Mast Step (or Girder)

[novara]

I have read posts on this site and the SeaBreeze website about replacing or rejuvenating mast steps. Ours has to go. We think aluminium will be our choice. I am interested in some info that Phillip (NSWsailor, Seaka) shared last year regarding the possibility of obtaining actual specifications for the Step/Girder. It would be marvellous to have these if possible, because I imagine the 3D slopes towards the bow and beams could be rather tricky to create. Or do the fabricators match exactly to the individual yacht?
How does the Step/Girder actually come off/out? I'm wondering if the bolts are embedded somehow.
Cheers, NB

[Phillip]

NB?,

Yes the bolts go right through, you will see in the cabin the twelve nuts [6 each side] of your main bulk head under the mast.
Some TH's have covered these nuts with fancy timber work.
These bolts can be a source of water entry and on Mk 2 & 3's [because of the composite deck] the water can end up in some distant places.

It's best to remove the Girder [mast step] and explain the that it has angles [not square] and have it re-manufactured.

Someone did this recently, so if you tell us where you are we can work out if you can use the same people.

I have had no luck with the original manufacturer, but if you live near Woy Woy NSW I can give you his details,
you may have better success than me with an actual order.

[novara]

Hi Phillip
Many thanks for your reply. Novara is at North Haven Marina, Adelaide. We have found a chap who has done some stainless work previously. He seems to think that aluminium would be good for the replacement (stainless being a bit extravagant). I guess that would then lead to the puzzle of what bolts to use to try and avoid the bimetallic corrosion. Any thoughts would be gratefully received. My brothers and I have decided to keep Novara, inherited from our father, however it does need some money spent. We will start with the mast step and then think about the deck resurface.
Cheers, NB

[Miker]

NB, even Aluminium may not be the best. Mine is Galvanised, as I think most are. Over the years it has been re-coated with various substances, but as epoxy paint is getting better and better, you may be able to remove, refurbish and replace. I guess it depends on how bad it looks once you have it off. Mine had years of pitted paint. Once sanded back to undercoat, there was no sign of structural damage. It now looks great with a silver rust proof epoxy paint.

[novara]

Thanks Miker
We have been maintaining our girder for about ten years with many processes. Sadly it is now delaminating and lumps coming away. You can probably imagine the filthy mess topsides. The real puzzle, checked again today, is that what we assumed were bolts have no exit in the cabin and without removing one, we assume they are like a coach screw. They are stainless and the rounded head is slotted.
I wonder if anyone else has a mast girder attached in similar fashion.
Cheers, NB

[Phillip]

Mine is anodised Aluminium with SS bolts set in silaflex. Been there some 15-20 years and still 100% OK.

Your bolts should be bolts, not coach screws, and the nuts could be concealed above the cabin lining.

I'm assuming you have a Mk 2 or 3?

Yes you could try taking one out now to see whats going on or wait until you drop the mast [better option].

[steve]

I suspect that few, if any, mark 3s have bolts holding the mast girder. Mine has coach screws.

The mark 3 has a substantial beam built into the underside of the deck moulding, and a fibreglass ceiling below the beam. It would be very difficult to fit bolts all the way through the beam.

Does anyone know what the beam is made from? I fitted some additional coach screws soon after I bought my boat and had to drill into the top of the beam to fit the coach screws. I do not remember any sawdust coming out as I drilled, so I assume that the beam is not timber. I wonder if it is a fibreglass box-beam.

The fixings will never be subject to upward stress, so I think that several thick coach screws will be more than adequate for the purpose.

Steve

[novara]

Steve ... Many thanks ... Hooray ... we are not alone.
Yes, Novara is a Mark III and the beam is encased in the fibreglass moulding that is the cabin ceiling or deck underside. It feels and sounds very solid ... not pleasant to bump one's head on. I haven't ever posted a photo but I'll try so that Mk I and Mk II owners can see what it looks like.
So when we remove the coach screws I guess we could get slightly larger gauge screws to go back in the same spots.
I guess with no sawdust you had fibreglass dust??
We expect to remove the mast in November so I have time to learn more from anyone else who has played with the girder.
Cheers, NB

[Mike]

Hi Novara,

I had the same issue with my girder. It turned out there was just about as much paint as metal!

I replaced it last year in Hobart. I took the old one to a fabricator who replicated it for $375 in Aluminium. There's a pic of it in another post. He had a few off cuts lying around which kept the cost down. I'd thought 8mm would be about right, but the fabricator was going to charge a lot more to cut into a fresh sheet of that, so the vertical pieces are now 10mm, and the curved piece 6mm, which doesn't have the holes the old steel one had.

The fabricator was about a half hour bicycle ride away from the boat, and I can tell you the Alloy replacement is a lot lighter in a backpack than the old steel one, despite all the missing metal!

I found the curve on the new one wasn't an exact match to the curve on the deck, with about a 10mm gap under it in the center. This wasn't such an issue as I was adding glass to stiffen the cabin top at the time anyway, so I built up the curve with extra layers of cloth radiating out from the center. The largest reaches from the cabin step down to the fwd hatch (its a Mk 1) and the smallest is just a small rectangle sitting under the middle of the girder. I then covered the bottom of the girder with glad wrap so it wouldn't stick, laid down some thickened resin, lined up the holes perfectly and pressed down. Later on i removed the girder and glad wrap, bedded it on sikaflex, and tightened the bolts. I was pretty happy with the result, its a perfect fit that looks smooth as it gently slopes up to accommodate the increased curve of the new girder, and its made that part of the boat immensely strong.

For the mast base I bought a block of tough plastic (I forget which type, but the plastic supplier recommended it for the job), routed it so the mast would slide over the top half, and added a drainage channel on each corner to match the 4 holes I drilled in the girder. I'll post a pic. Under that I put a piece of 10mm alloy sitting on a piece 3mm rubber (probably not really necessary), both cut to fit the girder and with the corners trimmed for drainage.

I'm fairly new to this type of work and there's probably better and easier ways to do it, but I'm happy with the result.

All the best,
Michael.

[Mike]

The new girder and mast base