S2 8.5 Mast Rake Problem

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Feb 23, 2011
6
S2 8.5 Buenos Aires, Puerto Nuñez
Hello, my name is Patrick from Buenos Aires, Argentina.
The mast is stepped on deck, and i notice that the base of the mast is erected at the stern (see photos). "Foto sacada desde proa/popa" = "Picture taken from the bow/stern"

Currently, the mast rake is about 15 cm aft.
¿How I can fix the inclination of the base of the mast? My intention is to become firm, and then correct the mast rake.
In this type of boat, which is the mast rake size? 5% maybe?

It is possible that the base of the mast has this rotten wood, and this is causing the problem?

Please, I need help. I'll be very grateful for your suggestions or comments, as in Argentina is almost impossible to get information on this ship.
There are only two S2 8.5 in Buenos Aires!

Attached some pictures that help you understand my idea, if my English is not so good!

https://picasaweb.google.com/111704586366554484500/MastilMast

THANK YOU!!!! :)
 

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Bron

.
Apr 19, 2010
74
s2 8.5 rocky river
Hello, my name is Patrick from Buenos Aires, Argentina.
The mast is stepped on deck, and i notice that the base of the mast is erected at the stern (see photos). "Foto sacada desde proa/popa" = "Picture taken from the bow/stern"

Currently, the mast rake is about 15 cm aft.
¿How I can fix the inclination of the base of the mast? My intention is to become firm, and then correct the mast rake.
In this type of boat, which is the mast rake size? 5% maybe?

It is possible that the base of the mast has this rotten wood, and this is causing the problem?

Please, I need help. I'll be very grateful for your suggestions or comments, as in Argentina is almost impossible to get information on this ship.
There are only two S2 8.5 in Buenos Aires!

Attached some pictures that help you understand my idea, if my English is not so good!

https://picasaweb.google.com/111704586366554484500/MastilMast

THANK YOU!!!! :)
Buenos dias Patrick:

I have a 1982 S2 8.5, Hull No. 088. Your mast step plate is different than mine. Mine has a similar step plate, but the attachement at the base of the mast is different. My mast sits flat and square on a base that fits about 1.25 cm up the inside shape of the mast. I'll send some pictures in a day or two. I have some at home and may have to take a few more. Yours seems to have a base with a slot that sits on top of an angle piece on top of the mast step. It almost looks like the base can rock back and forth with mast rake. I can't tell how the base is fixed to the angle or step plate to keep it in place.

I've also never measured the rake of my mast. I'll do that too and let you know what I find.

However, mast rake is genreally determined by the rigging. If mast is raked back 15 cm, shorten forestay to where mast is of desired rake.

My forestay has no adjustment. It is exactly the length specified in the owners manual - 37 feet, 7 3/4 inches, center of top pin to center of bottom pin (changed headstay last year when changing roller furling). Any tension adjustment on the forestay is done through adjusting the back stay

Regarding rotten wood, if the deck core is rotten, the step plate could get out of level and sink on one side or corner. If the post or bulkhead under the mast step is rotting, the deck around the step plate would start to flatten or become concave. That should be visible, but I see no sign of that iny our pictures.

To check for the deck shifting, look inside the cabin:
- are the bolts at the top of the main bulkhead pulling into the bulkhead. Look closely at the washers under the bolt heads. Is the top pressed into the bulhead and the bottom flat on the surface? If so, weight on the end of that bolt is pressing it down on the nut end.
- does the head door open and close properly, or does it bind.
- look at the trim piece against the ceiling above the head door. Has it dropped any at either end. Is it square to the door opening? It may be obvious under the ast where that trim piece attaches to the compression post under the mast. (It may not be a true compression post. It looks like trim pieces on the front and back of the main bulkhead. That bulkhead and trim pieces serve as the compression post.
- look at the floor where the post goes into the floor. Does the looklike its pressed down near the edge along the bulkhead?? If so, it may be that the bulkhead is moving and taking the floor with it.
- do you have a bilge access hole. If so you might be able to get a camera under there and take some pictures. I'll send some that I took.

Well, there's a start of what to look for. Let me know what you find.

Good luck.

Bron Taoras
S2 8.5 #088
Rocky River, Ohio, USA

Fell free to email me directly: taorasbk@aol.com
 

BobM

.
Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
Nice summary Bron. By the way the easiest way to check mask rake is to use your main halyard as a plumb bob. That is, put a weight on the end and measure the distance the line ends up away from the mast. As I recall, it should only be about an inch for a boat that size.
 

Bron

.
Apr 19, 2010
74
s2 8.5 rocky river
Here are a few pictures:

View of main bulkhead under the cabin sole. The tube is the drainfrom the shower pan in the head. Tabbing shows clearly, but I can't tell if the blackstuff is surface mold or rot.

Other file is miscellaneous pictures of the bilge as a FYI.
 

Bron

.
Apr 19, 2010
74
s2 8.5 rocky river
Patrick: The pictures did not come through on my earlier post. I'm trying again. The attached pdf file has four pictures:
1. The mast step on the deck. The bow(front) is to the left.
2. The mast section looking directly at the bottom of the mast. Square cut. Bow to the left again. The mast section fits over the mast step and keeps keeps the bottom of the mast in place. Mast rake is then adjusted by adjusting the backstay. Your set-up may be different.
3. The bow stem fitting. Notice the 4 inch extension plates that raised the bottomof the furling to the correct height for the jib dimensions and cut (High clew). There is no turnbuckle in the forestay. It's length is fixed.
4. Under the cabin sole looking forard toward the main bulkhead. The hose is from the shower pan in the head, just forward of the main bulkhead. The floor looks very square and tight to the main bulkhead, so Idon't believe there is any roth on the bse of the bulkhead.

Feel free to reply or write with any questions or comments.

Bron
 

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Feb 23, 2011
6
S2 8.5 Buenos Aires, Puerto Nuñez
Thanks Bron! Honestly, all your comments are very useful for me. Everything serves to try to solve my problem. I think the best way to reduce the lifting of the base of the mast, will be remove it and see what happens.

By the way, you with mainsail and genoa (what kind g1, g2, g3?) with apparent wind speed 10, 15 and 20 knots respectively, how is the speed boat in this three moments? I mean the speed set by log"speedometer", not by GPS.
I ask this because the changes you make in the rigging and mast, influence the speed of the boat

Thank very much again!!
 

Bron

.
Apr 19, 2010
74
s2 8.5 rocky river
Thanks Bron! Honestly, all your comments are very useful for me. Everything serves to try to solve my problem. I think the best way to reduce the lifting of the base of the mast, will be remove it and see what happens.

By the way, you with mainsail and genoa (what kind g1, g2, g3?) with apparent wind speed 10, 15 and 20 knots respectively, how is the speed boat in this three moments? I mean the speed set by log"speedometer", not by GPS.
I ask this because the changes you make in the rigging and mast, influence the speed of the boat

Thank very much again!!
I,d be very reluctant to remove the mast step plate. I don't see what good that will do unless you suspect rot under the step plate. Check for movement in the cabin under the mast first. Peel back the headliner againt the main bulkhead in the toilet area. You'll find a beam bolted to the bulkhead. Look for movement there. It's held in place with bolts thru the bulkhead. Look closely at those bolts to see if the are pulling down from the pressure. If so, add support to that beam.

As for speed, I only have two sails - main and 150 roller jib. I never plotted boat speed vs wind speed - too many variables.

Good luck.
 
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