sailboat bulkhead replacement

Building, restoration, and repair with epoxy

Replacing Damaged Bulkheads

By dan witucki.

Above: With her damaged bulkheads replaced, the Evelyn 32-2 sailboat RUSH is back in action. Several weeks later, the new bulkheads proved they could handle the stress of a heavy knockdown and a major storm during the infamous 2002 Chicago to Mackinac race.

If you race a sailboat long and hard enough, it eventually will reveal its weaknesses, sometimes violently. My friends and I race an Evelyn 32-2 called Rush. Less than a month before the 2002 Mackinaw races, we were competing in the Saginaw Bay Yacht Racing Association, Gravelly Shoals race. Throughout the race, the wind had been building and we were a little overpowered with a full main and 150% headsail. We had completed about 45 miles of the 50-mile race when the starboard chainplate decided it had enough and pulled out of the bulkhead.

The port bulkhead with the chainplate still attached.

Fortunately, Evelyn 32’s are designed with a stainless wire strut running from the chainplate down to near the mast step. This kept the rig from coming down; however, we were definitely done racing for a while.

After limping back to the dock and examining the damage, we decided to completely replace the bulkhead on both sides of the boat. Over the years, the chainplates had been leaking and had delaminated and rotted the plywood bulkheads. Before the accident, the bulkheads looked fine, but it was amazing to see afterward how badly they actually had deteriorated. With the end grain of the plywood bulkhead up against the underside of the deck, the chainplate was leaking directly onto the exposed end grain of the wood. Water damage was inevitable.

The next decision that had to be made was what material to use for the new bulkheads. The original, damaged bulkheads were made of ” marine grade mahogany plywood. However, we weren’t too anxious to use plywood again. It would be quick and easy, but we wanted something more bulletproof than plywood. After talking to Gougeon Technical Advisor, J.R. Watson , we decided to go with an epoxy/fiberglass composite called G-10. We selected ½” G-10 to replace the 5/8″ plywood. Because of G-10’s strength, we could have gone thinner yet. However, that would have made it more difficult to install and have everything else match up.

Removing the old, damaged bulkheads

Although I usually do most of the fiberglass and fairing work on Rush, John DeWyse did most of this job. The first step was to remove the shrouds and fasten them to the toe rail. Then it was time to go below and take the interior apart.

The starboard bulkhead where the chainplate let go was the result of accumulated water damage and heavy loads.

Luckily, Evelyn 32’s aren’t real plush, and this job went fairly quickly. We moved all the sails, equipment, and cushions from the bow and mid-section of the boat to the stern. Then we hung a tarp behind the companionway to keep the dust away from that area of the boat. We placed a large window fan over the front hatch, blowing out. With the companionway open, we had good ventilation. The next step was to carefully peel back the headliner and inner upholstery with a putty knife and tape them back out of the way. To cut the bulkheads free, John used a Roto Zip™ tool. This worked very quickly with minimal dust. He simply went down each side of the bulkhead, cutting the tabbing where the bulkhead met the hull and deck. He had both damaged bulkheads out after about 1½ hours. Then he used a 6″ grinder with a 40-grit disc to remove the old glass tabbing on the hull and underside of the deck. After that, we vacuumed up the dust.

Installing the new bulkheads

Since John was able to get the bulkheads out without damaging them further, they made perfect templates. When the G-10 arrived, we traced the bulkheads onto the new material using a black felt tip marker, modifying them slightly from the original design. We decided to extend the bottom of the bulkhead so that it could be bolted and glued to a floor frame that was below the original bulkhead. To cut the G-10 composite, we used a reciprocating saw with a carbide grit blade used for cutting cast iron and fiberglass.

John used a Roto Zip to cut the tabbing where the bulkhead met the hull and deck. The Roto Zip cut quickly and raised minimal amount of dust.

Cutting was rather slow; this stuff is tough. Taking turns, we were able to cut each bulkhead out in about an hour. The new bulkheads were taken down to the boat and put into place. After we had ground down a couple of high spots, they fit perfectly. Next, I ground and sanded a radius on the long straight edge, since this edge would be exposed to the interior. I finished preparing the bulkheads by using a random dual action sander with 80-grit paper to sand the edges where the tabbing will bond it to the hull and deck.

With the starboard bulkhead removed we were ready to remove the glass tabbing with a disc grinder.

With the bulkheads set into place, we cut strips of 738 Biaxial Fabric (with a mat backing) needed to tab the bulkheads into place. We cut enough to do both sides of the bulkheads with two layers of cloth, then set them aside. With the bulkheads still in place, we drilled three holes through the bottom of each bulkhead and through the floor frame. We used 3/8″ stainless bolts to fasten these together, but drilled 7/16″ holes. Later, when we glued in the bulkhead, we filled these holes with thickened glue, inserted the bolts, and tightened them down. This forms a very strong bond with all of the bolts loaded equally.

We later mounted the chainplates in the same manner. To glue the new bulkheads in place, we made a mixture of WEST SYSTEM® 105/206 epoxy thickened with 406 Filler to a peanut butter consistency. We removed one bulkhead and buttered the edge where it meets the hull and deck with a thick layer of epoxy using a plastic spreader. We also applied epoxy to the side of the frame where the new bulkhead overlapped it and in the three bolt holes in the bulkhead and stringer. We then clamped and bolted the bulkhead into place. John formed a fillet on both sides of the bulkheads where the glass tabbing would be applied, using more thickened epoxy and a plastic spreader with a radius cut on one corner.

After the epoxy had started to set, John wet out the fiberglass cloth with a mixture of 105/206 and applied the strips. The first strip had 60% of the cloth on the bulkhead and the second layer had 60% of the cloth on the hull side of the joint. This staggering of the glass forms a strong joint without the need to cut two different widths of glass. Air bubbles were worked out with a plastic spreader.

The next day, after careful measurement, we drilled the chainplate holes. Then we glued and bolted in the chainplates as previously described. We later caulked around them on deck. Then we cleaned and put the interior back together. We waited three days before installing the shrouds and tuning the rig. Although this bulkhead replacement job had looked rather intimidating, in reality, it was rather straightforward and we completed it in about 20 hours.

The bottom of the bulkhead/hull joint before the old tabbing was removed. We would extend the bottoms of the new bulkheads so they could be bonded to the side of the floor that ran transversely across the bottom of the hull.

Stress Test

Several weeks later, in the Chicago to Mackinac Island race, we tested our repair. During the second day of the race, the wind had been building and we were surfing, hitting 14’s, when we experienced a hard knockdown that laid the mast in the water. Later that evening, a strong storm tore through the fleet dismasting several 80′ boats, pitchpoling a 40′ catamaran and making a number of sail lofts very happy. We had the full main up and were in the process of taking down our chute when the storm hit. We were told it blew 60-70 knots (we had lost our instruments and masthead unit in the earlier knockdown). The boat and her new bulkheads weathered the storm just fine, and the crew’s nerves are nearly back to normal.

We used the old bulkhead as a template to layout the new bulkhead, and then sanded the edges of the new G-10 bulkhead to prepare the surfaces where the new tabbing will be bonded.

Two layers of 738 Biaxial Fabric tabbing were applied to each side of the bulkhead to reinforce the joint between the bulkhead and the hull and deck.

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Bulkhead replacement tabbing

Discussion in ' Sailboats ' started by boudica , May 27, 2024 at 9:30 AM .

boudica New Member

Hello I am replacing the main bulkhead in a 1975 Ranger 26 because it was rotted through. I have cut the new piece based on the old piece, except that the few inches near the hull was rotted through and I can't get an exact shape. I have found mixed information about the space between the bulkhead and the hull. I read to leave an 1/8" gap? Alternatively, a friend is trying to convince me that I should glue it into place as adhesives are stronger than tabbing and there are enough structural pieces it is being bolted to that it can't flex much anyway. He is a mechanical engineer and before that worked in fiberglass manufacturing of structural pieces (not boat related), but that still isn't boatbuilding. Can someone confirm that I need to do tabbing? And can someone explain what purpose it is serving structurally? I included a picture showing the ceiling, cabinet and settee connections it will have as well as where the old tabbing is. Thanks!  

Attached Files:

Pxl_20240519_040350987.jpg, pxl_20240511_223612996.jpg.

Tops Senior Member

Welcome to the forum Boudica Getting the new bulkhead shape closer should not be too difficult. Put the old one back in the original position and use 'tick sticks' (thin pieces of wood, cardboard can work in a pinch) and tape or hot glue gun them into place to make points to fair a copy of the curve. Picture is tick sticks placed to meet hull to make v-berth top panels without the existing by using cardboard as a substitute. As far as the detail for the bulkhead attachment, is it known if the bulkhead was acting like a partition or a structural member? The quantity of old holes makes it seem pretty important. Are the bigger holes for a chain plate?  

kapnD Senior Member

That doesn’t look like it was structurally tabbed in at all. The wall covering doesn’t look like fiberglass to me, and I see no evidence of fiberglass on the old piece. If it were holding a chain plate, it’s a miracle that it lasted long enough to rot!  

fallguy Senior Member

I’m not going to go into specifics and enter debate. The reason for tabbing is to spread the load. If it wasn’t tabbed before; don’t bother now is a general case. Consider a bond of a 3/4” piece of lumber 4” long. The bond area is 3 square inches. A load of X (say 30 pounds) is 10 psi. Now, extend the bond surface out 3” each side, the bond surface is now 3x12 plus 3 plus 3x12 or 75 square inches. So the 30 pound force is over that space and the psi loading is less than 0.5 versus 10 above. Now extend that case to an ocean load and multiply it by a factor of 20. The 10 psi load is 200 which exceeds most typical foam core compression loads. The one with tabbing is 600/75 or 8psi. So, unless your ME friend does the load analysis and knows the hull strength, he hasn’t earned his tea. A margin is desired. This is to avoid a hardspot that will cascade to the hull outer surface and result in a ridge in the hull. The margin can be filled with a foam pad or it can just be glued, but glues are also hard. You just want to avoid pressfitting the part or it will show.  

I appreciate the insights and friendly welcome. The fabric is hiding the tabbing, it was indeed tabbed in. Though I wonder how long it has been detached from the fiberglass, the wood was so rotted it crumbled everywhere the fiberglass was attached. That is why there doesn't appear to be any fiberglass on the old bulkhead, it disintegrated. It does hold a chainplate, it is located directly under the mast. It is a Gary Mull design and there is supposedly a structural metal beam spanning above the bulkheads under the mast. The boat does not have compression posts here or anywhere that I know of. On the subject of said beam, it is rusting and the rust is leaking through the bolts when it rains. I am going to work on the leaks above to end the leaking to both the beam and the chainplate. The question is, do I need to worry about corrosion of the beam that affects it's integrity? What do you suspect it is made of? Cast iron? Stainless? It is a 1975 Ranger 26, I haven't been able to find details on that. The boat is new to me. It sat neglected for at least two years as the water levels went so low no boats were able to be in the marina. The leaks got bad in that time, not sure it's maintenance before that. The included pictures shows in blue where the bolts are, and the yellow lines is where the tabbing was. I removed most of it, I was considering glueing the new bulkhead to the tabbing tha tis left. It is very stiff, where the rest was fairly thin and flexible. Though, maybe that is a boat sin? Because I am interested in understanding, @fallguy am I correct in saying the purpose of tabbing vs other means is that tabbing distributes the load more, leaving no heavy pressure spots on the hull? I think our tea-less ME thought the only purpose of the bulkhead was for strength to the chainplates. But actually, it is also for distributing the hull pressures. Is that close? I will leave a gap, and use the tick sticks to get a better shape. And it sounds like I will stick to tabbing. I am going to throw in more detailed pics to paint a more just picture of the project.  

I did not mean to offend your ME friend. But an ME ought to recognize a structural connections a bit. Tabbing does spread the loads. And it prevents certain lateral forces from damaging a thin 12mm to 20mm bond. The fact it was rotten threw him off, because when things are bad, anything is better! But I’m rebuilding a church basement and the minimum doesn’t make it nice or even right. Doing things right matters. Your boat has quite a bit of space between the BH longitudinally (seeing none), so do it right. The best way to fix is to remove all the paint and tab it back in with a couple layers of 1708 tapes. I recommend a 6” tape and a 4” tape at least, but if the old tabbing is thicker you could go 3 layers 6-4-4. All tape edges are always staggered and longest pieces applied first. In glasswork, we do not go for shingle effect. Longest first results in less air entrainment and less sand thru. As far as the metal, impossible for me to assess or even consider commenting on the information and my lack of direct knowledge. If there is a structural metal beam with corrosion; best inspect it while you can. I’d hatr for you to repair the BH and then need to remove it for a beam repair. Steel corrosion can be addressed by marine welding guys. It is always dangerous to weld around fiberglass; keep a water hose at the ready, a fire extinguisher is useless if resins get going.  

wet feet Senior Member

If I'm reading this right,that is the main structural bulkhead in the boat and needs to be totally reliable.It appears that the steel beam may bridge the central passage and transmit the compression load from the mast step to the rest of the hull via the bulkhead.Back in the early 1980's I was building 25 foot cruiser/racers that had a similar bulkhead,but with the port half extending to the boat centreline and we were using 5 plies of 200gsm mat on each side to bond that bulkhead to the hull and the first ply only went a couple of inches along the faces,with subsequent plies having an inch overlap on the preceding ply.The chainplates were attached with 5 3/8" bolts to spread the load.so you can get an idea of the loads that were imposed.With any doubt about the condition of the steel beam it would be good for peace of mind to determine the condition and replace if found dubious.It isn't hard to find a tiny camera that could be inserted inside a box section or you might find a tame surveyor with an ultrasonic thickness gauge.For the future you need to find how the moisture that caused the damage got in and make sure it can't happen again.Which may mean removing bolts from deck hardware and re-bedding combined with sealing all surfaces of the new woodwork.Also make sure that if wet goods are stowed in lockers beneath seats that there is a route for water droplets to escape into the bilge,where a pump can deal with it.Gary Mull designed boats that sail well and when you get afloat it will become apparent.  

It appears that the demolition of the bulkhead has stopped at the floor line. The worst of the rot is probably below that.  

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kapnD said: ↑ It appears that the demolition of the bulkhead has stopped at the floor line. The worst of the rot is probably below that. Click to expand...

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Repairing a rotten bulkhead..

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The hardest part of replacing a main bulkhead is getting the plywood into the cabin through the companionway, and getting access to the hull and deck on both sides of the new bulkhead to properly tab in the new bulkhead. Typically getting the plywood below decks means that you end up building the bulkhead out of multiple pieces of plywood that are less than 2- 2 1/2 feet wide depending on the width of the companionway, and laminating the bulkhead out of plywood that is half the thickness of the bulkhead so that you can stagger the joints. The repair technique really depends on your goals for the repair and your skills. Jeff  

Not being a structural engineer but having had some real-world experience with breaking things... I don't think I'd trust a scarfed-in repair. Sure, you could cut out an oval of new wood or fiberglass board that was a foot or so across (no corners, fewer stress concentrations) and then just replace the area where the chainplate bolts in. But all the stress is now being put on the edge of the join, which is what? 3/4" or inch thick bulkhead? Given some lateral movement forward or aft, I'm not sure how well that would hold. If I did it that way, I think I'd want to sister up overlapping larger plates, with a good 6" overlap, on both sides of the bulkhead. Wood, fiberglass board, or bronze or stainless plate, any one of them, just to ensure that the "plug" couldn't pop out of the bulkhead. All through-bolted together as well as epoxied. The alternative is replacing the whole bulkhead, which structurally and aesthetically is probably the only right way to go. But a lot of work, chewing out the old bulkhead, slicing clear whatver they've joined to it "forever", replacing that all again. Some of those nice Japanese hand saws, a bit of molding...and maybe a week or two working with your best friend? Congratulations on the paid off! And just what IS the boater's equivalent of a mortgage burning ceremony anyway?!  

I agree with Jeff, that if the majority of the bulkhead is sound you can, in theory at least make a repair that is every bit as strong as the original by scarfing in a section of bulkhead. Keep the thought though, that if you were to suffer a hard knockdown the momentary loadings on the chain-plates could easily be equal to half the breaking strength of the three wires that are trying to pull it through the deck. The ideal repair would be the whole bulkhead, but if you replace just the outboard section, and ensure a well fit scarf joint to the existing bulkhead and plenty of carefully applied tabbing to the hull you should be fine. Careful workmanship is the key. Personally I would not trust a horizontal joint, at right angles to the line of force. I would be comfortable only with a vertical scarf joint or perhaps a well fit half lap since glues function poorly in a tensile or straight pull application but very well in sheer, or trying to slide one part past its mate. As Hellosailor pointed out, you can gain insurance by sistering up a panel on the other side of the bulkhead and through bolting the works. Both sides would be better, but I see you don't have room aft. Feetup  

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Captain Levi's Fiberglass Boat Repair and Detailing

Fiberglass Boat Bulkhead Repair and Replacement

Fiberglass boats that go offshore in the Captain’s eye’s should have at least four water tight Bulkheads.

A collision bulkhead forward in the bow section. This compartment is used as a anchor rope storage compartment. If the boat is engaged in a head-on collision and the collision bulkhead doesn’t fail you are still afloat! A bulkhead forward of the main engine and bulkhead aft of the main make up for the engine compartment. Stuffing boxes for shafts through hull fittings below the water line are contained here. Hopefully, if they leak or the fiberglass boat hull gets breached below the water line, the water will be contained in the engine room. The bulkhead acts as a sound, heat and fire barrier as well.

Aft to the stern, another bulkhead makes up the Lazarette where the rudders are. Dropping a rudder offshore is a traumatic experience even for a well seasoned old salt! Bottom line survivability, matey. Pay attention to your fiberglass boat bulkhead!

Boat Bulkheads are constantly under attack. As the fiberglass boat hull runs through a sea, flexing and vibration occur stressing the bulkhead. Moisture in the bilge add to the problem. Heat from main engines, generators and vibration add to the stress. Bulkheads are structural members of the fiberglass boat hull adding the transverse strength to the boat hull and reducing flexing.

Prior to the late ninety’s most fiberglass boat builders used marine plywood for bulkheads. It was laminated to the fiberglass boat hull with polyester resin and fiberglass mat and fiberglass woven roving 24 oz. This process is known as taping-in or tabbing. Done correctly, the eight to twelve inch strips of fiberglass mat and fiberglass woven roving are wetted out with polyester resin laminated to the fiberglass boat hull and to the marine plywood bulkhead, making a strong connection. Over time and use it’s not uncommon to find the fiberglass de-laminate away from the plywood bulkhead or the plywood degrading. A close inspection will tell the tale. The 1977 thirty five foot solid fiberglass Bruno/Stillman Sport Fishermen came to Captain Levi for bulkhead replacement in 2003. Twenty Five years of time and offshore waters broke two of her bulkheads lose. The integrity of the marine plywood was gone.

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Replacing the Bulkheads in my Tanzer 22

Why replace the bulkheads.

When I had my Tanzer 22 surveyed, the report noted that there was some delamination of the plywood of the bulkhead due to moisture. Both sides have had water dripping in from the chainplates and both sides have had some water damage at the base.

Since the bulkhead support the chainplate which can put alot of tension on the wood, it's better to be safe than sorry, so I need to replace the bulkheads, and the bent chainplates.

The bulkheads also support a wood beam inside the fiberglass. This supports the mast and can have a lot of weight put on it when the boat is underway.

There is some damage on the bulkhead at the very left. The drips from the chainplate are also visible. My Tanzer has wood veneer not the plastic I've seen on some of the other boats.

There are 3 slot head bolts at the very top that need to be removed. As well there are some bolts inside the locker just back of the bulkhead.

There is also a moulding that run from the ceiling to the floor, 4 screws hold it against the bulkhead. it's strong enough to have some part in supporting the deck and mast above.

Nice easy to access nuts and bolts in the locker behind the bulkhead.

On the starbord side these bolts are under the sink and will be a tight fit to remove.

Small Mystery: Why is there a notch cut into the bulkhead on both sides of the boat. For curtains? Wiring? There is no structural reason that I can see.

Some damage to the outside layer of the veneer is visible in the corner. On the right the chainplate is clearly bent. This photo is of the starboard chainplate. The bottom image is of the slot where the chainplate goes into the interior. it's easy to see how it could allow water to get in if it's not perfectly well caulked and bedded. There was probably some water coming in after the chainplates were bent.

The chainplates get bent when the mast is lowered without loosening the side stays. If the metal is bent back it can cause metal fatigue so it's better to leave the chainplate bent than to try and straighten it back.

View from the front of the boat shows the fasteners. There is also some wiring to be removed, the lightning rod wire, and light fixture wire.

The chainplate backing plate is still in place. It has 4 nuts and bolts. (I took this photo before removing the chainplate)

Once all the screws were removed including the ones holding the wooden moulding in place it was simple to slide the bulkhead out. I wedged the moulding so it pushed up on the roof slightly. This allowed the bulkhead to slide out without any trouble.

Since the mast has been taken down for the winter storage there is no weight on the top of the cabin. I avoided walking on the top while I was doing this repair. I don't know if it matters.

I was worried that the roof might sag when the bulkhead was removed but that did not happen. I left the moulding in place to support it just in case.

I was also worried that the bulkhead would be wedged in place by a sagging deck but that is not the case. The good guys are winning again.

The plywood I removed was not in terrible shape. The chainplate holes were dry and the wood was not delaminated except for the thin veneer on the top. There was also slight discolouration on the very bottom where it had at one time stood in water. It is 3 layers thick with 2 very thin outside veneers.

I took the piece home where I have a piece of Meranti nice and flat on my dinner table waiting to be shaped. I had kept it from the Apple Pie Dinghy build.

The space looks very large and empty now that the bulkhead has been removed. I've left the moulding up to keep the roof from caving in! I'm joking, but I want to avoid any distortion that would make it harder to replace the new bulkhead.

Here is a link to my page about Marine Grade Plywood. There are very stringent requirements to be met if it's to be true marine plywood.

Now I need some information. Can I get a chainplate from Tanzer Parts, or do I just go to a metal shop and have them make me a replacement? I would like to know what the funny little cut out in the side of the bulkhead is for.

Since I hate slot screws with a passion, I will see if I can replace the original ones with Robertson head. It might be difficult since it looks like the originals were cut to fit. Maybe it's not a standard size.

I carefully aligned the old bulkhead onto the Meranti Plywood. it's 12mm I think, It always feel a bit silly to order a 4 feet x 8 feet x12 mm. sheet of plywood. Talk about mixed up units. The outer edge that is covered by the moulding is the only non beveled edge except for the little cut out. Every other edge has a slight angle. The sides are not straight either. It looks like someone took a sander or a grinder to fit it in the original Tanzer shop.

After marking the perimeter and all the bolt holes marked I asked Winston to inspect the piece before cutting. I then clamped the wood to the table. I drilled 2 of the marked holes at each corner of the bulkhead, to have a way of aligning the pieces after they are cut so that I can re align them with no shifting.

I used a jig saw with fine teeth blade. It cuts without leaving a burr. I guess it's slower than a regular blade but this plywood is brittle and the edges chip and tear out if the blade is coarser. On the Skerry build I used metal blades sometimes. It was slow but clean.

To make the bevels I used a combination of my random orbital sander, a file and sandpaper on a block and my hand plane. it's tedious to shape. My little plane worked in some places but others it was too hard and on end grain and the sander was faster.

New bulkhead piece is cut out and beveled. Tomorrow I will take it to the boat and spend a happy afternoon fiddling to fit it. I have no illusions that it will just slide in. After the fitting I know I will need to make it slightly smaller because I plan to epoxy and varnish the bulkhead and this will thicken it up again.

I've located a few machine shops nearby and I will now call them and see if they can fabricate new Tanzer Chainplates. I will not make it bigger. There was no sign of stress on the bulkhead and no distortion of the screwholes so I don't see the need. I will also not use thicker and thus stronger metal because I think I prefer to see damage on the chainplate where it is easy to spot than on the mast fitting or the stays, where damage might not be so obvious and more expensive to fix. When there is a lot of stress something has to give, I prefer to know what.

Should the chainplate fail there is always a chance of grabbing the end and tying it down to something on deck. There is no chance of doing this if it fails from the top of the mast.

The colour of the Meranti Plywood looks grayish but comes up a rich brown colour once finished as on my Apple Pie tender transom. I painted over the epoxy but the colour was very nice.

My day job interfered with my life and I did not get to the boat. I did get the chainplates made though.

I had left the original damaged chainplate at a machine shop near my home.

The shop is quite high end but so conveniently close that if I count even a fraction of my time it's worth paying a slightly higher price.

They did a fabulous job and the new Tanzer chainplates are absolutely identical except for the finish. They put a bit of a satin sheen on. They look very classy!

When I brought it in the owner said that there would be no problem making the part and that most of the time would be spent drawing the part in a CAD program. The actual machining is very fast and automated.

The shop is immaculate and the floor is full of huge automated cutters, lathes and tempering gismos. They also have a hands on room with more recognizable equipment and men who actually get dirty hands.

After drilling the various holes, I wrapped the new part in an old sheet and took it to the boat to check the fit. It was almost right. I need to allow for the slight curve of the angles of the fiberglass and cut a bit off the edge.

I also checked the mast head to see if the stays or the mast connection was damaged at all. I was worried that the wire might have pulled out of the connector. There was no damage and the stay was in good shape.

I still need to round the edge to accommodate the radius on the fiberglass.

The top edge also needs trimming to fit against the fiberglass rounded corner. Since these 2 edges won't be showing it's not too stressful.

The boat cover makes a tent and it's surprisingly warm and cosy inside. I can sit on the seat without touching the roof. When it gets cold and I want to work on the boat, I can set up a small heater.

I took the bulkhead home and sanded it slightly smaller and rounded the inside edges. After testing it for fit I'm happy. The bulkhead is quite tight but fits. I took it home and did a final adjustment to allow for the epoxy thickness and some varnish.

Sanded all the holes smooth. There was some burr left over after the drilling. Used a small file and rolled up sandpaper.

Sanded the whole surface and erased any pencil mark still on the edges.

I thinned the edge that has the trim so it will still fit in after the epoxy and varnish. Dusted everyting and I think I'm ready for epoxy.

Put the epoxy in warm water to warm it up after coming in from the cold garage. I'm using slow set to let it penetrate as much as possible. I like having lots of time to apply the epoxy without worrying.

Used a small paintbrush to coat all the drilled holes with epoxy. In particular the chainplate holes were saturated. If water ever comes in it won't ever get wet.

The Tanzer bulkhead now has a coat of epoxy on both sides (I used small nails stuck in the table to support the back side)

I paid particular attention to the edges to make sure they were saturated. I love to see the wood come alive after the first coat of finish. it's a lovely rich brown. Photo is a bit blotchy but it's quite even.

This is the point in the project where if I had to I could put the boat back together and it would work just fine. The rest is for appearances.

I was calculating how long I had spent so far. Take the bulkhead off the boat: 1 hr Mark it and cut 1.5 hrs Bevel the edges and fine tune the edge 1.5 hrs 2 tests on the boat and adjustments 2 hrs final sand and epoxy coat 1 hour So far a total of 7 hours, but no rushing involved. So this job takes about 12 hours at a leisurly rate completely re-assembled not counting getting the materials. I had all that from the floor repair. If I had done the 2 sides at the same time it would have saved time but I prefer to have some support on the bulkhead in case there is some sagging.

I've had enough of sanding epoxy. it's pretty smooth now. I've re-drilled the holes where epoxy had thickened the opening too much. I've tested the fit in the boat again and it's good.

it's interesting that the top had settled very slightly. I will be able to push it up but it had come down about 2 mm. I'm glad I left one bulkhead up and a support as well.

I'm using Behr spar varnish on the carefully dusted bulkhead. The colour is slightly browner than the original but it's a lovely colour. I'm planning to put several thin coats. I'm in no rush to finish.

First coat is on and drying. it's going to look nice on my little boat.

After several coats of varnish, I dulled it with extra fine steel wool and waxed it. The bulkhead feels lovely and has a nice dull shine. it's far from perfect but will pass the 4 feet rule. If you can't see a flaw at 4 feet it's good enough!

Finally a lovely sunny day and I brought the bulkhead and starting installing it on the Tanzer. I had to push up the top a small amount but there was no real difficulty. My port navigation lights have little screws protruding and one was digging into the bulkhead. I had to go unwrap the boat and unscrew it. I'll replace it with a slightly fatter and shorter screw that does not extend into the bulkhead.

I used an awl to line up the screw holes. It worked well and I got all my bolts in place. They all lined up perfectly. Beginners luck!! I though I would have to re-drill some but I got lucky. I intend to replace some of the bolts. The originals were slightly bent and seemed to have been cut to size from longer bolts. The chainplate hole was gummed up with old silicone. It took a long time to clean it up. When I can access the outside more easily I will clean up on deck and put 3M 4200 to seal the chainplate and the hole.

The lower nuts and bolts are in place as are the top ones. I plan to replace the top ones. The chainplate is loosely bolted in. All the holes lined up perfectly and the bulkhead fits. I tapped in the edge moulding but I plan to refinish it after the 2 bulkheads are installed. Right now I prefer to have it supporting the deck

The Starboard bulkhead is more damaged but I did not realize the extent of the rot.

Starboard Bulkhead

From the outside there seems to be minimal damage but once I took the bulkhead off the inside was quite rotten. The delamination is not severe except for the thin top veneer. There is rot for about 2 inches around the corner. The rest of the wood is quite strong. I'm wondering if some of the water came from the sink along with the leaky chainplate.

It was a bit trickier to remove this side because the sink is in the way and it's awkward not being able to stand nor sit. The nuts live under the counter too. The worst was my mistake. The outside moulding from the port side was held on only by screws. The starboard one is held by screws AND a nut and bolt. It took a while to figure this out. sigh!!! I thought the screw was not catching and just turning freely.

Spring is almost here and there is still lots to do with with boat. I'll get this bulkhead done more quickly now that I know how.

Launch looms closer now. I have completed the starboard bulkhead and sanded and varnished the vertical wood strips that trim the edges. Everything fits.

Everything went together quite well. I had to do a couple of fittings to get the bulkhead to slide in but nothing major. The trickiest part was putting the nuts on the bottom. There is not a lot of space between the sink and the bulkhead to hold the nuts. It's not hard particularly just fiddly and I kept dropping washers and having to hunt for them.

I removed the chainplate deck fittings and found that they had been seated with silicone. it's always difficult to remove all the old stuff and I had to scrape and sand the deck and the slot. I'm sure I left some inside the slot.

I put an extra large dollop of 3M 4200 and replaced the chainplate and secured it from the inside. I then gooped up around the chainplate and replaced the now cleaned fitting. I made a mess but I think I got the plate down and I don't think this will ever leak for as long as I'm alive. I was using compounds that had just began setting off so it was slightly thicker than when it's fresh so it resisted coming out of the tube. My inside caulking is not so very nice. It was setting quite quickly so I did not have lots of time to fiddle and clean as I went.

I finally got everything back together. The new bulkheads, the new chainplates waterproofed, all the screws and nuts tightened and the wood trim glued and screwed back in position.

I guess I will go back and tidy the caulking after it has set, but for now, I'm done! The good guys win again!

Small Print

This information is for general knowledge. I don't suggest that this is the only way or the best way to fix your bulkheads. Use your head and do your research.

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Bulkhead Replacement?

• Thread starter Fly_H23
• Start date Jun 28, 2012
• Oday Owner Forums
• Ask An Oday Owner

Ok, might sound stupid but is it possible to replace the bulkheads on an O'day 26 while it's still in the water? And with the mast still up? I'm thinking, do one side at a time and use the halyards as safety lines while I re-bed each sides chain plates? If the stays are slightly slackened so no excess compression forces other than weight of the mast on the compression post..? Am I crazy or just ignorant? I have access to a trailer so I can haul out. Dropping the mast I'd like to do only if it's advisable and prudent. The seller (not my boat yet) appears to have covered the original bulkheads or possibly a thinner replacement with cedar siding! It smells good but adds no structural support.  

Attachments

I would drop the mast and stow it on land and do all the bulkheads.  

You Need To Drop The Mast  

Drop the Mast. Better yet wait for winter.  

bria46 said: Drop the Mast. Better yet wait for winter. Click to expand

Gonna take one more look at the bulkheads this week before we make a decision to buy or not. The PO had a "carpenter" replace a lot of the woodwork inside, me thinks they either covered up the old bulkheads with cedar siding. The bulkheads may have been replaced with some sort of plywood then covered they covered it. PO has no knowledge of how the repairs were done, he just paid the carpenter to "fix" it. Makes me worry alrighty! Price is very very realistic given the condition. On the good side, she has a new roller furler, 140% genoa and new cushion covers throughout. I will defiantly pull her out if the bulkheads need done and do a bottom job as well. Will update as the saga continues.  

Most everything can be fixed. If it's decent shape and the price is right. I spent 18 mo rebuilding mine.  

True, but by the time I'm done I could probably buy a well maintained boat, right? I don't mind a repair or three but don't want to spend months on it.  

Fly_H23 said: True, but by the time I'm done I could probably buy a well maintained boat, right? I don't mind a repair or three but don't want to spend months on it. Click to expand

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