Has anyone tried flushing out the fuel tanks? I know they are baffled, but I'm reluctant to undr take the nasty business of removing the covers to clean out the tank. I know that Black Pearl had liners installed. My filter always seems to clog at the most inopertune moment, usually with guests onboard.
Dirty Fuel Tanks
- Thread starter Whit
- Start date
Can you get your fuel polished that far north? Would be the easiest thing and worth a try.
Nuttsy Idea?: Perhaps put some marbles in the tank and go sailing, then have the fuel polished.
Q's water tank is the much the same as your Challengers', removing the lid gives poor-to-fair access to the tank bottom; the forward baffle is within the tank lid's outline, but the tank extends another 16-18" forward. It was not possible to reach, let alone scrub the entire bottom, but at least there was no diesel being spread around the boat.
Earlier NE 38s had fiberglass fuel tanks but the lids were smaller; they would not have been a pleasure to clean, either.
Nuttsy Idea?: Perhaps put some marbles in the tank and go sailing, then have the fuel polished.
Q's water tank is the much the same as your Challengers', removing the lid gives poor-to-fair access to the tank bottom; the forward baffle is within the tank lid's outline, but the tank extends another 16-18" forward. It was not possible to reach, let alone scrub the entire bottom, but at least there was no diesel being spread around the boat.
Earlier NE 38s had fiberglass fuel tanks but the lids were smaller; they would not have been a pleasure to clean, either.
I haven't Whit. I just changed my Racor 500 primary a few days ago. I drained the bowl into a clear plastic cup. The first was quite dark and cloudy and became progressively cleaner for the next two. I don't have clogging problems and go usually two years between element changes on both the primary and secondary.Whit said:
I believe someone here may have drawn some fuel off the bottom of their tanks with a hand pump inserted through the fuel gauge. I was thinking I would try that end of season.
I agree, removing the bolts looks like a chore, many will spin in the fiberglass I'm sure, and require cutting. After all that, you may as well install new tanks. Doug is right, there are fuel polishers in our area, but I don't know how well it would work. It's a big sleeping dog down there.
Whit,
I removed the cover plates off of the fuel and water tanks of my 1964 Mistral. Since this was insalled by Halmatic, I would assume the method of installing the bolts and type of bolt material was the same. The head of the bolts are very well bonded into the fiberglass and it would be very unlikely that any of them would twist out. Of the 160 or so nuts I remove to get into my tanks, I broke about a dozen of them off due to corrosion but none of them "spun" in the fiberglass. ( I don't know the whole story, but the tops of my tanks may have been under water for over two years!!). The bolts and nuts appear to be standard grade and other than the number of them, was not an undaunting job. For what it's worth, I chased all the threads with a treading die before re-installing and used stainless nuts and washers as replacements, more so probably to make myself feel better than to make any future removal easier.
Hope this helps.
Bill Merrick
S/V Carmina
Seattle WA
I removed the cover plates off of the fuel and water tanks of my 1964 Mistral. Since this was insalled by Halmatic, I would assume the method of installing the bolts and type of bolt material was the same. The head of the bolts are very well bonded into the fiberglass and it would be very unlikely that any of them would twist out. Of the 160 or so nuts I remove to get into my tanks, I broke about a dozen of them off due to corrosion but none of them "spun" in the fiberglass. ( I don't know the whole story, but the tops of my tanks may have been under water for over two years!!). The bolts and nuts appear to be standard grade and other than the number of them, was not an undaunting job. For what it's worth, I chased all the threads with a treading die before re-installing and used stainless nuts and washers as replacements, more so probably to make myself feel better than to make any future removal easier.
Hope this helps.
Bill Merrick
S/V Carmina
Seattle WA
That's good to hear Bill. I suppose It would pay to use a penetrating oil prior to (long prior to) turning the nuts. I'm curious what you found when you removed the plates. How were the tanks baffled, what conditions were they in? Did sediment collect at the lowest points aft?Bill Merrick said:
If you coat the bolts with never-sieze (you can buy it at any good automative & most hardware stores) it will save many painfull hours down the road. We use it every time we change out a bolt on any machinery that might be prone to any corrosion. Keep in mind that the regular never-sieze has copper as one of the ingredients so don't use it on aluminum spars or any aluminum. There is a versionof never-sieze that has no copper for this reason.
Biobor or similar product will kill the algae that creates the black slim you see on your filters so after you clean your tanks use this or some thing similar as preventive maint. You could just use this to clean your tanks but plan on changing alot of filters as it brings the sludge up into suspension. Still with a small tank and not much sludge it might be a viable option. The algae grows on the interface of the fuel and any water in the bottom of the tank. By using it on a reg basis the water is emulsified and no problems.
I have started using a fuel additive due to the new ultra-low sulpher diesel. The sulpher or its properties (or whatever) apparently lubricate the injectors and with the sulpher absent it can create problems--or so I'm told. Any one else heard of this suggestion?
Biobor or similar product will kill the algae that creates the black slim you see on your filters so after you clean your tanks use this or some thing similar as preventive maint. You could just use this to clean your tanks but plan on changing alot of filters as it brings the sludge up into suspension. Still with a small tank and not much sludge it might be a viable option. The algae grows on the interface of the fuel and any water in the bottom of the tank. By using it on a reg basis the water is emulsified and no problems.
I have started using a fuel additive due to the new ultra-low sulpher diesel. The sulpher or its properties (or whatever) apparently lubricate the injectors and with the sulpher absent it can create problems--or so I'm told. Any one else heard of this suggestion?
Tom,
You asked about what I found in my tanks. The construction on my full keel Mistral may be quite different than on a Challenger but yes, the tanks were well baffled with fiberglass panels to minimize sloshing. The water tanks were painted with a white paint of some kind that was peeling. The fuel tank had a black tar like material pained on the sides ( remember the Mistral has integral tanks, no aluminum or steel inner tank). I tried removing the black coating but no solvents like acetone or laquer thinner seemed to desolve it. Since it was intact, I chose to leave it.
As far as other comments to my posting, I doused the studs and nuts with penetrating oil a half dozen times over several weeks before attempting to remove all the bolts with little benefit and I did use never sieze on the studs during re-assembling. For what it's worth, I always use the copper based rather than the aluminum base never sieze and have never had a problem with it in aluminum, copper, stainless or carbon steel. I seems the superior product to me over the aluminum base material which I would assume would not work well on an aluminum-stainless joint.
Bill
You asked about what I found in my tanks. The construction on my full keel Mistral may be quite different than on a Challenger but yes, the tanks were well baffled with fiberglass panels to minimize sloshing. The water tanks were painted with a white paint of some kind that was peeling. The fuel tank had a black tar like material pained on the sides ( remember the Mistral has integral tanks, no aluminum or steel inner tank). I tried removing the black coating but no solvents like acetone or laquer thinner seemed to desolve it. Since it was intact, I chose to leave it.
As far as other comments to my posting, I doused the studs and nuts with penetrating oil a half dozen times over several weeks before attempting to remove all the bolts with little benefit and I did use never sieze on the studs during re-assembling. For what it's worth, I always use the copper based rather than the aluminum base never sieze and have never had a problem with it in aluminum, copper, stainless or carbon steel. I seems the superior product to me over the aluminum base material which I would assume would not work well on an aluminum-stainless joint.
Bill
I've been cleaning out the tanks and making new covers, so I thought I would chime in even before I'm finished. The four covers were 3/8" steel plates with paint. Weight was ~60 lbs each. They were severely rusted on top - with thick flakes coming off, and a lot of dark sludge was in the filter. Attempts over the last few years to pump out the bottom of the fuel through the tank level sender hole brought up rusty steel bits. I soaked the nuts with penetrating oil (Kroil) for a month before removing the nuts. Only a few bolts broke, and one bolt rotated in the fiberglass and the nut was ground off. I have replaced all the bolts with stainless. The bolts were threaded through the fiberglass deck that holds the covers, and removing them (downward) took some work. The bolts are tightly threaded into the fiberglass. The outboard bolts did not have enough room below to allow their removal. They were apparently inserted into the fiberglass before the fiberglass deck piece was glassed into the hull. There was room to back off the bolts enough to saw off the heads, and to then remove the bolts from the top. I am replacing them with bolts from the top, with nuts beneath, after which I cut off the heads to leave studs sticking up like the rest of the bolts. I spent a fair amount of time sorting out how to get all this done once I was committed to replacing all the bolts.
The bottoms of the steel covers were raining down rust and paint strips into the fuel tank. At the deep aft end there was about an inch or so of rusty sediment saturated with black slime. Overall I removed a gallon or so of this from the tanks. I scrubbed out the tanks, and steamed them with a small steam cleaner (barely adequate). There was staining from Permatex that was used to seal the rubber gaskets beneath the covers, but overall its much cleaner now. I discovered one broken nut on a keel bolt (which are all exposed now). All the bronze nuts and bolts have a hard dark surface now that may be from the steel and rust in the fuel. I will replace all the nuts.
The new covers are 3/8 aluminum, chosen over stainless because its easier to handle, cut and drill. The supplier sheared the pieces to size. Nils Heldenberg(?) suggested using painted steel again, since it had lasted for 40 some years, but I thought Al would be an improvement. I have all aluminum fittings, and the only contact will be with stainless washers on each bolt.
The bottoms of the steel covers were raining down rust and paint strips into the fuel tank. At the deep aft end there was about an inch or so of rusty sediment saturated with black slime. Overall I removed a gallon or so of this from the tanks. I scrubbed out the tanks, and steamed them with a small steam cleaner (barely adequate). There was staining from Permatex that was used to seal the rubber gaskets beneath the covers, but overall its much cleaner now. I discovered one broken nut on a keel bolt (which are all exposed now). All the bronze nuts and bolts have a hard dark surface now that may be from the steel and rust in the fuel. I will replace all the nuts.
The new covers are 3/8 aluminum, chosen over stainless because its easier to handle, cut and drill. The supplier sheared the pieces to size. Nils Heldenberg(?) suggested using painted steel again, since it had lasted for 40 some years, but I thought Al would be an improvement. I have all aluminum fittings, and the only contact will be with stainless washers on each bolt.
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Here are more pictures of the tank construction. The bolts shown that had to have their heads sawed off are in the corner of the forward tank. There is a conduit in the outboard corner of the tank that can be seen that drains the forward bilge into the aft bilge.
Rick
Rick
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Wow! Thanks for these photos Rick.
And thanks to Bill as well, I've often wondered what's going on down there.
Quite a project Rick. I'm curious why you decided to redo the existing tanks as opposed to installing smaller tanks in the space? I suppose the reason many tanks were uncovered and new tanks built or fitted was due to leakage at the keel bolts that some owners have dealt with. But with no leaking problems, the tank as designed seems to work well, why not keep it?
There's very little rust on the tank tops on my boat which makes me wonder if they've been removed in the past and repainted? The rust your photos show is alarming, especially to think it was as bad below. I wonder about the lower face of my tops seeing those photos.
One other question to both Bill and Rick, I assume you saw no problems to the interior hull fiberglass when you were inside the tanks? Thanks again for the info, the photos are especially helpful.
And thanks to Bill as well, I've often wondered what's going on down there.
Quite a project Rick. I'm curious why you decided to redo the existing tanks as opposed to installing smaller tanks in the space? I suppose the reason many tanks were uncovered and new tanks built or fitted was due to leakage at the keel bolts that some owners have dealt with. But with no leaking problems, the tank as designed seems to work well, why not keep it?
There's very little rust on the tank tops on my boat which makes me wonder if they've been removed in the past and repainted? The rust your photos show is alarming, especially to think it was as bad below. I wonder about the lower face of my tops seeing those photos.
One other question to both Bill and Rick, I assume you saw no problems to the interior hull fiberglass when you were inside the tanks? Thanks again for the info, the photos are especially helpful.
Rick, quite a job you've done! What did you use for gasketing? Did you go to any effort to isolate the bolts and washers from the aluminum?
LeComte glassed over all the lid bolts which were installed from underneath, clearly done before the tanktop was installed. I don't know that they were threaded into the 'glass. LeComte glassed over all the keelbolts, too. Depending upon your fear of crevice corrosion in stainless, and your confidence in the watertightness of fiberglass, is your ability to enjoy comfort in the design!
I think you were right to renew/restore the existing design rather than drop a bladder in or have a metal tank made; I would not want to create more unverifiable conditions. LeComte was required to go to metal fuel tanks by USCG regs. by the time they built Quetzal. The monel tank is glassed in and hanging above the bottom of the keel (with room enough for me to have slid an Atomic 4 coil underneath it while trying to retrieve it!).
I wonder why Niels would promote using a steel lid? At the very least, I'd have suggested having the lid galvanized after fabrication. Clearly, my nutsy idea of expecting marbles rolling around the tank bottom as a way to loosen deposits before polishing was just that; they would not have made headway against a tarry mess of rust flakes.
I wonder how far the diesel penetrated into the 'glass?
LeComte glassed over all the lid bolts which were installed from underneath, clearly done before the tanktop was installed. I don't know that they were threaded into the 'glass. LeComte glassed over all the keelbolts, too. Depending upon your fear of crevice corrosion in stainless, and your confidence in the watertightness of fiberglass, is your ability to enjoy comfort in the design!
I think you were right to renew/restore the existing design rather than drop a bladder in or have a metal tank made; I would not want to create more unverifiable conditions. LeComte was required to go to metal fuel tanks by USCG regs. by the time they built Quetzal. The monel tank is glassed in and hanging above the bottom of the keel (with room enough for me to have slid an Atomic 4 coil underneath it while trying to retrieve it!).
I wonder why Niels would promote using a steel lid? At the very least, I'd have suggested having the lid galvanized after fabrication. Clearly, my nutsy idea of expecting marbles rolling around the tank bottom as a way to loosen deposits before polishing was just that; they would not have made headway against a tarry mess of rust flakes.
I wonder how far the diesel penetrated into the 'glass?
That was a concern of Neils H several years ago when I called Alden in regards to the fuel tanks if you had a leaking problem. He seemed to infer a better safe than sorry attitude. But if the tanks are not leaking (as mine are not), it seems like s fine set up, especially if you are planning some long voyages.
I guess, there just is no definitive information on this subject, yet.
An earlier LeComte, that a friend has, leaks diesel though a faulty layup around his lower gudgeon. Another friend tells of a new boat that he serviced which weeped water through a place that no one could find. Later, a hole was bored for a throughhull and water came out of a void in the laminate. When the throughull was installed, the leak stopped! By purest ill luck and poor workmanship, the boat leaked; by purest good fortune, the new throughhull blocked the void. Glad it was not my boat!
We read that fiberglass weeps a little water along the fibers; that's how you get wet laminate and perhaps causal of blistering. I still wonder if fiberglass is permeable by diesel; at the very least, one would be concerned about bonding repairs.
I recall that when I ground out the remains of tabbing that once had located engine beds in the Morgan 27, the stains of old bilgewater, gasoline and oil were quite deep into the surface. I ground maybe 1/8" in places, including a puddle of resin in the deep part. I bonded new engine beds and coated out the whole area in epoxy with no apparent ill effects.
But I still wonder...
We read that fiberglass weeps a little water along the fibers; that's how you get wet laminate and perhaps causal of blistering. I still wonder if fiberglass is permeable by diesel; at the very least, one would be concerned about bonding repairs.
I recall that when I ground out the remains of tabbing that once had located engine beds in the Morgan 27, the stains of old bilgewater, gasoline and oil were quite deep into the surface. I ground maybe 1/8" in places, including a puddle of resin in the deep part. I bonded new engine beds and coated out the whole area in epoxy with no apparent ill effects.
But I still wonder...
A comment was made earlier about using a galvenized steel lid for the fuel tank. I had heard that galvanized steel should not be used for a diesel fuel tank couldn't find a reference for that at the time I read the posting. I finally found it and note it below with a bit of hesitation.
Nigel Warren's book, Metal Corrosion in Boats states on page 197, in the section on fuel tanks, " Copper, brass, and galvanized steel react with diesel fuel." This is probably true but I've never heard of a concern with brass or copper fuel lines and fittings for diesel fuel so I'm a little puzzled about this statement in general.
Take it for what it is worth.
Bill Merrick
S/V Carmina
Seattle WA
Nigel Warren's book, Metal Corrosion in Boats states on page 197, in the section on fuel tanks, " Copper, brass, and galvanized steel react with diesel fuel." This is probably true but I've never heard of a concern with brass or copper fuel lines and fittings for diesel fuel so I'm a little puzzled about this statement in general.
Take it for what it is worth.
Bill Merrick
S/V Carmina
Seattle WA
I think the zinc in the galvanizing will leach out and injectors, et al don't like it. They always say no galv and no teflon tape in your fuel system. I think the tape will not hold up and you'll develope leaks. I always use pipe dope. A lot of "I think"s but really not sure!!
Well, the tanks are done and the boat sailing - got from Mattapoisett tp Quisset last Friday.
Answers to questions: There was no indication of degraded fiberglass in the tanks, although I'm not sure what it would look like. I briefly considered putting on a barrier coat, but after I saw the interior of the tanks and considered that there was at least some penetration I didn't think it was a good idea, since it probably wouldn't adhere. I didn't want to think about grinding the inside of the tank! The picture shows the staining of the fiberglass from the fuel, and a bit of the somewhat rough surface on the bottom. I didn't replace the tanks since that was a bigger job and would make the keel bolts hard to access. One keel bolt nut had broken, all had a hard black/brown finish and all nuts were unmovable. I doubled the nuts on the bolts that showed enough thread and replaced the broken nut. Rumerys put new tanks in Black Pearl, but she had a leaking centerboard trunk and there was little choice. I sealed all the bolts and nuts underside with 5200 (which may have been used before). I made new gaskets from 1/16" buna rubber from McMaster Carr, and used Permatex.
Comments: A lot more work than I expected, but we still have a couple of months of sailing! I put in a second pickup tube that bottoms in the lowest point in the tank, which is aft - see picture. This will be for pumping out the bottom of the tank, and is also a perfect dipstick tube for checking fuel level (I installed a VDO tube level sender as well). The main pickup is further forward starboard and off the bottom by an inch or so. The filler fitting is attached to a separate plate that lowers the profile and also provides an access port if needed (at least to one chamber). If the weld fails the smaller plate is all that needs to be replaced. Fittings will all be aluminum (Some are brass/bronze now but I will replace them next winter).
I have an electric fuel pump between two Racor 500 filters. I disconnect the pump output from the second filter input and pump from the tank to prime the pickup tube and first filter. This also let me pump out the tanks and store the fuel in jerry cans while I did the work. Works great - didn't have to bleed the engine after all the work.
Hope to see some of you on the water!
Rick
Rick
Answers to questions: There was no indication of degraded fiberglass in the tanks, although I'm not sure what it would look like. I briefly considered putting on a barrier coat, but after I saw the interior of the tanks and considered that there was at least some penetration I didn't think it was a good idea, since it probably wouldn't adhere. I didn't want to think about grinding the inside of the tank! The picture shows the staining of the fiberglass from the fuel, and a bit of the somewhat rough surface on the bottom. I didn't replace the tanks since that was a bigger job and would make the keel bolts hard to access. One keel bolt nut had broken, all had a hard black/brown finish and all nuts were unmovable. I doubled the nuts on the bolts that showed enough thread and replaced the broken nut. Rumerys put new tanks in Black Pearl, but she had a leaking centerboard trunk and there was little choice. I sealed all the bolts and nuts underside with 5200 (which may have been used before). I made new gaskets from 1/16" buna rubber from McMaster Carr, and used Permatex.
Comments: A lot more work than I expected, but we still have a couple of months of sailing! I put in a second pickup tube that bottoms in the lowest point in the tank, which is aft - see picture. This will be for pumping out the bottom of the tank, and is also a perfect dipstick tube for checking fuel level (I installed a VDO tube level sender as well). The main pickup is further forward starboard and off the bottom by an inch or so. The filler fitting is attached to a separate plate that lowers the profile and also provides an access port if needed (at least to one chamber). If the weld fails the smaller plate is all that needs to be replaced. Fittings will all be aluminum (Some are brass/bronze now but I will replace them next winter).
I have an electric fuel pump between two Racor 500 filters. I disconnect the pump output from the second filter input and pump from the tank to prime the pickup tube and first filter. This also let me pump out the tanks and store the fuel in jerry cans while I did the work. Works great - didn't have to bleed the engine after all the work.
Hope to see some of you on the water!
Rick
Rick
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Couldn't resist posting this picture of old and new fuel tank covers with a boat that has been waiting patiently but is ready to go when I am done! I have to say that Challengers have beautiful lines. Next winter: chainplate backing plates, which are still weeping through, even though drain holes have been drilled.
Rick
Rick
