Swan 37 mast base

Hi guys,

I know this has probably been covered before so I apoligise if its repetative.

I am working on a 37 from 1972 I think and the mast base/shoe is very badly corroded and needs to be replaced. The bottom two inches of the mast are badly corroded too but I think that is an easy fix compared to the metal frame in the boat.

My concern is how the steel structure is attached to the boat. I have searched a lot but cannot find any pics or info of one. My guess is that it was a galvinised steel frame with the keel bolts holding it in place, is this correct? To say that it is badly corroded would be an understatement, it is nothing but rust mostly. There is a central lifing point aft which is also corroded badly. I am guessing they are two seperate pieces of metal, it is hard to tell as they are mostly laminated over as are the keel bolts.

I need to replace the mast base/shoe but what concerns me is the keel bolts. If the are bolted through this rusty mess in the bilge as I suspect they are would they be badly corroded too?

Does anyone have experience replacing the mast base? Did you need to replace the keel bolts?

How hard is it, or is it even possible to replace the keel bolts? I imagine if its possible it might be prudent while doing this work to replace them all if its feasable. Any advice or information on the bolts would be greatly appreciated. I have no idea at this stage if the bolts are cast in to the keel or are threaded into a cage that is cast in or have a nut on the bottom of the keel and a rod bolt that goes through the entire keel. As I have not seen the boat out of the water yet I am just guessing.

This area of the boat is a mess to say the least but I am a qualified shipwright so not too daunted by the project but just want to know what I might be getting myself in for. I am quite keen as I like the boat and would be happy to get it sailing again.

Any help or advice would be greatly appreciated!

Hi Aussie,

I posted some pictures on Ice's thread " 2 small keelbox cracks" in Feb 2013, of the keel removed and bolt layout etc. They may not answer your question but could be useful!

Luckily our mast base required painting only which we did in situ.

Best of luck

Rob.
Sarabande 47/029

Dear Aussie
The mast step was an U-section of steel about ½ a metre long, and the mast had a cast aluminium shoe plug with two feet fitting into the U.
The keel bolts have their own steel washers, and are probably found on the sides or below the U-section, which had some filler material below in order to be horizontal.
The keel bolts are stainless AISI 316 while the washers are galvanized, and corrosionwise this means that the washers should work as sacrificial anodes and protect the stainless.
It is believed there are 17 bolt, of which 6 pairs, would appreciate to get this confirmed. The lifting eye sits on a separate steel plate.
Suggest you dig out the bolts and inspect their condition. As far as I know the bolts are cast in and can not be removed, except for the forwardmost bolt which may be removable downwards.
Does this yacht have a hull number?
Kind regards
Lars

Thanks for the replies!

So it seems like the keel bolts may well be ok, but we will never know until we start grinding. If they are not we have a big problem if they are cast into the keel!

Replacing the mast base may not be so hard if the bolts are not in bad shape. Im guessing if they are not then casting a new keel is necessary.

I think the hull number is 57 from memory.

On monday I hope to see the bottom of the boat and get some idea if there is rust coming out between the hull keel join

Thanks again!

Dear Aussie,

S&S Swan 37/057 should be FRINGALE, could you please confirm this is the Swan you are woriking on, and let us know her present location?Thanks

Fair winds!

matteo (38/067 Only You)

So I have been thinking about this more Has anyone heard of the bolts in a 37 being so corroded that replacement was necessary? The setup that Lars described is encouraging for this boat.

Sorry I am wrong about hte boat number, I have 37 in my head now from memory. The name is Saldran.