Waterproofing holes in Deck while they Dry

[hriehl1]

I am starting a refit of a Hinterhoeller HR28. I wish to pull all deck hardware for re-bedding, but if I encounter any damp core I'll also want to overdrill the holes, dig out some of the core around the holes, dry it out for a couple months (long enough? too long?) and then epoxy the voids and re-drill the original size holes before rebedding.

The question is how to dry-out open holes on a boat stored outdoors. I'll be covering the entire deck with a (supposedly) waterproof tarp... but is that good enough to keep water off the deck and out of the open holes?

I was thinking about making small plastic or styrene "patches" over each set of holes (cleat, stanchion base, whatever) for additional waterproofing. But those would not allow the holes to breathe and dry-out as well; and how to secures those patches to the deck for a waterproof seal (especially on non-skid). Would one use tape on smooth gelcoat, and maybe some type of putty on nonskid to seal the patches over the holes? If so, what types of tape and/or putty give a good seal and weather OK for a couple months?

Thanks for any thoughts anyone may have on this approach, or any that is better.

[Hirilondë]

The question is how to dry-out open holes on a boat stored outdoors. I'll be covering the entire deck with a (supposedly) waterproof tarp... but is that good enough to keep water off the deck and out of the open holes?

I don't think that is the question at all. I see 2 problems with the idea that you can even do this well enough to call it a proper repair:

1. Unless you do some kind of exploration, you will never know if you have removed all of the wet core. And unless you have removed all of the wet core and replaced it and any other repair work as the situation calls for you haven't fixed anything.

2. I don't think you can dry it out through a hole. And even if you could, the left over previously wet core is no longer doing its job of holding the outer and inner skins together in a structural manner.

First you need to pull the hardware, and then carefully investigate what you have. Until then you don't know what you have to do. It could be almost nothing. It could be a major recore project.

[Rachel]

As I was reading your post, I was thinking along the same lines as Hirilonde.

If a simple overdrilling around any particular fastener hole gets all of your wet core out, great, you're ready to re-fill with thickened epoxy.

If there is more wet core, I would not try to dry it out. I would cut it out. If it's a larger area, well, then I would re-core that area.

I don't think the "drying out" approach is worth the trouble, but that's me. If I'm going to bother doing the job at all, I want to know I've got all the bad stuff out and gone. On the other hand, I know that other people are okay with wet or damp core if it has not turned mushy or debonded.

But... sometimes working "around" a problem ends up being as hard or harder than just getting the proper fix over with, and yet you still don't have that good feeling that "Ahhh, that's done."

So, I would start by overdrilling and then see what you find, with the idea that you are probably going to cut out anything "bad," and put in new, good stuff.

Depending on how textured your deck is, you might try using 3M's Scotch Weather Resistant Masking Tape #225. This stuff looks a bit like duct tape, but is a whole 'nother animal. Think of it like blue tape you can leave on an outdoor surface for (literally.... ask me how I know) months and months without it turning to concrete like other tapes do. I have used it to cover holes until I could get back to them and do a proper job, although I have not used it on rough-textured areas.

Rachel

[Drew]

I have found the aluminum tape that is used on HVAC ducts works great for temporary hole sealing. i do NOT mean duct tape but the stuff that is like aluminum foil with sticky stuff on it and a paper peel away backing. It leaves a residue on removal but it does not break down in the sun and the residue is easily removed with the solvent du jour.

drew

[Ceasar Choppy]

I would agree that trying to dry out areas of wet balsa core will be difficult at best if done just through the holes. Even trying to dry out the balsa by removing a layer of skin is problematic and its just easier to replace. The only exception to this is if you find any wet areas of plywood core in reasonably good shape. The plywood is strong enough where you could just dry it out and replace the skin. But just trying to dry anything out by overdrilling the holes won't do it.

That said, you are only *anticipating* the worst. You haven't found any problems yet have you?

I did what you are planing several years ago to my Pearson 39, although I kept it localized so I didn't take everything off all at once. I used duct tape and even a generous dollop of silicone over the holes to keep the water out. I was surprised at how localized the water damage was. There were a few areas where the deck was wet in larger areas, and those areas I left for later. But the vast majority of wet spots were very localized and easy to repair by scraping out the wet core through the holes. I oversized the holes about 5/8" so that the hardware, once replaced, would cover the holes.

Later I had the boat shrink wrapped which allowed me to do more work without worrying about it.

Good Luck!

[hriehl1]

In short, no I do not even know if I have any (seriously) wet core... tap-soundings are consistent and sharp and there is just the very slightest flex in the area of the foredeck furthest from internal bulkheads and hull (under my 230 pounds). Less flex that my non-cored O'Day Daysailer. Sidedecks are stiff.

But, in the cabin on the headliner under a few fasteners are small (dime-sized) dark brown spots (easily wiped away with a damp cloth) which I take to be residual from at least a little seepage (from before it being stored under a tarp the past 3 years). So I am hoping any dampness is modest and localized.

As to fixing it "right", I understand the purists' view, but this is a $1200 boat I just want to get on the water. Sailing, not boat repair is my desire. So my goal is to overdrill-and-epoxy so it gets no worse, dry out the drilled holes for a few months if that might help, but I'm OK with a less than perfect end-result next spring.

[Hirilondë]

So my goal is to overdrill-and-epoxy so it gets no worse, dry out the drilled holes for a few months if that might help, but I'm OK with a less than perfect end-result next spring.

Have you ever used epoxy in a damp location? It has an interesting effect on the cure.

[Tim]

Maybe it'd be best to remove some of the hardware and get a sense of what you actually have going on with the core (if anything) before drawing any conclusions one way or another as to what repair approach you need to take.

That said, you can forget about effectively drying out wet core through small holes. It won't work to any significant effect, and then you're probably even worse off since you might have a false sense of having actually done something to help, when you really haven't.

Determine if, or to what extent, your core is damaged first; then figure out how (or if) to repair it based on those findings and your own needs. Overboring for epoxy-isolated fastener holes is a good technique for hardware installation in a sound deck, but is only an ineffective patchwork if the damage has already been done from the past installation.

[hriehl1]

Just to close this thread, my Hinterhoeller HR28 does not have a cored deck... solid glass all around.

Thanks all.

[Rachel]

Okay, but, before you close it (if you don't mind): I'm curious how the deck is supported, since it is core-less. Are there deck beams? Or? (Or is it possible that it is cored but that the core closes out around the perimeter, such as where stanchion bases are?)

Thanks for indulging me :)

Rachel

[hriehl1]

Actually, I may have spoken too soon. The foredeck (my primary concern) is definately not cored, and is supported by 2 full-width cross-beams on the underside between the V-berth bulkhead and anchor locker bulkhead. The afterdeck, entire cockpit, cabin walls & portlights and the bulkhead separating the cockpit and cabin are also definately not cored.

The roof of the main cabin (from the mast step leading aft) I am still not sure but I suspect it may be cored. There are no cross-members in the main cabin (from companionway forward 6 or 7 feet to the first bulkhead). It was dark when I removed the hardware so it will be a few days before I get back to it to verify.

I am worried it may be cored due to some seepage through the headliner in the main cabin only. I've gotten a few brown gooey droplets through the headliner, almost the color and consistency of teak oil. The headliner paint layer has some blisters or pimples that when punctured emit a drop or two of this ooze. It is either stain from plywood or balsa core... or it is teak oil (prior owner bragged how for 35+ years they oiled and oiled the exterior handrails and hatchboard tracks, and they were not very well bedded).

I've found precious little info on the Hinterhoeller HR28 on the www, but a couple references I did find indicated the decks were not cored (which surprises me somewhat since Hinterhoeller went on to found C&C, who were early pioneers not just coring decks, but hulls too).

Oh well, a guy can hope... I'm REALLY not keen on a re-core job.

[Hirilondë]

It is either stain from plywood or balsa core... or it is teak oil (prior owner bragged how for 35+ years they oiled and oiled the exterior handrails and hatchboard tracks, and they were not very well bedded).

Maybe, maybe not. Inspection and investigation are important in planning work for old boats, but do not read into things that which you have not proven. If you can not find believable documentation on the construction of the boat you can only assume or prove it yourself.

[hriehl1]

Agreed... what I do know is it is definately not cored anywhere except the main cabin roof. That I'll confirm when I next get to it in daylight. I do fear the worst though. Yet soundings topside are all solid and sharp... no dull thuds anywhere.

[Sailmachine]

I just thought I would chime in with my 2 cents. Just keep in mind that's all its worth. I am in the same situation of trying to repair a boat outdoors. Here is what I have done to prevent further core damage as a result of exposed core material from removed hardware. I removed all hardware noting which were into cored areas and which were into solid glass. I then counter sunk all holes to better accept filler and filled with resin. The holes that were through solid laminate I did not worry to much about, but those into cored areas were completely sealed off. With all holes sealed it can rain all it wants which it did last week with 23" of rain. My tarps did a lousy job of keeping the boat dry, but still no damage done. Now I can do the work on the deck as needed. This will include core replacement is several areas which I can tackle on sunny days.

I did dry out an old rudder one time by drilling 100's (maybe 1000's) of 1/4" holes into the teak core. I set the rudder under lots of halogen lights and left it for 6 months while I did other work on the boat. it did dry out and was lighter. But I don't think it would work with boat outside.

Pete