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Foredeck:  Recore After the Fact
This page was last updated on 26 November 2003.

To my disappointment, I discovered a section of the foredeck--nearly all the way forward on the starboard side--contained substantial core rot and lack of structure.  Dumbly, this was an area that I had not recored during the initial restoration of the boat, thinking that it was OK.  Whatever the reasons, I knew that I had to take care of the problem.

Tim's New Recore Mantra:  When recoring the deck of a boat, do the whole thing no matter what, you dope!

IM009351.JPG (173649 bytes)The first step to repairing this problem was to remove the bow pulpit.  An ongoing toerail repair required its removal for convenience's sake anyway.  Removing the pulpit was relatively straightforward.  First, I loosened the setscrews holding the pulpit to its bases, and removed the rail.  (Note:  I hate setscrews.  When reinstalling the pulpit and stanchions later, I plan to through bolt each connection in place of the setscrews.)  To remove the bases, from beneath I loosened the nuts and removed them, which was easy to do alone since the bolts are threaded through tapped holes in the deck.  Then, I removed the bolts from above and pulled off the bases.  The deck surface was compressed around the starboard aft base, which is central to the worst section of the rotted core.


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A few days later, I began some exploratory surgery to determine what my course of repair had to be.  With a hole saw chucked into my drill, I cut a few holes through the top skin in strategic locations to expose the core.  What I found was hardly unexpected:  saturated and dry-rotted core, throughout the general area from the starboard stem aft to just behind the pulpit base.

The inspection holes, along with careful sounding of the area, indicated that I needed to remove the anchor platform so as to access the entire area.  Sigh.  Fortunately, the platform came off quite easily, although the six bolts were so thoroughly bedded in polysulfide that it was a bit of a chore to get them to pull through the top.  Given the lack of good access beneath, I couldn't even bang the bolts up with a hammer, so I used vice grips from above to pull them out once I had removed the nuts beneath.


bowplatremoved.JPG (171454 bytes)The platform was installed in a heavy bed of polysulfide, so once I began the release process with a thin putty knife, the remainder broke free fairly easily with a medium-sized crowbar.  I carefully removed the heavy (!) platform and placed it on my bench for further dismantling and eventual refinishing before it was to be replaced later.


IM009420.JPG (144646 bytes)With the platform out of the way, I marked out an area to cut and then plunged in with my saw, cutting out a conservative area that I hoped would be sufficient.  I had to cut around the raised hole for the bronze cowl vent, as the hole was molded during original construction, and the core tapers off all around it so that bottom skin becomes one with the top skin.    Not really wanting to recreate the opening if I could help it, I cut around it, leaving it in place.

coreremovedforedeck.JPG (175213 bytes)The core was a mess--heavily saturated and in bad condition.  However, I was happy to see clean, dry core at the edges of my cut, except for at the aftermost end, where an additional cut would  be necessary to expose the remaining wet core.  I removed the broken and ruined core with a chisel and prepared for the replacement work ahead.  I elected to not reuse the top skin in this instance, since its thickness was inconsistent and the area was small enough that it would be just as easy to laminate new material.


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With the old core removed, I found that the wetness extended a bit farther aft than I had hoped, so I extended the opening along the starboard side, just past the hole where the water tank fill had been.  Careful sounding had indicated the edge of the wetness, and I cut just beyond.  I was pleased to find good core at the edges when I opened up this last section.

foredeckholes.JPG (190224 bytes)Now that the entire area was open, I spent some time reaming the core out from beneath the edges of the opening, and carefully checking the remainder of the foredeck for other issues before continuing.  There were three instances of top-skin delamination, which I marked with a pencil.  Minor exploratory surgery confirmed that the core was basically sound, so I planned for some epoxy injection in these areas to rebond the skin to the core.  I removed the large mooring bit, since it was located on the edge of one of the areas of debonding.  Then, I drilled a series of small holes (about 7/32") in the three areas, just through the topskin.  More on this later.


foredeckedgefilled.JPG (166706 bytes)Next, I ground the inner skin to remove resin and old core, and then installed tape from the inside to cover several screwholes and the like (to prevent resin from dripping into the boat).  Then, I filled the edges of the open area with thickened epoxy, pushing it deeply into the voids beneath the deck edges.   I used some extra to skim coat the entire inner skin for good measure.  When the epoxy cured, I washed off the blush and declared the area ready for new core.  However, since I was awaiting a delivery of the core material, I moved on to other projects that I could complete, leaving the foredeck core for later.


I decided to take care of the other jobs I wanted to complete on the foredeck:  injecting the debonded areas with epoxy resin to resecure the skin to the core.  I also took advantage of the situation to ream out the boltholes for the mooring bit and anchor platform with a 1" holesaw, passing just through the topskin and core, so that I could overfill the holes with epoxy to ensure that no water could ever enter the core through those openings.  (This had not been done originally, for whatever reason.) 

IM009435.JPG (158489 bytes)To inject the deck, I used unthickened epoxy resin and some small plastic syringes with the tip cut to fit inside the holed I had drilled.  The general idea is to inject resin into the holes until it wells up from neighboring holes, and so on.  It took a surprising amount of epoxy to complete the jobs--more than I had expected, though the amount was still relatively small (the syringe doesn't hold much).  I cleaned up the overspill, and then filled the reamed-out boltholes with thickened epoxy, tamping it down to ensure that there were no air voids.


After awaiting delivery of wood and core material for nearly a week, I set to work installing the core as soon as the material arrived.  Since the rest of the deck (at least those areas that have been addressed) is cored with marine plywood, I saw no reason to not use more plywood in this application.    While I waited, I created a template of the uncored area with which to pattern the new core and fiberglass overlay.

As a further caveat, I will repeat once again that the only reason I ever used plywood for a core material was that a free supply came with the boat.  Yes, I'm pleased with the results of my recore with the plywood, but would not willing choose plywood over balsa or Nida core were I starting fresh.

bs1088.JPG (157125 bytes)Anyway, I chose high quality 9mm Meranti plywood (to BS 1088 standards) to fill the void in the foredeck, as I have been pleased with this material for a multitude of uses in the past.  Using my template, I cut out a piece of the plywood to match, and made a few minor modifications after a test fit showed that the plywood was a bit oversized in a couple areas.  Thinking ahead, I removed sections of the core in way of the bolt locations for the anchor platform, around the pulpit base locations, and around the water tank fill at the after end.  These areas were to be filled with solid glass and epoxy.


4deckcore.JPG (172885 bytes)With the core cut to size, and the void fully prepared, I installed the core in place.  First, I wet out the core and the inner deck skin with unthickened epoxy, then I mixed up a fairly loose batch of epoxy thickened with silica, and toweled it thickly on to the inner deck skin.  I pressed the core into the bed of adhesive, and, as I did before during the main deck recore, secured it with several temporary screws.

More caveats:  this method worked for me, but will work only with a dense material like plywood.  Were I using balsa or Nida-core, I would support the deck from beneath and use weights or other means to prevent press the core into the epoxy, being careful not to weight it so much that all the epoxy was squeezed out of the joint.  Also, the screw method would not be effective if installing core into a finished area of the boat, since the screws penetrate the inner skin.  When I did the main recore, the interior was unfinished--hence, no harm.  And in this instance, the area being recored is entirely located above the unfinished chain locker forward.  All this being said, there is no harm from using the screws.


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Once the core was secured in place, I spent some time removing the epoxy that oozed out all around, and filling the gaps around the edges full of the thickened epoxy.  I also removed most of the spillout from the larger core cutouts around the stanchion bases and water tank fill, since I planned to install fiberglass in these areas.  I left the solid, thickened epoxy in place in the three openings around the anchor platform boltholes.  With this done, I left the core to cure, and worked on other projects.  Later, I cut some 17 oz. biaxial cloth to size and installed 4 layers in each of the larger openings, filling them a bit more than halfway.  I didn't dare add any more glass at the time, to prevent overheating as it cured.  Later, I filled the voids the rest of the way with material, finishing up with some thickened epoxy to bring the voids flush with the surrounding plywood..


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IM009464.JPG (184841 bytes)To prepare for final fiberglassing (the top skin was not in good enough shape to reuse, given the myriad holes in it), I installed some more of the thickened epoxy filler around the edges, creating fillets to make up the slight difference in height where needed.  This will allow the fiberglass layers to overlap onto the surrounding deck as needed, tying in the repair with the rest of the structure.  I left the fairing to cure overnight.


The next morning, the fairing was cured enough to fiberglass over--though it seemed to be curing very slowly, leading me to believe that I had mixed the material at slightly the incorrect ratio.  However, it was curing, and all indications were that it would cure fully given enough time.  I decided to go ahead with glassing over.

IM009473.JPG (162983 bytes)I cut enough material for two layers to cover the patch (17 oz. biaxial cloth) and overlap as needed onto the surrounding deck, and then mixed up enough epoxy for the job.  Laminating was straightforward, and I was pleased with the end result.

Late in the day, the fiberglass had kicked sufficiently for me to mix and trowel on a coat of fairing putty, the first of several required.  I left the putty--and the glass beneath--to cure overnight.


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fair4deck1.JPG (160376 bytes)The next day, after a thorough rough sanding, the foredeck section was ready for the first of several (2 or 3) applications of a smoother fairing putty--System Three Quik-Fair.  I mixed up a batch and troweled it on, covering the whole area.  The Quik-Fair is supposed to set within 3-4 hours to sandable state, but it was still too gummy to sand at the end of the day, so I left it overnight.  (Must be just that much too cool in the shop...)

The next day, I sanded the compound and applied a second coat as necessary.  Again, after allowing the material to fully cure, I sanded it, only to find that it required another spot application of filler here and there to take care of some minor unevenness.  Perhaps the longest part of any recore job is the final fairing, as it seems to require inordinate amounts of waiting time, if not actual application time (5 minutes of application and up to 24 hours to wait till the patch can be sanded...)


finalfairforedeck.jpg (37296 bytes)


4deckpainted.jpg (28489 bytes)With the fairing finally complete, I coated the patched areas with unthickened resin to seal, and, after waiting a day for the resin to cure, I sanded it smooth and applied a coat of Interlux Brightside white primer in preparation for the eventual nonskid application.  I left a strip unprimed along the toerail, since that area will receive Awlgrip primer and Awlgrip, and the Brightside primer is incompatible with those strong solvents.

 


Since the entire nonskid surface of the deck and coachroof was slated for refinishing, I left the primed areas on the foredeck (and the mast step) in their primed state, awaiting eventual final sanding and refinishing.  Before the nonskid was to be painted, I wanted to prime and paint the white deck edge with Awlgrip, so I proceeded with that step.  The area requiring paint was only about 10 feet or less in length, and just along the outer deck edge outboard of the nonskid area.

deckedgetape2.jpg (31024 bytes)When completing this deck repair, I originally gave thought as to where to create the "seam" in the Awlgrip paint that would be needed to patch the deck edge.  Awlgrip is next to impossible to blend, so I decided to remove the forwardmost stanchion base on the starboard side, which would give me an invisible place to create the transition between existing paint and the new.  The centerline seam, located at the stem, would be invisible beneath the anchor platform when it was reinstalled, so there was no trouble with that end.


deckedgetape.jpg (23762 bytes)Using a scribe, much as I did when I originally painted the decks three years ago, I marked a new line about 2" from the toerail, holding the scribe along the inside of the rail and drawing the corresponding line on the deck.  I simply set the scribe to the same width as the existing paint, and when the line was marked I applied some of my favorite silver masking tape along the line, being careful to keep a smooth and fair line that blended in well with the existing portion just aft of the repair.  I taped all the way back to the first stanchion base location, and taped across the stem as well.  Where the two sections of tape overlapped, I used a quarter to create a pleasing curve to the paint line, for a nice rounded corner (just as I did during the original painting project).  To complete the taping, I taped the inside of the toerail to protect it.


deckedgepaint2.jpg (28825 bytes)With the taping done, I sanded the 2" wide area with 220 grit sandpaper, which removed the small amount of Brightside primer that was inside the tape line, and also roughed up the surface of the already-painted area aft of the repair, onto which I would apply the new coats of paint.  After cleaning the area to remove dust, I solvent washed it with the appropriate US Paint product (Awl-Prep), and applied a coat of one of my least-favorite products:  Awl-Quik primer.  I used it because I had it on hand (and didn't have any of the preferred 545 primer), and the area was so small as to not particularly matter.  


foredeckedgeprime.jpg (29990 bytes)Over the course of two days, I applied three coats of Awl-Quik primer.  I mixed one small batch (1 Tbs each of base and converter, plus appropriate reducer) and applied two coats over a period of a few hours one afternoon; I stored it in the fridge overnight, which allowed me to reuse it the next day for the third and final coat.


After the third coat dried overnight, I sanded the primed area with 320 grit paper to smooth it.  The primer had laid down fairly well, so it was easy to sand the area smooth.  After cleaning away the dust and solvent washing, I prepared a small batch of Snow White Awlgrip to paint the deck edge.  I mixed the product as required and brushed it on the thin strip around the deck, using a foam brush.  The foam brushes work OK for small areas, but they don't lay the material down the way those expensive badger brushes do.  Because it's impossible to mix a tiny batch of Awlgrip (at least with the measuring cups I had around), I had plenty left over, so I stored it in the fridge in the hopes that I could use it the next day to apply one final coat, which would then complete the Awlgrip portion of the painting.

foredeckawlgrip.jpg (17558 bytes)The next day, I sanded the first coat lightly with 320 grit, and applied a second--and, as it turned out--final coat of Awlgrip, using the product I saved overnight in the fridge.  I only added a bit of reducer to decrease the viscosity.  Remember:  only the thin strip at the deck edge is Awlgrip.  The inner portion, which still looks terrible in this photo, is coated with Brightside primer.

To complete the foredeck work, all that remained was to repaint all the nonskid on the entire deck.   Please click here to read about that project.

 

 


Glissando, Pearson  Triton #381
www.triton381.com 

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