Bulkhead & Construction

[MarkRyan1981]

Hello all,

I read the below on an old post on YBW:

"I am the ex-owner of Ballad Hull No. 104.

She fell apart in the 2001 Fastnet Race. Albin had a very strange method of attaching the bulkheads. Nearly all builders use a top hat section and glass the ply bulkhead in. Albin used a GRP web and bolted on the ply bulkhead. On my boat, the webs tore away from the hull, which allowed the hull to V as the mast drove down.

Ended up with a 3mm wide and 400mm long split on the centre line and making water. The water was appearing in the forward bilge. This is about 300mm aft from the external split. Following this failure, the rest of the hull started to move and ended up as a mass of stress cracks. Looked like a dropped hard boiled egg.

I had a look at an Albin Cirrus the other day. Had exactly the same problem as my Ballad, but in its infancy.

She has been sold as a repair project for £ 5,000 with £ 8,000 worth of sails on board. So far, the insurers have declined my claim.

If you are after one, they are super boats, I suggest you look in scandanavia and avoid the UK. As the UK ones are pretty knackered by now. Apparently production stopped in 1989, in Denmark."

Mine is Ballad no 50, so needless to say, I want to make sure the bulkheads stay attached. I've been out in some heavy weather and reasonably heavy seas and Triola has been bullet proof. Has anyone experienced the above? Or strengthened the bulkheads to avoid the possibility of this happening?

Thanks all.

Regards,

The Ryan family
http://www.albinballad.co.uk

[Bob McGovern]

Thanks for posting that, Mark. I'd run across it during research on the Ballad. The bulkheads-bolted-to-tabbing construction method was hardly unique to Albin, nor were most other boats of the time period built with fully tabbed bulkheads. Even today, that level of construction detail favors higher-end builds. Since boats of the Ballad's age used almost exclusively polyester resin in their build, tabbing in wooden bulkheads was of limited extra benefit anyhow, unless tabbed thru the panel -- and that weakens the plywood near its edge.

Our bolt-on bulkheads are not quite adrift, but the bolts are certainly loosened over the years & it's easy to imagine the entire panel coming loose & doing some damage. Much of the problem (as with the chainplates) can be traced to lack of backing plates. The bolts have compressed into the plywood, then the nuts come loose and start backing off.

I hope to augment the existing tabs with epoxy and a second run of tabbing on the opposite face of major bulkheads ('top hat'). Then thrubolt. Truth is, ninety percent of the force on a bulkhead is in plane, so all the tabbing really has to do is hold the panel where it belongs. The layup then distributes tensile, bending & torsional forces. If Ballad 104's bulkhead came completely free ... yeah, that could do some damage. I'd also be really interested to see the condition of the mast step truss on #104.

[MarkRyan1981]

Thanks Bob, that's a cracking explanation (no pun intended), and shows that #104 could have been saved if the problem had been identified and addressed. I'll have a look at my bulkheads to see if there are any signs of the bulkheads bolts coming loose and add it to my list of jobs to strengthen them up. That said, I have no concerns about Triolas integrity as I have raced and sailed her in some pretty hairy conditions with gusts up to 40 knots and she has given no drama at any time.

What should I look for with the chain plates? I'm pretty sure mine have been replaced in the past - I'll post some photos up if I get down to her at the weekend.

Take a look at http://www.albinballad.co.uk/about-the-albin-ballad/, there are some great articles I collected on there (I note you are quite a new owner looking back at some of your previous posts!). How have you found her? Yours is a mite younger than my venerable classic

[Bob McGovern]

Fionn (1972 -- hull 18?) came to us a little scruffy. Typical neglect of some basics, like chainplates (leaky; original; carriage bolts pulling thru furniture), thru-hulls (brass/bronze gate valves), and hardware bedding. Nearly all hardware lacks suitable backing plates or solid core beneath; most nuts (including hull-to-deck bolts & lifeline stanchions have never been snugged & could be spun off with your fingers. Basically, the boat needed someone with a roll of butyl tape and a socket kit to go around and tighten what forty years of square chop has shaken loose.

Failing that, water has got in where it hadn't ought. The genoa track was apparently backed with a 1"x4" strip of rift sawn fir. I pulled the core out with my fingers, in sodden chunks. There's some gelcoat cracking where things have flexed. Nothing too bad for a boat this age. Overall, the bones look good. The work we face is similar to but less daunting than what Peter has done. We view a complete refit as a chance to rationalize some things (like chainplates & their loadpaths) & to upgrade certain production deficiencies (like bulkhead tabbing). One nice feature about the Ballad is the ease of taking the interior apart. Many USA production boats use FRP liners, puttied in before the deck goes on. These also sometimes come adrift, and then the boat is essentially worthless. There's not much on the Ballad a determined owner with a screwdriver can't get at & make good as new.

The sad thing about Fionn is the way it was stored on the hard, six months at a stretch, in a place the owners couldn't get to it or work on it. Then the winter-stored boats are launched en masse, usually in May, and they are parked in an urban marina where major repairs are not easily undertaken. The season is so short, owners just want to sail, not fix stuff.

The happy thing is we got a boat that has spent half its life on the hard, the other half in cold fresh water.

[Bob McGovern]

Finally after two years of walking backwards, we are beginning forward progress on Fionn. One side deck is re-skinned and the bulkheads are ready to be epoxied & tabbed in. The bulkheads were not connected to the deck proper in any way. To vertical coach sides, with three bolts -- but not the deck around the mast collar.

Has anyone tabbed the main bulkheads to the overhead, or otherwise connected the top of the boat to the bottom? I'm wondering if we should epoxy-tab the structure together, or just rely on angle brackets and/or tie rods, or both? We will be adding turning blocks to the deck to direct lines to the cockpit & we do not want the boat to flex like a bellows.

BTW, one of the modifications we are making is to eliminate the small 'jog' in the port side bulkhead. Ours juts out at a right angle; to enter the V berth, you have to twist your shoulders to avoid the mast, duck under the lintel, step over the threshold, AND try not to bang your knee on the bulkhead. Like this extremely yellow example on Yachtsnet.co.uk:


Later Ballads softened the angle a little. We simply continued the line of the bulkhead all the way to the floor and angled the bunk in to give more room skirting the mast. I worried it might remove an important structural 'triangle' from the bulkhead ... but it turns out that part of the bulkhead is not connected to the hull in any way! It was doing nothing but bruising Ballad sailors.

[MarkRyan1981]

As part of my fitout of Triola (which is experiencing quite a lot of mission creep (new gas fitout in copper, new galley, removal of skin fitting, Propex heater install, new Flexofold prop, fit out cockpit lockers, moving batteries to under the cockpit and making an enclosure up for them, new mast truss and the list goes on!!)) I checked the bolts holding the forward bulkheads on - they are finger loose!!! Another job to add to the great list then .

Plan is top 'top hat' the bulkheads on the opposite side to bolts in sections with three layers of glass using West System in each section, then re bolt with nylock nuts this time!! They won't be going anywhere then...

Is it just these two forward bulkheads that are worth top hatting?

[MarkRyan1981]

Boat goes in the water in three weeks! Hurrah. Finally got around to this job before the rig goes up on the new truss. Does anyone know what the thread is on the M10 ish sized bolts that hold the bulkheads on so I get get Nylocks for them please? 7/16 IMP?

I'll pop these bolts out, tophat the bits I can get to, and then torque back up the nylocks. About 50% of them were finger tight only!

[MarkRyan1981]

I think I am going to go with loctite blue rather than nylock nuts and use penny washers on either side to spread the load:

http://sds.loctite.com/us/content_data/ ... 10_Web.pdf

I've top hatted the top section of the main bulkhead on both sides, I havn't got to the forward one, but I figure the loctite solution should suffice there. I used two layers of light glass after creating a fillet with colloidal silica with peel ply on top.

Bolts removed and surface prepared (that headlining backing is horrible stuff!):


Top hat applied: