ISIS Headsail Attachment

[Trevor]

I'm a complete beginner to this hobby and on my recently acquired ISIS the tube that takes the headsail boom pivot has pulled out of the hull!  Before I glue it back in are there any recommendations as to the best way to set this up?

Also any links to web pages regarding the fittings and adjustments of an ISIS would be gratefully received as although my fellow club members are exceedingly knowledgeable and helpful I don't want to be a pain.

 

Cheers

Trevor

[Richard98]

Hi Trevor,

If this is an aluminium tube that exits the bottom of the hull and also the deck; then the following should help.

With the tube removed completely, roughen the inside of hull and underside of the deck to prepare for adhesion. Similarly roughen the tube for approx 10mm each end.

Note: the tube should have a little rod through it just above where it enters the hull. This is to secure the line that runs up the tube for the jib boom pivot.

Tack the tube into position with 5 minute epoxy - just a dab. Mask around the area to be fixed. Electrical tape is best, not masking tape.

Stick a piece of electrical tape over the hull exit. When the tack has set, mix some decent epoxy and dap a very little around the hull exit hole from the inside ( a cocktail stick is the ideal tool) The tape will allow the epoxy to flow  the space between the tube and the hull - only a drop or two though.

Then thicken the epoxy with colloidal silica or similar, to a "mayonaise" consistency and form neat fillets around the tube, top and bottom. The tape will prevent excess eopxy and make a neat job. Remember it does not need a lot, 10mm up/down the tube and added to the tube radius is more than sufficient.

When the epoxy is nearly set, it may be gently formed to neaten and the tape removed.

Epoxy and fillers are readily available in small quantities from model shops on line.

To refit the line down the tube have a look at the Sails etc web site, where a decent description of the simple process may be found.

Let us know how you get on.

Richard

 

 

[Trevor]

Thanks Richard. I will have a go at that in the morning.  It seems as though it has been done before as I have a bit of cleaning up to do first!

I have looked through a lot of Sailsetc documents but can't find the bit about the line in the tube.

Cheers

Trevor

Edited May 16, 2019 by Trevor

[Richard98]

Trevor,

Could not find it either.  However, have a look at the Ikon drawing located in Sails etc downloadable documents to see details of the tube fixing and the arrangement of the line.

Use D50 dyneema for the line and pass down from the top, each side of the pin. Make the knot outside the hull, I use a bowline, approx 10mm loop. Then hook the long piece of line back up the tube using a piece of rigging wire. Easy and quickly done. Do not forget to seal knots in dyneema with superglue.  The knots will come undone otherwise.

Ensure no glue gets on the pin or on the tube, future replacement will be difficult otherwise.

This is an excellent jib boom swivel for the No1 rig and works in the lightest of breezes, also transfers the load to the hull so no deck displacement to slacken the forestay.  A fillet web or recessed deck moulding transfers the deck stiffening to the other rig eyebolts in addition.

 

Richard

[Trevor]

Richard

I see those last few boats have the same system.  On closer inspection of my tube I find a ball with a hole located by three dimples a half inch from the bottom.  The line was knotted below the ball.  I'm wondering if I should install pin instead and loop the line back up to deck level to provide adjustability? 

Cheers

Trevor

[Richard98]

Trevor,

Don't like the sound of the ball and dimples in the tube. Might be easier to start from scratch with a new piece of tube and pin. Ikon drawing shows what is needed, including the nylon fitting at the top. I think Sails etc now use a slightly larger dia tube and nylon fitting than that shown on the drawing. I seem to remember that from recently building my Alternative, but cannot access it to measure. Worth checking since it makes fitting the line easier.

Adjustment is not possible since it is important to have the ring at the top as close as possible to the deck. This is very important, especially to take advantage of the low mast position of Isis.

Richard

 

[Trevor]

Richard

Sailsetc headsail swivel tube product code TUBEJ under Hull Parts shows the parts and the description that you gave earlier and useful pictures.  All ready to go now! Just need to take the plunge with the glue.

Cheers

Trevor

[Trevor]

So far so good.

Due to the difficulty of accessing the top of the tube under the deck I made a small collar to stop the tube pulling through the deck and added epoxy during assembly.  Having drilled the bottom the bottom of the tube I put a long pin through that was then glassed to the keel area in the same way other fittings are fixed.

Don't think that's coming out anytime soon!

Thanks for your help.

Cheers

Trevor