Bulkhead Water Damage at Chianplate . . .

[otherthan]

looks like only the top lawer of plywood is afected...need opinions on a solid way to fix?

I wanted to cut away the afected erea and aply panatrating epoxy, then level with thikened epoxy and finalise with a lawar of fiberglass...and also add a backing plate as the original has none, in fact the bolts have carved in the plywood.

thanks for any opinion
rgds

ps thats the only problem chianplate...all others are ok

[beetle]

Some thoughts -

you need to be rearly clear that in fact there is no other damage in the bulkhead that you cannot or have not yet seen (you said it's made of plywood, yes? - go digging with a sharp point and determine how far out from the chainplate the wood is damp, wet, or otherwise no good. Be aggressive with the sharp point).

if you re-use the bulkhead, do not waste time with penetrating epoxy - you will need to remove every bit of wood that is soft or otherwise degraded.

repair with solid glass (don't bother with filler, there's no structural quality that comes with filler). Be prepared to grind out a lot of bad plywood to get down to good plywood. Then apply glass over the bevelled plywood. Then be prepared to grind the glass to match the bulkhead surface.

you've got to solve the water intrusion problem before doing much more - where did the water come from, and then how are you going to stop it?

do NOT re-use any of the existing drilled bolt holes - drill all new holes. This will require drilling through the chainplate (go slow, use cobalt drill and lots of oil or cutting fluid on the drill bit if you've got it).

And that would be where I would start. This could easily wind up being a significant bulkhead patch before the bulkhead can continue taking the load the chainplate carries.

- rob/beetle

[James S]

Originally Posted by beetle

Some thoughts -

you need to be rearly clear that in fact there is no other damage in the bulkhead that you cannot or have not yet seen (you said it's made of plywood, yes? - go digging with a sharp point and determine how far out from the chainplate the wood is damp, wet, or otherwise no good. Be aggressive with the sharp point).

if you re-use the bulkhead, do not waste time with penetrating epoxy - you will need to remove every bit of wood that is soft or otherwise degraded.

repair with solid glass (don't bother with filler, there's no structural quality that comes with filler). Be prepared to grind out a lot of bad plywood to get down to good plywood. Then apply glass over the bevelled plywood. Then be prepared to grind the glass to match the bulkhead surface.

you've got to solve the water intrusion problem before doing much more - where did the water come from, and then how are you going to stop it?

do NOT re-use any of the existing drilled bolt holes - drill all new holes. This will require drilling through the chainplate (go slow, use cobalt drill and lots of oil or cutting fluid on the drill bit if you've got it).

And that would be where I would start. This could easily wind up being a significant bulkhead patch before the bulkhead can continue taking the load the chainplate carries.

- rob/beetle

I pretty much agree with beetle, except I'm not sure about not reusing the old bolt holes...I'm wondering why....if the concern is the integrity of the SS then I'm not sure that adding holes would help.

[otherthan]

a blade will only go thru the first lawar of plywood...bacteria (black mold) from condensation make it look worst then it is. all wood is dry now...the water came in via chainplate top, needs rebeding.

bolts have been epoxyed and no water has passed thru bolt holes...under chainplate wood is solid

ps Iv remouved the chainplate alredy

[svHyLyte]

I have seen more thn one chainplate with similar water intrusion/damage break.

Take the chainplate out and give it a good wack with a hammer. You may find that it breaks across one of the bolt-holes. In any case, I'd replace it considering how cheap they are. If the bulkhead is still (relatively) solid, I'd Git-Rot the hell out of the damagd area and then add a solid wood backing plate, grain ouriented vertically, on the back side with epoxy and perhaps a half dozen 1/4" wood screws into the undamaged bulkhead on either side of the damaged area. Use new bolts through the (hopefully) new chain plate with oversize cut-washers on the new bcking plate side of the bulkhead.

Good luck!

[Mimsy]

Having just gone through this (ugh), I would highly recommend doing a more thorough job than you suspect that you need. Remove all the areas where rot even touched it, scarph in new wood, epoxy, glass it in and then rebed your chainplates. Pain in the butt to be sure, but then you will know that it has been taken care of.

You absolutely have my sympathies- not a fun job and it will take 4 times what you think it will.

[PAR]

I also agree with most of what has been said. This isn't an area that gets removed for inspection often, so your "fix" needs to address this aspect of it's life. The easiest and most reasonable thing is to just replace the backing plate (plywood) with a new piece or better yet, some thing inert to moisture like G-10 (my first choice on a 'glass hull) or a stainless steel plate.

The same holes, if previously properly bonded, will work fine if re-using the plywood backing plate. If not properly bonded, now is the time to do this, it's easy and insures the bolts don't let moisture into the plywood.

As far as a surface treatment, if using epoxy (I naturally assumed you were) then a filler mixture will restore the surface without the need for fabric. Of course it needs to be a heavy structural mix, such as 50/50 milled fibers and silica. Toss in some wood flour to get a reasonable color. Cotton flock (like West System 403) can be substituted for milled fibers, though both mixed (like West System 405) is also good. Trowel in place and level as best as you can while wet, as sanding these heavy structural filler mixtures truly sucks. To make it smooth, use a piece of Mylar over the goo on the backing plate and lightly roll it onto the surface. When cured, peel the Mylar off to reveal a perfectly smooth, mirror like finish. Do not consider micro balloons, Q-cells or other light filler materials as they have poor compressive attributes.

[perchance]

[QUOTE=jobi;611639]looks like only the top lawer of plywood is afected...need opinions on a solid way to fix?

I wanted to cut away the afected erea and aply panatrating epoxy, then level with thikened epoxy and finalise with a lawar of fiberglass...and also add a backing plate as the original has none, in fact the bolts have carved in the plywood.

thanks for any opinion
rgds

ps thats the only problem chianplate...all others are ok[/
I just did this repair on my boat for the forward lower shroud.
1:Removed all rotted ply and beveled the edges.
2: Made a replacement section of marine grade plywood with beveled edges.
3: filled the gaps with thickened epoxy and glassed over with a layer of glass mat and roving.

The repair is in an area that is between the hanging locker and the vee berth so is not all that visible. The biggest problem doing this on a small boat is getting at the area to do the work.
I would say that the repaired area is stronger than the original wood.

[otherthan]

Originally Posted by PAR

I also agree with most of what has been said. This isn't an area that gets removed for inspection often, so your "fix" needs to address this aspect of it's life. The easiest and most reasonable thing is to just replace the backing plate (plywood) with a new piece or better yet, some thing inert to moisture like G-10 (my first choice on a 'glass hull) or a stainless steel plate.

The same holes, if previously properly bonded, will work fine if re-using the plywood backing plate. If not properly bonded, now is the time to do this, it's easy and insures the bolts don't let moisture into the plywood.

As far as a surface treatment, if using epoxy (I naturally assumed you were) then a filler mixture will restore the surface without the need for fabric. Of course it needs to be a heavy structural mix, such as 50/50 milled fibers and silica. Toss in some wood flour to get a reasonable color. Cotton flock (like West System 403) can be substituted for milled fibers, though both mixed (like West System 405) is also good. Trowel in place and level as best as you can while wet, as sanding these heavy structural filler mixtures truly sucks. To make it smooth, use a piece of Mylar over the goo on the backing plate and lightly roll it onto the surface. When cured, peel the Mylar off to reveal a perfectly smooth, mirror like finish. Do not consider micro balloons, Q-cells or other light filler materials as they have poor compressive attributes.

I want to carve all the afected wood and use a 2
to 1 epoxy mix with wood dust as a filler...then lay a wide lawer of fabric...then on both side of ply wood a stainless plate to witch the chainplate will be bolted.

this is overkill and none esthetic but I dont mind...hears a photo from the other side...I sanded to see the woods condition.

if I was to do a cosmetic repair, id instal outside hull chainplates...maybe thats the best option for my sailing intent???

[Mark Johnson]

I have done a number of these, as it is one of the most common of all repairs.

Many good ideas here, BTW... Best case scenario: If, after removing the chainplate and shelf, then grinding down to good, well bonded plys, with no delams... There is still 80% of the thickness still there, then you could:

After confirming that the bolt holes are not delaming, or punkey... carefully make a paper pattern of their locations, then drill them about twice as large. now tape over the deck slot well. Put IR "brooder lights" on each side of the bulkhead, about 4' away, pointing toward the scar, to dry it out... Also, coat the bare places as often as you can bring yourself to with acetone. Leave the lights going, and acetone coat the bare wood, for about a week. It needs to be bone dry.

Next, if it is really good dry wood, fill the oversized bolt holes with coats of just West resin first, until it will not absorb any more. Then, as soon as not runny, fill the holes with 50/50 mix of High D and silica fillers.

Next start the glass build up process with either biaxial fabric, or regular fabric cut on the bias, so that all fibers reinforce an upward pull. When mostly built back up, finish off with fillers, sand fair, and several topcoats of just resin. Then sand and paint, or cover with Formica or the like.

Then put the pattern up there and drill the bottom bolt hole. Put in the chailplate and install the bottom bolt. Now use the chainplate itself, (if made immobile first), as a template for the other holes.

Since these holes are now going through reinforced plastic, rather than wood, additional coats are unnecessary. Caulk in the chainplate, (with backing plate), and use a "moat" piece of hardware in the future around the slot, filled with caulk, to keep the chainplate from EVER leaking again. It may need to be rebedded on occasion, mine do!

Having said all of that, on a small boat, my first attempt is always to replace the bulkhead, IF it easy! It all depends on how much you have to tear up the boat to do this.

Good luck, M.

[zeehag]

externalize yur chainplates and keep them outside and replace the bulkhead with cpe'd ply and fiberglass--it does have a movement there from the boat--must maintain that grace or have further problem. LOOKS LIKE THE CHAINPLATE IS THE SOURCE OF THE LEAK-- remove the chainplate and place backing plates inside the boat anf plates outside .... epoxy it then caulk the crapouttadem. bulkhead-- cut away the bad stuff and place a cpe'd bit of marine grade ply and glass it in. done. veneer it for beauty. dont forget to angle the bulkhead end at the overhead for movement.

[otherthan]

Originally Posted by Mark Johnson

I have done a number of these, as it is one of the most common of all repairs.

Many good ideas here, BTW... Best case scenario: If, after removing the chainplate and shelf, then grinding down to good, well bonded plys, with no delams... There is still 80% of the thickness still there, then you could:

After confirming that the bolt holes are not delaming, or punkey... carefully make a paper pattern of their locations, then drill them about twice as large. now tape over the deck slot well. Put IR "brooder lights" on each side of the bulkhead, about 4' away, pointing toward the scar, to dry it out... Also, coat the bare places as often as you can bring yourself to with acetone. Leave the lights going, and acetone coat the bare wood, for about a week. It needs to be bone dry.

Next, if it is really good dry wood, fill the oversized bolt holes with coats of just West resin first, until it will not absorb any more. Then, as soon as not runny, fill the holes with 50/50 mix of High D and silica fillers.

Next start the glass build up process with either biaxial fabric, or regular fabric cut on the bias, so that all fibers reinforce an upward pull. When mostly built back up, finish off with fillers, sand fair, and several topcoats of just resin. Then sand and paint, or cover with Formica or the like.

Then put the pattern up there and drill the bottom bolt hole. Put in the chailplate and install the bottom bolt. Now use the chainplate itself, (if made immobile first), as a template for the other holes.

Since these holes are now going through reinforced plastic, rather than wood, additional coats are unnecessary. Caulk in the chainplate, (with backing plate), and use a "moat" piece of hardware in the future around the slot, filled with caulk, to keep the chainplate from EVER leaking again. It may need to be rebedded on occasion, mine do!

Having said all of that, on a small boat, my first attempt is always to replace the bulkhead, IF it easy! It all depends on how much you have to tear up the boat to do this.

Good luck, M.

Thanks Mark
I will do it your way...I can see a better and stronger resistance to upward pull the way you do it.
cheers

[MichaelC]

When I first started to look for a retirement sailboat, everything was, of course, production fiberglas. Those interior chainplates [in addition to the marconi rigs themselves] kept me from making offers on several boats before I finally threw up my hands, bought materials and started to build my own [again]. If you don't do external chainplates, then replace the ones you've got with ones twice as long, then follow the advice on this thread. There are lots of stresses on those chainplates and they need to be very strong.

[otherthan]

Michael id love to put exterior chainplates, especialy 3 on each side.

to me that would be a real improuvement...and final.

also I feal as you do and would do larger chainplates inside...however lets not forget the boat was built in 1964 and is still solid, they have never failed.

sure the boat was left on the hard a few years with water inside, other then this its a good old boat...I cant say that new boats will ever have such life expectency.

cheers

[beetle]

Originally Posted by zeehag

with cpe'd ply and fiberglass

what is "cpe'd" ply and fiberglass? this one's got me scratching the old cranium.