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Anatomy of an Investigator??
Posted: Fri Jun 19, 2009 9:38 pm
by Ozzie
While browsing threads on TSP I have noted reference to "cored deck" I which is as I understand it timber between two layers of glass. Does the 563 have a cored deck? I'm curious because I intend to get my standing rigging redone on the next haul out and add a few other hull fittings. Research indicated fixing through core requires more care than a straight glass deck.
I intend to get the chain plates replaced as well . All my standing rigging is I suspect original. The boat had not had much use in its lifetime and spent much of the previous 10 years before my purchase, under cover. After 3 years of mooring it is still visually ok other than a tea stained forestay. This browning I am told does not mean it is weak but I am not taking chances. I want to push the boat a bit harder this season and new rigging will make me feel more confident to do this. 30 years is not bad for rigging.
Also does the 563 have perspex or poly (lexen) as original windows

I have crazing on two windows and may look at replacements
Cheers
Re: Anatomy of an Investigator??
Posted: Sat Jun 20, 2009 11:12 am
by RobertB
Hi Ozzie, Yes, well certainly the cabin top is cored. I had read this somewhere before I bought the boat, being advised to check that the deck and cabin top were not spongy - which indicates that water has got into the core.
When I installed my vent, just in front of the mast tabenacle, but, far enough away as to not comprimise its strength, the cabin top had a core of ply, about 19 millimetres thick, with about 3 mls of fibreglass on the top and on the bottom.
One is advised to cut a larger hole, and then to seal the edges of the hole with fibreglass, ot better still, to fill the hole with fibreglass,totally sealing the core again, and then drill the hole size you require for your fitting.
http://www.boatus.com/boattech/Casey/39.htm
The link above explains it very well. This is also a great place for lots of sailing info.
Hope that helps.
Cheers, Robert
Re: Anatomy of an Investigator??
Posted: Sat Jun 20, 2009 11:55 am
by Yara50
Regular replacement of chain plate u bolts is a must. Take a lot of care to seal the holes. The corrosion which can occur is called crevice corrosion, when there is a small gap. It can cut through stainless like a knife.
Also when replacing the shrouds (side stays) get them professionally done with straight swaged ends. The old home made loop swaged ends are another possible corrosion point. I did the forestay myself with the loop swage, as I believe it is not as critical as the shrouds, especially standard Investigator 563 shrouds, where there is only one per side.
Re: Anatomy of an Investigator??
Posted: Sat Jun 20, 2009 10:06 pm
by Ozzie
Thanks Robert and Ian
I am surprised the core is so thick but I assume thats why the 563 feels so solid underfoot. Robert that is a good site I have added it to my favourites.
What kind of vent did you use, that was one of my planned additions. I want a screw down type for heavy weather but I also considered a solar powered one which would help to keep the boat ventilated on the mooring. We had one in the roof of the Maui camper we hired in NZ and I was impressed with the way it worked, not sure how well they keep water out though.
I assume the cost effective way is to take the rigging off and take it to the rigger to duplicate it, or do they prefer to fit it to the boat in sit. Never done it before. Ian when replacing the U bolts were you able to find the same size? i assume they are a generic thing. If they were longer or shorter obviously the shrouds would need to be adjusted accordingly. maybe its better to do this then get the rigger in.
Re: Anatomy of an Investigator??
Posted: Sun Jun 21, 2009 12:15 pm
by Yara50
The U bolts are standard items. I took my old rigging to the rigger and he used them as a template. Also, we have stay adjusters to vary the length and hence the tension. They have a set of pin holes so that adjustment is in distinct steps.
Re: Anatomy of an Investigator??
Posted: Sun Jun 21, 2009 12:48 pm
by BobK
While we are on the subject of stays, mine is rigged as it was when I bought the boat. But I could go another hole longer or several holes shorter on the sidestays.
Appears to me that going shorter would add some aft mast rake, or going longer less rake etc.,
Has anybody an opinion on mast rake?
Re: Anatomy of an Investigator??
Posted: Sun Jun 21, 2009 2:18 pm
by Yara50
If you have the original design with backstays, changing the shroud length has minimal effect on mast rake. Only on the boats with the shrouds mounted further aft, does it make a difference.
The mast should be vertical, and this is set by the length of the forestay. The shroud tension is set by the shroud adjustment, however there was some debate in the old days about the flexibility of the cabin top and the side decks, and their influence on the tensions. The previous owner of Yara fitted a brace under the mast position in the cabin.
Re: Anatomy of an Investigator??
Posted: Sun Jun 21, 2009 9:31 pm
by RobertB
Hi,
I fitted a cheap plastic mushroom vent. It was only $9.95 I think. It can be screwed down tight for weather proofing, it has a built in mozzie mesh and adjustable height, which can be adjusted from in the cabin, or from on top (by spinning the mushroom) which is handy, if you think you're about to step on it, you screw it down so that it will not break.
I see in Practical Boat Owner, issue Number 487, July 2007, they test 10 different vents and conclude that "all mushroom vents are good.......pulling air out of the test box (used to simulate a cabin) by the venturi effect." They go on to suggest that they are best for "over galley area". This suits me perfectly as I have it over the forecastle bunk.....hmmm no comments about flatulence please bob...
Cheers, Robert
Re: Anatomy of an Investigator??
Posted: Sun Jun 21, 2009 9:35 pm
by RobertB
On the subject of mast rake, my boat had a rake towards to rear when I first got her. I also had problems with weather helm. Some (or most) of this was due to overpowering the rig, but I did straighten up the rake and this seemed to assist.
I use a little mast bend (possible on the 7/8 rig) to flatten the main in high winds, but not for long, prefering to reef and let the boat sit upright a little more.
Cheers, Robert