Ideas Needed for Re-sealing Pulpit and Fore Deck

[GOLE IV]

I had a different aproach, I worked form above, gravity helps.
After supporting the deck from below, identified the damage area, looking for weak or soft spots.
Then cut the top deck layer, clean up the roten balsa, put a layer of mat ,replaced the balsa and glassed back the cut area of the top deck.


The black square in the photo is 3/4 steel plate

 

[bobk]

The pulpit came up cleanly. See pictures. The specks are splinters from the block of plywood in the center. This appears to be a Hatteras installation. The screws in the plywood are all bronze Robertsons. Core damage is quite limited.

The reason for these issues is the original design. 1, there is no effective way to seal the bolts at the deck level. 2, The winch bolts through the pulpit platform to the deck. Four of the bolts did not go cleanly through the stack of plywood (sorry, the holes are covered with the grey duct tape), and two did. But even if they did, the stresses on the core with the undersized backing blocks would allow the core to compress and caulk around the bolts to fail and leak.



Bobk

 

[Genesis]

Cool - be glad you caught it and fix it correctly.....

 

[Walter P]

It seems to me that the reason we have these issues is water intrusion and the existing design doesn't lend itself to preventing a recurrance in a few years. What does everyone think about if I remove the top skin under the pulpit again and just remove the new balsa and build up the whole section with mulitple layers of fiberglas. The plywood under the pulpit could also be replaced with solid glass. Obviously it would add a few lbs and a little cost but I can't see it ever failing again.

Walt

 

[TopHattandTails]

What about removing pulpit or good? That would solve the problem too. Just refinish, and add a light weight aluminum fortress anchor with rope. No more dock banger either...

 

[GJH]

Brian, that's not a bad idea if you don't anchor out very much. You seldom see sport fishing "battlewagons" such as the new Hatts illustrated above with pulpits, which are considered a point of failure when you stick the nose into a lot of water as those guys are prone to do. A few may still have a windlass. They do still anchor, sometimes in very deep water, but just temporarily. If no windlass, they can use the old anchor ball trick to bring the anchor up.

 

[SKYCHENEY]

Getting rid of the pulpit also means reconfiguring the railings, etc. Plus, these old classics just look right with the pulpit on there. Fix it right and you won't have any more issues. Most of these with poor installation lasted for 20-30 years. I doubt many of us will still have the same boat in another 20.

 

[bobk]

I anchor a lot in the ICW muck and having the anchor dangling over the bow makes washing it off convenient, so it is going back on.

Walt, I see no issue with all glass, but you do not need to be so thick. My issue is localized enough that the mech will clean out the old balsa core and replace with thickened epoxy. He will add an extra layer of glass to the underside of the deck inside the anchor locker for good measure. Your plan to over drill the mounting holes and back fill with epoxy ought to last the rest of your ownership and beyond.

But the original Hatteras design still bugs me. Engineers ought to know better. Were bean counters involved thirty years ago?

One other thing. That plywood block shown in the above photo was probably intended to help support the winch. As best as I can tell, it touched the under side of the pulpit in only one corner. We are replacing this with a mahogony block that will be fitted a little better. And I'm considering putting a bead of caulk around the edge to contact the underside of the pulpit. That bead can then be used to contain some thickened epoxy to fill in the remaining space. I'll use some release paper just in case it needs to come up again. But at least there will be solid support for the compressive load of the bolts.

The other 'innovation' (over kill) will be to fit flanged SS pipes into the chain fall and rope fall. That way any future leak should drip into the locker without getting to the core (which will be epoxy coated anyway.

Bobk

 

[Genesis]

My solution was to do this:

1. Remove the entire core in the area around the pulpit. This in my case wasn't optional as it was trashed.

2. Replace with marine ply soaked in thinned epoxy and laid up into the space with thickened epoxy. Replace lower skin with heavy fiberglass cloth. Since this was all in the locker I didn't care if it looked good -- only that it was strong as hell. We now have an intact (but much stronger than the original, as the core is epoxy-soaked plywood) laminate and the lower laminate is heavy cloth.

3. Drill new oversized penetrations where the old ones were. Remove (new) core in the drilled holes.

4. Fill those core areas with thickened epoxy, then re-drill through the epoxy. It is now impossible for water that gets into the fastener area to get into the core.

5. Re-fasten and put it back together using UV-resistant 4200.

IMHO that's what should have been done in the first place -- the laminate in that area should have been done with epoxy-soaked marine ply instead of balsa as it has massively-superior compressive strength. Then the penetrations should have been drilled oversize, filled, and re-drilled through the epoxy, denying any possibility of water intrusion into the core.

Oh yeah, and no bare plywood under the pulpit either. I built up the underside of the pulpit with resin and cloth and took my time to avoid the exothermic problems that would definitely occur if you tried to do it "all at once". The goal there was to provide a solid foundation for the windlass -- if there wasn't one I wouldn't have bothered, but I wanted a solid connection between the Windlass and the deck so the blocking had to (IMHO) be replaced -- with something that can't rot.

If that had been done the first time it wouldn't have gone bad.

 

[34Hatt]

Or just use Coosa

 

[Boatsb]

Or just use Coosa

No way is coosa the best way to go.

Its a closed cell foam core that can be ordered in different densities depending on your needs. It's coated with a bonding agent for the polyester resin and is lighter than plywood and easier to work. Where would the challenge be?

 

[bobk]

Agree, as a foam, Coosa will be more compressable than mahogony or a laminate. That is part of the leak issues we all have.... the cores are under compression and eventually allow the sealant to start to leak as the wood cores compress.

Bobk

 

[34Hatt]

Coosa is a direct replacement to plywood

 

[Boatsb]

No it's not. It's lighter and better for use as a core. However as a structural component it differs from plywood and different densities of the coosa are better suited for different applications

 

[bobk]

Here are pictures of the underside of the pulpit area. The damage is quite localized and seems largely due to the compression of the core by the winch bolts.

The underside area will be covered with a 1/8" fiberglass panel, filled with thickened epoxy, re-drilled etc. There will be no compressible core remaining where there are bolts. Heavy backing plates for bolts etc. And I'm having flanged SS pipes made up for the chain and rope falls so any potential leaks will be directed into the locker without touching wood.

Is there supposed to be a seal to keep water from running down the Galley Maid windlass shaft?

Bobk

 

[Boatsb]

Here are pictures of the underside of the pulpit area. The damage is quite localized and seems largely due to the compression of the core by the winch bolts.

The underside area will be covered with a 1/8" fiberglass panel, filled with thickened epoxy, re-drilled etc. There will be no compressible core remaining where there are bolts. Heavy backing plates for bolts etc. And I'm having flanged SS pipes made up for the chain and rope falls so any potential leaks will be directed into the locker without touching wood.

Is there supposed to be a seal to keep water from running down the Galley Maid windlass shaft?

Bobk

That looks like the backing was inadequate when it was installed. Was it a factory install? I see people doing things like that thinking a fender washer is enough backing for a windless when they really need a 1/4" plate ( alum or stainless ) to spread the stress over a much larger area.

My fighting chair mount has more backing than that and had much less stress on it.

 

[bobk]

That looks like the backing was inadequate when it was installed. Was it a factory install? I see people doing things like that thinking a fender washer is enough backing for a windless when they really need a 1/4" plate ( alum or stainless ) to spread the stress over a much larger area.

My fighting chair mount has more backing than that and had much less stress on it.

This was indeed a factory install. The backing, which I didn't post a picture of, was a two inch thick mahogony disc. But no matter the backing, there is too much compressive stress on the balsa core.

Note also the darkened fiberglass in the damaged areas. The resin seems to have dissolved. Looks like an ortho resin with no hydrolysis resistance. And it is very thin!

Bobk

 

[spindrift]

Gents:I had a similar coring failure problem on a 40 foot sailboat I use to own and race. A good solution that the project manager at the yard came up with was to replace the coring with high-density PVC. The boat had an aluminum toe rail so we actually removed all of the through bolts securing the toe rail to the deck, dry fit a piece of masonite to bridge the entire triangle on the forward underside of the deck. Then we used the template to cut the HD PVC, dry fit it, then bonded with West System and mechanically secured with through bolts. The key is to use one of the excellent 3M sealers to bed the through bolts (rail to deck) through.

While the configuration of most Hatts is a bit different up forward, you do have the pulpit, winch bolts etc. that could add a mechanical fastening to the HD PVC which is on the underside of the deck.

Like others have stated earlier in this thread, there are two key factors that created the leaks in the first place. The first, is core compression (substitution with HD PVC) will address that issue. The second is leaks that appear through all through deck penetrations over time (windlass bolts, pulpit bolts etc.). What we have seen up in the northeast is that many of the older boats (pre 1990s used a dolphinite type of bedding compound that dries out over time. The new flexible sealers (notably good 3 M products) have much better longevity.

The reality is, that on a periodic basis deck hardware has to be pulled, cleaned, re-sealed. However, while a pain the tushy this is far less costly and a less messy job than getting into core-replacement.

Spin

 

[Triskele]

BobK,
I did th same thing on Little Skooch. I removed with a trim router 2 foot squares from the underside in the Vee and locker area. Cleaned out the bad core and dried it out. Then with straight unthickened West System I made 2 foot sandwitch 3/4 inch thick of glass and balsa. Then I pushed it up with a tall scissors jack and plywood covered with a plastic trash bag. Let it cure over night. Then removed the jack and bag moved on to the next 2 foot patch. Anything bigger was too hard to handle by myself. I think if you had two people you could get much bigger patches which would help a great deal.

Very strong, very messy, did not cost much but terrible job over all. And guess what? I get to do it again with Big Skooch. I can't wait.

Skooch
New Bern NC

How did you make the 3/4" glass and balsa "sandwich"? Did you glass over the balsa to create a core that would then be layed between the deck skins?