Looking for replacement mast foot

[Refueler]

While lowering mast for this winter storage - we missed fact that the mast foot pivot was frozen. As mast pivoted do9wn into the Y cradle - the mast foot shattered round the pivot bolt.

The foot item is of course the old style cast alloy type and its been passed to local specialist Metal Workshop - they consider the item to be old age and not likely to be strong repair. They have suggested cutting away a larger section, create new and mill to shape / requirements.

To be honest - I am also not so sure a repair would be strong enough as I only do mast up / down using that pivot .. I have 3 bridges to negotiate from my home mooring to get to baltic. If I was using vertical lifts - then it would not be such a concern.

This is the section they advise to cut away and replace :

If I can source a replacement - that would be best .. 2nd hand or even new if available.

If anyone has such an item - first of course we'd need to check dimensions - so please can you measure it at various angles / lines to see if it fits ?

Prefer obviously UK or EU sourced as shipping such a heavy item is going to be an issue.

For anyone not familiar with such a mast mount :

 

[ghostlymoron]

It would help if you told us what make and model of your boat.
It might be better to fabricate a complete new mast foot in stainless.

 

[Corribee Boy]

I had this problem with the Corribee. I tried to get a replacement, or have a copy milled (starting price £400!) or just file one myself from a billet of alloy (£120).

I ended up cutting out the broken 'heel' and replacing it with an alloy tongue inserted and pinned into the main casting. Once the mast is up the load is directly downward so the tongue's only function is to locate the mast foot as it's lifted. I also made the pivot hole oversize to allow some tolerance: the stays and gin pole are strong enough to control the mast, whereas the foot demonstrably wasn't!

See: Mast Heel Questions | YBW Forum

 

[Corribee Boy]

My Solution:

The new tongue is the brighter metal secured by a roll pin, the broken tang is sawn off at right angles and the yellow is Duralac.

 

[Refueler]

It would help if you told us what make and model of your boat.
It might be better to fabricate a complete new mast foot in stainless.

[

Unwise to use Stainless - mast is anodised alloy. Yes I could consider with Duralac or other barrier - but think it prudent to stay with masts original concept.

Boat is a Sunrider 25 - but in reality is not much use as the mast is believed to have been a shortened one from a larger boat .. When measured - the mast has spreaders at a lower mark than would be normal for such a mast length - giving idea that a lengthy was cut of the bottom. The halyard cleats and boom fitting are a little lower supporting this idea.
This was also reason that I could not fabricate a tabernacle style to replace the old foot. There is not enough mast section below cleats and halyard winch fitted to that section.

It is why I asked if anyone had such a fitting - that measurements would be best made and I would check against the mast.

 

[Refueler]

I considered doing away with the pivot action - but with the bridges and so on - it would be a bad idea.

I have an A frame setup that works well for the 3 bridges and at home mooring. To do without pivot would mean a vertical lift and that I do not have.

 

[Supertramp]

I considered doing away with the pivot action - but with the bridges and so on - it would be a bad idea.

I have an A frame setup that works well for the 3 bridges and at home mooring. To do without pivot would mean a vertical lift and that I do not have.

What about a tabernacle? You would need to drill a hole through the foot of the mast and tidy up the broken base. Make sure it's very well fastened to the cabin top with serious diameter bolts and a glassed in backing plate. Don't ask how I know....

 

[William_H]

I think your welder will be able to rebuild the bottom of the mast base. I am not sure if he would through away the broken bits and build up the whole area with ali or try to glue broken bits back. I am inclined to think throw away and build up. Probably cheaper and easier than whole new style of pivoting base. ol'will

 

[Neeves]

I don't doubt anything you say but if the mast is a one off, and the base cut off, that implies the broken fitting was custom made - or someone cut the mast specifically to fit an off the shelf fitting. Casting a one off fitting would be extortionate.

I appreciate you said no stainless - but many of the fittings on aluminium masts are stainless and protection is possible. I don't recall a mast failing recently where a member has complained about corrosion between mast (aluminium) and a stainless fitting. I note you have what look like stainless bolts holding sheaves and don't see any corrosion

Why not fit an off the shelf piece of stainless pipe to the shaft base, bolted or riveted, separate mast from pipe with a polymer of your choice. The pipe chosen to fit mast, as is. Then simply weld splines to allow for rotation. Making a new fitting from stainless does not appear to be much more than careful measurement and welding.

Jonathan

 

[coopec]

A while back I melted three tonne of lead scrap and cast the "ingots" in a steel channel section. (I did it in my backyard while the neighbors were away )

If it was mine I'd make up a timber mold, melt a whole lot of aluminum scrap and pour the molten metal into the mold. You'd then have to do some drilling. (When you pour the molten metal it must be done in one go: that may be a problem)

Have you spoken to any foundry in your area? (Not a big firm - just a small versatile operation)

 

[Daverw]

I’ve had a number of cast Ali items repaired over the last couple of years, stantion bases,, winch handles modified and brackets. All welded with either broken bit stuck back on or Ali plate glued and machined. All have been as strong as original so not sure why your guy has suggested otherwise. Ali welding is quite specialised though and this may be the issue. Find an experienced coded pipe welder that’s who does mine

 

[Refueler]

OK ... lets work through and thanks for replies.

Yes - I could use stainless but would prefer to stay with Alloy.

I only suspect mast has been 'cropped' at bottom as the cross trees and fittings are lower than would be normal. This also mean that there is only a small section below fittings to use for a Tabernacle. If I was to add section to mast to fit a tabernacle - that would then mean all new rigging ..... and the design of that section to work.

The Cast original is over 50yrs old and the Metal Master I am using considers the metal may have passed its 'sell by date' and become more brittle - he is expert in all manner of specialist welding - example : He has contract for Swedish Aero to fabricate in Dural Aerospace items. We have considered using Dural in fact to fabricate new if necessary. Dural will be many times stronger and lighter than the cast original.

The Mast foot is not custom - its standard item for mast of that 'diameter'. If I could source a replacement to just bolt on - I would.

All sorts of ideas are still being thrown around by myself and the 'Metals Guy' .... but at present the most realistic is to cut away the extended part and rebuild - then mill.

Its really annoying - if I could travel back to UK and not get stuck with Covid limitations - I could solve this easily .... it would not be hard with all the people in yachting world I know - to find a 2nd hand replacement.

 

[bluerm166]

In the event that you fail to find a replacement and you don't like the 'tongue ' idea and you don't want to shell out for an expert repair
why not simply bolt a profiled plate with pivot hole on both outer sides of the fitting using the apparently convenient bolt positions.So no reduction of present strength,in fact an improvement and the sheaves would remain accessible.

 

[Refueler]

In the event that you fail to find a replacement and you don't like the 'tongue ' idea and you don't want to shell out for an expert repair
why not simply bolt a profiled plate with pivot hole on both outer sides of the fitting using the apparently convenient bolt positions.So no reduction of present strength,in fact an improvement and the sheaves would remain accessible.

The possibility of using the sheave bolts hasd crossed our mind .. when we measured - the side plates would be outside of the deck metal and could end up bearing onto the GRP ...

But it is still a good alternative and not off the list.

The bolts actually a replacement for the pins that originally carried the sheaves. Through age - the small screws that held the locking plates corroded and this was easiest way to sort. Instead of drilling out the screws and retapping - remember this is cast - we decided to use bolts instead.

I had new pin / plate fittings made - but the screws were the part that proved the need for change ..

Old :

New

 

[bluerm166]

There is no reason why such side plates need extend outside the profile of the original pivot (assuming the plate is of structural quality and needs only a small margin on the hole ) so would not hit the deck - from your original photo it appears that they would in any case hit the base of the inverted tee mount and not the deck.
If the lowering mechanism properly holds the mast on the centreline the strain on the foot and mount should not be excessive during hoisting.Barrel spacers fitted between such new plates on the pivot bolt would ensure the plates remain central,assuming that the existing failed 'stubs' are cut out of the way .

 

[Refueler]

There is no reason why such side plates need extend outside the profile of the original pivot (assuming the plate is of structural quality and needs only a small margin on the hole ) so would not hit the deck - from your original photo it appears that they would in any case hit the base of the inverted tee mount and not the deck.
If the lowering mechanism properly holds the mast on the centreline the strain on the foot and mount should not be excessive during hoisting.Barrel spacers fitted between such new plates on the pivot bolt would ensure the plates remain central,assuming that the existing failed 'stubs' are cut out of the way .

That has been a discussion with the Metals guy ... once we sort - I'll update the thread with what was done. I would still like a replacement if I could get one !!

 

[ianat182]

I think the tabernacle idea proposed is your better option two outer stainless diamond shaped washers drilled to suit a belled stainless tube and that tube passes through the mast about 18" from the base and is belled on the opposite end as well with a stainless otherdiamond shape washer ,and another washer, bolt and nyloc nut as the pivot; lowering the mast and raising should be easier and safer. Your "A" frame would still work without or else a rope through the bow roller and a strut.
The Broads yachts for instance have to do this operation quite frequently during a cruise . Probably your present method too would retain fore and aft straightness.The diamond washers ( epoxied ) serve to stiffen the pivot area and are to help prevent chafe of the mast by the bolt .

The' Chandlery Barge,' Riverside Yard at Bursledon ,Hampshire hold stock of many obsolete mast fittings et al ; an enquiry with photo and dimensions of your broken mast foot may produce a chance of a match. Google them for their contact details.


ianat182

 

[ianat182]

As a follow-up may I refer you to a previous YBW post by CAER URFA on 28/9/2014 regarding the construction of his tabernacle and particularly that the author used TWO bolts through the mast one lower than I had suggested;also th mast foot does not actually touch some comproethe mast step in order to allow the arc made when lowering it; this space can be taken up by a small piece of wood to fill and allow some firmness in that space. Similar problem to your own is discussed there. The attachment shown I was unable to access for some reason perhaps out of date , perhaps a PM to CAER URFA may help.

ianat182

 

[ianat182]

One last offering!!
Fabricate two stainless steel billets, one for each side of the base,say,3/8"-1/2"thick . Drill 3 Holes, the forward two to match the existing ones, front and the one for the halyard pulleys The third hole needs to match the position required to pass a bolt through the broken eye and of the diameter to suit the pivot eye; each bar to be ended with a radius to allow for the pivoting mast movements. A bush or piece of tube,something to true the ovality of the pivot eye , may be necessary. The 2 existing bolt diameters are probably OK but need to be longer by at least 1.5". The third one perhaps larger diameter.
This arrangement will leave the sheaves in their present location for use as normal.

 

[Refueler]

Tabernacle has been measured and found not to be viable. To use such would mean significant alteration to the mast itself as well as replacement of standing rigging.

At present Metals guy is fashioning Dural plates to fit either side of original foot ... with tube bearing supports from plates to centre welded pivot ...

Its all taking time as they are busy with a lot of Aerospace items backlog due to Covid.

BUT - if anyone could source and advise on a replacement original design foot ... I am still interested.