Repairing a rotten bulkhead

hennypenny

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Hi All,

My Bavaria 31 had an anchor windlass installed approximately 10 years ago which is located in the chain locker on a shelf. The wires run through the v berth bulkhead but weren’t sealed properly and now the lower right hand side quarter of the bulkhead has rotted and the foam lining on the side of the cabin has also repeatedly gotten wet and is falling off. Water comes in every time it rains or when waves come across the deck.

How easy would it be to replace just a section of the bulkhead, and what are the options to do this. Or is it better to just replace the whole bulkhead? Is it possible to do this DIY?

Thanks all look forward to hearing your thoughts!
 
Very possible as a DIY job and if done properly is just as strong as new if you do a section. Cut out the rotten part as far back as it goes. Bevel the edge of what's left and cut a new piece of marine ply to suit and match the bevel. Scarf it in with epoxy glue and then add several layers of fibreglass over the top each side to cover old and new in total and of course ensure the new wiring holes you drill are properly sealed.
 
Very possible as a DIY job and if done properly is just as strong as new if you do a section. Cut out the rotten part as far back as it goes. Bevel the edge of what's left and cut a new piece of marine ply to suit and match the bevel. Scarf it in with epoxy glue and then add several layers of fibreglass over the top each side to cover old and new in total and of course ensure the new wiring holes you drill are properly sealed.

You have been watching too much sail life

 
Just done similar to my recently acquired Sadler. Not too difficult.
1) carefully remove foam lining if to be reused.
2) cut out all rotting wood. Jig saw, hammer & chisel, whatever.
3) stick a piece of ply onto anchor locker side of bulkhead. Large enough to cover hole(s), symmetrical looks best, as thin as you like. Fibreglass this whole patch in place. Epoxy resin best with a couple of layers of woven roving with good overlap to original bulkhead.
4) cut ply of same thickness as original bulkhead to roughly fill the “holes” on cabin side of bulkhead. Stick in place with epoxy or waterproof glue. When dry, fill in with car body filler or similar and sand flush. Recover with lining or cut a piece of 4mm ply to cover inner bulkhead.

No special skills required. Any decent ply—- marine not neccessary.
 
I had to do something similar on my boat.

I cut out the rotten plywood and cut pieces to fit the spaces left pieces. I fixed these in place with epoxy and also fitted a large plywood backing piece over the whole area so I now have a bulkhead 1" thick instead of 1/2" thick. Much stronger than the original and the slight additional weight has made no difference to the handling of the boat.

I used Robbins Super-Elite plywood and WEST epoxy
 
You have been watching too much sail life


Never seen that one but I have just finished a year long refit on a 35 year old catamaran that needed extensive work like this and all was done DIY ( in fact about 3000 hours of my time over the year ) - I would give the video a watch but to be honest I need a LONG break from anything to do with boat repair...
 
I had to do the same when I bought our boat years ago - the survey identified that the babystay through the deck was not sealed properly and water had rotten the ply bulkhead. After removing all the roof lining etc I cut out the rotten ply. I deliberately made it larger than necessary as the original ply had been covered in wood coloured Formica(as were a lot of boats of that era). I then cut a piece of ply to fit, epoxied in place. I also added a 3mm stainless plate to cover the upper 3" of the join and over the adjacent doorway. The formica was refitted and the join covered with a strip of varnished teak strip, both in the fore cabin and adjacent heads. The stainless strip was also bolted to the new and existing ply. Head lining replaced and you would hard pushed to see the repair. Oh, and I resealed the babystay cover plate! I was dreading the job but actually was not difficult.
 
Trying to fibreglass a piece of ply into an anchor locker with your head in the hole and feet in the air will be no joke,
obviously i cannot see the situation but i might consider placing a layer of grp over the ply on the anchor side first before putting it in the hole. The idea being to ensure that side is well sealed. Filleting it around the edge may bedifficult as the bit you cannot get towill be the bit that leaks. Hence the need to seal face an edges of the ply first.
just a thought!!!
 
I am in the middle of a similar repair. Looking back to when I was considering how to tackle the job I wish I had the skill and confidence to remove the old bulkhead and start afresh. I have used a lot of epoxy and spent a lot of time fiddling around and still have to make the repair look presentable on the forward cabin side. One problem was the worse areas of rot were underneath the tabbing. It is very difficult removing the old ply and inserting the new and making sure it is bonded to the hull.
 
I am in the middle of a similar repair. Looking back to when I was considering how to tackle the job I wish I had the skill and confidence to remove the old bulkhead and start afresh. I have used a lot of epoxy and spent a lot of time fiddling around and still have to make the repair look presentable on the forward cabin side. One problem was the worse areas of rot were underneath the tabbing. It is very difficult removing the old ply and inserting the new and making sure it is bonded to the hull.

Did you leave the old tabbing in place? I'm facing a similar job this winter. Thinking about cutting out the rotten bits of ply and adding the new section in bits cut like jigsaw pieces as you see in boat kits. Was going to fit the hull-to section by leaving the old tabbing in place but trimmed back a bit and glue it in place with tec 7 or Sikaflex and then stainless flat head screws through the tabbing before the Tec 7 has gone off. Glass over the lot. Havent decided whether Ill remove the screws or leave them in place yet
 
Did you leave the old tabbing in place? I'm facing a similar job this winter. Thinking about cutting out the rotten bits of ply and adding the new section in bits cut like jigsaw pieces as you see in boat kits. Was going to fit the hull-to section by leaving the old tabbing in place but trimmed back a bit and glue it in place with tec 7 or Sikaflex and then stainless flat head screws through the tabbing before the Tec 7 has gone off. Glass over the lot. Havent decided whether Ill remove the screws or leave them in place yet
I left the tabbing intact but that was largely due to my reluctance to remove intact parts of the boat. A bit irrational as obviously for tabbing to work it needs to be attached to a sound material eg plywood. On my repair I am covering the entire bulkhead and tabbing with layers of glass fibre - starting with powder bound csm and then using the lightest weight combination mat.
Your method sounds like it would work and uses less material than mine.
Good luck
 
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