Crushed & cracked keel

[S/V AMITY]

  Have been looking at a 365 for possible purchase.  She has all the features I'm after... ketch rig, rub rail, no iffy modifications, low-hours engine and has the appearance of being generally well cared for.  Usual problems are evident such as mast step corrosion, a bit of non-ABYC wiring, frozen turnbuckles & some localized skin-to-core delamination around the cabin top opening for the mast but nothing I'd consider fatal.  These items I can fix.

  One spot of concern is an area of crushed & cracked glass at the after end of the keel caused by bad blocking... picture attached.  Have done glass repairs of a "normal" nature but tackling this repair raises some questions as to how this repair should be done.  I was taught early on that both sides (inside & outside) of the repair area need to be ground out and feathered back to solid laminate.  Access to the bottom inside of the hollow keel is not practical/possible since I can't reach it.  Am interested in hearing how others in the group have made the repair.

Thanks,  Jim

[S/V Deo Volente]

Hopefully the marina will be taking responsibility for the faulty blocking. Here is a link to a similar repair.
http://www.galleywenchtales.com/2016/03/uh-oh-haul-out-surprise.html

[S/V AMITY]

Yup. Same problem, same location.  What was the process for laying in the vermiculite/epoxy mix in the deep bilge?

[S/V Deo Volente]

He is on this forum, SVJOURNEY you may want to pm him.

[S/V AMITY]

  The sounding I did in the area around the keel crack seemed to indicate the damage is fairly localized.  As the boat is a two day sail from here I think I'd just caulk the crack to limit leakage, bring her down and haul out immediately for the permanent repair.

  Only "survey" done so far was the one I did when we first looked her over.  Will have a professional go over her when the cover comes off.  Standing rigging & associated fittings appear original.  Found no split swages or candy-striped wire at deck level. Due to age it will all be replaced.  Running rigging is worn but serviceable for the short term. Sails were not inspected. Winches all need complete disassembly & service.  No obvious signs of water intrusion or staining below.  Limited view of two chain plates shows they're probably original and are past due for replacement.  Fortunately, these are relatively easy to access.  Only change we'll make to the rig will be to add a club jib stay... same as Dale's (Maruska).

[SVJourney]

Remove the vdrive for better access to the bilge.  You gotta be a skinny guy (or hire one) but it is doable.

The vermiculite is added in 2 inch lifts.  Anymore than that at a time and you risk a thermal runaway when it kicks off.  The mix was VERY thick and was spread with a trowel.  The keel is now pretty much bomb proof.

That job cost me a bit over $2k US.  I'll gladly answer any other questions you might have.

[SVJourney]

From another post on this forum:

Re: The Bottomless Bilge
« Reply #19 on: September 12, 2016, 09:45:46 PM »

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This last year in New Zealand, Journeys bilge started leaking out on the ground when we were blocked up on the hardstand.  Come to find out there was a crack there that opened up when all the weight of the boat was placed on it.  Anyone with a standard bilge would be well advised to NOT let the yard crew block your boat there.  It balances and stands well with the blocking under the lead part of the keel only.

So it was a big repair, and we went a long extra mile to make sure that area was bullet proof during the process.  What we did:
Repaired the hull to original, then added several layers outside to tie in the repair.  After fairing, you have a hard time tell there was a repair done there.
   Added many layers of glass on the inside so that the hull in that area is over 2 inches thick.
   We looked at the cement option, but wanted the fill to be integral to the structure.  The fiberglass guys in Whangarei suggested using vermiculite. (which can be bought at any home and garden store as it is used as a soil additive.(cheap!))with epoxy resin to seal it and bind it together and in place.  This was poured in ~2 inch lifts to ensure that nothing got too hot as the resin kicked off.  Total lift was about 8 inches. The vermiculite can absorb impact if the hull gets hit hard enough to compromise the 2 inch thick hull.
   Then 4 layers of glass cloth on top to finish it off inside.
   Bilge paint and reinstall the pumps.

So this gives us a solid structure that is almost a foot thick for very little money. The vermiculite can absorb impact if the hull gets hit hard enough to compromise the 2 inch thick hull.  No rock is ever going to compromise the water integrity in this area. No more worries about the deep bilge being a danger. Bonus is that I can now reach and clean my bilge without serious pain.

[S/V AMITY]

  That vermiculite mix looks like a good solution.  Be a lot easier to keep the bilge clean.

  Before we leave this subject does anyone have a calculation or estimate of the gallon capacity of that keel area?  Am idly wondering if an auxiliary bladder fuel tank would be practical or worthwhile in that space.

[Nereid]

You can do a relatively easy one side repair of that area.. If you match the fiber orientation and layers matched with necessary over lap. I would not recommend doing less layers that the original, but also if you ad access layers it changes the shear force load path and can cause other areas to fail.
Do a scarf repair (grind towards the crack at a certain penetration angle to account for the amount of layers and adequate overlap. Its a very solid way to do a one sided repair.

[Sandy]

In almost any other material one would recommend drilling out the end of the crack. After grinding out the crack and filling the hole you can almost guarantee that the crack propagating further is forever eliminated.

Amity: the mast corrosion should almost be expected, but it isnt fatal. You can easily acquire a new step and cut from the mast the appropriate amount, or go custom like I did. What you do need to do is consider the cost of mast out mast in, which isnt inconsiderable, but does allow other repairs and checks along the way. You know it depends on what you intend to do. I might be alone in this but I think you just cant buy boats like this new anymore. For everything else buy the boat and spend the same again fixing her up, and you will be quite near the mark one expects to ocean cruise with some care.

Also diesels of the Perkins ilk are almost continuously rebuildable, and not beyond the average sailor although initially perhaps a bit of a reach. Mines at what I consider the halflife of 4000 hours.

[Nereid]

When it comes to E-Glass, Carbon Fiber.. or other composites. The best practice is to grind out the damage area at a tapered angle until all the damage is removed. Unlike homogeneous material (like metal), composites rely on fiber strength and matrix rigidity (High modulus of Elastisity). I wouldn't recommend doing the same crack stopping technique on Composites for a number of reasons:
-The strength of the hull in that area is now only as strong as the filler (if you fill the hole and crack with epoxy). In metal and most woods drilling a hole at the end of the crack is effectively creating 'crack tip blunting' which works in these homogeneous materials due to their simplistic ability to receive loads in all directions and have similar strength.
-The load path will create higher stresses in the region of the hole, due to the change in stiffness in the area (epoxy is not as stiff/lower-rigidity) than that of e-glass or carbon fiber. Therefore as the laminate/hull is loaded (the flexure of the laminates) results in more of the force/load being supported by the repair filler.

The best option is to grind out the damaged area and replace with e-glass fabric (woven, heavy woven, omni mat).
This is a similar process to how the Aerospace world does Composite Repairs

West systems has a pretty good document on e-glass and aramid/kevlar repair:
http://www.westsystem.com/wp-content/uploads/Fiberglass-Manual-2015.pdf

Take a look, and don't fret--Its actually pretty easy to do!
-Isaac

[Sandy]

thanks Isaak

[Nereid]

Yup..
The only thing about this outdated manual is when applying the repair plys:
Place/cut the smallest patch and place on repair area first then use larger sizes (should be a 0.5" difference between plys)
So for example in the manual they say to put the largest ply down first-do the opposite and put the smallest one down first. The reasoning is because of delamination and water penetration. Having a pyramid shape means there is only one ply adhering the rest to the repair area. Instead of this, put the smallest repair ply down first then the larger plys (increasing in size until the amount of plys have been met). Not only is it structurally better to have the plys in an upside down pyramid (due to the shear flow/load path traveling through each ply (best when adjacent to) as apposed to having a distance between the repair-area ply and the ply meant to patch it, but it also means that in-order for water to penetrate the repair it has to now go through every ply in the repair to get in as apposed to just one in the pyramid shape.
A lot more yards have started to do this the past decade but some are still on the old way of thinking.
..Let me know if you have any questions, as i'm sure I made it as clear as mud. Ha
-Isaac

[S/V AMITY]

  Nereid & ZULU40... good info!

  I did the upside-down pyramid technique on our current boat when I moved two seacock locations for the head.  Only change made was that since I had clear access to the inside of the hull area in question I laid in a sacrificial glass cloth covering backer on the interior side.  On the exterior where I'd previously ground out an 8X size bevel around the hole & started laying in small pieces of cloth and built up larger & larger till the area was proud of the surrounding plane of the hull... about 10-12 plies in ~22 degree orientations.  Ground the cured glass down then finished with a longboard.

  Went to the interior and ground off the sacrificial glass cloth back to match the hull form.  Could have left it but its nice have repair areas neat & tidy.  Finished the interior repair area with 2 coats of 2 part polyurethane to seal.  Exterior area was coated with 4 coats of barrier.  Sounding the area with a mallet betrays no change in sound.

  If I do go ahead with this boat (and the urgent keel repair) likely I'll build up the keel thickness with a sizeable number of additional plies all around that thin deep bilge area and extend it up to the turn of the bilge to distribute the load.  This will make that after end thicker in section which will be faired so that there is no visible step.  Hopefully this will eliminate that designed-in keel weakness and will tolerate the hauling crew blocking her where they see fit.  Also be better peace of mind when we ground on an "uncharted" hard spot.