Deck Delamination / Core Problems

[ebb]

'Lo John,  Corecell-A is definitly a marine foam and has superior impact resistance and bonding properties.  See, for a comparative overview:
http://boatdesign.net/articles/foam-core-properties/
...hope that works

Thanks Mike, for explaining the mechanical properties of fiber vs silica.  If it is strength you crave then kevlar pulp is the filler you need.  It is said that for a given thixotropic gel you need much less quantity than silica.  (Compared to flocked cotton, don't know - but cotton comes from Arkansas and Kevlar from some nasty military/industrial plant)  And that probably means the kevlar mix will 'flow' better into all the incidental spaces in a recore.

Also, I would not get gridded foam - unless you're vacuum-bagging.  IE, imco, the cuts can only weaken the finished deck if they are not all totally filled with resin.

[ebb]

Think I might try some.  Found an outfit called
//www.fibreglast.com
in Brookville OH.   Want to try it for filleting, especially exterior.  100% silica is always difficult to sand/shape, even the next day.  Cotton sounds like you might have a longer window.  See how Kevlar responds.  Said to be the lightest of the fillers  (including silica?) so maybe you can get strength without sag (as I've found anyway, mixing silica and glass powder) using only kevlar.

[ElBeethoven]

I have a quick (hopefully) question for Sprite and anyone else who has worked with Corecell: it being foam, does it soak up epoxy at twice the rate that closed-cell honeycomb or the like would? Basically, for a new deck, should I order 6, 9 or 12 gallons of epoxy? etc?

And Sprite thanks again for the Noah's tip. New deck core for the whole boat: $76.20 + shipping. Not a bad deal, you might say.

Fair winds,

Jeremy

[Mike Goodwin]

It is closed cel foam , hardly any absorbtion at all.

[ElBeethoven]

So I have yet another question (BIG surprise there):

On #120, the core in coachroof over the v-berth is SHOT on the starboard side, the ENTIRE starboard side, including down and around the portlight. Or at least, the vertical walls around the portlight are compressible if there is, in fact, no core there. I have reread this entire thread, the more recent thread about recore we had going, searched the web, read the articles suggested, scanned my books, etc., and I cannot find ANYTHING about what to do if the VERTICAL faces of the coachroof are soft.

So what IS in the vertical walls? How would one go about repairing it if it IS rotten? Fill it with epoxy a little at a time? Without slicing off the whole coachroof, how could one be certain that bottom "joint" is void-free where new core (or whatever) meets the deck?

Anybody?

P.S. At least it was "encouraging" to find several cases of coachroof recore from the OUTSIDE, as I had planned on going in from the cabin. I've definitely changed my mind on that one. :-)

[ebb]

Vertical sides are hollow.  Check out what the rebuilders are doing.

[Bill]

See the first post in this thread.  It has a link to Bill Sandifer's article on recoring an Ariel -- including the coachroof.  And, more info on deck recoring.

[mrgnstrn]

...ElBeethoven....please clarify where the problem is....

are the vertical faces you worry about the ones in the "saloon", the main interior space with the non-moving ports/windows?

or the vertical faces you can see/touch in the forward cabin / forepeak?

if the former....then don't worry so much...you are compressing the cabin liner into the deck structure.  There is nothing between them...because the cabin liner is supposed to be cosmetic, really.  This is not true forward of the  mast in the forward cabin.  No liner in there, just the "other side" of the deck.

[Bill]

Deck delamination, deck core problems & A-120 core problem threads are merged.  If you have only read the latest thread, please read the first posts for more information.  Doing so will likely answer more questions.  

Just a reminder:  Always search for your subject before starting another thread . . .

[ElBeethoven]

Tim Lackey had this to say when I emailed him. It pretty much takes care of my question:

The sides of the cabin trunk are not truly hollow.  What you have is a solid structural laminate, running from somewhere in the rounded curve at the top edge (where it transitions to the coachroof) down to the sidedeck level. There is an interior liner made of very thin and flimsy fiberglass that has no structural relevance at all; it is for appearance only.  There is generally a variable amount of space between the two, which may lead to the impression that it is hollow.  Generally, it's not necessary to do anything to the cabin sides, but if you have severe movment as a result of a horribly deteriorated coachroof, you may need to perform repairs.

The exact situation you have, coupled with your skills and what sort of access you can gain to the area from inside or out, will dictate your repair method.  If you needed to repair the sides of the trunk, it would be easy, but you might have to compromise the interior liner to gain proper access. That's the problem with molded liners:  they block access for the repairs that most boats eventually need.  I think it would be too much work for dubious gain to try and open and then patch the liner, which is no great shakes to begin with, so if you did need to go this route, I'd suggest considering some other sort of interior covering that pleased your sense of aesthetics.

Recoring is messy and time-consuming, but is not technically difficult. Just remember that the whole point is to bond the new core WELL to both bottom and top skins (that is, no voids and firmly affixed), and to prevent the possibility of any water getting into the core again, even with a non-organic core material.  Solid laminate in way of deck hardware and openings, and around all fastener locations is the best way to go.  At a minimum, be sure to overbore and refill (with epoxy) boltholes when installing hardware.  The hardest part of the job is creating the fair and smooth surface at the end that you need for a fine finish.

Good luck!  It's a great learning process.

Tim

[ebb]

Thanks to Tim for being so patient and generous.

However, in different forms and differing personalities The SEARCH button on top of this page would have, with a bit of patience, gotten A/C pertinent  information on the subject.

[ElBeethoven]

With all due respect, I have spent innumerable hours pouring over this website for the last several months gleaning and searching for every piece of information I could about the Ariel in general, and NOWHERE have I personally found any information regarding the sides of the coachroof, their structural composition, if they may need reinforcing or how one would go about attacking such a project. Additionally, my manual arrived yesterday, and I am very much looking forward to digesting it in toto and searching through it for any information regarding the above question I had. In my first cursory review, I have already identified several additional projects which have been placed on my ever-growing To-Do List.

As I mentioned, Tim's kind reply addressed my specific issue, so I consider the matter closed, and again I would like to thank everyone that has replied to my many other inquiries. The information from this board's members has already saved me well over $1000 and countless of hours of future frustration.

Fair winds,

Jeremy

[Sprite]

It is solid laid up glass where the port and starboard windows are in the vberth and main cabin except for where the companion door is, that part of the cabin is a sandwich of glass plywood glass. I found out when I took out a knot meter that had seen better days.


Hope this helps

John

[Sprite]

Oh I forgot it is definitely laid up glass because I saw it taking out my windows

John :eek:

[natalie e.]

Now that I am on the right page I am on to my next project of removing the two decks on each side of the cabin from the chain plates back almost to the winches. I have read the good old boat article attached to this forum and understand cutting away the top fiberglass skin to reuse then removing the old core. I did not understand cutting and laying in the new core in 3" strips, shouldn't the new core be layed in whole on top of the epoxy mesh. Also any idea of the thickness of core (marine plywood)? I am contemplateing removing the foredecks also, they are not as mushey but are giving way.
Thanks in advance for all your help. I will show pics of my motor city girl as I continue my dream.