Wooden mast swap to Aluminium

[djyacht]

My boat has a 25 feet tabernacle stepped wooden mast, wooden boom. I have repaired some rot on the mast over the years but have an opportunity to buy an ally mast and boom, (deck stepped) of the right height with all of the associated rigging and fittings at a reaonable price.

Is this a feasible swapover - any views welcomed.


David

 

[30boat]

I don't see why not.Do you intend to retain the tabernacle or deck step the mast?

 

[knuterikt]

My boat has a 25 feet tabernacle stepped wooden mast, wooden boom. I have repaired some rot on the mast over the years but have an opportunity to buy an ally mast and boom, (deck stepped) of the right height with all of the associated rigging and fittings at a reaonable price.

Is this a feasible swapover - any views welcomed.


David

It's feasible but there are more than just the length of the mast to consider.
The strength of the mast profile must be strong enough to match you boats righting moment (if the mast come from a boat with much smaller displacement this could be e problem).
The angle of the spreaders must match your chain plates, if not this must be adjusted (change the spreader angles or move the chain plates)

 

[merlin3688]

What boat do you have, as mentioned the mast and rigging need to be correct for your boat, do you know the make of the alloy mast and what boat it came off, may be able to give you some inertia numbers to see if its suitable.

 

[djyacht]

Thanks for responses. My boat is an Island Plastics IP24 - Ive no idea what the alloy mast is from unfortunately....

 

[merlin3688]

I seem to remember Z Spars making a mast for the IP24 using the Z230 section.
Detail of this section below
Z230
122 82 (Size)
143 69 (Inertias
2.3 (Wall thickness)
2.3 (Weight per KG)
8 (Luff rope dia)
23-26 (Approx Yacht length)

If you can measure the mast you have it needs to be similar to the above. Mast I guess would have been between 8 and 9mtrs and 4 or 5mm rigging.

 

[William_H]

Much depends on the type of rig the boat has and what you want to end up with. Now a lot of wooden masted boats (gaff rig especially) do not have a backstay but have cap shrouds mounted weel aft of abeam the mast. This allowed for a large roach on the mainsail so large area short mast. The mast you get is probably a mast head rig. ie cap shrouds abeam the mast and a backstay. This is probably a better more robust rig but may require you move chain plates and add chain plates for backstay.
You will need 2 backstay chain plates if you have transom mounted rudder/tiller. One if the tiller is forward of the transom.
For a mast head rig you will need either 2 more intermediate side stays going forward on each side or a single int. forestay to locate the middle of the mast.
If your main sail has the large roach then it will foul the backstay. You can fit a long crane to the backstay and or have the mast higher or cut the roach out of the mainsail.
I think this well stayed mast head rig will allow that the mast may not be as stiff as the old wooden one.
Now I may have the wrong idea (guess) here as your wooden mast may be a mast head rig already but if not you may need lots of changes or simply substitute the new for old but Iam not sure that would be a good idea. olewill

 

[Iliade]

I was not aware of IP24s having a wooden mast, but I guess many were home completed?

You will almost certainly notice a change in the inertia of the mast, making her a little less seakindly

 

[djyacht]

Thank you for all the replies and thoughts- clearly this is not a straightforward undertaking, especially as the boom is wooden and the foresail is self tacking with wooden boom also.

I`ll therefore leave it as it is and make sure I inspect thoroughly at each haul out.

David