making mast cutouts

[phorvati]

Could I just use a good jigsaw with metal blade to make a mast cutout for a halyard exit block. If not what kind tool is there for making mast cutouts?
Petar

[hellosailor]

Petar, it is just aluminum. I'd suggest making two holes with a regular drill, to give you the top and bottom of the slot, and then using the jigsaw to connect them. You'd want to use a Dremel tool or hand files to polish the edges nice and smooth, and make sure they won't chafe the line. That usually means bevelling the inside edge of the top of the slot.

But you may also find that modern lines can and will CUT aluminum masts. You can put a stainless halyard exit plate over the slot, so the halyards just polsih against the stainless rather than cutting into the mast. (Gentler on the halyards, too.)

Check the bar located between your spreaders--internal halyards can also cut into that. Since you can't really get in there to anti-chafe it, you just need to keep an eye on it and replace it if it wears.

[phorvati]

Ok. I'll try the jig saw. And I'll smooth out the edges and round out the corners.
Thanks,
Petar

[Talbot]

you need stainless on the inside as well as the outside of the mast to prevent halyard wear through the aluminium. Some manufacturers have a purpose designed fitting that provides the slot. Mine sold two small pieces of stainless that had to be popriveted above(inside) and below (outside) the slot. The one inside was a real PITA, but it was a cheap solution.

There is a danger in weakening the mast unlesss you cut the slots in the right place. I got the mast manufacturer to provide proper drawings for a very small fee.

Once the slots are in place, you have the fun of getting the halyards in place. Dont forget that most masts havefore and aft strengthening bars down through the mast, so you need to ensure that the halyard does not get the wrong side of that bar, or it will eventually cut through it.

[GordMay]

When using internal halyards a fitting must be provided for the mast where the halyards exit the mast.
The simplest fitting is merely a hole through the mast fitted with an “Exit Plate” (Fairlead, or Exit Gate)) to prevent chafing the line.
Another arrangement is to use “Exit Box & Block” (Sheave, or Coaming Pulley), which not only acts as a fairlead, but has a sheave incorporated to change direction of the halyards as well as preventing chafing of the line. These fittings are usually fitted into the mast near the base. In selecting coaming pulleys and sheave boxes, be sure the sheave of the fitting will protrude far enough into the mast so the halyards will not chafe along the inside mast surface.

Halyard Mast Exit Plates - Snap-In Plastic or Riveted S/S:
http://www.rigrite.com/Spars/Isomat_...it_plates.html

Exit Blocks c/w Sheave:
http://www.rigrite.com/Spars/Isomat_...exit_block.htm

HTH, Gord

[phorvati]

Thanks guys,
Actually, I managed to bring over the rigger that designed and put my rig together 30 years ago. He took back to the shop the suspect upper portion of the upper shrowds, forestay and backstay. My mast was pumping quite a bit and the rod end near the upper most tangs shows some fatigue. He took the backstay to replace the insulators(SSB). And the forestay was actually 5/16 wire braid which we'll convert back to -10 rod. Meanwhile since I wanted the inner forestay with runners for flying the storm gyb, he brought me the inner forestay tang. We marked the positions, and he explained where to drill for the running backstays and inner forestay. He also explained how to move the spinnaker topping lift exit sheave down to serve as a sheave for the storm gyb halyard. A really nice, down-to-earth guy. We also went over the radar installation. Since he is so busy he'll be doing the stays , with insulators at the shop, and I'll do installation of the mast hardware.
The exit plate/sheave that I have for spinnaker pole topping lift the rigger said its a rare type that is no longer made. Its better than whats available nowdays. So I'll be just relocating it down below the second spreader.
Anyway, I was trying to find information on mast hardware installation for a long while. I got the Riggers Apprentice from Brion Toss. I regularly read his forum. But what I learned in 1-2 hours yesterday, it would have probably taken me about a 6 months at the rate I was going. So I am really happy. We'll see when the damage comes in but he seems very reasonable especially since suggesting that I do some of the work.
Petar

[Gallivanters]

Petar,

SELDEN has just the hardware you need - SS slot fittings cost less than $20 ea & sheave boxes cost about twice that. They come in various sizes.

I recently added two Selden slot fittings into our aluminum mast. One rivit secures the fitting in place.

Remember... Measure Twice - Cut Once

First I masked the area with blue tape, next I made a paper template to be sure of the cut I was about to make, then I traced the template onto the tape, next I drilled pilot holes in center of end radius, then enlarged holes to to proper diameter and finally carefully cut material between holes with metal blade in a jigsaw.

That was the easy part.

Our mast is 66 ft and now has six internal lines for halyards & topping lifts. Some scoundrel ran off with all of the lines while the mast was stored in the boatyard - before we bought her.

With the mast on stands, we used a 100 ft wire snake to pull each halyard (one at a time) and cranked hard on the winches to make them "bar tight" in order to remove sagging and get them off the inside wall so as not to interfere with the next runs. When the three stbd halyards looked good we rolled the mast 180 degrees and repeated the process. Luckily, there were conduits for all the wiring and none of the internal lines got twisted around anything in the process.

If the mast is stepped... first tighten all other halyards to make them plumb within the mast. Then list the vessel about ten degrees to the intended side which new halyard is to exit mast. Go aloft and feed a short length of bicycle chain attached to a messenger line over the sheave and employ gravity to find the most direct route to the new slot. Have someone on deck looking for the chain to appear at the slot and use a bent wire to fish it out through the new slot. It's better to run the new halyard outside the mast up to the person aloft and feed it down while the person on deck carefully pulls the messenger. And it's much easier to accomplish if you wait to install the exit hardware last.

That's how we did it, anyway, and I'm sure other people will offer other ideas.

Good luck,

Kirk

[phorvati]

The mast is down and I don't have problems running messengers. All the halyard exit points are staggered and have double sheaves in them. I am only moving my existent sheave lower the be located below the point where I am putting the inner forestay tang. So I dont' really want to get a new exit box. I was glad that cutting aluminum was pretty easy with the metal jig saw. I still have more to cut.
One thing I am warried about is weakening the mast. Each one of the halyard sheaves has a 1"x5" opening in the mast. The exception are the mast head ones, and I have three at the mast head. But then I also have three more opening near the top but below masthead. On the lower end the exits are all staggered but still with double sheaves in them and an oppening of about 1"-5". I would be curious to hear how close are any of those mast openings to any of the loading points like spreaders or mast tangs for anyone else? I guess it all depends on the rig design, mast dimentions, and wall thickness, etc. On mine, they are all pretty far off with exception of the upper tangs that are located within 6" of several of those sheave openings. But there's not a lot of bending at the mast head. Most of the rake is put in the mid section between the first and second spreader. Now that I put the radar mount there I wonder if going to windward with a lot of backstay tention and 6" mast rake, my radar will end up pointing to the sky or more towards the water. The orientation will definately change as the points of chain change.

[SkiprJohn]

Aloha phorvati,
I'm going to be adding inner forestay and running backstays. Would like to see your setup when you get it installed. Can you send a photo of the tangs?
Kind Regards, --JohnL--