Hunter mast foot plate and wood pad

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Trevelyan

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Hi everyone,
Finally got around to helping a friend get his Hunter 701 craned in and put the mast up and... crunch the alloy mast foot plate (the bit that sits on deck) cracked - see photo. This was largely thanks to over-enthusiastic crane action on mast, don't ask why we weren't putting it up by hand. So...
-Can anyone recommend what type of wood should be used to replace the small wooden pad under the alloy foot plate? The existing one looks fairly pickled.
-Any advice about repair by welding a plate to the bottom, or replacement? Should I get an alloy one cast or stainless?

Any advice much appreciated

Trevelyan
 
Trevelyan said:
Hi everyone,
Finally got around to helping a friend get his Hunter 701 craned in and put the mast up and... crunch the alloy mast foot plate (the bit that sits on deck) cracked - see photo. This was largely thanks to over-enthusiastic crane action on mast, don't ask why we weren't putting it up by hand. So...
-Can anyone recommend what type of wood should be used to replace the small wooden pad under the alloy foot plate? The existing one looks fairly pickled.
-Any advice about repair by welding a plate to the bottom, or replacement? Should I get an alloy one cast or stainless?

Any advice much appreciated

Trevelyan
Click to expand...

A nice piece of teak ( or similar ) would do the job under the mast step.

The mast heel fitting is aluminium I guess so if you get a new mast step cast also make it in aluminium. ( You don't want stainless and aluminium together ... dissimilar metals and all that )

The existing one looks repairable..
Its usually the lugs that get broken when people are raising the mast by hand!
 
Mast base

From the photo the base has broken due to uneven collapse of the under base. I think that if the under base is replaced and flat (rightangles to the mast) then the base could be repaired by fitting screws down through the 2 halves of Ali on each side of the fracture. This area is subject to huge pressures straight down ward but at least not cause any tendency for the 2 halves to move apart.
My mast base filler block was made of Ali and after many years it corroded away. I replaced the wedge shape with chopped strand mat fibreglass and polyester resin. It was easy to make the wedge shape by laying up more glass on the aft half than the front half in graduated layers. I was able to grind away the raggedy sides to make it all look respectable on hardening.
Note I think it is important that when sailing the wooden or f/g block under neath the base is shaped so that the mast is supported with equal pressure front and back. Difficult on a sloping cabin top. good luck olewill
 
Am going to get the foot alloy welded onto an ally plate, will then think about drilling holes at new centres. Hopefully the plate will be thin enough not to affect the rig too much (enough travel left on the bottle screw thingymabobs on the shrouds) - may have to make new wood foot plate a bit thinner. I did wonder about trying to get a new foot (or pair) - but the mast is about 30 years old (international yacht equipment) - surely the shape of the mast sections has changed since then or the foot design? It never rains but it pours... Trev
 
Trevelyan,

it's sometimes possible to graft new mast foot sections on, Sailspar have a selection and get asked to do this sometimes, as accidents like yours happen quite often.

They can't help every time but if it's possible they will, just take a tracing of the mast section and send it to them with dimensions and photo's, as much info as poss I'd think.

I have no connection with Sailspar, just found them incredibly helpful when I had a rig query.
 
Seajet - thanks very much for that suggestion, will give them a ring and see if they've come across this particular mast type before. At least then I'll know if the repair attempt doesn't cut it I have a plan B. I have been cringing at drilling out the rivets and taking off the foot section from the bottom of my mast as that then means I've got to get the new one rivetted back on - I don't have anything beefy enough to rivet it myself and the mast is too big to transport easily, so in solving one problem another appears.... Trev
 
Trevelyan,

may I ask whereabouts in the country you are ? I have decent rivet tongs and am used to doing that sort of thing.

I think Sailspar would need as good an idea of the section as possible to be able to comment.
 
Seajet - I'm down in Cornwall, so not too convenient for anywhere! I will see if welding a backing plate to the broken bits works; if not then I'll have to take to the bottom of the mast and start pulling to bits... :-( Trev
 
Do you actually need the pivot lugs?

If not get some alloy machined to replicate the mast step.

Actually, if you are adventurous you could make a mast step like I had on a previous boat which would include an alloy plate with a hardwood bevelled plug bolted to the top. The hardwood plug fits into the heel of the mast.
All it's doing is locating the mast to stop it sliding off sideways. The rigging pulls the mast down onto the alloy plate.
 
Trevelyan said:
Seajet - I'm down in Cornwall, so not too convenient for anywhere! I will see if welding a backing plate to the broken bits works; if not then I'll have to take to the bottom of the mast and start pulling to bits... :-( Trev
Click to expand...

Oh well, that's the tin hat on that plan then !

I'm sure there are people around with the facilities, maybe a club or boatyard ?

Good luck.
 
Trevelyan said:
Seajet - thanks very much for that suggestion, will give them a ring and see if they've come across this particular mast type before. At least then I'll know if the repair attempt doesn't cut it I have a plan B. I have been cringing at drilling out the rivets and taking off the foot section from the bottom of my mast as that then means I've got to get the new one rivetted back on - I don't have anything beefy enough to rivet it myself and the mast is too big to transport easily, so in solving one problem another appears.... Trev
Click to expand...


Drilling out the rivets should be no problem. Use an oversize drill and just drill until the heads come off then punch the rest in.

You may be able to hire a heavy duty pop riveter from a tool hire shop .. if you are lucky

But Tool station have a pretty decent lazy tongs one for only about £16.
Not one for cheap tools but cannot fault this one.
It will set up to 1/4" rivets ... but I'd not try stainless ones that size.

I bought one and have set 5mm Monel rivets ok
 
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Thanks VicS for the pointers re. riveter. Good idea too Lakesailor - I could get away with an alloy plate and a circular hardwood plug. Have had the remains of the mast foot plate alloy welded onto an ally backplate, so hopefully that will hold ok. Have fashioned a replacement wood foot plate for it all to sit on, as the original one was fairly picked. Now need to put the whole lot together. Presumably I don't want to seal the wood plate to the deck nor the alloy mast plate to it to let the whole lot breathe, or am I wrong?! Best wishes Trev
 
Trevelyan said:
Thanks VicS for the pointers re. riveter. Good idea too Lakesailor - I could get away with an alloy plate and a circular hardwood plug. Have had the remains of the mast foot plate alloy welded onto an ally backplate, so hopefully that will hold ok. Have fashioned a replacement wood foot plate for it all to sit on, as the original one was fairly picked. Now need to put the whole lot together. Presumably I don't want to seal the wood plate to the deck nor the alloy mast plate to it to let the whole lot breathe, or am I wrong?! Best wishes Trev
Click to expand...

I dont know how all this is fastened down to the deck.
You will need to seal the holes around the fasteners in the deck to prevent water ingress I would think.

I think you will need to seal the joint between the aluminium plate and the wood or water will penetrate and the plate will corrode.

Personally I think I would seal everything. I think I would also paint the underside of the plate with zinc chromate primer ( I have some but you may not now be able to get it)
 
alternative to rivets.

Trevelyan said:
Seajet - thanks very much for that suggestion, will give them a ring and see if they've come across this particular mast type before. At least then I'll know if the repair attempt doesn't cut it I have a plan B. I have been cringing at drilling out the rivets and taking off the foot section from the bottom of my mast as that then means I've got to get the new one rivetted back on - I don't have anything beefy enough to rivet it myself and the mast is too big to transport easily, so in solving one problem another appears.... Trev
Click to expand...

Coincidentally i have spent my free time this weekend fabricating a new mast foot plate for my 26 ft trailer-sailor. Not dissimilar to yours but probably a simpler design.Mine was bronze and also broken. Just old age and corrosion i think. It was broken when i bought the boat and strapped up with bits of aluminium riveted to it which was rather ugly.
My new one is fabricated from 2 sections of stainless angle cut to shape and welded together to make a channel. Most time is in cleaning grinding and refinishing the stainless.
Any way the point of my post is regarding the attachment of the mast foot.
A couple of years ago I replaced the rivets on my mast and and also the boom end fittings with countersunk 6mm x 12 mm stainless steel machine screws.
I just drilled into the aluminium base piece and then tapped it out and then countersunk the holes in the Mast.
Cost of a 6 mm tap set if you don't have one is relatively trivial. This job can be done with a tap wrench and small battery drill so can be done anywhere.
You need to use a loctite or other product on the screws to prevent the corrosion between the stainless and aluminium.

I just had the end fittings off the boom yesterday to re-run the reefing lines, and all i needed to remove and replace the end fittings was a screw driver.
It made it all very easy.
Don't know if it would work for your situation?

My next challenge, like yours, is to refit the new mast step so that the weight of the mast is squarely on the foot and not on the pivot pin when mast is up and the rigging is tensioned.

Good luck.
 
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Hi John - thanks for your detailed reply and implicit tip re getting the weight distribution right. This is another headache for me as its a friend's boat, I haven't been involved with the right tensioning before, I've made a new wood foot plate block (attempted to copy the angle from the old one) clearly need to get the angle of the foot plate and the tensioning of the forestay/backstay/lowers(fore/aft) right to get the whole thing right. I have a similar feeling as you towards rivets - will try to replace with screws if I find I do need to pull the mast side of things apart.

VicS - the whole thing is getting a soaking from water down the mast etc anyhow, so is corrosion a problem? Not sure of correct answer on this! Yes will deffo seal around bolt holes to keep water out of boat.

Trev
 
VicS - the whole thing is getting a soaking from water down the mast etc anyhow, so is corrosion a problem? Not sure of correct answer on this! Yes will deffo seal around bolt holes to keep water out of boat.
Click to expand...
Corrosion of aluminum is always a potential problem. Some alloys seem to be very corrosion resistant while others aren't. Even the ones that aren't dont seem corrode on the surface where they are exposed to the air. I guess they form a nice adherent oxide film that protects them but in places where the air does not reach but water can be trapped, ie behind or under them they seem to corrode. I suppose its a mechanism similar to crevice corrosion of stainless steel.
 
Hi Chas - thanks for the thought - however boat is *old* and the rig was made by international yacht equipment, who now no longer make rigging... ARRGHH! Trev
 
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