Front deck core replacement bulkhead removal and refit

[Restoration man]

The core of my front deck around the winch and cleats is wet on my 1975 storebro biscay 31 that I’m restoring , I plan on fixing this from inside as I don’t want to ruin the none slip on the deck ,to do it this way entails removing the front bulkhead that also is the chain locker , it’s only glassed / tabbed in on the inside, it would be easy enough to run a multi tool around the outside and cut the tabbing off flush with the hull but it’s going to be impossible for me to fit through the little door to re tab / fiberglass this back in place , this leaves me with a couple of options as I see it ,

1) cut the bulkhead out leaving 4” of the original wood still attached to the tabbing and then make a new bulkhead and when time comes to refit drill some holes through both and use some carriage bolts and nuts the type that have dome head and little square on the back of the head and and put epoxy between the wood and bolt it together, see photo shopped picture

2) try run my multi tool between the tabbing and the rear face of the bulkhead separate them I might just about be able to get in enough to do that, see photo that should leave just the tabbing that is quite thick , and when time comes to go back together again use same nuts bolts as no1 and basically epoxy it back on and use the nuts and bolts as well,

Thankfully the bulkhead is only attached down the to sides and not across the top ,

Option 2 would be better as I won’t have to make a new chain locker bulkhead ,

I could also tabb it from the outside but there not really enough depth to get wide enough tab As it would be seen when side panels go back on ,but I could do this where it won’t be seen as a belt and braces approach, If I do either of the other other ways ,
The bulkheads are obviously fitted before the superstructure, I do wonder if they made the tabbing prior to fitting the bulkheads and just glued the bulkheads on as tabbing has a cut edge and is very neat , all the other bulkheads use same neatly cut tabs ,

 

[Restoration man]

Better photos hopefully

 

[Boathook]

I would go for option 1 as it leaves part of the bulkhead in place. I would seal the cut edge left with resin to stop damp getting in, etc. The new bulkhead would only possibly require screws or even only an adhesive sealant to hold in place unless you want to act as a collision bulkhead which means the door would require replacing with something else.
Option 2 sounds good, but in reality I suspect difficult to run down between tab and bulkhead without wrecking on or other.

 

[Elessar]

The core of my front deck around the winch and cleats is wet on my 1975 storebro biscay 31 that I’m restoring , I plan on fixing this from inside as I don’t want to ruin the none slip on the deck ,to do it this way entails removing the front bulkhead that also is the chain locker , it’s only glassed / tabbed in on the inside, it would be easy enough to run a multi tool around the outside and cut the tabbing off flush with the hull but it’s going to be impossible for me to fit through the little door to re tab / fiberglass this back in place , this leaves me with a couple of options as I see it ,

1) cut the bulkhead out leaving 4” of the original wood still attached to the tabbing and then make a new bulkhead and when time comes to refit drill some holes through both and use some carriage bolts and nuts the type that have dome head and little square on the back of the head and and put epoxy between the wood and bolt it together, see photo shopped picture

2) try run my multi tool between the tabbing and the rear face of the bulkhead separate them I might just about be able to get in enough to do that, see photo that should leave just the tabbing that is quite thick , and when time comes to go back together again use same nuts bolts as no1 and basically epoxy it back on and use the nuts and bolts as well,

Thankfully the bulkhead is only attached down the to sides and not across the top ,

Option 2 would be better as I won’t have to make a new chain locker bulkhead ,

I could also tabb it from the outside but there not really enough depth to get wide enough tab As it would be seen when side panels go back on ,but I could do this where it won’t be seen as a belt and braces approach, If I do either of the other other ways ,
The bulkheads are obviously fitted before the superstructure, I do wonder if they made the tabbing prior to fitting the bulkheads and just glued the bulkheads on as tabbing has a cut edge and is very neat , all the other bulkheads use same neatly cut tabs ,

I presume you are removing the inner skin, hacking out the old rotten core, replacing that with foam or ply and glassing over that?

If so just leave the bulkhead where it is. It will be loose when you remove the old core, but the new foam or ply will easily slot in behind it.

Glass in you new tabs onto the bulkhead as you glass over the new ply/ foam.

 

[Restoration man]

I presume you are removing the inner skin, hacking out the old rotten core, replacing that with foam or ply and glassing over that?

If so just leave the bulkhead where it is. It will be loose when you remove the old core, but the new foam or ply will easily slot in behind it.

Glass in you new tabs onto the bulkhead as you glass over the new ply/ foam.

Hi mark, the core that needs replacing is inside the chain locker ,that part of the core is ply, the rest of the front deck is fine, that part i think is balsa core ,
I’ve got a tramex and rest of front deck reads low and sounds out fine when hammer tested ,the front deck is only wet from the chain locker bulkhead forward to the pointy end ,they must have sealed the transition between the ply and the balsa , so I’m only replacing the core that is inside the chain locker these no way I can get in that little hole and cut the inner skin and replace the core out without removing the bulkhead, hope that makes sense,
Nick

 

[KevinV]

Could you get through a hole this size?



Then you can just screw and glue a batten to the inside to give a lip, screw the cutout onto that lip with a bit of silicone in between and put a neat bit of trim over the cut (or not bother if the cut is neat enough). Easy to do, no re-manufacturing, easy to seal, and removable if you ever need in there again?

If that hole's not big enough you could apply the same principle to the whole bulkhead

 

[Restoration man]

Could you get through a hole this size?

View attachment 131524

Then you can just screw and glue a batten to the inside to give a lip, screw the cutout onto that lip with a bit of silicone in between and put a neat bit of trim over the cut (or not bother if the cut is neat enough). Easy to do, no re-manufacturing, easy to seal, and removable if you ever need in there again?

If that hole's not big enough you could apply the same principle to the whole bulkhead

At a push I can get one arm and my head in that’s about it , Im struggling to understand your suggestion that I should screw a batton to the inside , I can’t picture where ? The bulkhead is currently fibetglased To the hull with some kind of tabbing where I’ve just indicated on the photo below, but all the attachment is on the inside of the chain locker , if you look at the second photo this is taken from inside the chain locker , and that’s the tabbing I’m referring to ,my worry is that this bulkhead is Structual part of the boat and I feel it needs a very good attachment , not just a few self tappers and bit of sikaflex ,

 

[upcountry2]

Bite the bullit carefully take out the whole bulkhead and use as a template and fit new, the old one looks past it anyway.
will be far easier and quicker in the long run….

 

[Keith-i]

If it were me I would cut the entire bulkhead out so that you can do the repair. I would then tab it back in with the tabbing on the easy (cabin) side. If you do it neatly you could then cover the exposed bit of tabbing with some vinyl covered trim or similar. I have something very similar on my boat and it looks absolutely fine. A strip of 3mm ply is cut to shape to follow the contours of the hull and vinyl lining is stretched over it and glued in place. This trim is then secured with small screws at intervals with screw caps.

 

[Restoration man]

If it were me I would cut the entire bulkhead out so that you can do the repair. I would then tab it back in with the tabbing on the easy (cabin) side. If you do it neatly you could then cover the exposed bit of tabbing with some vinyl covered trim or similar. I have something very similar on my boat and it looks absolutely fine. A strip of 3mm ply is cut to shape to follow the contours of the hull and vinyl lining is stretched over it and glued in place. This trim is then secured with small screws at intervals with screw caps.

That looks neat?
I might do it like that thanks

 

[SvenH]

One thing to consider is that working below is a pain, to put it mildly.

I fitted a new bulkhead two winters back and spent a lot of time in that area.
And even though you seem to have more space than I have, you will need to work with epoxy overhead and that is not going to be easy.

In my view you would be better off trying to find a way to reduce the downsides of working from the top of the deck.

 

[Motor_Sailor]

One thing to consider is that working below is a pain, to put it mildly.

I fitted a new bulkhead two winters back and spent a lot of time in that area.
And even though you seem to have more space than I have, you will need to work with epoxy overhead and that is not going to be easy.

In my view you would be better off trying to find a way to reduce the downsides of working from the top of the deck.

Read this over and over until it sinks in! This is the word!
Leave the bulkhead alone and work downhand from above to replace any core.

 

[Restoration man]

Read this over and over until it sinks in! This is the word!
Leave the bulkhead alone and work downhand from above to replace any core.

Thanks for your concern , but it’s getting done from underneath ???? ,
I’m not prepared to destroy the Structual integrity of the front deck , the inner skin is stupidly thin and easily removed ,it would be madness in my eyes to cut out perfectly good much thicker front deck ,then have to re glass this up, then fill and fair , then I would then have to ether cover the complete deck and catwalks with either trackmark or kiwi grip , I couldn’t live with the side decks not matching the front decks , the boat is out of the water for 12 months so I’ve got plenty of time to do this repair,

 

[dankilb]

Not easy laminating overhead like that - but not impossible. I'd suggest wetting out the layup on a sheet of peel-ply on the floor/bench, just one or (max) two layers of cloth at a time, and with a helper you should be able to get those up in one go and take advantage of the fact that, with care (and some luck!), epoxy is tacky enough to hold up its own weight once you've rolled it and it starts to gel. With peel ply, it's easy to build up more layers if/as required (whether cured or still tacky).

I'm also in the camp of suggesting to remove the entire bulkhead, not worry too much about preserving the tabbing in its entirety (although it will help locate the re-installed bulkhead) and then re-tabbing from the accessible side to take advantage of the strength of new epoxy tabbing.

We replaced about 6m of rotten bulkhead bottoms/tabbings in total and the re-tabbing, itself, was the least of the work (and probably the most of the strength!).

 

[Restoration man]

Not easy laminating overhead like that - but not impossible. I'd suggest wetting out the layup on a sheet of peel-ply on the floor/bench, just one or (max) two layers of cloth at a time, and with a helper you should be able to get those up in one go and take advantage of the fact that, with care (and some luck!), epoxy is tacky enough to hold up its own weight once you've rolled it and it starts to gel. With peel ply, it's easy to build up more layers if/as required (whether cured or still tacky).

I'm also in the camp of suggesting to remove the entire bulkhead, not worry too much about preserving the tabbing in its entirety (although it will help locate the re-installed bulkhead) and then re-tabbing from the accessible side to take advantage of the strength of new epoxy tabbing.

We replaced about 6m of rotten bulkhead bottoms/tabbings in total and the re-tabbing, itself, was the least of the work (and probably the most of the strength!).

Not easy laminating overhead like that - but not impossible. I'd suggest wetting out the layup on a sheet of peel-ply on the floor/bench, just one or (max) two layers of cloth at a time, and with a helper you should be able to get those up in one go and take advantage of the fact that, with care (and some luck!), epoxy is tacky enough to hold up its own weight once you've rolled it and it starts to gel. With peel ply, it's easy to build up more layers if/as required (whether cured or still tacky).

I'm also in the camp of suggesting to remove the entire bulkhead, not worry too much about preserving the tabbing in its entirety (although it will help locate the re-installed bulkhead) and then re-tabbing from the accessible side to take advantage of the strength of new epoxy tabbing.

We replaced about 6m of rotten bulkhead bottoms/tabbings in total and the re-tabbing, itself, was the least of the work (and probably the most of the strength!).

I was Considering epoxy and peel ply and just doing it in smaller more manageable pieces , I’ve also thought about using polyester laminating resin as that doesn’t fully set until you use wax in it , that way I can let go off and add to it when its set at my leasure but epoxy is prob better

 

[Scarron]

Deffo use epoxy for all tabbing work, the bond strength to ply is vastly better than polyester.

The bulkheads on my 1960's motorboat had all broken out over the years. So I gouged out a criss-cross pattern into the ply surface with a multi tool to add a decent key and then filleted in a nice big radius to the corners with thickened epoxy. Following this up by overlaminating with epoxy and cloth has strengthend the boat immeasurably.

 

[KevinV]

At a push I can get one arm and my head in that’s about it , Im struggling to understand your suggestion that I should screw a batton to the inside , I can’t picture where ? The bulkhead is currently fibetglased To the hull with some kind of tabbing where I’ve just indicated on the photo below, but all the attachment is on the inside of the chain locker , if you look at the second photo this is taken from inside the chain locker , and that’s the tabbing I’m referring to ,my worry is that this bulkhead is Structual part of the boat and I feel it needs a very good attachment , not just a few self tappers and bit of sikaflex , View attachment 131529View attachment 131530

Sorry if I wasn't clear - I meant whether you could fit through a hole the size of the red box I drew - it would avoid all the issues and cost involved in completely remaking the bulkhead, like getting the shelf rests to align and suchlike.
Like so:

You could make the hole bigger than I drew, I just went with a simple rectangle fro ease of drawing/ cutting

 

[Restoration man]

Sorry if I wasn't clear - I meant whether you could fit through a hole the size of the red box I drew - it would avoid all the issues and cost involved in completely remaking the bulkhead, like getting the shelf rests to align and suchlike.
Like so:
View attachment 131560
You could make the hole bigger than I drew, I just went with a simple rectangle fro ease of drawing/ cutting

Thanks kev i get you now , I originally thought you ment could I get in the hole that was already there , unfortunately I wouldn’t be able to do the job on the core with the size hole you indicated, im going to need to remove the complete bulkhead or poss leave 4” down each side and even then it will be a tough job working in that tight pointy end , im going down Saturday and removing the winch and the deck cleats before I remove the bulkhead as I don’t want to be standing on the deck with the bulkhead removed just in case it flexes to much

 

[bristoljim]

Thanks kev i get you now , I originally thought you ment could I get in the hole that was already there , unfortunately I wouldn’t be able to do the job on the core with the size hole you indicated, im going to need to remove the complete bulkhead or poss leave 4” down each side and even then it will be a tough job working in that tight pointy end , im going down Saturday and removing the winch and the deck cleats before I remove the bulkhead as I don’t want to be standing on the deck with the bulkhead removed just in case it flexes to much

How are you intending to stick the [ply to the underside of the deck ?. low expansion PU foam ?Have you considered doing it in wide strips,say 18" wide - pre glassing the underside completely before fitting , then you only have to handle glass (tape ??)over the joints , much easier overhead than large areas.
Jim

 

[KevinV]

Thanks kev i get you now , I originally thought you ment could I get in the hole that was already there , unfortunately I wouldn’t be able to do the job on the core with the size hole you indicated, im going to need to remove the complete bulkhead or poss leave 4” down each side and even then it will be a tough job working in that tight pointy end , im going down Saturday and removing the winch and the deck cleats before I remove the bulkhead as I don’t want to be standing on the deck with the bulkhead removed just in case it flexes to much

I've been wedged in a few "pointy ends" myself, so I don't envy you one bit. Do you have some old cushions you can put in there? Makes it slightly less painful on the old back. Good luck.