Westerly Griffon Mast Compression

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alla_breve

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Hello,
Ive had my Griffon for about 6 years now, and the base of the mast has always looked like this (see pics), I was just wondering how worried I should be! The rigging has not slackened off in that time (ive got a tension gauge), nothing looks out of place at the bulkhead below, the door to the fore cabin opens and closes as it always has, but as you can see the mast step is about 1/4" "sunk" down.
Anybody else had this? or know what is under the mast step supporting it?, bit of ply maybe?!
Thanks
Tim

mast2.jpgmast3.jpg
 
I am pretty sure there is a plywood pad used to spread the compression load of themast. Most likely there has been some water ingress and has rotted the plywood. Check inside to see the compression post is still firmly on the GRP. If so the easiest fix would be to remove the mast aand mast fitting, then open the area from on deck. Replace the plywood and rebuild the exterior with epoxy and mat to a similar thickness. This was it keeps all the dust out of the cabin and you will only need to make sure it is smooth before painting with deck paint.
 
One of our club members had exactly the same issue with his Griffon.
He did as Concerto suggests, working from the top down. Carefully cut away the step, removed the rotten plywood pad, installed a new pad (epoxied to prevent water ingress) and then re-glassed/gelcoated the step back into place. Now all good with no sign of the compression. I can ask him for any advice if needed?
 
Thanks for replies. Yes any advice would be welcomed Micky, especially as to materials used. Did he crane the mast off, or it it possible to "jack" it up enough?
Tim
 
Yes, mast down I'm afraid, but after 6 years of ownership, it will give you a good chance to check the rigging and electrics on the mast!
I'll try and find out from the club member any info, may be a week or two as I wont be down there for a few weeks.
 
On the other hand if it is plywood that has decomposed then remaining material (GRP) is still under compression and so very capable of taking the mast loads. So why not just leave it as is? ol'will
 
William_H said:
On the other hand if it is plywood that has decomposed then remaining material (GRP) is still under compression and so very capable of taking the mast loads. So why not just leave it as is? ol'will
Click to expand...

Inclined to agree that if its been stable for 6+ years just leave ... but I think I would want to remove all the paint in the area to inspect the state of the GRP and the gelcoat
 
mickywillis said:
Yes, mast down I'm afraid, but after 6 years of ownership, it will give you a good chance to check the rigging and electrics on the mast!
I'll try and find out from the club member any info, may be a week or two as I wont be down there for a few weeks.
Click to expand...

That's fine, thank you.
 
How about this for a plan of attack then:

Mast down
Remove mast step and hack out anything rotten
Replace ply pad ("painted" with epoxy for water seal?)
Glass mat and polyester resin over pad to build up to original shape and height ( min 2-3 layers?)
Brush on gelcoat (couple of coats?)
Replace mast step and paint with deck paint
Mast back

As regards the mast, I'm thinking of the possibility of just freeing off the rigging enough, so that its supported at the top, then some sort of collar/bracket clamped round the base, then a couple of bottle jacks onto the collar to lift it a couple of inches to clear the step, then swing it forward (pull on baby stay), to give enough room to work. Lower it onto a temporary pad. Do job then reverse process.
Replies in the form of % chances of it working please, from 0-99%!!!! (nothing's ever guaranteed to work on a boat!)
 
alla_breve said:
As regards the mast, I'm thinking of the possibility of just freeing off the rigging enough, so that its supported at the top, then some sort of collar/bracket clamped round the base, then a couple of bottle jacks onto the collar to lift it a couple of inches to clear the step, then swing it forward (pull on baby stay), to give enough room to work. Lower it onto a temporary pad. Do job then reverse process.
Replies in the form of % chances of it working please, from 0-99%!!!! (nothing's ever guaranteed to work on a boat!)
Click to expand...

That's an awful lot of faffing about, and I would want the mast out of the way so I can work on it unhindered.
 
We have our own hand operated mast crane at LSC in Poole and I have dropped my Griffon mast every year for the last 20 years...

Can be done you need 3 people - inc. 1 on the crane.

So if you can find a crane(or two story building!!!) that has the boom above the cross trees (4 or 5 inches is the minimum) it is easy.

take off the baby stays

take the strain (very slightly) at the cross trees.
Take off the back stay

undo the cap shrouds and fore stay
wind up the crane

Just drop the mast down the deck.
one person guides the roller furling.
one person guides the mast

lay mast on:
Couple of fence posts at the stern forming a H above your head.

Plank across the pulpit

once down - disconnect forestay and slide furling more central - for and aft.

Job done.
 
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