Screwing into the mast

[Slow_boat]

I intend to fit lazyjacks to both masts of my Countess 33 ketch but am worried about the screws holding the cheek blocks just above the top set of spreaders, and the cleats at the bottom of the mast base, protruding into the mast and damaging either the haliards , the vhf cable, masthead light cable or the radar cable. Is this likely to be a problem or am I worrying un-necessarily?

Would pop rivets be a better idea?

The masts are Kemp from 1994.

Any advice gratefully accepted.

 

[sailorman]

I intend to fit lazyjacks to both masts of my Countess 33 ketch but am worried about the screws holding the cheek blocks just above the top set of spreaders, and the cleats at the bottom of the mast base, protruding into the mast and damaging either the haliards , the vhf cable, masthead light cable or the radar cable. Is this likely to be a problem or am I worrying un-necessarily?

Would pop rivets be a better idea?

The masts are Kemp from 1994.

Any advice gratefully accepted.

yes Monel rivets

 

[lustyd]

I just used screws the right length to avoid them sticking too far in. I suspect that the cleats were designed the right depth to allow for this on standard lengths of screw since there was 2-3mm of screw sticking out which is the thickness of my mast and more than enough to hold the cleats. When I put the blocks on they will be rivets. Both instances you want to use duralac but don't worry about the screws if you don't make them too long.

 

[simonfraser]

yes Monel rivets

+1

Could be an expensive mistake if the screws damage your halyards.

 

[Tim Good]

Stainless rivets deffo. I fit a radar reflector the other day. One issue is getting enough weight on the pop rivet gun whilst swinging around from a halyard in a fresh easterly! When the rivet eventually takes, the bang makes you think your falling. Didn't get easier after 8 of the bleeding things.

 

[MASH]

Tap holes and use appropriate length cut down bolts?

Rivets protrude inside and can chafe cables. Be careful with the drill too.

 

[trapezeartist]

I have done jobs like that with self-tapping screws. Run the screws in without the fitting first, to cut the thread. Then measure or calculate the length of thread to just reach the inside face of the mast with minimal protrusion. Cut the screws down to the required length, perhaps 1mm overlength, and then file the end to ensure the thread is good and there is a slight dome on anything that protrudes. Finally stick it all together, with duralac on the screws and the contact face.

 

[nigelmercier]

I intend to fit lazyjacks ... but am worried about the screws holding the cheek blocks just above the top set of spreaders...

My lazyjack blocks are on the spreaders. It gives a wider throat for the sail to drop into. Originally they were not cleated to the mast, but looped back to the sail tidy; I've since modified this, but I just looped the jack halyard round the top of an existing cleat.

 

[VicS]

What ever fasteners you use; Monel pop rivets or stainless self tapping screws or machine screws put them in with a tab of barium chromate paste ( Duralac) or Tef-Gel to prevent corrosion.

 

[nigelmercier]

... put them in with a tab of barium chromate paste ( Duralac) or Tef-Gel to prevent corrosion.

Is there any reason why aluminum rivets could not be used for this purpose?

 

[VicS]

Is there any reason why aluminum rivets could not be used for this purpose?

Probably not. They are not going to take a lot of load are they. My steaming light bracket was rivetted on with ordinary ¹/₈" aluminium pop rivets 35 years ago .. it is still there unless it has fallen off recently!

 

[srm]

Put the lazy jack blocks on the spreaders a few inches clear of the mast. You will find this makes hoisting the sail a lot easier as there is a wider gap for the top of the sail to pass through.

 

[William_H]

I second the use of metal thread screws of correct ie min length into a thread cut with a tap. Put the tap into a battery low speed drill very easy. Use Duralac as said. But yes Ali pop rivets are OK. good luck olewill

 

[Tim Good]

Put the lazy jack blocks on the spreaders a few inches clear of the mast. You will find this makes hoisting the sail a lot easier as there is a wider gap for the top of the sail to pass through.

+1

Not how mine are but if I did them again I'd do it as above.

 

[Slow_boat]

Put the lazy jack blocks on the spreaders a few inches clear of the mast. You will find this makes hoisting the sail a lot easier as there is a wider gap for the top of the sail to pass through.

That was the original plan but having searched this forum, it would appear to risk pulling the spreaders down and risking the mast.

 

[macd]

I intend to fit lazyjacks to both masts of my Countess 33 ketch but am worried about...the cleats at the bottom of the mast base, protruding into the mast and damaging either the haliards , the vhf cable, masthead light cable or the radar cable. Is this likely to be a problem or am I worrying un-necessarily?

Suggest you don't put cleats on the mast base: there's probably quite enough clutter there already. Barton shroud cleats on the...well, shrouds, obviously...are more than up to the job and simple to fit. Even in far sunnier climes than yours, they suffer no noticeable UV damage. They're also handy for flag halyards, particularly if you use the type with one horn and one ring: looping the halyard through the ring means it cannot escape.

I'd also suggest that you make the lazy jack lines long enough so that if necessary they can be dropped and pulled into the mast near the boom fitting. This makes raising the main on a dark night much easier since there's nothing to snag on the battens.

 

[srm]

That was the original plan but having searched this forum, it would appear to risk pulling the spreaders down and risking the mast.

You do indeed risk your mast if the spreaders do not bisect the shroud angle at their tip. However there are ways around this without making more holes in the mast and thus weakening it.
My current Kemp mast has clamps on the ends of the spreaders to lock them to the shrouds and they cope with the lazyjacks for a heavy fully battened mainsail probably larger than yours. If your spreaders do not have end clamps it would be worth while fitting ss cable clamps (used to make wire eyes) to the shrouds below the ends of the spreaders. I have fitted lazy jacks on the spreaders to a number of boats, including a 42 ft classic with wooden mast, without any problems. However, I always keep the boom end topping lift so that the lazy jacks simply control the sail and rarely have to take the full weight of the boom and sail.
I would also suggest that you have sufficient line on the tails of the lazy jacks so that you can ease away and pull it clear of the sail on the lee side should you want to raise the sail on a close reach.

 

[Slow_boat]

Thanks, folks.
Looks like I'm back to plan A with a lighter heart; lazy jack blocks on upper (clamped) spreaders, long enough to slacken and hook round reefing horns and use existing flag halyard cleats.

6mm laid line from screwfix should do the job. How do Barton get away with their prices?

 

[macd]

6mm laid line from screwfix should do the job. How do Barton get away with their prices?

Sorry, should have mentioned: 6m line plenty for this job. Worth using nylon thimbles where one line runs through another.

 

[srm]

Sorry, should have mentioned: 6m line plenty for this job. Worth using nylon thimbles where one line runs through another.

If the lazy jacks are not doubling as the topping lift you do not even need the nylon eyes - once set up there will be little or no movement of the 'limbs' so all that is needed is an eye tied in the single line for the looped line to run through. You could also use stainless steel rings for the limbs to run through. I have made up lazy jacks without any running parts (other than through the spreader blocks) and they worked well. The Barton kit is way over the top for most boats under 50 ft, but then they want to sell blocks.

If you have tubular spreaders the blocks can be tightly lashed to the spreaders. I use the tarred nylon twine sold for working on fishing gear as each turn can be stretched tight. Have to buy it by the roll, but one roll lasts me for a few years of whippings, lashings, pulling halyards and wires through the mast, etc.