Budgeting the Build of a 35' steel sailboat; worthwhile costs vs. extravagance

[Jack Hickson]

The first number is the tensile strength, the second the freezing rate. Looks like they upped the tensile strength. Nothing reduces the odds of slag inclusion nearly as well as 6011, as nothing penetrates as well.
In his latest book , Roberts says he designs his skegs to fall off if they hit anything. Looks like he succeeded . Nothing attaching the skeg to the skin alone is anywhere near as strong as running it up inside.

[welder/fitter]

Originally Posted by Jack Hickson

The first number is the tensile strength, the second the freezing rate. Looks like they upped the tensile strength. Nothing reduces the odds of slag inclusion nearly as well as 6011, as nothing penetrates as well.
In his latest book , Roberts says he designs his skegs to fall off if they hit anything. Looks like he succeeded . Nothing attaching the skeg to the skin alone is anywhere near as strong as running it up inside.

AWS uses a standardized coding system to identify SMAW electrodes. Codes are printed on the side of each SMAW electrode and represent specific properties. For the mild steel electrodes mentioned previously, here is how the AWS system works:

◦The letter E indicates an electrode.
◦The first two digits represent the resulting weld's minimum tensile strength, measured in pounds per square inch (PSI). For example, the number 70 in a E7018 electrode indicates that the electrode will produce a weld bead with a minimum tensile strength of 70,000 PSI.
◦The third digit represents the welding positions for which the electrode can be used. For example, 1 means the electrode can be used in all positions and 2 means it can be used on flat and horizontal.
◦The fourth digit represents the coating type and the type of welding current (AC, DC, or both) that can be used with the electrode.

[MikeJohns]

Originally Posted by Jack Hickson

.........
In his latest book , Roberts says he designs his skegs to fall off if they hit anything. Looks like he succeeded . .........

Brent

What book ?

Searching Roberts latest book and he says:
"skegs can be vulnerable to damage and must be designed to withstand a grounding"
Nowhere does he say they should fall off which seems rather questionable since they are supporting the rudder heel bearing.

So I'm interested, where did you get this from?

[Jack Hickson]

He said skegs should not be too strongly attached to the hull, as you want them to break away if they hit anything. I'll check the bookstores and get back to you.

[welder/fitter]

On the Bruce Roberts web-site, the last thing that BR seems to be supporting is break-away skegs:

ROBERTS SAFETY SKEG: Back in the late 1960’s when we started to design boats with skegs they seems to be the answer to all steering and handling problems sometimes associated with the long keel / rudder hung off the back of the keel configuration. Alas time has proven that the skeg is one of the most vulnerable items of the underwater area of your sailboat. One solution was the Roberts ‘Contemporary Long Keel’ which has proved to have most of the benefits of the skeg and none of the vulnerability of the normal skeg. A more recent development in combines the benefits of a skeg and long fin keel arrangement; this is achieved by tying the aft end of the keel to bottom of the skeg by way of a bar or heel; see sketch for detail.
http://www.bruceroberts.com/public/HTML/NEW-ITEMS.htm

However, Discussions of what a specific designer may/may not have said are way off topic, imho.

[TeddyDiver]

Originally Posted by welder/fitter

this is achieved by tying the aft end of the keel to bottom of the skeg by way of a bar or heel

That's about what I've been a bit considering lately, with the difference of having twin rudders. Point being easier shaft removal (incase), landing the boat like a bilge keelers do and better protected screw..

[welder/fitter]

Originally Posted by TeddyDiver

That's about what I've been a bit considering lately, with the difference of having twin rudders. Point being easier shaft removal (incase), landing the boat like a bilge keelers do and better protected screw..

I wanted to point out that BR's introduction of the "safety skeg" doesn't support Brent's suggestion that BR wants his skegs to break off, rather, that he has addressed what he considered a potential weakness. Personally,
my concern would be that the bar on the safety skeg design would be a place for all kinds of crap to get caught on. In our waters, it wouldn't take long to collect several hundred pounds of seaweed. An adaption of the "Brewer bite" would add support, yet, not offer more appendages for stuff to become hung-up on. Just a thought.

Mike

[Jack Hickson]

Originally Posted by welder/fitter

I wanted to point out that BR's introduction of the "safety skeg" doesn't support Brent's suggestion that BR wants his skegs to break off, rather, that he has addressed what he considered a potential weakness. Personally,
my concern would be that the bar on the safety skeg design would be a place for all kinds of crap to get caught on. In our waters, it wouldn't take long to collect several hundred pounds of seaweed. An adaption of the "Brewer bite" would add support, yet, not offer more appendages for stuff to become hung-up on. Just a thought.

Mike

Agreed. A big BC log in rough water, in the middle of the night there, could be real exciting. They even snag on the open bow sometimes , Enough trouble and excitement getting them free. . I wouldn't want it any more exciting.
A friend ,finding a Roberts 53 in Austraila ,which had sunk in the night from a skeg failure, welded a couple of flatbars from the hull either side of the skeg to the bottom, on his Roberts 53 skeg before finishing his circumnavigation. I saw several more hauled out in Sidney, who had done the same to their Roberts skegs.

[Jack Hickson]

Originally Posted by TeddyDiver

That's about what I've been a bit considering lately, with the difference of having twin rudders. Point being easier shaft removal (incase), landing the boat like a bilge keelers do and better protected screw..

Center of gravity for most boats is too far aft to let twin rudders enable you to dry out on them. She'd fall down by the bow every time. Only twin keels let you dry out ,on most hull shapes.

[TeddyDiver]

Originally Posted by Jack Hickson

She'd fall down by the bow every time. Only twin keels let you dry out ,on most hull shapes.

Like I said it's in a thought stage still (rudders). Anyway it's with a long keel and some movable ballast so it's not going tip to nose, not even stern towards the shore.. but let's not get sidetracked

[Jack Hickson]

Full length keels put an extra 400 lbs of steel in the stern, where you need it least. It leaves you with an area under the engine which is hard to maintain, but can't be used for tankage without a huge weight penalty in the end, too far aft.
Boats have zero tendency to fall down by the stern when dried out. The LCG is just too far forward for that. .