Mac 26S replacement mast too heavy?

[Mickyfin]

I recently have been lured back into sailing after a long absence. I've picked up a "bargain" Mac 26S, and have one concern. The prior owner stated that he had bent the original mast and replaced it with a heavy duty one that was more difficult for him to raise.
I haven't had the boat in the water yet, but I'm concerned that the heavier mast might be iffy on a water ballast boat known to be somewhat tippy.
I suspect that when the M26S replaced the M25, that the stock M25 masts may have been used on the new M26S model.
I have compared my 26S replacement mast with that on a 25. Both are 28' feet long and all attachment points are the same. The replacement is visibly heavier, with a 3" X 4 1/2" oval profile instead of the smaller M25 3" X 4" teardrop profile. Using a bathroom scale, it looks like the replacement is about 17 pounds heavier at around 70 pounds. It looked like it would weigh more.
I am open to any input. If the 26S mast was originally the same as the 25, do you think the extra 17 (maybe 20) pounds will have a significant effect on the boat? If needed, I might be able to swap masts, since the heavier mast would have far less impact on the heavily ballasted 25. Any thoughts? Thanks.

 

[Freedom77]

When we bought Freedom in 1976, I asked Roger to rig with and S106 mast as opposed to stock S104 with the intent of rigging masthead instead of fractional which allowed for bigger headsails. At the time I was doing a lot of long distance California coastal racing. I didn't have any problems with larger extrusion. If your yacht is fractional rig then there is, most likely, no need for heavier mast.

 

[rgranger]

Might be a little out of the box but what if you put 20 pounds of salt in the ballast tank to offset the weight above?

 

[Mickyfin]

I recently have been lured back into sailing after a long absence. I've picked up a "bargain" Mac 26S, and have one concern. The prior owner stated that he had bent the original mast and replaced it with a heavy duty one that was more difficult for him to raise.
I haven't had the boat in the water yet, but I'm concerned that the heavier mast might be iffy on a water ballast boat known to be somewhat tippy.
I suspect that when the M26S replaced the M25, that the stock M25 masts may have been used on the new M26S model.
I have compared my 26S replacement mast with that on a 25. Both are 28' feet long and all attachment points are the same. The replacement is visibly heavier, with a 3" X 4 1/2" oval profile instead of the smaller M25 3" X 4" teardrop profile. Using a bathroom scale, it looks like the replacement is about 17 pounds heavier at around 70 pounds. It looked like it would weigh more.
I am open to any input. If the 26S mast was originally the same as the 25, do you think the extra 17 (maybe 20) pounds will have a significant effect on the boat? If needed, I might be able to swap masts, since the heavier mast would have far less impact on the heavily ballasted 25. Any thoughts? Thanks.

 

[Mickyfin]

More ballast is a possibility. I'm hoping for some input from a 26S owner who might be able to speculate what effect the additional weight will have.

 

[rgranger]

I understand... the H26 is also a water ballast boat.

 

[srimes]

Weight aloft is bad for performance and racers will go to extreme lengths to reduce it. But I don't think this is your main concern. If this is a trailer boat the weight will be a hassle, but not the end of the world. Just try it and see how it does. It'll probably be just fine and if it isn't you can look to upgrade.

The M25 is far from a "heavy ballasted" boat. The M26 has over twice as much ballast, it's just located higher so it's less efficient.

20lb high on the mast has way more impact than 20 lb of ballast. The M26 has 1200lb ballast. 20lb is less than 2%.

 

[Eclectic]

Also keep in mind that the 17 pounds (maybe 20) is distributed along the whole length of the mast.

As mentioned try it out and see how it goes.

The original mast extrusion is available from Blue Water Yachts without hardware. Wonder what the shipping would look like.


Best Regards

 

[Mickyfin]

Thank you both. That's the kind of input that I was hoping to find. I probably have focused so much
on the aspect of initial stability in a water ballast boat(apprehension of the unknown), that I hadn't even considered actual ballast weight. Thanks for the good info.

 

[Tedd]

Love the way @rgranger thinks!

Along those lines, I worked out that a Mac 26S has about 32.5 lb more water ballast when it's filled with seawater than when it's filled with fresh water. The center of mass of the mast is quite a lot further from the center of buoyancy than the center of mass of the water ballast is, but I would guess that your 17 lb heavier mast with seawater ballast would probably give about the same righting moment as the light mast with freshwater ballast. In other words, not a lot of difference. There are also inertia effects to consider but, again, I suspect we're talking a pretty small effect.

Here's another way of thinking about it. If you weigh 75 pounds more than me then the drop in righting moment when you stand next to the mast, holding on, compared to me standing next to the mast, holding on, is probably about the same as the difference between a 70 lb mast and a 53 lb mast. So it's like you have a fat crew member going forward.

How does the larger extrusion fit into the foot bracket?

 

[Mickyfin]

Gosh, I thought I was a fairly sharp old guy, but I'm very much humbled by the knowledge you guys have. I expected some off the cuff comments, but it is truly amazing that a person can pose a question like this out
there somewhere on the internet, and receive this kind of credible response.

I kinda knew that rgranger was suggesting adding some weight to the ballast tank, but didn't see the big picture of transforming freshwater to heavier saltwater until ted spelled it out.
Both masts are 3" wide, and will fit in the foot bracket width wise. What I do wonder about is how well the mast will raise. The replacement footprint is 1/2" longer, and looks like it will dig into the foot bracket as it goes up. The mast is held by a single bolt that goes through vertical slots on either side of the foot bracket. I'm not familiar with this type of attachment, but it looks like I might be able to put a 1" block under the horizontal mast near the foot bracket, which would allow the mast to pivot upward without contacting the foot bracket, and then drop down the 1" as it approaches a vertical position(I hope). Thanks again for the help.

 

[srimes]

Along those lines, I worked out that a Mac 26S has about 32.5 lb more water ballast when it's filled with seawater than when it's filled with fresh water. The center of mass of the mast is quite a lot further from the center of buoyancy than the center of mass of the water ballast is, but I would guess that your 17 lb heavier mast with seawater ballast would probably give about the same righting moment as the light mast with freshwater ballast. In other words, not a lot of difference.

No way, unless you're saying that the the righting moments of a stock boat is about the same as with the heavier mast. That 17lb is 14 ft up from the cabin top. Probably about 17ft from center of gravity. The ballast tank is what, 3 ft from cg? Better make that 100lb of salt.

Also, note that boats float higher in salt water. Having the ballast match the water you're in reduces the change. Not that thats a big deal.

Both masts are 3" wide, and will fit in the foot bracket width wise. What I do wonder about is how well the mast will raise. The replacement footprint is 1/2" longer, and looks like it will dig into the foot bracket as it goes up. The mast is held by a single bolt that goes through vertical slots on either side of the foot bracket. I'm not familiar with this type of attachment, but it looks like I might be able to put a 1" block under the horizontal mast near the foot bracket, which would allow the mast to pivot upward without contacting the foot bracket, and then drop down the 1" as it approaches a vertical position(I hope). Thanks again for the help.

Sounds like you have a different bracket. Can you take a picture? Mine doesn't hinge on the mast itself: a bracket is bolted to the mast, and that hinges with the bracket attached to the deck. The hinge pin is offset so there's no digging and when down the edge of the mast of slightly raised off the deck.

 

[Eclectic]

When raising with a gin pole (or by hand ) the mast base will allow a little lift in the vertical slots. This should allow the mast to clear the deck plate provided the hole in the mast was placed correctly. The vertically slotted design eliminated the need to round one side of the mast bottom for gin pole raising.

Best Regards

 

[Mickyfin]

Here's a picture of the foot bracket. After cleaning some scuz off, I can see that the mast has been digging into it when raised. The column to the side is a PVC mast support.
I'll include a picture of the mast base later if I can't do it now. After looking closer, I can see that the mast through bolt hole is much closer to the backside of the mast. It's pretty well wallowed out, but being placed so far back, it looks like it should have held the mast high enough in the bracket to prevent scraping the foot bracket when the mast is raised. Probably hard to understand without seeing. (May have to send pictures separately).

In my own defense, I only gave $2000 for the boat/trailer, good 9.9 merc, main, jib, spinnaker, CDI Furler(all like new), never used pop up enclosure plus a separate mosquito screen cover, HDPE rudder and lots of other goodies.

 

[Mickyfin]

 

[srimes]

Here's a picture of the foot bracket. After cleaning some scuz off, I can see that the mast has been digging into it when raised. The column to the side is a PVC mast support.
I'll include a picture of the mast base later if I can't do it now. After looking closer, I can see that the mast through bolt hole is much closer to the backside of the mast. It's pretty well wallowed out, but being placed so far back, it looks like it should have held the mast high enough in the bracket to prevent scraping the foot bracket when the mast is raised. Probably hard to understand without seeing. (May have to send pictures separately).

In my own defense, I only gave $2000 for the boat/trailer, good 9.9 merc, main, jib, spinnaker, CDI Furler(all like new), never used pop up enclosure plus a separate mosquito screen cover, HDPE rudder and lots of other goodies.

Hey nothing to apologize for these are fine boats! And everything in that price range needs some work.

I wouldn't worry too much about the scuff marks, but the holes in the mast are huge. Almost like 2 or 3 holes were drilled and connected. Have you raised the mast yet?

If you don't like how it works you can upgrade to the hinge style. Parts available from blue water yachts.

MAST STEP, HINGED, MAST FOOT ONLY, 26X

Blue Water Yachts is the only factory authorized distributor for MacGregor sailboat parts and accessories. We sell factory replacement and upgrade sails, fiberglass rudders, centerboards and daggerboard, replacement plexiglass windows for most MacGregor boats. Also Venture sailboats and...

shop.bwyachts.com

MAST STEP, HINGED, DECK PLATE ONLY, 26X

Blue Water Yachts is the only factory authorized distributor for MacGregor sailboat parts and accessories. We sell factory replacement and upgrade sails, fiberglass rudders, centerboards and daggerboard, replacement plexiglass windows for most MacGregor boats. Also Venture sailboats and...

shop.bwyachts.com

 

[Tedd]

No way, unless you're saying that the the righting moments of a stock boat is about the same as with the heavier mast. That 17lb is 14 ft up from the cabin top. Probably about 17ft from center of gravity. The ballast tank is what, 3 ft from cg? Better make that 100lb of salt.

It's actually the change relative to the center of buoyancy that matters, not the change relative to the center of mass. That's why I wrote it that way. And the center of buoyancy is quite a bit higher than the center of mass, probably closer to my 2:1 ratio than your 5.7:1 ratio.

 

[Tedd]

@Mickyfin :

Crickey, that's one skookum mast extrusion! I'd be tempted to drill 1" lightening holes all up the sides. Well, not really. I'd probably replace it with stock and use that one to make a beam in my house, or something.

 

[srimes]

It's actually the change relative to the center of buoyancy that matters, not the change relative to the center of mass. That's why I wrote it that way. And the center of buoyancy is quite a bit higher than the center of mass, probably closer to my 2:1 ratio than your 5.7:1 ratio.

Huh? Almost all boats have cb lower than cg, but that's beside the point. Righting moment depends on horizontal distance between cg and cb. Changing the mast won't change cb until it hits the water and I'm guessing @Mickyfin would prefer not to heel that far . Raising cg makes a boat less stable, and cg is changed by adding or removing weight relative to cg.

 

[Mickyfin]

Ted, I'm glad you could see that it is a fairly stout mast and that I'm not just a whiner. As near as I can judge, the walls look about twice as thick as the M25 mast. I suspect that the replacement came off a larger boat and was shortened. I still havn't tried raising it.
I've been trying to figure out how to correct the wallowed out holes in the foot of the mast.
I'm considering fabricating an insert or plug for the bottom of the mast and then redrilling for the through bolt. I could trace an outline of the base, and use it as a template to make the plug out of wood, a chunk of fiberglass, 2 or 3 inch Starboard or maybe layers of 1/4 " aluminum bolted together. Anyone have any suggestions? I may need to start a new thread.
Ted are you an Aussie? I never have met one.