Deck core repair - Do I have everything I need?

[Cheechako]

Originally Posted by redpointist

I don't know about a world circumnavigation, but I would like to go around South America (probably through the straights, not Cape Horn)! I hate the thought of having water in the core and its what bothers me most about the condition of the boat so I'd like to get it knocked out soon. I feel like I can tackle a recore if I plan everything out well, and would feel better about it than injecting epoxy, even if that might work well enough for now.

(also the boat and me are located in Tennessee for now, so I'm not missing out on any epic sailing or anything by taking on projects)

If you are planning to round the Horn inside or outside in an Aloha 34... you're a braver man than me! There will be a l ot of water under the keel before you tackle that I imagine.

[Ketchgould]

You'll need throw away gloves. That's plenty of resin. Did you look at mas system, no blush...which is nice.

I bought biaxial on eBay, it was 70% cheaper.

It's easy work. You will probably run into more areas than you thought you had damage. I covered my repairs with kiwi grip, highly recommend!

Stick with the slow hardener for sure.

You'll need a good grinder and five abrasive disks for it.

[SkiprJohn]

You've mentioned 3 times at least that you intend to replace the core with end core balsa. In my opinion for that repair I'd get some very good plywood that does not soak up water and saturate, layer it to the same thickess as your core and install it as the core rather than the balsa. Just a thought.

Maybe the experts can chime in on that idea too instead of arguing about epoxy vs poly. I personally like epoxy but the finish is hard to match if your repair isn't gelcoat.

kind regards,

[Nicholson58]

Originally Posted by SkiprJohn

You've mentioned 3 times at least that you intend to replace the core with end core balsa. In my opinion for that repair I'd get some very good plywood that does not soak up water and saturate, layer it to the same thickess as your core and install it as the core rather than the balsa. Just a thought.

Maybe the experts can chime in on that idea too instead of arguing about epoxy vs poly. I personally like epoxy but the finish is hard to match if your repair isn't gelcoat.

kind regards,

Use US COMPOSITES Epoxy 635 thin resin; no blush; use microballoons as filler. pour it or pump it in place. You can get empty, refillable calk cartridges. The compressive strength is 3000 psi - way greater than foam or balsa filler and it is totally waterproof forever. Refer to my post above on making a matching mold for the deck pebbles.

[Ketchgould]

I used divinycell foam. I don't think the core material matters so much as water is probably bound to get there someday again anyway, try as you will to bed everything perfect.

I used foam as it will not absorb water, ever.

[boatpoker]

I have three close friends who do FRP repair and I also spend a lot of time in the biggest repair shop in Ontario. A good portion of their winter income is derived from rebuilding saturated foam core rudders. Foam is however an acceptable choice for deck/trunk work if (always if) well bonded (I prefer Corecell).

Balsa is an excellent material if installed properly it will last for decades. Wet balsa is universally the fault of sloppy builders.
Don't use plywood .... just ask anyone with a Taiwan Tub.

[Ketchgould]

You need vinegar too. It removes dried epoxy from skin

[minaret]

Originally Posted by boatpoker

I have three close friends who do FRP repair and I also spend a lot of time in the biggest repair shop in Ontario. A good portion of their winter income is derived from rebuilding saturated foam core rudders. Foam is however an acceptable choice for deck/trunk work if (always if) well bonded (I prefer Corecell).

Balsa is an excellent material if installed properly it will last for decades. Wet balsa is universally the fault of sloppy builders.
Don't use plywood .... just ask anyone with a Taiwan Tub.

The foam in rudders is invariably pour foam, a totally different animal than closed cell PVC or polyurethane core material.


I've seen plenty of rotten balsa core result from hairline fractures which were almost invisible and ignored for too long. Not the builders fault.


Couldn't agree more about ply. I usually replace balsa core with foam, and ply core with Coosa. Similar properties, but non organic and proof against rot and saturation.

[boatpoker]

Originally Posted by minaret

The foam in rudders is invariably pour foam, a totally different animal than closed cell PVC or polyurethane core material.

Yet still advertised as closed cell foam.

[minaret]

Originally Posted by boatpoker

Yet still advertised as closed cell foam.

We both know that one is more susceptible to moisture degradation than the other. Can you imagine what would happen if all rudders were built with balsa core?

[boatpoker]

completely agree, there is a right job for every material ....

in the OP's case it's balsa and poly

[HappyMdRSailor]

Originally Posted by redpointist

The headliner is molded in, not removable, and has a definate pattern, not just textured. The screws you see are not holding on a removable headliner. Those screws fasten the forward handrail to the cabin top from the inside (I'm considering through bolting them at some point).

I thought so... and what a crap install of the rails too huh??? It's a wonder that the mfg didn't plumb a fresh water fill right under those rail fasteners... *sigh* .... (Picturing in my mind Utopia where all builders take the best construction/fitting methods from others)

Originally Posted by minaret

This is a very small recore, totally doable. The skills you pick up here will stand you in good stead too. Especially working with Gelcoat, as your whole boat is finished in it. If you can learn to match and blend, you will never need an expensive paint job and will be able to keep your exterior looking new all by yourself.

Exactly my point below about 20 posts prior! (and I'm about 9, 970 gallons short of minaret's resin use)

Originally Posted by HappyMdRSailor

You can do this... It will take longer, and be harder than you think... BUT... In the end you are going to learn a TON... Be proud of yourself... AND... Be able to tackle another resin project with confidence...

I do resin glass/shizzit all the time now as second nature.... Almost the worlds perfect fab/construction/fun material... Instead of buying resin only for a specific project... I've always got a gallon/hardener deployed right on the bench... Just a couple squirts away from another exothermic reaction!

Originally Posted by HappyMdRSailor

Remind me gently if I ever ask your advice... and then do the complete opposite...

By gentle... I mean a blunt object with some mass, or your foam shaper...

(my opinion on the importance of taking advantage of a world class expert at out disposal)

Originally Posted by redpointist

(also the boat and me are located in Tennessee for now, so I'm not missing out on any epic sailing or anything by taking on projects)

Where you at man? I'm over by Pickwick....

[redpointist]

Ahh! OK, so I went to the website on the 5 gallon pail of Core Bond 4001, they only sell through distributors, so I called them to find one near me, and low and behold there is a place in Knoxville, Tn where I'm located called Advanced Plastics. They should be a good source for resin and glass! Anyways, I call them up and they have a 5 gallon bucket of the stuff, BUT....its located at their Alabama location. I bet shipping on that would run $50 with hazardous material fees and whatnot. My question is, is it worth trying to get that bucket up here, or would it be well enough to do the bond with a polyester resin thickened up with some milled glass? In assuming that's mostly what the Core Bond 4001 is?

EDIT: I've had an epiphany....after all this back and forth with epoxy vs polyester, I wonder...Can I bond the core and the top skin with epoxy, and then use polyester for the surface joint which will be gelcoated? It seems this would give me the best of both worlds.

[redpointist]

Also, I should point out that my "epiphany" of epoxy to bond the core and then polyester for the surface joint wasn't my idea. I was reading "This Old Boat" by Don Casey and thats the procedure his book reccomends for my scenario.

[colemj]

Originally Posted by smj

No. Secondary bonding with polyester is fine as long as the polyester it's bonding to is still green, if not green the adhesion strength of polyester goes way down. That's when I believe epoxy should be used. I've seen way to many polyester secondary bonds fail to feel comfortable with it.


Sent from my iPad using Tapatalk

What do you consider "green"? Our boat during its build had polyester secondary bonding of structural components done over a month after the hulls were complete - no bonding problems after 15yrs.

I am doing a lot of construction right now adding length to the sterns. I needed to remove a piece of polyester tabbing connecting the new build to the original hull and tried to remove it with chisel and hammer. I had to resort to grinding it off with a grinder because I could not get the bond to release.

Certainly that deck area of the OP is not going to experience any type of forces that would make even a poorly done bond fail. He could pretty much superglue it and be OK there.

Mark