Hi Collin, responses inline. Cheers, Randy
> On Jan 18, 2018, at 8:49 PM, Collin Ferguson via CnC-List > <cnc-list@cnc-list.com> wrote: > > My mast step stringers were in very bad shape and the mast plate was dropping > into the bilge so I'm replacing the step this winter. I have a few > questions... > > 1). Terminology wise, are the lateral plywood supports considered the mast > step or stringers? Or is the heavy cast iron plate that sits on top of them > called the mast step? My understanding of the terminology is that the lateral plywood pieces are called the mast step supports. In my boat (C&C 30 MK I hull #7, built September 1972) what sits on top of the supports is an oak block about 2” thick, 8” wide, and 16” long. That is the mast step. Mounted on top of the mast step is an aluminum box that the mast sits in, i.e. the mast box. > 2). I've read the very helpful documents about others who have taken on this > task. They have used GPO-3 or other non wood materials. I would like to use > epoxy coated hardwood because I'm much more comfortable shaping the wood to > fit in. If it lasts 20 years I'll be more that happy. The original plywood > lasted 40 so I would think it should. My question is, what type of wood? I > was thinking White oak or Mahogany. I’d think you’d want something super hard. See https://en.wikipedia.org/wiki/Janka_hardness_test. I considered Ipe and Cumaru for new cabintop handrails for Grenadine, but went with traditional teak in the end. Both Ipe and Cumaru are very hard woods, oily which is good for water repellency, and less expensive than teak. But caveat emptor, I’m not expert on woods and woodworking. > 3). How important is it that the 3 new pieces go all the way to the keel? Of > the 3 current supports only the forward most support went all the way to the > base of the bilge, the other two had enough space between them and the bottom > of the bilge to pass a large diameter bilge hose through. I'm not sure if > that was original or if one of the PO's modified them to run the hose. There > were many failed repairs to the original structure. I believe the design intent was for the weight and compressive load of the mast to be borne by the bilge shoulders, not by the top of the keel stub. Therefore I don’t think it’s super-important for the new supports to rest on the top of the keel stub. Grenadine’s original supports had little contact with the top of the keel stub, and her new supports have none. And it’s important to leave space below the supports for water to come forward to that lowest sump under the mast step (and for bilge plumbing to pass through). There’s a term for that space, drain holes effectively, but I forget the term. > > 4). I'm thinking about putting an automatic bilge pump in between the pieces > under the mast. The current setup only had a hose running in there to a > manual whale pump. Is it a good idea to put a small automatic pump in there? > Yeah I put an 1100gph Rule in there on my boat. Described in https://drive.google.com/open?id=0B-NqAxQ6JxFTUlhmbUs4YTZlZnM > Thanks, > > Collin > 1974 C&C 30 MK1 > Libra > Baltimore > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray >
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