Building Paterson 8 in Dubai

[phil_kirk]

Solution: Wet out the cloth on the buttered foam, trim the overlapping cloth to fit the desired overlap before overlapping it.

Caution: clean the scisors with thinners to avoid using lots of pairs.

We've probably gone through about 5 pairs of scisors during our build.  Since they all came from a pound shop it's not a great outlay.

being a bit nerdy and thinking this through I would keep one pair of scisors for cutting peal ply which is a pain with anything but sharp scisors. Then avoid where possible getting the other scisors covered in resin.  Difficult to achieve but a laudable target.

[roland_trim]

During our build we had a Hierarchy of scissors (often corrupted by visitors, btu we were glad of the company). By the end I became rather an***y retentive about the misuse of the scissors reserved for the peel ply. Sounds like a League of Gentleman sketch:

"Black for paper, chrome for string, the blue one from this hook do swing.
We keep them clean, don’t be mistaken, for kitchen jobs like trimming bacon."

Back to the thread:
I'd worry about the carbon wanting to move under the bag, it seemed to strech out a little when under pressure in the initial hits. After a few scratched chin's we decided that we would do the bottom and sides in 2 hits. Hit 1 sides to chine  intersection (not round the chine), hit 2 entire bottom panel (over the chine). Yes we did pre-sand the foam for the overlap, but I think this was overkill as you will want some filler on it to sand back to anyway.

[Phil Alderson]

Wet out in place would help the movement issue, I have mostly been wetting out on a table lately so get a lot of stretching.

I got a pair of Teflon coated scissors a few years ago, I chip the cured epoxy from them every so often and then recoat in release wax. They are starting to get a bit blunt now, but have done quite a bit of work.

I also use release wax on plastic spreaders, and occasionally on pots so I can clean up eisly.

[doug1720]

I thought the other day that where you are expecting to overlap cloths on the outer layer of the hull shell you could just sand a little more foam away.  This way you only have to build up localy near the overlap if you happen to have sanded off too much.  If the overlaps stand slightly proud you end up ffilling everywhere else to fair in these high points.

Thanks for the advice.  I spent a lot more time preparing and checking the cloth fits, etc before having a go at the outer shell.  Was a lot harder to get it correct but got there in the end.  i ended up with more like shrinkage and so next time would have larger overlaps when curtting the cloth.  Vacuum went on really well and have left it to take a trip to Iraq.
I am off on the Dubai Muscat and then to Canada on Business and so a few weeks off.
I intend to take a lot of time over the hull fairing and multi task with lots of the other jobs so I do not get totally fed up.

I have a couple of pics that I will put on once I am back in Dubai.

Doug

[doug1720]

I am now considering the crew deck and am still undecided on the eventual design.  I am thinking about the 49er style that fills the entire inside of the hull versus having a little of the hull side exposed with the crew deck below gunwhale height.  One of my thoughts to not having the 49er style is that I would have to put more fittings like the racks through the deck.  Maybe simpler to have all that fitting above the crew deck?

Any thoughts on this would be appreciated.

Thanks,

Doug

[Phil Alderson]

I changed 2686 from having a sunken crew deck to one where it was flush with the inner gunnals, and the modified version was much easier to sail.

I did not have any of the wing support bars puncture the deck with the modified layout, however I was not hanging the rig loads on them so they did not need to be as strong.

[doug1720]

I changed 2686 from having a sunken crew deck to one where it was flush with the inner gunnals, and the modified version was much easier to sail.

I did not have any of the wing support bars puncture the deck with the modified layout, however I was not hanging the rig loads on them so they did not need to be as strong.

Thanks for the information.  I suppose I would feel happier about seperating racks from the rig.  I need to design what comes up through the crew deck...have you got any pictures of what that looks like on your boat?

Doug

[roland_trim]

Photos attached show how our structure on EJ was done. The rear rack support was bonded down onto the deck (not shown brilliantly).

These come with a warning - we haven't sailed this enough to know if it will break...

[Banshee Ambulance]

Would anything stop you having the rack support tubes in the place where the tie bars are and keep the whole thing below the deck?

[roland_trim]

The concept behind this one was that the tension strut passes through the hull skin, this is lower to the water and has little drag if it gets wet (which it does).  The compression member is higher and presents lots of drag when it is in the water (but by then so is the rig!).

Yes It would be possible to replace the struts by a bending member - like a beam stuck through/on the deck. We chose not to do this and copied Aunti Dot as I like things that are in tension/compresion or put basically - triangular 

[Phil Alderson]

There are quite a few pictures showing how it went together originally and after the rebuild on;
http://www.sailingsource.com/cherub/test/doku.php/boats/2686

The hull is a bit wider than the E5 which made it eisier to put the shroud points on the hull.

[Banshee Ambulance]

The concept behind this one was that the tension strut passes through the hull skin, this is lower to the water and has little drag if it gets wet (which it does).  The compression member is higher and presents lots of drag when it is in the water (but by then so is the rig!).

Yes It would be possible to replace the struts by a bending member - like a beam stuck through/on the deck. We chose not to do this and copied Aunti Dot as I like things that are in tension/compresion or put basically - triangular 

I cant work out how to do this on the new boat. I know I want a fore deck as I want quite a lot of freeboard and a low false floor but cant work out how to fit all the structural bits in and have space for a retracting pole and chut.

[doug1720]

Guys, Thanks very much for all the input.  I am off sailing on the Dubai Muscat tomorrow and so up to my eyes in getting the boat ready, etc.
If the breeze is good I can get back early next week to Dubai I will do some research on all the information and come to some conclusions.  The work will have to wait until I return from Canada on the 19 December!
Thanks,

Doug

[phil_kirk]

RS405 ,

The older designs such as the DOG had a false floor that went all the way to the bow and then a foredeck over the top.  The modern boats have just got rid of the fore deck. Makes rigging some of the systems much easier and saves weight and time in the build.

The E5 has the same freeboard as the DOG at the bow. 

It's quite straight forward to bring the compression beams to the mast stump as on the E5 and the connection to the gunnel is quite easy to allow for when trimming the deeck to size.  I reffer you to the CD of photos. The tension stay needs to be integrated before the deck goes on but again is not difficult to do if you use the dry fitted beams to support the outboard ends.

With the narrow hulls i would have thought that you would struggle to provide enough support to the mast by only attaching the shrouds at the gunnels.  We have a shroud base of 1.5m. Other boats have shown that you can go narrower and wider.

[JimC]

The older designs such as the DOG had a false floor that went all the way to the bow and then a foredeck over the top.  The modern boats have just got rid of the fore deck. Makes rigging some of the systems much easier and saves weight and time in the build.

Its worth nothing that IMHO you cannot do without the foredeck on a predominantly glass boat - even top quality biaxial glass as we used in the early 80s. The structure will bend significantly under rig loads: you need the extra support for the topsides. I can't comment on carbon boats, but a very interesting experiment would be to measure the distance between gunwhales at say three points between the mast and forestay both with the rig tension off and with it on.  Repeatable differences mean that the boat is bending under load which is unlikely to be a good thing. Another useful exercise for those prepared to take the trouble is to make the same measurements before and after sailing without taking the rig tension off, and also to measure the rig tension before and after sailing. All this will tell you what is happening to the structure under load.