most of the hatch's underside glass to expose two large rotten core ares~~~
The one at the "Donzi" lock knob was about a six inch 3/4 circle~~~
For some reason on this Doni 18 they ran the core very close-up to the lock knob !
I never saw this on another 18 hatch !

But I also found a much larger twelve inch circle around a small star shaped impact gel-coat crack area that you would hardly notice on the top center of the hatch.
I suspect the hatch at one time hit the aft lifting ring at one time or another in the boat's past life .

Since the boat had been sitting outside uncovered for 25+ years in the rain & snow almost the entire hatch core had wicked-in water .

It was literally saturated with water in there !

No small wonder this old engine hatch cover was so darn heavy !

Now I have seen everything !

Pismo
02-28-2011, 08:13 PM
Wood free boats...the answer.

Just Say N20
02-28-2011, 08:18 PM
Wood free boats...the answer.

Yes, if the question is, "How do you make a boat more noisey when running down the lake?"

:lol9:

I'm just kidding, but wood does have some remarkable sound deadening qualities in a boat hull.

silverghost
02-28-2011, 09:23 PM
My Father owned several all-wooden boats over the years ~~~and they sure were quiet !
Chris~Craft ~~~Lyman
The big wooden cabin cruisers owned by friends were much quieter than the later fiberglass boats~~~

I never heard of a hatch core rotting !

Has anyone else seen this ?

There was a big bubble in the laminate lay-up from the hatch latch "Donzi" knob area to the core which was very close by~~~
The water went from this latch penetration hole through the large bubble and into the front leading edge of the hatch core !

I never saw a Donzi engine hatch with a core placed this close to it's front leading edge !
&~~~~
I never saw this BIG a curved wood core on a Donzi 18 or 16 hatch cover !
Why is this one so darn BIG ?

The impact star shaped gel & laminate cracks at it's rear is another issue in itself !
I believe George Carter spoke of this problem issue ?
Possibly from a hatch cover "Blow-Over" at one time or another !

Don't ya just love balsa cores, plywood stringers, and transoms ~~~
in these great old boats ?

Who said Fiberglass boats don't rot ?

gcarter
03-01-2011, 06:13 AM
Here ya go......
About six years ago, almost to the day!
I'll say this, the damaged gel is very difficult to completely repair from the inside. You have to start from the inside, but after the repair is complete, the gel needs to be re-done from the outside to completely remove all the little cracks that will keep coming back and printing through.
Blowovers are tough, not only from the lifting ring, but also from the stress applied to the hinge screws.

http://www.donzi.net/forums/showthread.php?t=38677

Also, I didn't have the correct thickness of balsa end grain core material, and I made up the difference w/Core-Mat.....not ideal, but it worked.
I ended up adding lifting struts to the hatch, and not only do you have a lot more convenience, but they'll eliminate blow overs.

Pismo
03-01-2011, 06:46 AM
Yes, if the question is, "How do you make a boat more noisey when running down the lake?"
:lol9:
I'm just kidding, but wood does have some remarkable sound deadening qualities in a boat hull.

Makes sense, wood is great, too bad it rots.

It is the encapsulation that rots it more quickly. Water always gets in somehow and then it can't dry.

I love wooden boats, have a '58 Lyman.

silverghost
03-01-2011, 01:51 PM
I remember in the mid 1960s- late 1970s guys were fiberglassing the bottoms of great old mahogany wood runabout boats~~~
Most were fiberglassed to just above the waterline.

My uncle did this to a great Century Coronado instead of replacing it's single ply batten-seam mahogany bottom.
Everyone thought it would be a quick & long-term fix for an old leaky wood bottom.

My Father resisted the pressure to do this to his mahogany boat too~~~
Instead he paid an old master wood boatbuilder to totally re-plank his mahogany bottom at a fairly high cost .

Within three seasons the Century's old bottom was totally rotten and the fiberglass was falling off it's bottom like a hull comming out of it's factory mold.
As the wood swelled & expanded the fiberglass just got loose & pulled away~~~

My Father's properly restored & re-planked mahogany bottom is still going strong some 40+ years later !

The Fiberglassed wooden boats are mostly all gone now~~~
They just rotted away !
The ones that had rain water trapped inside them rotted much faster than the ones that were only exposed to salt water~~~
BUT~~
All the fiberglassed bottoms eventually failed & eventually rotted !

The fiberglass bottom shell trapped water between the fiberglass and the wood~~~
Perfect conditions for wood-rot~~~
Dark,& Constantly wet with fresh water~~~
This was a wood-rot science project just wating to happen !

Sadly a lot of really great wooden classics were lost to rot in this very same way !

Pismo
03-02-2011, 08:21 AM
I remember in the mid 1960s- late 1970s guys were fiberglassing the bottoms of great old mahogany wood runabout boats~~~
Most were fiberglassed to just above the waterline.

My uncle did this to a great Century Coronado instead of replacing it's single ply batten-seam mahogany bottom.
Everyone thought it would be a quick & long-term fix for an old leaky wood bottom.

My Father resisted the pressure to do this to his mahogany boat too~~~
Instead he paid an old master wood boatbuilder to totally re-plank his mahogany bottom at a fairly high cost .

Within three seasons the Century's old bottom was totally rotten and the fiberglass was falling off it's bottom like a hull comming out of it's factory mold.
As the wood swelled & expanded the fiberglass just got loose & pulled away~~~

My Father's properly restored & re-planked mahogany bottom is still going strong some 40+ years later !

The Fiberglassed wooden boats are mostly all gone now~~~
They just rotted away !
The ones that had rain water trapped inside them rotted much faster than the ones that were only exposed to salt water~~~
BUT~~
All the fiberglassed bottoms eventually failed & eventually rotted !

The fiberglass bottom shell trapped water between the fiberglass and the wood~~~
Perfect conditions for wood-rot~~~
Dark,& Constantly wet with fresh water~~~
This was a wood-rot science project just wating to happen !

Sadly a lot of really great wooden classics were lost to rot in this very same way !

Not to mention the new breed of encapsulated new wooden boats like Hacker Crafts which were supposed to last forever and their bottoms all rotted away in 10-20 years while the original 40-50s construction methods are still going strong. Wood and glass don't mix. One or the other.