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PHRF Racing a Mac25 - Summer 2017 After Action Report

Posted: Thu Sep 28, 2017 3:15 pm
by Sisu
About 2 years ago when my girlfriend and I spied a tired old Mac 25 on the side of the road for a few hundred bucks, I was in the market for a race boat. I had been crewing on scows here on Lake Winnebago for several years and was getting the itch to skipper again. I was looking at maybe a C-Scow, an I-20, or a Laser.

We bought the Mac thinking it would be a fun winter project and let us do some cruising around the Midwest. But I couldn't help myself and started outfitting the deck like it was a Farr 40. Should we add cruising mods like lazy jacks and roller furling? Nope - upgrade the primary winches, add secondary winches to the cabintop, all lines led aft, cam cleats for the sheets, upgrade the halyards, add spinnaker halyard, topping lift, foreguy, pole rings, spinnaker pole, symmetrical spinnaker off an E-Scow (they have been made obsolete by the new asyms so you can find them surplus around here), new Hyde 155% #1, twings, boom vang, adjustable backstay, and let's race this thing! Most upgrades were thriftily achieved with the help of eBay (my favorite snag - box of 5 rope clutches and assorted expensive racing blocks for $150; description: "I have no idea what any of this stuff is").

The first night we raced, about the only good thing we could say was that from the first race to the second race of the night we cut the amount we were in last by in half. I was beginning to suspect this whole racing thing was a horrible mistake. Yet, we stuck with it and ended the season with three second place finishes - the last race of the summer series, the labor day race (singlehanded), and the last Fall fun race. Yes, you can race a 30+ year old Mac25 in spinnaker fleet and do decently well. Would we do better in another boat? Maybe, but it's more fun when we beat boats with our garage band program right now, and it's still a comfortable, trailerable cruiser.

The good:
-When sailed properly, the boat does remarkably well in heavy air. I thought for sure light winds would be our specialty but so far we're doing best in the heavy stuff.
-Ideal crew size is around 4 - Skipper/Main Trimmer, Headsail Trimmer, Pit, and Bow. Adding a 5th helps in breeze.
-The boat performs well with a symmetrical kite sailing medium-deep angles. It took a Melges 24 an amazingly long amount of time to pass us downwind on a breezy day. Stability in breeze is good, only one scary moment all summer.

The bad:
-Our boat has a fairly pronounced "dent" in the bottom where the aft end sags off the trailer bunks. Looks like it was on the trailer for a long time prior to us getting it. No idea how much speed it's costing up but I'm sure it's some.
-There is very bad weather helm with more than about 10 degrees of heel. In a good gust upwind if we don't ease the main properly we'll lose rudder authority and round up pretty easily.
-The OEM blade jib is cut very high and sheets too far outboard to point well. We actually found it was best to use the windward sheet to pull the crew a little higher.
-The mainsheet location is not ideal, particularly for sheeting upwind on port tack. I put some very weird strain on my elbow trying to sheet with the block essentially behind me.
-Bad leeway upwind in light/medium air.

Some fixes I would like to make this winter. Seeking advice on any of these:
-Big project, but correct the deformity in the hull. I'm thinking we use a jack between that part of the bottom the cockpit floor (use some flexible lumber to spread out the load), then glass in some stringers.
-Build a new rudder to a proper NACA foil shape.
-Strip, fair, and re-seal the keel.
-Install new sheeting tracks for the blade jib and acquire a new sail. I like Grady's use of the J/22 jib on his 26. It would be about a 90% on a Mac25 but the sail area is more than our current blade.
-Re-route mainsheet to block on the cockpit floor in front of tiller. Install a traveler if I can find an affordable one.
-Replace OEM stay adjusters with proper turnbuckles, install BWY speader base upgrade (rigid terminal on mast vs swivel-bolt), consider upgrading standing rigging size.
-Upgrade to new-style gooseneck.
-Do all the other cruising mods we still want to do.

It's going to be a busy winter, but this year was motivating! Sorry for the novel, but hopefully this will be a good resource for anyone considering racing a Mac, in addition to what has already been written elsewhere.

Re: PHRF Racing a Mac25 - Summer 2017 After Action Report

Posted: Tue Oct 03, 2017 11:28 am
Congrats on your racing success. I too have raced my 25 with good results. I re-rigged mine boat so I could use J24 headsails, which you can pick up used for cheap. For your weatherhelm issue, how much mast rake do you have? The factory instructions has you setting the mast with excessive rake to make the boat "safe". Meaning it will round up in a gust. Cut your rake down to 1 or 2 degrees and see what happens. No need to increase your rigs wire size (except increase the forestay to 5/32) as the strength od the hull is way less than the 5/32 wire you currently have. The more you tension the rig, the "skinnier" the boat gets as you pull the sides of the hull inwards. Checkout my dual main sheet setup ... ?view=1402 and also my U-tube channel has a lot of Mac sailing videos.

Re: PHRF Racing a Mac25 - Summer 2017 After Action Report

Posted: Wed Nov 15, 2017 9:17 am
by Sisu
Thanks for the advice! I've been cautioned by others about tensioning the rig too much given that the chainplates are not anchored to a bulkhead as they are on most boats of the size (we don't really have bulkheads either, more like partitions that sometimes bear load). I've bought some turnbuckles off eBay, which look to be the right size for my existing shrouds. I'll look into a forestay upgrade and re-check the rake.

I really like your J/24 setup but I already bought a new Hyde genoa last year so I think we'll stay committed to the original rig. Plus, we rarely sail to our rating as it is.