Beneteau First 405 keel bolts

[prof_mariner]

Hi,

I'm looking at a 1987 Beneteau First 405 that looks to have some of the typical issues of the Beneteaus of that vintage. One area that concerns me most are the keel bolts. The keel on Beneteaus of that vintage are cast iron and galvanized, high tensile steel bolts were used to secure it to the floor of the boat. The keel bolts on this boat are pretty badly rusted, and the very aft most bolt appears to be directly under the Perkins diesel engine. I've already done a bit of homework on the subject but after talking to the local Beneteau dealer I've gotten some conflicting opinions on how to handle the issues.

The advice I found on the internet recommends I clean up the rusty bolts and replace them one by one with galvanized, high tensile steel replacements available through Beneteau USA.

The local Beneteau dealer said what they do now is to drill new holes (though the floor and into the cast iron keel) and install new stainless steel bolts.

I'm not sure I like that idea for several reasons:

1 - I fear the use of dissimilar metals (cast iron + stainless steel) will cause bigger headaches down the road.

2 - Stainless is weaker than high tensile galvanized (what the original bolts were made of).

3 - When it comes time to sell the boat it's surely to get the scrutiny of the marine surveyor.

Opinions anyone?

The real sticky issue will likely be that keel bolt that is directly under the engine. There's maybe 4 - 6 inches of clearance under the engine so it will be darn near impossible to pull the old bold out without first lifting the engine. I wasn't really able to see the condition of that bolt on my last visit, but when I poked my fingers in the hole it felt like it was in really bad shape.

Anyone else have a F405 and have any ideas how to handle this?

[gts1544]

prof mariner, We have replaced the keel bolts in our 1986 Beneteau Idylle 11.5 M , based in the BVI, several times now due to the biannual insurance survey complaining about corrosion on the heads due to bilge residual water. First, we purchased the 14 keel bolts from Beneteau USA at great savings over procuring them down there. Be sure to buy a couple of extras, just in case! Second, This last time, we had the keel bolt heads painted with an epoxy paint to ward off corrosion and it seems to be working. Third, we installed a garboard drain, which can be opened when the boat is stored up on the hard, thus ensuring a dry bilge during storage. It will also ensure a very wet bilge if you don't remember to reinstall it prior to splashing!

[neilpride]

If you want peace of mind i guess you need to discover the real condition of the bolts, use a small mirror and a flashlight and scrape the rust in top of the bolts, superficial rust and corrosion are 2 diferents things, if the easy reach bolts after a good brushing and cleaning looks ok, can be ok also the bolts in that tight engine room spot, ss and steel are far away in the galvanic scale , if bolts are complety toasted , i think mate you need to pull up this engine anyway, regarding making new holes and screwing new bolts i vote to replace the old ones and install new ones, Good Luck.

[prof_mariner]

Thanks, both of your comments echoed my thoughts exactly. I'm going to give Beneteau USA a call tomorrow to find out what they have to say. Hopefully they still have those keel bolts or at least a source for them.

@neilpride - I can only do a visual inspection since I don't own the boat, but the bolts appear to be much more corroded than just surface rust. The washers under the bolt heads are almost completely gone.

[avant]

I replaced the bolts in my 1985 First 435 2 years ago.

I used the bolts supplied from Beneteau, with washers they also supplied (the original bolts did not have washers). Cost was very fair, I think $10-15 ea.

The original bolts did look horrible with rust, but on extraction the hidden working surfaces were all ok. One reason for the change was a fear that if left much longer it would become near impossible as the exposed surfaces continued to corrode. One bolt did require the removal of the hot water tank to access. I can't comment on the problems the engine location might cause in the F405.

After installation, all the bolt heads and washers were cleaned and brushed with a thick coat of clear epoxy. Clear epoxy was used so I could see through to the bolts and monitor their condition. I have seen other boats that poured a deeper coat of epoxy on the bolts, resulting in a hockey puck like epoxy plug on the bolt, which might be more durable in the long term, but what I have seems to be standing up fine and allows clear visual access for inspection. As the original bolts were good for ~25 years without the epoxy clear coat, I have high hopes that this renewal will be good for a bit longer.

I do not see any point in changing to SS bolts at increased expense and perhaps a danger of crevice corrosion over time, but that's just my opinion.

[prof_mariner]

@avant - Thanks. You'll be happy to know that the tech I spoke with at Beneteau USA pretty much echoed what you said. On the newer model boats, however, they've switched to stainless steel bolts to secure the cast iron keels. If I can locate them, my intention will be to replace them with galvanized and, like yourself, seal them with clear epoxy.

[dwessner]

Question for Avant: Have a First 345 from 1985 and am exploring replacement of keel bolts. I see that you have replaced bolts on your 435. Can you tell me: did you drop your keel before installing new bolts, or did you replace them one at a time with the keel in place? If in place, did you replace on land? Was it a deep draft fin keel or shoal draft? Did you need to open up part of the interior floor boards in order to get to all of the bolts? Sorry for all the questions but it appears you have done a tremendous job, based on your comments in this thread.

If anyone else has advice, please let me know. Trying to make up mind about a keel bolt replacement that has been estimated between 5-12K from a really topnotch marine repair shop.

Thx!

[prof_mariner]

Mine are done. Bottom line, if your keel / hull joint isn't leaking there isn't any reason to drop the keel. I have the deep keel model F405 and did mine one by one in the slip. Had to lift the floor boards to do it. Hardest part was finding the right tools (impact wrench, compressor and sockets) to do the job. Fortunately, Harbor Freight had most things and friends had everything else. My bilge is bone dry and bolts replaced.

[avant]

Avant Answers:

1) did you drop your keel before installing new bolts, or did you replace them one at a time with the keel in place? In place, the driver for this decision was an excellent keel/hull joint with no weeping, movement, or apparent damage to the joint or adhesive.

2) If in place, did you replace on land? Yes, on land, and I would think it is worth the cost of a haul out as extra assurance for the integrity of the keel/hull joint. Doing them one by each in the water it's possible the joint could open a bit and be compromised, blocked on land it can't.

3) Was it a deep draft fin keel or shoal draft? Deep, 8'

4) Did you need to open up part of the interior floor boards in order to get to all of the bolts? No, but had to remove and replace the hot water heater to get at one or two of them. The 405 wil be different, of course. If you call beneteau they can tell you how many bolts there are, and you can eyeball their locations to get some estimate of the difficulty. We had 13 bolts, and we saw and counted 12 before we got the number from Beneteau. The 13th we didn't see (it was the one under the hot water tank, obscured by the tank, wiring and hoses).

We got the bolts and washers from Beneteau USA, they had them in stock and reasonably priced. Our only departure from the original install was to have the bolt heads brushed with clear epoxy after install to preserve them long term. Two years later, they appear the same as the day they were installed. The work was about 3 days of yard labour, using 1-2 workers, and none of the bolts snapped off or was too hard to get out. If one of the bolts had snapped or needed extra persuasion, it would have been ugly, labour-wise. You do need a huge socket wrench, piece of pipe to extend the wrench handle, and a massive torque wrench to do the job. As I think I mentioned, the parts of the bolts we couldn't see before taking them out were just fine. They appeared as new.

On the 405, isn't the engine over at least some of the bolts? You may need to lift it to get at them, and that would lead to higher labour costs.