Thoughts on Steel Spars ?

[quidam]

"One must be constantly on guard against advocates of the "Be reasonable and do it the hard and expensive way" school of thought. That type of elitist thinking has ballooned the cost of boats, and cruising , far beyond what it need be, and beyond the reach of too many low income cruisers, for no benefit."
Brent Swain

Brent, I like that quote so much I want to use it in my profile. I just cant figure out how to do it.
I do need to keep in mind that I'm going to have two mast not just the one like before.
I am now at the point where I need to hire someone to help with the design of the whole rig. I saw that Brion Toss does consultations and I have left a message at his office but my call has not been returned as of yet.

Deep Frz, thanks for the info on the books you mention. I think I'll pass on the square tubing, although a tapered octagonal spar would be pretty cool.

[quidam]

I have spoken with Toss and now I am in the process of calculating the weight of the internal ballast (old bulldozer track pins set in coal tar), and the lead on the keel. The plans for this boat is the half hull. Anyone have any experience taking lines off a half hull or know how its done. I would be great to be able to send him some drawings of the lines. Also, anyone know how to determine displacement?

[44'cruisingcat]

Originally Posted by quidam

"One must be constantly on guard against advocates of the "Be reasonable and do it the hard and expensive way" school of thought. That type of elitist thinking has ballooned the cost of boats, and cruising , far beyond what it need be, and beyond the reach of too many low income cruisers, for no benefit."
Brent Swain

.

It's a good quote. But which is easier - completely sealing and testing steel tube to make it airtight, having to run external halyards and committing yourself to regular mast climbs for painting, or using an unpainted, open ended aluminium tube with the option of internal halyards?

[Kym]

Hello Cruising Cat, can you give me a bit more detail on this Nyalic to paint aluminium. I have a loverly old Spencer which has corrosion at the last metre or so of toe rail and would like to wire brush away the oxide and clean it up . But this will start more corrosion unless I seal it with ???? I was considering brushing with vinegar but seems a bit iffy to me??

[Brent Swain]

Originally Posted by Evan

Proper spar engineering shouldn't be done on internet forums. Really.

********. A thousand heads are better than one, and far less likely to have tunnel vision, or be governed by"Yachtie "( fill my pockets) biases.
Brent

[Brent Swain]

Originally Posted by 44'cruisingcat

It's a good quote. But which is easier - completely sealing and testing steel tube to make it airtight, having to run external halyards and committing yourself to regular mast climbs for painting, or using an unpainted, open ended aluminium tube with the option of internal halyards?

I'd use external halyards regardless of what the mast is made of. A sealed mast can considerably increase ultimate stability, and makes running new halyards in far easier . Welding fittings on a steel mast is much easier , cheaper, and more structurally reliable. Maintenance on a well painted steel mast is minimal. Once up every three years is all the maintenance you woud need. Add to this the extra time you spend on the treadmill paying for an aluminium mast ,, lost cruising time, and steel is much easier.
Brent

[Brent Swain]

Originally Posted by quidam

I have spoken with Toss and now I am in the process of calculating the weight of the internal ballast (old bulldozer track pins set in coal tar), and the lead on the keel. The plans for this boat is the half hull. Anyone have any experience taking lines off a half hull or know how its done. I would be great to be able to send him some drawings of the lines. Also, anyone know how to determine displacement?

Drafting supplies have a bendy (Like lead ) plastic coated spline that is easy to use, for cheap.
Brent

[Pblais]

A thousand heads are better than one, and far less likely to have tunnel vision, or be governed by"Yachtie "( fill my pockets) biases.

Sorry, it does not work that way. 1,000 idiots is not a real answer to bet on. Conventional wisdom is not always right and in critical moments is most often wrong. Sorry Brent, but you are still only one. I don't claim to be an authority of those with less than normal capacities. We are not prepared to certify members of Cruisers Forum. Some may be better than idiots. That still is nothing to bet your life on. Advice here is coincidental with reality. There is a degree of desire to be helpful and members can judge that the results on their own.

[quidam]

Brent, thanks for the tip on the bendable spline.

No decision has been made yet on the mast material, The rigger wants to determine dynamic stability and that sort of thing. He then will calculate the needed dimensions and weights in both steel and aluminum. I'm really hoping I can go with steel. I'm now in the process of making some detailed drawings that will help with figuring it all out. I've tried the equation for calculating D/L, but I must be doing something wrong. The LWL is 38' and I think the net displacement is 14 tons. Not sure what the gross is but I'm guessing it is around 18.
The boat draws 4 1/2', the engine (witch sits below the waterline) weighs 3800 lbs. The internal ballast weighs approx 3100 lbs., and there is a lead shoe that is 1" thick by 6" wide that runs for 25' of the keel.

To those that have recommeded a used aluminum spar, It wont work. The loads are coming from all directions so the mast should be round in section. This is coming from an experienced rigger (not me).

As I said in the origonal post, both mast will be on tabernacles, I will be able to lower them from deck, so maintenance will be easy.

The rig I have in mind will be a blending of old and new; no internal halliards, no sheet winches, It will have ratlines, pinrails with belaying pins, synthetic standing rigging, and roller furling.

[MidLandOne]

Originally Posted by Pblais

Sorry, it does not work that way. 1,000 idiots is not a real answer to bet on. Conventional wisdom is not always right and in critical moments is most often wrong. Sorry Brent, but you are still only one. I don't claim to be an authority of those with less than normal capacities. We are not prepared to certify members of Cruisers Forum. Some may be better than idiots. That still is nothing to bet your life on. Advice here is coincidental with reality. There is a degree of desire to be helpful and members can judge that the results on their own.

A friend upon having a browse through some boating forums for the first time was completely bemused - he couldn't understand how all the idiots he saw on them could ever have held down the type of job that would give them enough income to buy a boat .

[Bash]

Originally Posted by Pblais

Advice here is coincidental with reality.

When I hold office hours tomorrow, there shall be a sign on the door quoting, "Advice here is coincidental with reality."

[harlaken]

I have to ask the basic questions here.
First, if cost is a primary issue then get how about a second hand stick? Most if not all riggers will have something kicking around as will nearly any yard. Depending on your negotiating skills you can easily pick something up for less than a virgin piece of steel tubing.

Second, why the need to weld? Any fitting actual rigging is attached to (tangs, mastheads, etc.) is bolt on or bolt through. Any custom fittings can be welded separately out of stainless or aluminum and then bolted in to place. This includes spreader bases, goosenecks, doubling plates, etc.

Third, painting aluminum is easy it's just a tad pricier. I've had the best luck with the awlgrip line of products. Any boat chandlerie should be able to get it without issue.

All of that being said, I recognize in a general way what you are trying to accomplish and I think in your specific case that steel would be fine considering you're looking at a shorter single stick vs. the old heavy gaff rig. Just don't limit yourself. The specific issues you mentioned are all minor to non-existant. The downside to steel is that once you get a little rust or a little wear it starts to look like something from a shrimp boat.

[quidam]

Originally Posted by harlaken

I have to ask the basic questions here.
First, if cost is a primary issue then get how about a second hand stick? Most if not all riggers will have something kicking around as will nearly any yard. Depending on your negotiating skills you can easily pick something up for less than a virgin piece of steel tubing.

Second, why the need to weld? Any fitting actual rigging is attached to (tangs, mastheads, etc.) is bolt on or bolt through. Any custom fittings can be welded separately out of stainless or aluminum and then bolted in to place. This includes spreader bases, goosenecks, doubling plates, etc.

Third, painting aluminum is easy it's just a tad pricier. I've had the best luck with the awlgrip line of products. Any boat chandlerie should be able to get it without issue.

All of that being said, I recognize in a general way what you are trying to accomplish and I think in your specific case that steel would be fine considering you're looking at a shorter single stick vs. the old heavy gaff rig. Just don't limit yourself. The specific issues you mentioned are all minor to non-existant. The downside to steel is that once you get a little rust or a little wear it starts to look like something from a shrimp boat.

On a sailboat the largest loads on the mast are fore and aft. (thats why a typical aluminum mast is oval in shape, to make it stronger in a fore and aft plane) On the rig I am going to build the side loads are greater, (at least on the mizzen). An oval mast set sideways would look pretty goofy, hence the decision to use a mast round in section. I also like the idea of the mast being airtight. That requires welding. I've put alot of work in this boat and asthectics are also important to me, hence the decision to taper the last ten feet. That requires welding. The paravane supporting hardware requires welding as well as the tabernacles and roller furling supports.

As I have said several times in this thread: I AM NOT COMMITED TO USING STEEL. I would prefer steel because it is easier to weld, (I have the equipment and ability) and paint. No decision will be made until the dynamic stability has been calculated. Hell, I might even need to add more external ballast.
If the rigger thinks I should use aluminum, I will do all the fabrication and hire a welder when everything is ready.

Painting with any two part polyurethane should'nt be taken lightly. This is really nasty stuff, and you need a supplied air respirator, full face mask (most people dont realize that this **** enters your system through your eyes), barrier creams, and a full tyveck suit. I dont take working with chemicals lightly. I use alot of epoxy and I always use disposable gloves, respirator, and goggles.I have freinds with this paint on there boats and they all complain that you cant touch it up and get it to match. This doesnt bother me but if steel gets a scratch and starts to rust its easy to touch it up. Maintenence on steel is'nt difficult you just need to stay on top of it. I am used to that, this is a wooden boat.

There will be two mast on this boat, look at my avitar.

[Boats]

Mast loading:
Fore

[harlaken]

Ignore the above. I realized too late that I was posting under a friends account.

Mast loading:
The depth of section in an oval mast shouldn't suggest that the loads experienced by a rig are greatest fore and aft. In fact (for a long list of reasons) the backstay typically carries the lightest load in a rig. That depth of section is generally (there are many exceptions) designed to resist fore and aft bending because it's in that direction that a mast is least supported. This is particularly true of a single lowers rig. A mast is first and foremost a compression member. It's a well designed rig which supports the loads.
You mentioned roller furling. Are you mounting behind-mast furling? If so you need to crunch the numbers on the loads that imparts to your section. Round may not be an option for you at all in the diameters you are needing.
Doublers for a hinged tabernacle can be bolted in place. I don't know your intended set-up though, I'm just speaking in general terms.

Taper:
Many sticks you'll find in the second hand market are already markedly tapered. This is particularly true of boats which carried a fractional rig. You may also look for a used stick from a cat boat such as a freedom or nonsuch. These are round, very stout, and carry a very nice taper.
On a side note the Brion Toss forum recently had a good thread on cutting and tapering an aluminum spar if you do end up going with aluminum extrusion from scratch.

Paint:
I don't take two-part paints lightly. I have years of hands on experience painting aluminum spars. You are absolutely right in that touching up individual spots in awlgrip is nearly impossible but most often it is not necessary. 99% of all good looking painted spars you'll see are awl-grip jobs.
The material does require some careful safety set-up. Epoxy particles will set up in your lungs and to my knowledge NEVER break down. However, the act of painting itself is easy and it is possible for an amateur to get professional results their first attempt. Don't let the paints reputation scare you off. Just please invest in a decent safety setup.

As for the steel/aluminum question, the last bit of my previous post was to say that I think steel in your specific situation would be an acceptable choice. My post was aimed towards the general question of steel vs aluminum.