Realistic expectations when re-coring deck?

[Project_Mayhem]

I found that my foredeck was waterlogged and rotting when I resealed some hardware last season. I have a few questions regarding the process:

• How many hours does a job like this typically take? I only have access to the yard on the weekends
• Would you cut at the edge or outside of the tread/textured area of the fiberglass?
• Would you approach this job from above or below? I know a few people have mentioned they preferred to do it from below

 

[rgranger]

I did something similar on a Rhodes 22 and chose to come from under. My reasoning was that I could cover the damage with carpet tile and no one would be the wiser. On my H26, the PO cut into the core around the solar vent. I'm guessing they were inspecting it for dammage... You could always see the faint outline of the cut. I even painted over it with some rubberized paint and textured it to look similar and after a few seasons of flexing, you could see the faint line of the cut again. If you can get at it from underneath, then I would do that and then stick carpet tiles over the ceiling to hide your work.

My father is an accomplished amature woodworker and one of his favorite sayings is...

"The difference between a good carpenter and a great carpenter is that a great carpenter knows how to hide his mistakes".

If you go at it from the top you will always be able to see it unless you plan to do an entire antiskid resurfacing.

https://www.lowes.com/pl/Outdoor--Carpet-carpet-tile-Flooring/4294934338?refinement=4294546694

 

[jssailem]

One of my goto resources.. BoatworksToday if you want to find discussions about fiberglass repair ideas.

Here is his idea on "Soft Core" repairs.

 

[rgranger]

One of my goto resources.. BoatworksToday if you want to find discussions about fiberglass repair ideas.

I love this guy...

 

[dlochner]

Would you approach this job from above or below? I know a few people have mentioned they preferred to do it from below

If the boat has a fiberglass headliner, then approaching it from below will mean more work and frustration. If the underside of the deck is covered in vinyl or carpet, then, it will be possible. Although you will be working against gravity.

 

[jssailem]

you will be working against gravity.

Dave identifies a very good point here. The fiberglass resin process is exothermic. This makes the resin runny as it heats up. It will drop on your nose as you put the core up into the space.

 

[garymalmgren]

These are only my opinions and not rock solid truths but:
How many hours does a job like this typically take? I only have access to the yard on the weekends

If your boat is out in the open weather will be a big factor.
If you have family or business commitments time will be anther factor.
The size of the area that you will need to replace will also need to be factored in.
To answer you question, You are looking at months, not hours.

Would you cut at the edge or outside of the tread/textured area of the fiberglass?

Ideally I would remove the toerail and cut as close to the edge as possible to hide any joints going longitudinal.
However you will have to cut across the deck at some point and the will be seen.


Would you approach this job from above or below? I know a few people have mentioned they preferred to do it from below

This would depend on the current condition of your boat.
If it looks near new (or pristine as the ads say) working from below will keep it looking that way.
If it showing some wear and tear, removing the foredeck in two or three sections is an option.
The space constraints (lockers. chain lockers, bulkheads ) will really come into play if you are working from below.
Neither way (above or below) will be fast, but working from below would probably take more time.
Also, working from below allows you to avoid the problem of rain and inclement (high winds) weather.

Lastly, how large is the soft area?

gay

 

[PaulK]

We had rot/delam problems in the cabin top of our J/36. We attacked from below because we didn't want to turn the cabin top into a mess of screwy-looking nonskid and have to rebuild everything. Our overhead had no lining- simply an inner layer of fiberglass & gelcoat. We cut open the inside for as far as it was wet/rotted and removed the balsa. The sections were about a foot across and six to eight feet long -- all along the handrails and under the winches & cleats, where water had gotten in. We let it dry for a bit, and replaced the core, then covered it with 'glass. After that we had a pro shoot new gelcoat over it, to match the rest of the cabin overhead. Sticking stuff up against gravity is not fun. It helps to thicken the epoxy mix a bit so it doesn't drip so much. More recently we found that the core under our main foredeck cleat had rotted out. For that we removed the cleat and opened up a hole in the top where the cleat had been. That allowed us to clear out the damaged/wet core, which was not extensive. Then we used epoxygoop to fill the space, relaid fiberglass over that and sanded it all smooth before remounting the cleat. After that we had to repaint the deck - though we had planned to do that anyway.
In your situation, working from inside may make work conditions nicer temperature and precipitation-wise. It would also avoid having to paint the deck. If you can remove any inner overhead lining without too much trouble, opening it up from the inside might be the way to go.

 

[thinwater]

From below if possible. And I have done it both ways. Article in PS soon.

No, it does not drip on you if you know the tricks. Not at all.

• Thicken the epoxy for placing core. No drips. You would do this working from the top too. Just how much takes practice, since you want it thin enough to push up into the kerfs.
• Put the epoxy on the core before placing, not on the overhead. Obviously. Flex it to push the epoxy into the kerfs.
• The core must be slit deeply enough to be floppy. This helps it conform, but also helps it cling.
• Pre-wet all of the glass on a work surface. There should be VERY little application of epoxy overhead. Just a few touch ups.
• Roll every layer into place. This is how you get good contact and strength.
• Work in small areas, no larger than you can easily press in place (core and glass). Fill gaps with putty and overlap glass as needed. Do NOT try to put up big sections.
• Not too many layers at once; avoid the exotherm. First the core, then wait an hour or two. Then 2 layers of glass, then wait untill it kicks a little. Then finish glass and smoothing.

Yes, it takes some practice and some skills, but it's easy once you get it down. Much easier than perfectly finishing the non-skid.

Maybe 3-4 days, some of them quite short, some just an hour or two in the evening. (This obviously depends on the area and how efficient you are with fiberglass work. I am speaking of 2-15 square feet. The OP has a small boat. Might be 5-7 days if complex. Days with no work don' count.)

Do NOT try to work below recommended temperatures. Ventilate the boat with a box fan in the bow hatch.

 

[rgranger]

I'm with @thinwater with respect to working in small segments at a time. He mentioned pre-wetting the glass. A trick I learned from a friend who builds airplanes is to get a piece of visqueen (or any polyethlyene sheeting) and place your fiberglass on the sheet and wet it there on the sheet with the comfort of a nice flat surface to work on. Then add the second piece of glass and wet that (and third if you are going thicker) and squeegee out the excess resin on the sheet (but don't get too agresive with the squeegee). Then pick up the visqueen and take it into the boat and tape it into place with some masking tape and let the resin kick. Once it has kicked, you can peel off the visqueen and you will have a nice smooth finish and you didn't drip any resin throughout your boat in transit.

If you are going to do multiple layers of fiberglass cloth, you want the edges to overlap. And since you are basically setting it up in reveres on the visqueen you need the largest piece to go on the plastic first and the subsequent layers are each a little smaller. I've repaird a hole in a hull in this manner and did as many as six layers at a time.

The visqueen trick is something you can practice at home before you try it on your boat. Cut a hole in a pice of plywood, bevel the edges, put on a backing plate (cover the plate with visqueen first to it won't stick to the final patch) and then try patching the hole with several layers of glass using the the meathod described above. You will quickly get the feel for how much resin to use and how many layers to use for the desired thickness and final look.

You can get visqueen in the paint section at Lowes (plastic drop cloth) just make sure you get the thicker stuff. If you have an odd shaped patch to fill, you can trace it out on the visqueen with a sharpie and then take it back to the workbench and use that as a template to cut out your fiberglass pieces.

 

[Project_Mayhem]

I forgot to mention that it's in heated storage. Being on the second floor, it's one of the warmest areas in the yard (still boggles my mind that the floor is strong enough for all those boats)

The deck has a skin on the top (outside), core and another skin on the underside. There is no carpeting or soft liner. I don't have an issue adding one either. I'd probably go with foam teak if I approached from below.

I'm not sure how large of an area needs to be replaced since I havent cut into it. I suspect it's no less than a foot away from the sample area. There's a 2" port for the rode so I had good access to the core when I removed the fitting. It was black, wet mush. I'm surprised the deck doesn't feel soft under my feet

Based on the couple of gelcote repairs I've seen in progress, it seems like you could get some excellent results on smooth surfaces if properly color matched and sanded. Antiskid on the other hand seems very difficult to get good results without redoing the whole area. Thoughts?

• Roll every layer into place. This is how you get good contact and strength.
• Work in small areas, no larger than you can easily press in place (core and glass). Fill gaps with putty and overlap glass as needed. Do NOT try to put up big sections.
• Not too many layers at once; avoid the exotherm. First the core, then wait an hour or two. Then 2 layers of glass, then wait until it kicks a little. Then finish glass and smoothing.

Thank you for the excellent tips and advice. So extra cloth/mat will be added even if the original skin is re-applied? Should the wood core be added in multiple layers or just the mat/cloth? Are you able to divulge what month the article will be published?

 

[william24424]

Attacked from below, not a difficult job because I could remove entire anchor locker cover. Water entered from hinge screw holes....Lesson learned... MAKE SURE you properly bevel/caulk any holes through fiberglass. Not a fun job, however it's an important one, good luck.

 

[PaulK]

I forgot to mention that it's in heated storage. Being on the second floor, it's one of the warmest areas in the yard (still boggles my mind that the floor is strong enough for all those boats)
The deck has a skin on the top (outside), core and another skin on the underside. There is no carpeting or soft liner. I don't have an issue adding one either.
Based on the couple of gelcote repairs I've seen in progress, it seems like you could get some excellent results on smooth surfaces if properly color matched and sanded. Antiskid on the other hand seems very difficult to get good results without redoing the whole area. Thoughts?

So extra cloth/mat will be added even if the original skin is re-applied? Should the wood core be added in multiple layers or just the mat/cloth? Are you able to divulge what month the article will be published?

You, answered your own question about attacking from the top or the bottom, so you're going in from underneath. It is probably not worth it to re-use the original skin, though that will depend upon how big the pieces are that you are able to cut out. Getting it cleaned up enough to lie flat could be a good bit of work too, and glassing it in may create weak spots along its edges, all around. Coring goes in as a single layer. Be sure to match the existing thickness. As Thin suggests, it should not take very long to do, but it can be messy until you work out the techniques.

 

[Project_Mayhem]

Going from above sounds like a much more pleasant experience plus air bubbles will float to the top and gravity will help pull the resin into the cracks. I'm still deciding on above or below. Responses about my gelcote question may also help with this decision.

Should core material be beveled at the edges just like fiberglass?

 

[SailingLoto]

I would 100% plan on doing this from above and use polyester vs epoxy due to ease if application and cost. Tap around with a hammer, drill some small test holes to find the extent of the rot and proceed. If the core isn't rotten it's a huge pain in butt to remove the glass skin on top. Cut small and work your way out to the edge of the rot. I prefer thickening with milled glass vs aerosil/cabosil as the latter can become brittle.

The whole process is less than fun, but rewarding in the end. If you do not already have one, get a good oscillating multi tool and a couple good carbide blades, an angle grinder and some 36 and 60 grit discs.

Is the storage facility cool with you doing this? I for one would be rather irate if my boat were covered in dust because you recored your deck 2 boats over from mine and I paid good money to store it there.

 

[Project_Mayhem]

I would 100% plan on doing this from above and use polyester vs epoxy due to ease if application and cost. Tap around with a hammer, drill some small test holes to find the extent of the rot and proceed. If the core isn't rotten it's a huge pain in butt to remove the glass skin on top. Cut small and work your way out to the edge of the rot. I prefer thickening with milled glass vs aerosil/cabosil as the latter can become brittle.

The whole process is less than fun, but rewarding in the end. If you do not already have one, get a good oscillating multi tool and a couple good carbide blades, an angle grinder and some 36 and 60 grit discs.

Is the storage facility cool with you doing this? I for one would be rather irate if my boat were covered in dust because you recored your deck 2 boats over from mine and I paid good money to store it there.

I have about 3/4 gallon of TotalBoat Traditional epoxy. What makes the polyester easier to use in this case? I've done a fair amount fiberglass with epoxy.
All the boats that are in indoor storage are draped in plastic. I do additional plastic taped off as best as possible and I have a shop vac get gets used anytime I'm cutting/sanding/grinding fiberglass. Seems to work reasonably well

Congrats on the new boat!

 

[rgranger]

I would 100% plan on doing this from above and use polyester vs epoxy due to ease if application and cost. Tap around with a hammer, drill some small test holes to find the extent of the rot and proceed. If the core isn't rotten it's a huge pain in butt to remove the glass skin on top. Cut small and work your way out to the edge of the rot. I prefer thickening with milled glass vs aerosil/cabosil as the latter can become brittle.

The whole process is less than fun, but rewarding in the end. If you do not already have one, get a good oscillating multi tool and a couple good carbide blades, an angle grinder and some 36 and 60 grit discs.

Is the storage facility cool with you doing this? I for one would be rather irate if my boat were covered in dust because you recored your deck 2 boats over from mine and I paid good money to store it there.

@SailingLoto gave great advice on the multitool and grinder.

Im not sure that I agree with the recommendation of polyester over epoxy. I've worked with both and I hope to never use polyester ever again. YMMV

From my experiences I find that epoxy cleans up quickly with white vinegar so long as it is not fully cured. In fact the vinegar and epoxy undergo an acid/base neutralization reaction so the vinegar actually digests the epoxy... I keep a bottle of vinegar and a roll of paper towels handy and wipe down all of my tools when I'm done with each application....if you accidently spill or drip some epoxy, wipe it up with some vinegar and your mess is gone...and epoxy has little odor. When I work with polyester I feel like I can smell it in my nose for days and I've yet to find a solvent that completly gets it all up with ease. But more importantly, epoxy sticks better to fully cured fiberglass than does polyester. I don't know SailingLoto's definition of "ease". If he is talking about the mixing to exact ratios part, he is correct. Polyester is more forgiving than epoxy. But most of the distributors of epoxy (I like JamesTown distributors) sell pumps that eactly measure out what you need. So you pump twice on bottle A and once on bottle B ... stir and wait the requisite time and you are good to go. Epoxy is less tolerant of UV exposure than polyester so if your final product is exposed, it will need to be painted. Again, YMMV

 

[PaulK]

Epoxy "sticks" better to the balsacore and other laminates, and is easier to thicken with micro balloons (as Thin suggests) so that it doesn't drip. Though it is cheaper, polyester resin is notorious for not binding well to wood. Bonds to old polyester laminates can also be suspect. Epoxy would make the most sense here, since it is a relatively small job and you want everything to stick together well.
If you cut through the top of the deck you will have to a/ match up nonskid areas of the deck afterwards. (It would look screwy if the nonskid faded out and then faded back in a few inches later.) b/match up NON -nonskid areas of the deck afterwards. (Same thing- it would look screwy if the smooth sections of the deck suddenly weren't.) c/ make the repair joints less obvious. This could mean re-gelcoating the section you worked on, though this would probably need to be done professionally. Matching the color to the rest of the deck can be tricky. Then you would need to re-do the nonskid, because the gelcoat will fill it in. If it comes out the wrong color, it is still the color you picked. Maybe it will fade to match. Another way to hide the obvious repair in the deck done from above would be to paint it. To make it all the same color this would involve painting the entire deck. This would be a major multi-step operation that might take weeks, though you are lucky to be inside and heated. If you paint, it will need repainting. If you paint with one-part (easy, less expensive) it will need repainting sooner. If you paint with 2-part (a bit trickier and more expensive) it will need repainting later. You pick.

 

[thinwater]

... Thank you for the excellent tips and advice. So extra cloth/mat will be added even if the original skin is re-applied? Should the wood core be added in multiple layers or just the mat/cloth? Are you able to divulge what month the article will be published?

If working from the inside I would NEVER reuse the skin. There is zero chance it will fit well and bond well to the core unless you use a lot of bog... and how would you clamp it in place? There will be areas of poor bonding. Do NOT reuse the inner skin.

I don't like reusing the outerskin for the same reason. Too hard to bond. The new core will never be precisely the same thickness, down to the bump, as the old core. Lay a new skin. A repair was done from the outside on my current boat and it was HORRIBLE with thick bog and very poor bonding/scarf to the existing deck. And this is why I like working from the inside. You can focus on bonding instead of finish.

Do NOT layup more than two layers when working overhead. It will fall off on you. Finish does not matter, so forget the visqueen; it will just make it impossible to roll out the air and excess resin (excess resin is heavy and cracks). Just work on a large plastic sheet, such as a large cutting board. Precut the glass if possible, or have a helper cut and hand. Change gloves every 10 minutes, before they get sticky.

Nope, would not use polyester. I have several times, and I would not use it for this. The secondary bonding is weaker.

You are replacing old core. No bevel needed.

Paul is right about balsa bonding better. If you use Corecel or similar, score it extra to make it floppy enough to conform to the old stuff. Be careful removing the old core; it's easy to go through the skin. I like a wire cup brush on a drill for most of the removal. Take it easy.

I've done whole ceilings this way. Keep it simple, work small, and work steady.

 

[Project_Mayhem]

From my experiences I find that epoxy cleans up quickly with white vinegar so long as it is not fully cured. In fact the vinegar and epoxy undergo an acid/base neutralization reaction so the vinegar actually digests the epoxy

Thanks for the vinegar tip. Sounds much better than solvents!

If working from the inside I would NEVER reuse the skin. There is zero chance it will fit well and bond well to the core unless you use a lot of bog... and how would you clamp it in place? There will be areas of poor bonding. Do NOT reuse the inner skin.

I don't like reusing the outerskin for the same reason. Too hard to bond. The new core will never be precisely the same thickness, down to the bump, as the old core. Lay a new skin. A repair was done from the outside on my current boat and it was HORRIBLE with thick bog and very poor bonding/scarf to the existing deck. And this is why I like working from the inside. You can focus on bonding instead of finish.

Do NOT layup more than two layers when working overhead. It will fall off on you. Finish does not matter, so forget the visqueen; it will just make it impossible to roll out the air and excess resin (excess resin is heavy and cracks). Just work on a large plastic sheet, such as a large cutting board. Precut the glass if possible, or have a helper cut and hand. Change gloves every 10 minutes, before they get sticky.

Nope, would not use polyester. I have several times, and I would not use it for this. The secondary bonding is weaker.

You are replacing old core. No bevel needed.

Paul is right about balsa bonding better. If you use Corecel or similar, score it extra to make it floppy enough to conform to the old stuff. Be careful removing the old core; it's easy to go through the skin. I like a wire cup brush on a drill for most of the removal. Take it easy.

I've done whole ceilings this way. Keep it simple, work small, and work steady.

Wow! This is outstanding advice! Thank you! Based on the fact that it's very difficult to reuse the old skin, I think I'll take your suggestion and do this repair from below. Does the new "skin" provide any structural support? I'm trying to determine the appropriate cloth to use. I assume standard 6oz is appropriate for this application?

I plan on using balsa. If it lasted for the past 40 years, it'll outlast the boat. Is there such a thing as "marine grade balsa" or can I buy regular balsa and add scores/cuts with a table saw?