a few questions on my new M25

[abruzzi]

So, I got my M25 home yesterday, and today I'm going over everything, and had a few quick questions.

- Mast top: The top of the mast is open--not closed top to keep things out. Is that normal, or is it missing a piece?

- Boom joint: The piece at the forward end of the boom that attaches to the pivot, is pretty loose in the boom. Is that normal or common? The pin that holds it in place is pretty banged up and one of the holes on the boom is ovaled. Would it be a stupid idea to shave a quarter inch off the boom length and redrill new holes, or would that be too much and affect other things?

- Shrouds/Stays: When I picked up the boat, the mast was up, and the seller helped me lower it, before we did that, I noticed that the forestay was tight, but the rest of the standing rigging was pretty loose--almost floppy loose. I'm guessing that is not correct. About what should the tension be on the different shrouds/stays? Do you just eyeball the tension, or use a gauge?

- What size are the clevis pins on the standing rigging? A bunch have been replaced by bolts and I'd like to buy a couple dozen and replace everything.

thanks,

Geof

[GaryMayo]

Welcome to the forum. As a new Mac 25 owner as wel, I wish us both great times ahead.

[abruzzi]

One more question to add to my list. The keel lock down bolt is missing (not the pivot bolt.) any idea the length and diameter?

Geof

[snotnosetommy]

Hey, Geof, welcome to Mac 25 World.

The mast top is supposed to be open. I stuffed a piece of foam in mine because a wren nested in there while the mast was down this spring. No wrens were harmed.
The boom pivot stud is floppy as heck on my ship and I'm fine with that. If you wanna whack some off and redrill, it's not likely to hurt anything. BTW, the gooseneck bolt that goes thru the mast was always snagging my jib sheets in lite winds, so I switched to the newer version from BWY (http://www.bwyachts.com/BWYParts/info.htm) which has no thru-bolt.
My shroud clevis pins are 1/4" , same as the forestay. The upper and lower shrouds should not be sloppy. Pretty snug, but not too tight. When the boat is heeled underway, the lee shrouds should have a little slack. You can get a Loos guage, but I don't know the values.
Never had my lock bolt out, so don't know. The pivot bolt is 5/8" Stick a bolt in and see. I don't lock my keel down, but let it rest against the lock bolt.

The M25 is a good ship. The archives here are exceedingly useful. Happy sailing.

[TOMV]

When I bought my 25 (my first boat) the standing rigging was all loosy-goosey.
I decided to go with new shrouds that were tunrbuckled.
Once pinned into the tangs they could be tightened.

[Catigale]

As a really rough guide, you shouldn't be able to deflect the shrouds with hand pressure whereas if you lean your body weight on them they will move 2-3 inches. Too loose is more dangerous than too tight, since it allows both fatigue failure and shock loading.

[abruzzi]

Thanks for the info. The boat came with a nicopress/crimper, so I may just rebuild all the standing rigging with turn buckles. I'm hoping to be ready for a test sail in a month, but there is a lot to do.

By the way--when researching this boat, I was surprised that there isn't any good structured informations sources, mostly just forums with more powersailors than anything. When I was looking at a relatively rare boat like the Kittiwake 23 I found more info online that I did on the Mac 25. So I was thinking of setting up a wiki for gathering info on the earlier Macs. What do you think of that idea?

Geof

[abruzzi]

Actually, speaking of turnbuckles, any idea if item #3107-000 on bwyachts.com has the same or similar adjustment range as the sliding tangs (or what ever they're called)? If so they could be a drop in replacement without requiring new shrouds.

Geof

[Catigale]

One word of caution...the sliding tangs are much more robust than turnbuckles and are less likely to be damaged during trailering than same. Generally on Macs, once you get the rigging tuned right, it stays put.

[Gare Bear]

In response to a couple of Abruzzi's questions:

I too am a Macgregor M25 owner. I do not know what the shroud and backstay/forestay tension values should be, but I can say the following from experience and advice from knowledgeable sources:
1. Do not tension the shrouds and stays too tightly as it could put the mast support post between mast step and cabin floor through the floor or at least deform the boat floor.
2. If you do not cause damage to the boat floor with the belowdecks mast support, you may deform the boat under sail if shrouds/stays are too tight.
3. My local chandlery told me to set the shrouds up so that when heeling under sail the lee shrouds should show reduced tension, but not be loose. They suggested I initially set the forestay and backstay so that the mast was nearly vertical at the base but had a slight aft bend.
4. Concerning the keel lockdown bolt: If you just rest the keel against the bolt when the keel is down, you will eventually hammer the lockdown bolt backwards and enlarge the hole in the keel box structure. Apparently the former owners of my boat did just that, with damage resulting as described.
5. A safety concern with the keel lockdown bolt: The boat may not right itself if the boat were to be knocked down and the keel swing against the boat. Also, if the keel were to swing against the bottom of the boat in a knockdown, it could damage the hull.
6. Because my keel lockdown bolt hole in the keel box structure was wallowed out from the keel impacting it in an unlocked condition, the keel pumps a small amount of water through the locking holes. I don't think it would be enough to endanger the boat, but I found it disconcerting so fashioned a makeshift gasket using some firm, closed-cell foam backed by some firm plastic washers. So far, not even a drop of water has come through.

[MacStonge]

Welcome! My 84 Mac25 came with a black plastic cap riveted into the masthead. The support arm for the Windex is screwed to that. Sure looks original.