Ways to Add 6ft to the BOTTOM of a mast?

[rslifkin]

Originally Posted by Chotu

And that’s basically the entire idea of the pedestal. My drawing back on page 9,534 somewhere is exactly that.

Any random larger mast section with a couple bulkheads in it would work great for this too.

Putting bulkheads in it complicates things a bit. If you can live with a little extra weight and pick out materials strong enough to just use a tube with end plates it might be easier to find someone to weld it together.

[Chotu]

Originally Posted by rslifkin

Putting bulkheads in it complicates things a bit. If you can live with a little extra weight and pick out materials strong enough to just use a tube with end plates it might be easier to find someone to weld it together.

Actually, I wonder if it is more weight? The bulkheads themselves are quite a bit of surface area and volume of aluminum. My vision was that the bulkheads would positively carry any load straight through to the deck where it belongs. However, the tube of aluminum that is the mast does the exact same thing. So like you said, why couldn’t you pick out a tube of aluminum that’s a little bit stronger than the mast and let that do the work?

Does anybody object to this idea? Hollow tube with a thicker wall section than the mast and some end plates?

Maybe drop the top end plate 6” or more down into the tube and screw right through to screw the mast to the tube (or other mast section)?

[Chotu]

Well, after all this time has gone by, all I have been able to do is find a mask section that is bigger than the one I have. Maybe I can just make some kind of mast step inside that.

[Chotu]

Also, I have not been able to find any spar sections that work for anything. None for the mask. None for the bow tube. Nothing. What am I left with her options?

Do I really have to go and get these custom made somewhere? That’s a lot more money than I was hoping to spend.

[Buzzman]

Originally Posted by Chotu

Also, I have not been able to find any spar sections that work for anything. None for the mask. None for the bow tube. Nothing. What am I left with her options?

Do I really have to go and get these custom made somewhere? That’s a lot more money than I was hoping to spend.

If the larger cross-sectional area mast section you've found is only 10-20% larger, and is the same thickness as the old mast, it should be able to be welded to the old one easily enough.
My suggestion (from paast experience of this issue) is to, as you surmise, weld a 'step' down inside the new mast section, with locating strips or cleats somewhow to line the old mast up and centre it as it goes in.
Weld the bas to the step.
THEN, get a qualified sheet-metal worker who works with aluminum sheeting, to make a up a 'cone' that wraps around the old mast and comes out to the new mast.
Obvioulsy, it needs to be rolled and shaped to suit both elliptic openings, and not be a plain circular-base cone.
Then weld this sheet to the new and the old sections to brace across the join.
Bingo, new, longer mast.

As for the other spars, what ever you do it will require adaptive surgery.

My feeling is - if you can't afford this, then you probably can't afford to be sailing such a large and costly boat.

But I know you are also a cheapskate.... lol


So, keep looking something will turn up.

But, seriously, T6061 ally tube is not THAT expensive. I was quoted less than $100 for a 3m section with 4mm thickness from a normal metals supplier here in Oz. Can't imagine it would be that much more over Stateside.


Sure, extruded, specialist mast tubing is expensive. Limited market, limited buyers.


But PLAIN tubing? Much more widely used, lots more of it made...

Get a naval architect/engineer to spec the tube, and it might be fine for a bow pole. Then simply get the same sheet-metal worker to weld some ally plate on top for somewhere to stand, and bingo, ne bowsprit. Add a dolphin striker and Robert's your mother's brother..!

[rslifkin]

For the pedestal I'd talk to a local fabricator about taking a thick walled piece of pipe or tube and welding a thick plate onto each end. Then just find a way to attach it to the boat and put a mast step on top.

Maybe leave a square plate on the bottom, make a pad on the deck for it to sit on and just bolt it down.

[Chotu]

Originally Posted by rslifkin

For the pedestal I'd talk to a local fabricator about taking a thick walled piece of pipe or tube and welding a thick plate onto each end. Then just find a way to attach it to the boat and put a mast step on top.

Maybe leave a square plate on the bottom, make a pad on the deck for it to sit on and just bolt it down.

That’s pretty much what I’m thinking of doing with the mast section I found that is larger than the mast.

I figure if the pedestal at least has a similar cross section shape and diameter to the mast, it won’t look bad.

You and Buzzman are kind of talking about the same thing. And so am I.

I think it might be settled for this piece. I think it can be done this way using the Mast larger section.

But when it comes to the other part I need, does anybody know where I can try to find this? It seems like a lot of smaller monohulls would have this as a mast. But I did not find any.

9.5” x 5” with 5/32 wall thickness. 18ft long.

Came up with nothing at Don’s Salvage today. Went to some marinas. Nothing. Sailor man says no mast sections at all.

Where else can I look for this?

[GRIT]

I've been away from this thread for a while, so if I'm off base, just ignore this post. I was looking at "cat" videos (not the furry kind) and came upon this one that shows a support "post" under the mast. It certainly isn't 6 feet, but maybe 3.5 feet or so from the very bottom, and maybe 24 inches from the last of the horizontal support from the cabintop.

https://www.youtube.com/watch?v=0yhNNmRq_Vc

At about 30 seconds in, you'll see what is likely a composite "post", which might give you some ideas. Forgive me if this problem has already been solutioned.

Cheers.
Paul.

[Chotu]

Thank you Grit. And thank you everyone. I think Grit is winning out here. That’s the way to go.

I was going to have it made out of 1/4” inch aluminum by a metal fabricator. 26” at the base and 58” high.

It didn’t turn out that I needed 6 feet. It was a little less than that. 58 inches is all I need. With a 26 inch base, that should be just fine to handle any side loads.

Making it out of fiberglass is really tempting. Anybody have any thoughts as to that? I hate to work with the goo, but it would be a lot lighter weight I think than the aluminum. And also easier to put together because I don’t have to wait forever..

[rslifkin]

I see no reason you can't make it out of fiberglass. Any material strong enough will do the job, it's just a question of what you can get done most easily.

[Chotu]

Originally Posted by rslifkin

I see no reason you can't make it out of fiberglass. Any material strong enough will do the job, it's just a question of what you can get done most easily.

Unfortunately I don’t have the translation between quarter inch aluminum and fiberglass. Not sure what to do in that area.

The mast itself is made out of 3/16” aluminum. I figured I would bump it up a 16th, and put some angle on the corners of the aluminum to keep them in shape. And the flange at the bottom to bolt it to the deck.

No idea how to translate that into Fiberglass.

So potentially that may not be the easiest route even though I have to wait for the welders and machinists forever.