I am thinking of cutting my Inner Liner like this. Is there any reason why I would be better not too? I would not think there would be much strength lost from this cutout, but not sure. I'm trying to get to the Bow Eye to repair it and the access would be nice for other repairs in the area. But not if there is a significant loss of strength. BTW, looks great as all of your mods Cuscus.
Cutting the Inner Liner?
- Thread starter RonRock
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Sure, go ahead. No appreciable loss of strength. You'll just want to make a plywood cover to keep the flotation foam inside.
I would put a hole in the center, and use a beckson port to cover it, I definitly wouldn't cut it at the top like that, you don't need it for access and it eliminates any reinforcement that the bulkhead provides. Roger wasn't known for putting unnecessary fiberglass in his boats...
The Mac 25 is very similar to the V-25. I agree with Tomo42. The hull liner is an integral part of the boat and adds strength. If you did cut it out like Thecuscus I'd make sure to put in a plywood or aluminum frame fastened securely as a strengther. It's amazing how much a boat will warp under sail/wind pressure. Every time I put on a piece of deck hardware I back it up with a heavy aluminum plate as large as possible. I've seen cleats ripped out of decks. Not pretty.
I just would not allow the water to drain under the vberth, it is hard for any water to get to the bilge pump and then there is all the foam in there.
I don't know about the powersailors, but on the earlier boats, the liner is structural, supporting the hull which is less than 1/4" thick in that area. The forestay attaches just forward of the bulkhead.
There has been an interesting split of opinions on this. When I first looked at the opening I thought it was a great idea. I don't need the area for chain storage, but if it was open why not? But there is a lot of "stuff" in that part of the boat that could be much easier to access with the cutout. From my point of view, and I am not even close to a structural engineer, just a seat of the pants engineer, anyway from my point of view that area should not have much stress on it. It is at the upper point of the bow, above waterline. And has the strength of the point going down and the deck above. But I really do not know anything about boats and the stresses that they are under. That is why I asked. So far it looks like it is 50/50 or close.
I bet you "old guys'" get sick of us newbs coming around asking stupid questions. But I will say it has been fun for me to ask these stupid questions. With each one I learn a bit more about my new found joy.
Thanks,
Ron
I bet you "old guys'" get sick of us newbs coming around asking stupid questions. But I will say it has been fun for me to ask these stupid questions. With each one I learn a bit more about my new found joy.
Thanks,
Ron
I cut out an opening...
.. big enough to get to the bottom of the ....
...anchor roller mount and you can also see the chainplate for the forestay...
http://purplesagetradingpost.com/sumner/macgregor2/rigging-17.html
... I needed the opening bigger than a round port hatch to get my arms and such in there. For the S anyway I'm more than comfortable with an opening like above structure wise. I agree that I wouldn't cut out the top if you didn't need to.
I covered it with a...
...simple piece of plywood. We usually have so much...
..in the V-berth that you can't see it especially since we lengthened the V-berth and store stuff in that area.
I did replace all of the foam when done. I'd considered an anchor locker, but I love the way our rode bags work and we anchor every night so getting on and off anchor quickly and easily is very important to us,
Sum
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.. big enough to get to the bottom of the ....
...anchor roller mount and you can also see the chainplate for the forestay...
http://purplesagetradingpost.com/sumner/macgregor2/rigging-17.html
... I needed the opening bigger than a round port hatch to get my arms and such in there. For the S anyway I'm more than comfortable with an opening like above structure wise. I agree that I wouldn't cut out the top if you didn't need to.
I covered it with a...
...simple piece of plywood. We usually have so much...
..in the V-berth that you can't see it especially since we lengthened the V-berth and store stuff in that area.
I did replace all of the foam when done. I'd considered an anchor locker, but I love the way our rode bags work and we anchor every night so getting on and off anchor quickly and easily is very important to us,
Sum
[FONT=Arial, sans-serif]============================[/FONT]
Our Endeavour 37
Our MacGregor 26-S Pages
Our Trips to Utah, Idaho, Canada, Florida
Mac-Venture Links
I store 150' of 3/8" rode and 20' of chain in that area, haven't cut it, but am thinking of putting an access port so I can seal off the bottom and add a drain out the side, I am not real thrilled about the water draining through the boat to the bilge.
Don't worry about "stupid" questions, better than mistakes.
The bow is fairly heavily stressed, the forestay attaches there, the genoa attaches there, the bow eye attaches there, the anchor attaches there... I tension my forestay as tight as it can go without warping the boat, about 250lbs, you can tell because the loos gauge doesn't go any higher. I've cut a few holes in my boat, including for a larger forward hatch, and my goal is to reinforce the are so that it is at least as strong as it was originally.
Don't worry about "stupid" questions, better than mistakes.
The bow is fairly heavily stressed, the forestay attaches there, the genoa attaches there, the bow eye attaches there, the anchor attaches there... I tension my forestay as tight as it can go without warping the boat, about 250lbs, you can tell because the loos gauge doesn't go any higher. I've cut a few holes in my boat, including for a larger forward hatch, and my goal is to reinforce the are so that it is at least as strong as it was originally.
If it were me, and I likely will soon, I would round it like an airplane window. Sharp corners a are weak and have a larger chance of cracking from the corners under stress. Look at your other openings, they are all rounded.
Just my humble opinion
Just my humble opinion
your lucky if your hull is 1/4" thick at the chain plate, much less the liner which is probably closer to 1/32 to 1/16" thick, there's no where on an new M where the hull is thicker then 1/4 to 3/8" except at corners or junctions with other structure.
If all you want to do is repair the bow eye, why not just install an access port/deck plate?
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