Digging in the deck

[Stephan]

I've decided to try a unconventional way of fixing some wet spots in my deck. I wanted to avoid weakening my deck too much, so I thought instead of totally detaching the top FG layer, I'd drill out some big holes and poke the wood out from there:



Indeed the balsa was totally wet and had mostly detached from the fiberglass. My next steps will be to remove the wood below the rims of the holes, maybe with a wire brush attachment for my Dremel or drill, dry it some more, and then fill it all with epoxy. Maybe try to thread some pieces of FG in there, too. I'd cap it with the round deck pieces I saved, fill the gaps, and fair it.

What do you think?

[Tony G]

I recall a recore job being done by cutting discs in the top skin. The author numbered all the holes and discs. If I recall correctly, Good Old Boat featured the article in one of their issues. I bet if you contacted Karen Larson she could give you the issue number.

[bill@ariel231]

the holesaw method will work too but with all the patching of the deck, you may find it more time consuming than reaching for the circular saw to remove the top skin... at least that has been my approach for A-231 and other boats. The downside of the circular saw method is you will want to remove all hardware from the deck, and the project may quickly turn into a complete deck recore (not hard, just time consuming).

Nothing wrong with patching the bad spots and getting back out there this season. good luck!

[carl291]

It appears in the photos that the core is bad in an area where there is no deck hardware. This would lead me to think that this entire deck area is bad. If I were to make the type of repair your doing just to get back to sailing I would use balsa to go back in your holes and not all epoxy. My reason would be that this area will have to repaired in the future and I would not want to grind all that epoxy out at a later date. The balsa grinds away a lot quicker and is a quicker and cheaper filler material. Just a thought.

[mbd]

I remember that GOB article. It was done with a much smaller hole saw though.

To add to Carl's post - if you don't address where the water is getting into the core and to keep it from getting in in the first place, fill the holes with core-cell of another closed cell foam products so you won't be repeating the same repair a few years down the road.

You may also want to take a normal drill bit and drill exploratory holes out from a bad area until you get to good balsa just to "map out" the areas you'll need to address and to get an idea of how extensive a repair you have on your hands. It would also give you an idea of where the water is getting in. It goes without saying to be sure not to drill all the way through the inner skin...

[Tony G]

Stephan,

Bill, Carl and Mike are right. You don't want to put a whole lot of effort and money into it if you are just going to tear it all out and do it over again in the near future. Using a smaller drill bit and 'mapping out' the wet spots is a very sound and good idea. If you can accertian where the water is getting in, you could address the ingress. Then if the decks are not delaminated too significantly, you could recore the areas most important for strength and safety (chain plate penetration, load carrying hardware, stantion bases) and with a little planning leave the larger, open deck areas to be recored after the sailing season.

Having said that, the safety of the captain and crew is most important followed by assuring the ship is sound enough to get out and sail. And of course, pictures help.

[ebb]

There have been other thread(s) on this subject in this Forum.

I agree that the holesaw/disk method will preserve the camber and integrity of the deck. But I also agree with bill that if you have extensive rot cutting out panels of deck will prove easier. However that depends on your inner skin of the composite. If it is as thin as is is on LittleGull you may have a problem keeping integrity when you work on it scraping off the rotten balsa.
IE you may have to support the inner skin from the inside if you remove large pieces of foredeck.

HOWEVER, it is evident from the photos that to get good results you will have to remove all fittings from the deck. I agree with numbering and mapping each and every disk removed. While the making of the deck unit by Pearson required some precision in the construct of the composite/sandwich there could be anomolies that would not allow interchanging the disks, even if they are all cut with the same holesaw.
For instance when you drill closer to the toerail or the cabin you will find that the core peters out and becomes solid frp.

The balsa core on LittleGull is 3/8", however I did not have to redo the deck. So my suggestions are practical ones. If you continue with the disk method you might be able to pass a router over the hole to clean out the rot. I would probably screw on a slightly longer plate on the router made out of acrylic (so you can see the work better) and span the holes easier. You can ofcourse scrape them out - but a straight bit will give you an exact cleanout without messing with the inner skin.
Since you will be putting back in the holes a 3/8" disk of divinylcell (med density pvc closed cell foam - my recommendation) have a clean hole makes many clean holes easier to do. This foam is 'structural' foam. Whereas endgrain balsa which is also a good choiuce if you are replacing with lots of well buttered epoxy. Still the pvc foam can be tailored to a hole very easily, the foam will take a feathered edge and will marry just as well if not better than balsa with the hole.
Get plain, not scored, foam. Make your disks from the foam with the same holesaw.
Bosch makes a quick change holesaw system that make it easier to push the disk out from the blade.
But you can make a guide block out of dense ply or board by running the holesaw through it. Then position the block where you want a hole and cut in without the centering drill bit. The foam will take poking better than the endgrain balsa.

I would undercut or clean out a 1/4" or so around the rim of the hole so that the epoxy goop and foam disk will never want to pop out. You will want to dry as much as possible with a heatgun, hair-drier or a heater, etc the core in the areas you are not disking. Pushing the exhaust from a hot vacuum cleaner into the holes would work good too imco.
I think it a better idea to leave tunafish in the hole to soak up epoxy that you will be injecting into these areas thru smaller holes after you have finished the disk repair stage.*
If you have water in the tunafish you might drill some holes up into the core from inside to drain. Of course you can't do this on the side decks of an Ariel. But you should make a valiant attempt to dry the remaining core.
Make sure the returned disk is at the level of the original deck - not above. Orientating marks are made with a pencil before you remove the disk. Three swipes with the pencil across the cut, they'll be different on each disk, and you will have number each disk so that the skin is put back orientated exactly where it came from.

I'm going to assume you've run into Ebb's rant on using epoxy on old polyester to get the best bond.
I won't recommend West System epoxies. You want to use 100% solids, no solvent, laminating epoxy as your base. Use fumed silica as your thickener and milled or cut glass to add strength to your goop where you need it.

You might mark where stanchions are going and instead of putting a wood insert/core just build it up solid with Xmat (epoxy friendly mat) and cloth.
After you have sanded the deck and probably removed most of the original gelcoat and anti-skid you may want to tie together your new plugged deck with a single layer of fiberglass cloth over everything you've done.

OK, No Problem
Good luck
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*Smith's CPES system may have been upgraded for core repair. But I would NOT inject water-thin CPES into the remaining rot areas. The stuff does not set up hard, which is what you want. You want to inject laminating epoxy into the skin. Laminating epoxy is made to wet stuff out. If you have dry/semi dry tunafish the epoxy will soak in and you'll end up with something hard. If you have no tunafish in places, you can inject a loose mix of epoxy and aerocil that will buildup in the hole with a syringe It's not perfect but if you're careful the deck will last another 50 years!

[commanderpete]

The traditional re-core method would be the best way. Otherwise, some alternative method would be common practice.

But, I think you have a workable plan. It looks like you have access to the whole sidedeck from the dics holes you've cut.

You can get a thin wheel attachment for the drill and rout out the old balsa as far in as it will reach between the skins. Something like this (8 inch size)(if it's thin enough):

http://www.jamestowndistributors.com...nd+Strip+Disc#

To get in deeper, you could stick a long drill bit in between the skins using a right angle drill or attachment.

Maybe even make your own wire drill attachment: cut lengths of wire and bundle them together into a brush. Put the bundled end of the wire brush into the drill chuck.

Wrap an acetone soaked rag around the brush to finish preparing the surface.

Squirt thickened epoxy in there. Then soak cloth sheets in thickened epoxy and jam them in as far as they will go.

A few air gaps won't matter. The fiberglass will make a corrugated core between the skins and it will be immensely strong.

For the disc holes you've cut, You might want to use balsa or other core material there.

The scraps from cutting the core material, and other fiberglass mish-mash, can be shoved between the skins.

I would also do one or both of the stantion bases shown in your pics, without core.

[Stephan]

Guys,

thank you all so much for your advice and the time you spent writing your responses. This is the reason why I love this group and want to remain a member, in spite of having a stretch ariel.
I'm going to go over each response a little more tomorrow, but I can clarify a few things now:
1. The wet area is limited to the area where I put those four holes and a few inches further. There's another soft area on the foredeck, but I won't tackle it yet, it's not really that bad. If I had to remove more of the deck I'd indeed use the 'traditional' method of cutting the upper skin off.
2. The area I drilled open is right at the entrance gate in my lifelines. People keep stepping on there, and I had some mold just below there in cracks in the inner liner, clearly fed by this moisture.
3. You can see that the PO had attempted a repair of this area many years ago. The deck under the stanchion bases is filled in with epoxy it seems. The bases are rock solid. However, you can see a rectangular crack where the repair was done. This is in my opinion the place where water seeped in. There is no other source I can think of. I think the repairer did not chamfer this area and so the crack developed.
4. The balsa core is indeed apparently just 3/8 in thick. It appears, from looking at the disks, uniformly thick, so the disks are probably interchangeable if I cannot figure out anymore which is which. I hope.

As promised I will write more tomorrow.
I had ordered MAS epoxy and slow hardener from Defender, but they didn't send me the hardener yet. I was planning to increase the strength of the cut areas by using epoxy instead of balsa, since I didn't expect the discs themselves to be able to add much strength.

Stephan

[ebb]

Tried to scare up the guy who disked his whole deck.
I think it was a Triton or a stretch Ariel.
He is an ER doc and I wondered at the time what techniques he used in his Emergency.
Actually the disk method of access and repair for small areas of rot is perfect. Almost anything is going to work well - including filling the holes with glass.
I will argue that replacing the tunafish with disks of pvc foam is almost as structural and strong as solid glass - and you'll be using less epoxy.
Imco, after you have restored the disk areas you might drill holes into the remaining rot areas and inject straight epoxy. Or drill in slightly larger holes thru the deck to inject in epoxy gel mixture. This will erase the hollow sound when you tap the deck. The syringe is a two ounce model and some frp suppliers now carry them*. It makes it ridiculously easy to get gelled epoxy into tight areas, for instance under the rim of a disk excavation where you have removed sodden balsa. Imco.

The injection technique might also be seen as creating a dam in the core to stop water migration.
It also is a good idea to remove your thru-deck fastenings sometime and give them the epoxy treatment. Because 99.99% of all deckrot comes from unsealed holes in the deck. imco
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*TAP Plastics syringe applicator

[Tony G]

It very well may have been Mark Parker, MD. The hull number evades me at this time but she was a Triton named All Ways. Mark planted the idea of wood toerails in my mind. I think he did teak decks on her with plastic composite faux teak. It was a shame they never posted larger pics of All Ways on any site I've found. He spends some time down in Belize near Punta Gorda and Placencia sailing cats now, if I recall correctly. Sorry for the sidebar-I gotta strike while the iron is hot with this mind.
********************
Yup. It was Mr. Parker. We've discussed him here before regarding those 'trex' decks. Oh yeah, it is Triton 516...

[Stephan]

Jesus, that looks scary. If I had that much deck to recore, I'd really do the 'cut it all off' route.

[Stephan]

Well, one thing I didn't realize when I started this hole digging idea was that the deck has a much stronger outward tilt than I imagined. So today when I mixed the epoxy I added, as you had suggested, the balsa chips I had extracted to try to make the epoxy more viscous. That didn't really have much of an effect, unfortunately.
I had taped off the boundaries, fortunately, so the overspill that resulted was limited, however, I ended up having the inboard (upper) disks not totally immersed in epoxy, while the outward ones were overflowing.
I feared disaster, but after an hour of curing time I could pull off the tape and get most of the overspill off. I added a smaller batch of epoxy later to try to fill the inboard gaps, but I will have to repeat that exercise in a few days because there are still more gaps.
Next I'll have to fair the area and repaint, with a bit of anti skid (sand or something), too.
I didn't take photos of this stage, it's looking a bit embarrassing, actually, but when the next batch is on I will

[ebb]

I'm flaberglassted. Have to reread your post in the morning.

[Stephan]

Ebb, is it so confusingly written? I did choose the route of pouring epoxy only, and not to add new core. I didn't make that explicit indeed.
I think next time (I hope there won't be next time) I'd choose the traditional method. The hole method doesn't allow the introduction of new core, and grinding out the old core is much harder and not as complete when you have to go through the holes. Nevertheless the wirebrush disk did work pretty good and allowed me to get most of the old wood out. The rest was sufficiently dried.