Flimsy deck on bow and tabernacle. Backplate

[Mike25]

Flimsy deck and bow cleat. Post n bow backplate needed. The po had cut a 1.5" by 1.5 hole in forward bow, probably for shore power and the cleat and bow rail were dangerously flexing. This 1975 beauty is worn and only a thin sheet of original fiberglass was holding the hardware. The tabernacle was also in question the 3 holes were wallowed out and cracked. I'm installing a bulkhead so when the compression post came out the deck flex was incredibly scary. Here are pics of what I did. What do you think? Should I resin the plywood? I know a sheet of ss or aluminum where the washers are would be optimal but cost of stainless is a problem.

 

[Project_Mayhem]

Is there plywood inside the boat's fiberglass? If so, you need to find out if it's rotted before doing anything else. You can try tapping the area and listening to the sounds. Rotted areas usually have a duller sound. But that isn't a guarantee that what you hear is accurate. It's more of an indicator in my opinion. My deck sounded and felt solid but low and behold, it had a lot of rot in the same area as yours. This often happens when holes are left unsealed or sealant has failed.

 

[Mike25]

Thanks Project Mahem good point. There is no core or multi layers its just fiberglass. There are 2 stringers running a beam fore of the compression post. You can imagine the flex without the post installed. It's a pop top so just behind the tabernacle the shape is formed with a lip that adds strength moving back to the coaming.

 

[Project_Mayhem]

The proper thing to do would be to use marine grade plywood and laminate it in epoxy. The next best thing would be to use outdoor rated plywood and laminate it to your boat.

Now with that said, your boat has survived nearly 50 years without this extra material. Assuming that there is nothing else wrong I'd like to propose a different approach. I tore apart the bottom of my foredeck last summer. Grinding away at old fiberglass and balsa was by far the most miserable boat project I've ever tackled. Laminating yours requires removal of paint before hand so it wouldnt be as bad. What I'm proposing is to get some outdoor 1/2-3/4" grade plywood, give it a good coat or two of epoxy to seal it and then install it on the boat. Double up on fender washers for your hardware and be sure to use some Bed-IT to seal all the hardware. Stronger than new!

I'm sure some other opinions will be posted

 

[Mike25]

How does one go about repairing a rotted core. It has taken me time to figure my deck has a core in select areas. It is a pop top and it appears most of that is with core. There 2 narrow areas sloping down away from the pop top away from center that may have a core. Other than that nothing forward of the tabernacle has a core.

I'm concerned because one repair day I had a pot of wet epoxy and duct tape, to seal the hole bottom, and I sealed every hole I could reach. Most glued up nicely but a few just sucked up the epoxy and took more. They never completely topped off like the single layer holes.
Any suggestions appreciated

 

[Project_Mayhem]

How does one go about repairing a rotted core

There's a few different techniques depending on the application. West Marine's fiberglass manual is considered by many to be the holy grail. BoatWorks Today also has some excellent material. If memory serves me correctly, West's manual usually states to tear out the rotten material, clean it up, wipe it down with solvent, apply a couple layers of epoxy and 1708 cloth, add balsa and then some more fiberglass cloth

They never completely topped off like the single layer holes.

Use more thickener. Sometimes multiple applications are needed. Syringes to inject the epoxy help make application easier. You can also use products like Thixo or Adtech P100 (available from Express Composites)

 

[Mike25]

I'm almost sure the second application will finish sealing the hole. It's amazing how the mixed resin retains surface tension even though I'm using slow cure hardener. I wish I had anticipated hollow space cause I have large volume syringes. This boat does not have a liner above the rub rail and it's a mystery where there is core and not. The areas that were 1st attention "bow rail/cleat and tabernacle" are just a single layer an 1/8 inch or less. Backing plates resolved those concerns and sealing the top deck will grant a stopping point.

Now that new keel winch is installed along with newly fabricated rudder and castle I'm ready to splash. I should start new threads on those endeavors cause plenty of unexpected hurdles surfaced. Crawling in bilge at transom revealed a split cockpit drain hose. What a nightmare that oversight could cause. More to come, stay tuned. Wanna hear an unusual occurrence. My trailer is an aluminum I beam construction where 2 bunks are made of 4 by 6 wood beams at least 8 feet or longer. The trailer floats at launch!

 

[THECUSCUS]

There is plywood core basically everywhere there is the non-skid surface (usually the baby blue areas on a Mac)

This is how I reinforced mine and made the tabernacle bigger to match the plate.


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[Mike25]

Wow that's solid. If you have a 25 and the keel winch is just inside the companion way how do you monitor the keel position when the winch drum is out of sight? The PO cracked the trunk top by over tightening while raising the keel. Many thanks.

 

[Project_Mayhem]

One little tip... If you need to keep resin on the outer skin of the fiberglass while reducing the absorption, put a piece of tape on the top of the filled hole. It's useful when the resin just keeps seeping inside a cored deck and you're just trying to seal off a hole. Yes, filling it in entirely or ripping up the deck is the correct way but some boats have a lifetime supply of projects. I also do this same trick to reduce sanding when filling in small holes as the cured resin ends up being pretty flush with the surface

 

[THECUSCUS]

I keep track of keel position by counting turns of the winch handle. I know how many turns it takes to line the keel lockdown bolt holes up, which would be the full down position. when cranking the keel up, i stop when i feel resistance.

 

[Mike25]

Yesterday was 1st splash! Win or fail you decide. After custom cut of 8mm main sheet and connecting new double pulley on boom, installing last bolts on bulkhead and registration numbers, new tires on trailer we rolled to the lake. Last gas station stoped to get fuel for outboard and saw grease all over new rim and wheel and up trailer and boat. Buddy bearing cap/dust cap had flew off. Group discussion said find part store and begin curbside repair or go home. 1.5 hours later at ramp we tried to MANually step mast. I should of had a system and will next time but I've done before with ease. 2 64 year old overweight boys and 1 16 year old adult struggled, (I was younger 10 yrs ago) got it set but the captain was pulling the forestay and it was 4 inches short. Not anticipating the norm an upper stay at chainplate was misaligned and broke the stay out of the spreader end. It's now 6 pm we're tried but NOT defeated. Lowered mast (I'm not sure how weak the rigging is without the spreader connected) and don't want to find out. Launched and motored around for more than an hour. Tested the keel and winch, new rudder and castle work fine. The keel moves up and down great but there is no hole for locking pin/bolt in down position. This is same boat where keel cable attachment is 6" forward of wear pin. Could PO have put pivot bolt in wrong hole. I don't think geometry willl allow it but just a thought. Must be replaced keel, it's a little short and no locking hole. The hole is there in the trunk and you see the keel head as it lowers but no hole. What a shakedown. I won't even discuss the trailering and ride home except we are safe and I need a winch post, oh yeah there is a bent axle too. Ready to retool and retry. Found spreader end at BWY.

 

[Tsatzsue]

I have never locked my keel down.