Hi all,
We have a 1984 Beneteau First 38 and have just spent the last 4 days removing 20 Keel Bolts.
DÉESSE has a keel-stepped mast and it is nearly impossible to stop water from making its way down the inside of the mast. Yes, there is “internal dam” within the mast that is located at deck level to divert water that comes down the ID of the mast through a drain hole that exits to the deck. However, after 32 years of service, the “dam” does not appear to be watertight.
We do not have any noticeable leakage through the keel bolt holes and thus are not planning on dropping the keel to reseal the hull to keel joint. Once the bolts are removed and inspected the lack of rust or presence of rust on the lower sections of the bolts will be a good indicator as to whether the hull/keel joint is or is not still tight.
Prior owner was not too vigilant in ensuring that there was no water coming in through/around the mast, through the mast boot, through the shaft log, and through the speed/depth transducers. Thus, the bilge was continuously wet and the heads of the keel bolts rusted over time.
In various forums and Facebook groups we have noted others with similar questions. Thus, here is the procedure we followed:
We contacted Beneteau USA and they were able to provide vintage 1985 “Keel Attachment” drawing for First 38. The First 38’s of that era had 2 keel options
Bad news: There are 21 bolts to remove! (Although we have only found 20.)
Beneteau recommends “DACROMATISED” (i.e., galvanized) carbon steel bolts since the keel is iron. We have ordered a complete set from Beneteau with appropriate washers.
The keel bolts are the same size for both the deep and shoal keels. Only the number of bolts needed varies.
Bolt Spec: 20 mm (0.78 inch) OD x 80 mm (3.14 inch) length with ~70 mm (2.76 inch) of exposed threads which will need a 1 3/16” (30.16 mm) socket. (We will try 30 mm socket.)
We are on the hard here in Chicago and DÉESSE is on a cradle stored inside. It took us 4 days to remove (1 by 1) the keel bolts. First task was to find the 21 keel bolts shown in the Beneteau drawing. We only found 20 and suspect that the furthest aft keel bolt shown on the drawing was not installed on our keel.
Location of bolts:
Starting from BOW:
Work Procedure:
We have a 1984 Beneteau First 38 and have just spent the last 4 days removing 20 Keel Bolts.
DÉESSE has a keel-stepped mast and it is nearly impossible to stop water from making its way down the inside of the mast. Yes, there is “internal dam” within the mast that is located at deck level to divert water that comes down the ID of the mast through a drain hole that exits to the deck. However, after 32 years of service, the “dam” does not appear to be watertight.
We do not have any noticeable leakage through the keel bolt holes and thus are not planning on dropping the keel to reseal the hull to keel joint. Once the bolts are removed and inspected the lack of rust or presence of rust on the lower sections of the bolts will be a good indicator as to whether the hull/keel joint is or is not still tight.
Prior owner was not too vigilant in ensuring that there was no water coming in through/around the mast, through the mast boot, through the shaft log, and through the speed/depth transducers. Thus, the bilge was continuously wet and the heads of the keel bolts rusted over time.
In various forums and Facebook groups we have noted others with similar questions. Thus, here is the procedure we followed:
We contacted Beneteau USA and they were able to provide vintage 1985 “Keel Attachment” drawing for First 38. The First 38’s of that era had 2 keel options
- Deep Keel, Iron, 2.1 meter (6.9 ft) draft, 2840 kg (6261 lbs), 14 keel bolts
- Shoal Keel, Iron, 1.5 meter (4.9 ft) draft, 3300 kg (7275 lbs), 21 keel bolts
Bad news: There are 21 bolts to remove! (Although we have only found 20.)
Beneteau recommends “DACROMATISED” (i.e., galvanized) carbon steel bolts since the keel is iron. We have ordered a complete set from Beneteau with appropriate washers.
The keel bolts are the same size for both the deep and shoal keels. Only the number of bolts needed varies.
Bolt Spec: 20 mm (0.78 inch) OD x 80 mm (3.14 inch) length with ~70 mm (2.76 inch) of exposed threads which will need a 1 3/16” (30.16 mm) socket. (We will try 30 mm socket.)
We are on the hard here in Chicago and DÉESSE is on a cradle stored inside. It took us 4 days to remove (1 by 1) the keel bolts. First task was to find the 21 keel bolts shown in the Beneteau drawing. We only found 20 and suspect that the furthest aft keel bolt shown on the drawing was not installed on our keel.
Location of bolts:
Starting from BOW:
- 1 in the section adjacent to the forward head (required removing a portion of the internal liner to access the bolt)
- 4 in the section just forward of the mast
- 4 in the section just aft of the mast (2 of these are partially under the corner of the mast step base)
- 2 in the section where bilge pump is located
- 4 in the section in next section aft
- 4 in the section in next section aft
- 1 in the section in furthest aft section
- 1 just 34 cm (13.38 inch) aft of the one listed above <- NOT FOUND
Work Procedure:
- Using digital calipers, we measured the size of what remains of the rusted bolt heads. Although they all may have been 30 mm bolt heads when new, after 32 years of being exposed to bilge water, they now ranged from 22 to 30 mm. Thus, I bought 22, 24, 27, 28, and 30 mm sockets.
- Remove still flexible (although not watertight) layer of sealant that covered some of the bolt heads.
- Remove loose rust/scale with wire brush attached to drill.
- Some bolts had round washers, some square washers, and some both (round on top of square).
- Using a DREMEL with a heavy-duty cut-off disc, the bolt head was separated from the washer by cutting horizontally at the junction between the base of the bolt head and the top of the washer. It took about 1 disc per bolt to cut around each of the bolt heads. Rationale for this cut is to separate the bolt from the washer. If the bolt is attached (rusted) to the washer the amount of force required to remove the bolt is (a) force to extract the bolt from the threads in the socket in the keel, PLUS (b) the force required to turn the washer which is attached to the fiberglass hull with adhesive. By separating the bolt from the washer, the force required to remove the bolt is significantly reduced since ONLY the bolt is rotating.
- Next step was to “square up” the 6 sides of the bolt head so that I could have any chance of forcing one of the sockets onto the bolt head.
- I then used a hammer to force fit the socket onto the rusted bolt head. I then used a DEWALT battery powered impact wrench to break free the bolt. I was only able to get the bolt to loosen by a ~ ½ turn with the impact wrench, as the impact wrench was only able to break loose the bolt. The impact wrench was not able to fully unscrew the bolt since there was considerable amount of sealant (again still flexible) surrounding the bolt in hole drilled in the hull for the bolt. I had to manually unscrew the bolt with a socket wrench until the sealant – which was still attached - broker loose. At that time, I was able to use the impact wrench to unscrew the remainder of the bolt – easily and quickly.
- Upon removal each of the 20 mm OD x 80 mm L (with ~70 mm of exposed threads) bolts were inspected and condition noted as follows:
- Severely rusted bolt head (originally ~10 mm height)
- 5 mm thick washer
- 13 mm (hull thickness of ~ ½ inch) upper section <- upper portion rusted from water coming in from water in bilge
- 52 mm of bolt in receiving socket in keel <- essentially as new without rust thus indicating no leak at hull/keel seam
- Check: 5 + 13 + 52 = 70 mm
- Severely rusted bolt head (originally ~10 mm height)
- We removed the bolts, one at a time, and then reinserted the original bolts – for now.
- Our intent at this time was to simply confirm that each keel bolt could be removed. If during this process we had snapped off a keel bolt or simply encountered one that would not budge we would have had to (a) remove remainder of keel bolts, (b) grind off the head of the keel bolt which would not budge, (c) lift the hull and/or drop the keel to expose the stubborn keel bolts, and (d) use a pipe wrench to forcibly unscrew the stubborn bolt.
- New keel bolts & washers are on order from BENETEAU USA.
- We will be installing the new keel bolts in a week or so. We have yet to decide what type of sealant to use in the gap between the bolt and the slightly oversized hole drilled in the hull. It is definitely not 3M 5200 or 4200. It is still flexible after 32 years. Anyone have any idea as to what it may be?
