Replacing All bulkheads in a Hunter 27 Cherubini...

[aajimb]

I just adopted a Hunter 27, early 80's. It's a project boat but clean fresh water history. All the bulkheads had been removed for refinishing. During the process, someone made off with them. I bought the boat sans interior woodwork! But it was a great deal for a great project boat... isn't it always?

I need someone with a Hunter 27, like mine, to give me the dimensions of three things:

1. The compression post.
3. The vee-berth bulkhead height at openings, port and starboard, of the climb-through. In other words, where the opening is to crawl into the vee berth, what's the height of the port and starboard bulkhead edge?

If you can measure the thickness of the bulkheads, that would be appreciated, too. The main bulkhead "shadow" appears to be 3/4" to 1" thick. The vee berth doesn't indicate any thickness, so any help you can provide would be great! BTW I plan to laminate up to 2" on the new bulkheads I'm putting together.

Thanks, that should do it. The liner shows very little evidence of the bulkheads, only small screw holes every several inches. Are these boats really that weakly braced?

I'm thinking of glassing the new bulkheads in and through-bolting them, also. Anybody done that before can give advice, would be appreciated. Also, any other info / advice on stiffening the hulls for more stamina?

Thanks,

Jim B
S/V The Next Adventure!

 

[David in Sandusky]

Away from our boat!

We are 2 1/2 hrs. away from Lady Lillie, so I can't get dimensions.

JC II, son of the designer strengthened the hull of his h25. An archive search should get you a good description. Our '77 h27 has such a thick hull, the it's not needed, but construction varied through the run.

I'd search this site for nearby owners. A visit to one of our boats would give you a lot of info beyond just dimensions!

 

[rbietry]

I have a 81 and will be going to it Monday to winterized it so I should be able to get you whatever measurements and photos you need.
In the meantime, I did open the compression post once several years ago for inspection and my memory is it was two 2"x"4's for the structural part.
As for the bulkhead support, photos in the different documents I have found seam to indicate they are built up before the deck is bonded to the hull. I have not seen any obvious hardware connecting them to the deck. As suggested, JCII would be a better resource for this information.

 

[aajimb]

Re: Away from our boat!

Thanks for the perspective and idea. Will do. Happy holidays!

 

[DianaOfBurlington]

New everything-?

Jim--

I would count on using 1/2" plywood for all of the bulkheads. It's not the thickness; it's the resistance to flexing that counts and you can accomplish this by interconnecting plenty of perpendicular members like bunktops and longitudinal bulkheads.

You can get these bulkheads' shapes and sizes very, very close on your own by making templates. At the shop we use doorskin-- very thin (1/16") lauan panels ripped into 2" strips. Get it as a *real* lumberyard. You snap these (with bare hands) into short lengths and lay them, on edge, along the perimeter of where the panel will be, and use squeeze clamps and hot glue to put them together. A big bulkhead like the v-berth one might be done in two pieces, both because you don't have plywood that big and because you would never get it in place all-in-one anyway. Do not be afraid to screw temporary beams onto the halves to get them aligned properly (I have made this mistake before). Using a white-pine 1x4, screwed edge-to the plywood across the seams (make it like 5-6 ft long; screwed all along about every 12"), makes it good and stiff. And ensure it is perpendicular to the centerline! --mine wasn't from the factory; and I blamed my own bad carpentry till I discovered that. You can use white-pine 1x2s for the cleats to hold the bunktop and other bulkheads. It's all the factory did.

Avoid all pretenses at hardwood fixes, like using oak and maple because people believe they are 'strong'. They'll rot like they're supposed to. Instead, use clean, straight, knotless softwoods, like white pine and fir, and saturate them to kingdom come with WEST epoxy before assembly. Then, you'll be assembling sealed, finished members without much concern for where water will seep in. Use WEST or 5200 in assembly-- that's better than the factory did..

One trick which you have, at present, the very best opportunity to use, is to apply a fat bead of 5200 along the edge of the plywood bulkheads before pressing them into the inside of the hull. This isn't really for adhesion (though it will work for that). It's to fill the uneven edge of the cut plywood bulkhead where it meets the uneven fiberglass layup of the hull. Water intrusion into the edge of plywood along the hull is the NUMBER-ONE cause of rotting plywood bulkheads. Jam this 5200 into all the gaps there, smear it into a fat (about 1/2"; use your thumb) bead along both faces, and then lay the 'glass over it. The perfection of the fit, therefore, isn't crucial at all. You don't even have to wait for the 5200 to cure (actually it's better if you don't). Grind/plane/sand the plywood down to about 36 grit prior to this. Epoxy is actually perfectly good to use in this application, rather than polyester (which won't stick as well to the wood)-- providing you have solved the flex problem. The bond to the hull (provided there is no shape distortion from the bulkhead's absence) should be rock-solid. Your goal here is 'egg-crating' -- making a rigid honeycomb framework out of all the inner plywood structure. If the hull structure can't flex, trust me-- the boat will just move a little bit more water instead. It can't be 'too' stiff.

There are two schools of thought about what plywood to use. Oh-- by all means use something good; but, in these days of epoxy, marine plywood is overrated. Few modern builders use it exclusively. Also, you will hear debate on both sides about using veneered plywood, which is very pretty but also expensive, versus veneering the plywood yourself, which saves the money items for only the parts you see and like. For Diana I made pretty much everything out of very nice lauan or birch cabinetry-grade plywood in 1/2" and 3/8", and then I painted it with Easypoxy. Looks like a million bucks. And so long as teak-veneered plywood remains open (not varnished or sealed in epoxy) it's conducive to becoming saturated.

By 'laminate' I believe you mean the lap of the 'glass up into the face of the bulkhead. If so, make it more like 3" each way. You can get good 6" fiberglass tape, both mat and cloth, at WM. Snip it along the inside edge and lay the flaps over each other along the plywood. There is no reason, as I said, to thicken the plywood itself. Thick plywood is actually a waste of space and weight. Ideally the boat would be stiffer with lots of 3/8"-plywood bulkheads, locker dividers, shelves, etc., all securely bonded to the hull. Anything that touches the hull and doesn't have to be removed for maintenance should be 'glassed into place. All of it helps.

I don't know how you intend to 'through-bolt' anything; but what would be the purpose? Avoid all holes drilled into or through the fiberglass.

For now leave the compression post for later. Get the bulkheads in place, even shim them if you come up a touch short, and fit the post into the 'finished' dimension afterwards. It should always go in just a hair tight-- providing your endgrain is safely saturated.

If you get me more details I may be able to apply what I know a little better. Keep us all updated with your progress! --and lock up your stuff from now one!

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[fnuttersny]

Re: New everything-?

If if you are working in that area anyway I would consider pulling out the entire mast support/compression post assembly and replacing it with a a metal pipe. I inserted a 3'' aluminum pipe with a "saddle" on it (picture a T) the shape of mast step on deck. Drilled a 3" hole through the cabin in way of mast step and inserted the post right on down to cabin floor. MY mast now is effectively keel stepped, leaks around original step eliminated, and I have saddle (1/2" aluminum plate) to which I bolted the mast "fitting" Also now have metal to bolt stuff to at mast bottom. The entire assembly is rock solid. Also gained a few critical inched in head because of radius on pipe instead of "box beam" 2/4 trim etc. Wiring is run trough "stand pipe" cemented though deck in convenient location with water proof fittings 1 inch IP size. as used in construction industry for roof electrical feeds.

 

[DianaOfBurlington]

Avoid metal

I respect fnutter's suggestion-- it's what we did with Raider 33s. But you might want to avoid metal for this application. We've all heard nightmarish stories here of corroding metal parts in the bilge with some of these Hunters. Your better bet is to install a nice-fitting plywood bulkhead, the edges treated as I have suggested, and then to bond to it, even using just screws (it's how it was done by the factory), and to not worry about it for another 25 years.

I know I will take more flak for this (when don't I?), but please believe me that the real reason the factory used aluminum extrusions as compression posts (or bases for same) is not because they are 'stronger'. It's because, in production, it's cheaper to buy and install a pre-fabricated part from a subcontractor than it is to have your own hourly labor cut, fit and properly epoxy-treat a piece of wood in the factory wood mill. This is the real reason you see lots of the first-generation Hunter features slowly disappearing in later series.

A well-fitted hunk of the right sort of wood, properly treated in WEST epoxy, will outlast your ownership of the boat and probably the next guy's too. What I learned from rebuilding 90 percent of my boat is that in 1972-1977 Hunter had not graduated to the epoxy age. Any responsible effort you make to remedy this will add years and strength to your boat. All of the epoxy in my 1974 boat was put there by me. I really do contend that it's stronger and more durable than it was when new-- and that's saying something, because after 40 years the parts I didn't rebuild are good and solid (that's why I didn't rebuild them!).

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