Formosa sailing boats

[al.woodrat]

Hi all. Hope this coming sailing season will be trouble free for all of you. I was on a french forum a few days ago and this guy mentioned an apparently well publicised sinking of a Formosa 51 near the Balearic Islands in the seventies or eighties... giving for cause of wrecking the fact that the hull opened in two parts lengthwise due to a "glue failure"!!!!! Can any learned Formosa/TaChiao enthousiast here confirm/contredict this rather strange method of build in two half-hulls stuck together? (I thought these sturdy yachts were built in one part...) Thank you. Al

[rcmpegasus]

I have a Formosa 51 and it was built in two halves and glued together. I suspect it's true of all of them. I find it hard to believe that they could split apart though, it's a huge joint area.

[al.woodrat]

Originally Posted by rcmpegasus

I have a Formosa 51 and it was built in two halves and glued together. I suspect it's true of all of them. I find it hard to believe that they could split apart though, it's a huge joint area.

Thank you rcmpegasus for this reply. Do you or anyone else happen to know how they do it (if there is a mechanical way to keep them together like fastenings/steel floors etc...)? Congrats on your choice of yacht, they have always been my favorite GRP boats. Safe sailing all. Al

[boatpoker]

The hull is not two halves glued together. The molds of almost every sailboat and certainly all full keel sailboats are made in two halves which are bolted together.

After the hull is laid up (in one piece) the mold is taken apart. This is done because it is simply much easier to get the hull out of the mold this way. It is also done because the top lip opening of the mold is sometimes smaller than other parts of the hull (think tumblehome or reverse transom)

[al.woodrat]

Originally Posted by boatpoker

The hull is not two halves glued together. The molds of almost every sailboat and certainly all full keel sailboats are made in two halves which are bolted together.

After the hull is laid up (in one piece) the mold is taken apart. This is done because it is simply much easier to get the hull out of the mold this way. It is also done because the top lip opening of the mold is sometimes smaller than other parts of the hull (think tumblehome or reverse transom)

Thank you boatpoker... What you say is how I thought ALL GRP boats were built (I am a boat builder myself but know not much about GRP) but apparently, from what this guy was saying on the french forum and what the owner of a Formosa 51 says above, they seems to be built in two half-hulls glued together.... strange.

[zeehag]

most of them hold up well... i wont vouch for sunk ones.
there was a formosa 51 on the rocks here in zihuatenejo last year--is now up and sailing nicely , doesnt even look like hole was made, which it was.
fomosas are a mighty tough old boat. i know--i sail one. mine is built in fbb yard in taipei, as were most of the formosas, and all the 51s, allegedly. first ct boats were built by fbb also. (formosa boat builders)
for the best formosa info, there is the formosa owners group on yahoo which changed name to leaky teaky yacht club-for linky see my signature.

[boatpoker]

I've surveyed several of these and they were all a single mold layup from a split mold. I find it very hard to believe that some of them were done that way and some "glued" together.

I believe the "glued" comments were made by uninformed people who misunderstood the split mold process.

[zeehag]

Originally Posted by boatpoker

I've surveyed several of these and they were all a single mold layup from a split mold. I find it very hard to believe that some of them were done that way and some "glued" together.

I believe the "glued" comments were made by uninformed people who misunderstood the split mold process.

thankyou ....
is mostly why i referred opp to leaky teaky yacht club, the best source for formosa information. we are formosas we sail formosas and we fix our formosas....come ask and learn about these truly cool boats.

[yacht_planb]

Hey there...Just signed up for the Leaky Teaky Yacht club. Been living aboard my HF 51 in Miami now for 6 years!

[NahanniV]

Originally Posted by boatpoker

The hull is not two halves glued together. The molds of almost every sailboat and certainly all full keel sailboats are made in two halves which are bolted together.

After the hull is laid up (in one piece) the mold is taken apart. This is done because it is simply much easier to get the hull out of the mold this way. It is also done because the top lip opening of the mold is sometimes smaller than other parts of the hull (think tumblehome or reverse transom)

I don't know about Formosa's, but, some boat hulls were laid up in two separate halves. Then the molds are brought together and the halves laminated (glued) together. I think it gives better access for hand laminating.

Have a look at this:
How a Hallberg-Rassy hull is built

[al.woodrat]

Thank you guys, now I have the answer to my question... I'd never have thought it was a building method for "big" boats but then again there are many more things I don't know... Cheers and safe sailing all.

[Rayallyn]

Many boats were built in half sections and then bolted and "glued" together. Even some of the early Rhodes designs were built this way.
Ray

[boatpoker]

Originally Posted by NahanniV

I don't know about Formosa's, but, some boat hulls were laid up in two separate halves. Then the molds are brought together and the halves laminated (glued) together. I think it gives better access for hand laminating.

Have a look at this:
How a Hallberg-Rassy hull is built

If you read carefully and follow the photos you'll see that only the skinout mat is laid in the half mold, then the molf is brought together and the structural laminate is laid in. The quote below is from the Hallberg site you referenced.

The parts of the hull are laminated together before the mold is opened. The points where the parts are put together are laminated so carefully that this will be the strongest part of the hull.

[NahanniV]

Originally Posted by boatpoker

If you read carefully and follow the photos you'll see that only the skinout mat is laid in the half mold, then the molf is brought together and the structural laminate is laid in. The quote below is from the Hallberg site you referenced.

The parts of the hull are laminated together before the mold is opened. The points where the parts are put together are laminated so carefully that this will be the strongest part of the hull.

I am certain that some hulls have been built as separate halves and then laminated together.

Perhaps this example is clearer:

The Hull - Linjett

"Within 16 hours after the last layer has been applied, the two halves of the hull are put together. The timing is of upmost importance during construction of the hull in order to obtain an even and solid structure and avoid delamination. Even the hull's two halves are assembled and bonded with several layers of laminate that make them fully homogeneous."

[boatpoker]

I did not say that none were built of two halves, I said that Formosa was not.
However if you read your own example you'll see that after the mold is joined, the two halves are joined together with structural laminate and neither bolted nor glued together.

"Even the hull's two halves are assembled and bonded with several layers of laminate that make them fully homogeneous".