Re-bedding fuel fill on teak deck (CHB)

socalrider · Jul 1, 2020

Hi all,

Attending to one of the items picked up on the survey on our CHB 41 Trawler - seems like a pretty common story: fuel filler bedding failed, leaks drained down the fuel line to the top of the fuel tank.

I'm going to replace the fuel tank eventually, but thought I'd try and salvage it first now that I've spent a bit more time crawling around the top of the tank (it's tight down there!). The corrosion does seem to be limited to just around the fuel fill and I suspect it only started recently, so hitting it with a wire brush, cleaning with acetone and painting with Corroseal might save it, or buy me some more years.

First though, I've gotta stop the leak by re-bedding the fitting, and replace the degraded fuel line while I'm there. Getting the fitting out is proving to be tough: one of the three brass screws is buggered and it's proving tough to break the thing loose. Advice on process is welcome - I'm thinking about whether I could find a piece of threaded pipe to screw into the fitting to give myself some leverage?

Finally, what's the best process for bedding hardware on a teak deck? The fitting is not flush - it appears to sit on top of the teak. I can take some pics tomorrow when I'm back down there. I've bedded deck hardware on fiberglass, but it seems with this there's an extra interface between the teak and the fiberglass that needs to be accommodated and I'm not quite clear how.

Thanks in advance!

Comodave · Jul 2, 2020

socalrider said:
Hi all,

Attending to one of the items picked up on the survey on our CHB 41 Trawler - seems like a pretty common story: fuel filler bedding failed, leaks drained down the fuel line to the top of the fuel tank.

I'm going to replace the fuel tank eventually, but thought I'd try and salvage it first now that I've spent a bit more time crawling around the top of the tank (it's tight down there!). The corrosion does seem to be limited to just around the fuel fill and I suspect it only started recently, so hitting it with a wire brush, cleaning with acetone and painting with Corroseal might save it, or buy me some more years.

First though, I've gotta stop the leak by re-bedding the fitting, and replace the degraded fuel line while I'm there. Getting the fitting out is proving to be tough: one of the three brass screws is buggered and it's proving tough to break the thing loose. Advice on process is welcome - I'm thinking about whether I could find a piece of threaded pipe to screw into the fitting to give myself some leverage?

Finally, what's the best process for bedding hardware on a teak deck? The fitting is not flush - it appears to sit on top of the teak. I can take some pics tomorrow when I'm back down there. I've bedded deck hardware on fiberglass, but it seems with this there's an extra interface between the teak and the fiberglass that needs to be accommodated and I'm not quite clear how.

Thanks in advance!

As to the screw you cannot get out, is this a screw that is going into the deck to hold the fitting in place? If so maybe drilling the head off the screw.

As to bedding the fitting, it is going to be tough to seal it very well on top of the teak deck. Off the top of my head I think maybe cutting the teak back from the fitting about an 1” and then getting some G10 fiberglass and cut a donut of it to fit up next to the teak and the middle to fit the filler fitting. Then glass it to the deck and seal around it with a teak caulk. Make the G10 thick enough so that the filler will be proud of the deck. Then bed the filler to the G10 with butyl tape. That way you should have a good water seal. And by making the fitting proud it will make it more difficult for water to get into the fuel tank because of a worn O ring on the cap. Water will flow around the filler rather than flow over the cap. You could make a jig to route a big O where the teak deck needs to be removed and you will get a nice cut in the teak.

BrianG · Jul 2, 2020

photo?

Pete Meisinger · Jul 2, 2020

Drilling the head off a brass screw is easy. Once the hardware is removed the remaining screw will walk out with a pair of vice grips.

People will tell you 4200 or 5200 for bedding but I have the proper answer..

There is an OLD product called "Bedding Compound". The normal marine purveyors should handle it. It is a gooey beige putty like compound which seals tightly, does not harden and actually does what it is supposed to do.

A few bucks for about eight ounces, the can will last the average boat owner his entire life.

pete

timb · Jul 2, 2020

i think dave has a good idea and mine is leaking also .i tried resealing to no avail but it not hurting my new plastic tank . i even fixed bung and sealed screws around the filler . it's possible the water is traveling through the core from another area . i know yikes.

jleonard · Jul 2, 2020

I would use TDS 440 the same stuff used as caulking between the teak decks.

Also, last year I saw some rust on top of my port tank. After removing the insulation panels and cutting about 12 inches of the luan I scraped up the loose stuff with a putty knife.
Then bought a 3 part fuel tank sealing kit from Eastwood and applied it to the top and as much as I could reach with a small roller.
Even though it was rusty, it was still very solid(where I could get to it).

Always Late · Jul 2, 2020

I recently resealed mine with TDS 440 and had no leaks during the recent tropical storm we just had down here on the gulf coast. My first time using TDS and i am liking it. Re-caulking my teak decks in sections and did tank fills first.

koliver · Jul 2, 2020

Butyl Tape

socalrider · Jul 2, 2020

koliver said:
Butyl Tape

Thanks guys, this is really helpful. I'll try and get a pic shortly.

Comodave's suggestion seems like the most secure (also the most work). For those advocating a simpler solution (like the Butyl Tape, which I saw in other posts - actually have some on order) I imagine you need to seal both at the top fiberglass, the teak surface, and the screws. Is this realistically achievable? Any tips?

Comodave · Jul 2, 2020

Yes, my way is a lot of work, but it is also the best solution. I would epoxy the G10 down to the deck with thickened epoxy. Then use TDS 440 to caulk a joint around the G10 in between the teak. Jamestown Distributers has the G10. You don’t really need the structural qualities of G10 but I suggested it because it comes in different thickness and sizes. That way you don’t have to layup a thick piece of fiberglass yourself. I would take a router and set it to the depth of the teak and whatever is under the teak down to the top of the fiberglass deck. Make a template that will give you the proper size hole got the G10. After removing any screws that may get in the way of the router, route the teak out. Then set the G10 in place with thickened epoxy. After it goes off tape where the TDS440 goes so you don’t get it all over. Caulk the seam around the G10 and then install the filler fitting with butyl tape from Compass Marine, it is really quality butyl. Then enjoy the leak free filler...

koliver · Jul 2, 2020

socalrider said:
Thanks guys, this is really helpful. I'll try and get a pic shortly.

Comodave's suggestion seems like the most secure (also the most work). For those advocating a simpler solution (like the Butyl Tape, which I saw in other posts - actually have some on order) I imagine you need to seal both at the top fiberglass, the teak surface, and the screws. Is this realistically achievable? Any tips?

You don't disclose the type of boat you have, other than a picture that looks like a typical Taiwan build.
If so, the teak deck is laid in a black adhesive, probably a polysulfide, then screwed through the adhesive to the fibreglass decking, maybe into the core, maybe not, then the screw covered with a bung and the spaces between the boards filled with black caulking, which may be what was used under the teak as well. The teak itself doesn't leak through the adhesive, so if you can seal to the teak, you shouldn't need to do more further down.

I had deck fittings removed and replaced over 20 yrs ago when doing a project in the lazarette. The shipwright doing the job used fresh caulking (black unidentifiable sh*t) between the fitting and the teak and it has been impervious ever since. That location allows a good view of the top and of the underside.

socalrider · Jul 6, 2020

Snapped a pic today FYI. Have some butyl tape coming on Wednesday from Compas Marine. Biggest challenge I think will be access to the underside. Thanks for the advice; I’ll figure out how much effort to put into this once I have it apart I think.

Oh, and it’s a ‘79 CHB 41 trawler.

Comodave · Jul 6, 2020

Are you going to try to raise it up above the deck level?

socalrider · Jul 6, 2020

Comodave said:
Are you going to try to raise it up above the deck level?

I’m gonna pull it, take a good look, have a beer and give it a good think. Might have to wait a few weeks, as we may be headed to Catalina next week.

I think your solution is the best, but more effort. And I have six deck fills, and haven’t fully figured out the condition of the teak and decks and if there’s a bigger project in store. Boat is still new so feeling her out.

I might do a quicker fix first. We’ll see.

FF · Jul 6, 2020

What ever goop or tape you chose remember all things bedded are on the PM list and will need to be done in 5-7 years

5200 is a disaster as it is a glue.

Time and effort counts to me so I used Dolphinite , lasts as long as other goops, but is a snap to remove ,( scrape with a chisel) and reapply.

It cleans up easily so reinstalling window trim , usually messy , is easy to finish quickly..

bayview · Jul 6, 2020

It needs to be sealed where it penetrates the deck under the teak incase water is getting under the teak.

Insequent · Aug 5, 2020

When the OP started this thread, and from some other posts, I realised I needed to attend to my own fuel fills, I had been getting a bit of water in the fuel tanks, readily removed by the racors, for a number of months but thought it was from the marina pumps. When I checked the deck plates i could see some were loose. The existing deck plates were bedded in 2012, so I guess it was time to re-bed anyway.

However, I did not like the existing deck plates. They had a protrusion of 1/2" as well as an intrusion of 7/16" so were needlessly bulky and a trip hazard. This was exacerbated by the PO having sanding almost 1/8" of the teak desks over the previous 30 years. Pics show them. Under the deck plate were the fuel fills proper with a hose tail below leading to the tanks. Those fill were embedded into the GRP sandwich below the teak.

After I lot of searching online I found some low profile replacements at my local chandler for a better price than anywhere online. Quite a surprise! I then had the screw caps engraved. The new ones have 4mm protrusion only. I'm very happy with them. I used sealant between them and the underlying fuel fills as well as on the teak around the deck plate flange.

Re-bedding fuel fill on teak deck (CHB)

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