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S&S Swan Maintenance - 411 Aluminium strut in forepeak
31 July 2015 - 22:50
#1
Join Date: 01 February 2007
Posts: 234

411 Aluminium strut in forepeak
I have just removed the head linings in the forepeak to try identify the source of a leak. We found that the aluminium tube which is bolted at the bottom to a half bulkhead and at the top glassed into the ceiling has corroded at the top end badly.

1. What is the purpose of this strut?
2. Should we replace with stainless or aluminium?

01 August 2015 - 19:38
#2
Join Date: 27 January 2011
Posts: 141

Hi John,

We have that one too. I so far assumed that it is a reinforcement for the cutter stay. (which is currently not rigged on our boat).

Christian 411/028

02 August 2015 - 11:04
#3
Join Date: 30 January 2007
Posts: 462

I agree with Christian: as far as I know all 411 originally have it. It is needed as an extension down to the base of the hull for the baby forestay (aka staysailstay).
Daniel, 411/004

02 August 2015 - 13:19
#4
Join Date: 01 February 2007
Posts: 234

Please see picture. I guess given its location supporting the baby stay seems logical. My stay sail is permanently rigged and attached just over the bulkhead to the anchor locker so no re inforcing was required to stop the upward loads.

Any thoughts on why it has corroded just at the point of the glass fibre fixing.

Is the top of the tube welded to anything else example a flat section or it it just a tube that is glassed in?

John B
411 010

03 August 2015 - 09:16
#5
Join Date: 02 January 2008
Posts: 1547

Dear John
There is a track on the deck centerline to which the inner forestay attaches, and the tube resists this load. There is a flange at the upper end, through bolted to the track.
You mention a leak, the corrosion is likely to be the result of a wet overhead panel being in contact with the aluminium tube. Either this has been going on for a very long time, or it has been speeded up by an electrical leak in this area.
Is there water in the tube?
The leak needs to be eliminated.
Kind regards
Lars

03 August 2015 - 15:01
#6
Join Date: 01 February 2007
Posts: 234

Lars thanks for the information. Is the flange an internal part of the tube or is it a welded extension i.e. T section welded onto the tube end?

03 August 2015 - 16:14
#7
Join Date: 02 January 2008
Posts: 1547

John
Would guess there is a horizontal flange welded to the tube end.
Any other 411 with similar problems?
Lars

03 August 2015 - 17:34
#8
Join Date: 01 February 2007
Posts: 234

Lars, I am removing tube tomorrow and will take some photographs. I am looking to replace the tie bar with a stainless rod as their will be with less corrosion issues to worry about in the future 40 years!!!

06 August 2015 - 13:57
#9
Join Date: 01 February 2007
Posts: 234

The pictures show the problems. When the deck was replaced some years ago the track to which the babystay was attached was refitted slightly out of position too far forward. This meant that the tie rod / tube was forced backwards at the bottom when attached to the bulkhead. The strain on the bolts joining the T section to the stainless deck track let in water. The corrosion started. I am going to replace the tie tube with a wire and bottle screw attached to both the same positions as before with new stainless brackets. To move the stainless track on the fore deck back by 4 or 5 cm is not worth the effort.

Stainless track on deck out of position

Bottom of tie tube out of postion by 4 or 5 CM

T section exposed under deck

14 August 2015 - 14:39
#10
Join Date: 01 February 2007
Posts: 234

We manufactured the bottom section so that same holes were used as previously. The top section was made using the top of the tie bar as a template. Both fixings were made in stainless with 8 mm wire and bottle screw to tension up when in the water.

14 August 2015 - 17:04
#11
Join Date: 30 January 2007
Posts: 462

Great job, John!
If I will ever need it, I will follow your track.
Daniel, 411/004

14 August 2015 - 18:31
#12
Join Date: 06 September 2013
Posts: 53

All of you other 411 owners are making my restoration/maintenance much easier. Thanks John, Daniel, et al

Don F
411/11

15 August 2015 - 18:33
#13
Join Date: 01 February 2007
Posts: 234

The lesson learned is always be on site when any work is being done on our yachts. Photo and check every little detail.
Fortunately I have worked with this boat yard for many years so they admitted making the error when replacing the track. We split the costs.
John B
411 010

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