Recently, I got to wonering about something on my internal-ballasted keel, and had at the ballast cavity down low with a drill...two gallons of water or so later, I was satisfied, curiosity-wise. I'd seen a bit on the net with a fellow's Renegade in which the keel was saturated and full of water here...his repair was rather involved and used a good bit of foam.
It's worth note that after some research I found that urethane pouring foam does not do well if moisure is present in the long run. Spendy, too...
My father-in-law happened to work at Pearson in 1963 and confirms that indeed they dumped a bunch of sawdust in the bottom of the cavity, lowered in the ballast pig, and wedged it with balsa scrap before glassing over the top. Hmmm...balsa. Water. Uhhhh.... I don't like it one bit.
Also happens that my buddy's Renegade had a keel that went "clunk" in the night, so to speak. Ripped out the floors and cut away the glass to get at the cavity...he had no water down there, but not enough in the way of wedging, as in none that he could see at all! Ooops!
Personally, I like his fix, but I'm a bit afraid to do it...hence the question for Mr. Tim.
Buddy Jay filled the entire thing with cheap-o boatyard resin, gallons at a time. His comments were that 1) he did it in the winter, 2)he mixed the resin "real cold" 3) the boat was indeed in the rather cold water at the time, and 4) it took about a month to kick off all the way...all nine gallons!
I have deep respect, hard learned, for the dreaded exothermic reaction, myself, having nearly set a Ranger 23 on fire while filling in a crushed encapsulated aluminum mastbeam with epoxy resin once. Wow!
In other words, I'm chicken.
Given an ambient temperature of about 70 degrees and the boat on the hard, how much poly resin can I safely Pour into that ballast cavity at once, and how should i catalyze it? Do i pretend it's 110 degrees out and mix for that?
Thanks for any advice you can give,
Dave
Advice on poly resin?
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Tim
- Shipwright Extraordinaire
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- Joined: Tue Apr 01, 2003 6:39 pm
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- Boat Type: Pearson Triton
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Well...
I personally would not perform that "repair" on my boat. (Not that I could, since I have external ballast.)
That said, here are some general comments.
1. You have described the biggest problem witn encapsulated internal ballast: improper construction techniques that allow, over time, water to get in to the voids around the ballast, where it festers and causes unseen--and unknown--damage. I look for signs of this very situation every time I look at a boat with internal ballast, and find signs of water absorbtion or improper fiberglass adhesion (depending on the construction technique) very frequently. Especially in old Pearsons of various types. It doesn't take much at all to allow water into the various voids, as you discovered.
2. If it took 9 months to fully cure, he must have mixed it really, really cold. Like, he added virtually no hardener, especially given the known cooling effect of the surrounding water. At least he avoided the heat-related problems that would be, as you point out, such a major concern doing this sort of job!
3. Polyester resin in a solid mass is indescribably weak, sort of like that colored sugary candy "glass" we used to make as kids. I can just see that becoming a fractured mess full of voids down the road, leaving things just they way they started--or worse.
4. With luck, the use of polyester resin in boatbuilding will eventually go the route of copper sheathing on boat bottoms. Save the polyester resin for building bathtubs, cars, and other land-based items. Boats deserve full vinylester layup or, even better, epoxy. How long will it take the boating public to demand these superior resins in their new boat construction, despite the higher cost (which would come down if these resins were used more widely)? The mostly-unwilling-to-pay-for-quality public is a long way from accepting this, but these same folk are still dealing with the inherent imperfections of polyester resin in their boats on a daily basis. (i.e. blisters, lack of proper adhesion to cores and wooden structure, etc.)
5. If you go this route (and this is not an endorsement), at least add some form of structural filler (choppings) to the resin, keeping the mass loose enough to pour, of course. Take it slow, and add no more than 1/2 or 1 gallon at a time (depending on the size of the cavity--i.e.how confined is it, and how much of a resin "block" will there be in a given spot). Wait for the previous pour to cure before adding more, but pour the new, if possible, while the previous one is still "green", so as to get that primary bond between the levels. Don't over cool the resin, necessarily--just don't create too much of a solid mass all at once.
Tim
I personally would not perform that "repair" on my boat. (Not that I could, since I have external ballast.)
That said, here are some general comments.
1. You have described the biggest problem witn encapsulated internal ballast: improper construction techniques that allow, over time, water to get in to the voids around the ballast, where it festers and causes unseen--and unknown--damage. I look for signs of this very situation every time I look at a boat with internal ballast, and find signs of water absorbtion or improper fiberglass adhesion (depending on the construction technique) very frequently. Especially in old Pearsons of various types. It doesn't take much at all to allow water into the various voids, as you discovered.
2. If it took 9 months to fully cure, he must have mixed it really, really cold. Like, he added virtually no hardener, especially given the known cooling effect of the surrounding water. At least he avoided the heat-related problems that would be, as you point out, such a major concern doing this sort of job!
3. Polyester resin in a solid mass is indescribably weak, sort of like that colored sugary candy "glass" we used to make as kids. I can just see that becoming a fractured mess full of voids down the road, leaving things just they way they started--or worse.
4. With luck, the use of polyester resin in boatbuilding will eventually go the route of copper sheathing on boat bottoms. Save the polyester resin for building bathtubs, cars, and other land-based items. Boats deserve full vinylester layup or, even better, epoxy. How long will it take the boating public to demand these superior resins in their new boat construction, despite the higher cost (which would come down if these resins were used more widely)? The mostly-unwilling-to-pay-for-quality public is a long way from accepting this, but these same folk are still dealing with the inherent imperfections of polyester resin in their boats on a daily basis. (i.e. blisters, lack of proper adhesion to cores and wooden structure, etc.)
5. If you go this route (and this is not an endorsement), at least add some form of structural filler (choppings) to the resin, keeping the mass loose enough to pour, of course. Take it slow, and add no more than 1/2 or 1 gallon at a time (depending on the size of the cavity--i.e.how confined is it, and how much of a resin "block" will there be in a given spot). Wait for the previous pour to cure before adding more, but pour the new, if possible, while the previous one is still "green", so as to get that primary bond between the levels. Don't over cool the resin, necessarily--just don't create too much of a solid mass all at once.
Tim
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Dave 397
Stuff in the cavity
Actually, it took Jay's renegade keel one month to kick the nine gallons...
Cookie crumbs or not, my thinking is at least there's mass in there...just something to hold things jammed in, like the balsa is now (or at least supposedly is now).
At the same time, while I am nuts for weight reduction, I don't mind putting extra weight in the keel given my extra six feet of mast Vs. the standard fractional rig...pour it full of sand? Sand with resin in layers?
Any suggestion is appreciated...'twill be hard to put much mill fiber in thru the little 1/2" holes once mixed with the resin.
One other thought occurred, which was to open the cavity completely by grinding away the over-glassing joint, then packing in all manner of scrap 'glass cloth and such before pouring it full...sort of what I did to that Ranger (thru a 3" holesaw cut under the mast step) before I got carried away with pouring the epoxy and made the big smokeshow.
Only problem is, maybe, that when they lowered the pig in, the hull was in a mold...as opposed to a whole boat standing on the keel right now...makes me a bit nervous to cut all that loose, as i don't know how much load the keel shell itself is bearing as opposed to the keel/ballast/over-the-top 'glass assembly as it were.
Any further thoughts/suggestions/sympathies?
Thanks,
Dave
Cookie crumbs or not, my thinking is at least there's mass in there...just something to hold things jammed in, like the balsa is now (or at least supposedly is now).
At the same time, while I am nuts for weight reduction, I don't mind putting extra weight in the keel given my extra six feet of mast Vs. the standard fractional rig...pour it full of sand? Sand with resin in layers?
Any suggestion is appreciated...'twill be hard to put much mill fiber in thru the little 1/2" holes once mixed with the resin.
One other thought occurred, which was to open the cavity completely by grinding away the over-glassing joint, then packing in all manner of scrap 'glass cloth and such before pouring it full...sort of what I did to that Ranger (thru a 3" holesaw cut under the mast step) before I got carried away with pouring the epoxy and made the big smokeshow.
Only problem is, maybe, that when they lowered the pig in, the hull was in a mold...as opposed to a whole boat standing on the keel right now...makes me a bit nervous to cut all that loose, as i don't know how much load the keel shell itself is bearing as opposed to the keel/ballast/over-the-top 'glass assembly as it were.
Any further thoughts/suggestions/sympathies?
Thanks,
Dave
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dugong
Keel Cavity
This reminds me rather painfully of a problem I had been chasing for years (is it years now really? oh dear!) The bilge was dirty, oily and smelly.. you know: a bilge. After removing the leaky engine and floor, I scrubbed it clean and did some cosmetic work on the bilge surfaces.
None-the-less, next time it rained the bilge was again full of very oily water. For the longest time I couldn't figure out where the oil was coming from - I had made progress with the water intrusion - so eventually it was simply a constant oily ooze that accumulated - finally figured out it was coming from the keel cavity.
I opened it up to find an inch of space each side of the lead, with the rotten remains of balsa ballast padding completely soaked with oil. I guess at some point past, the bilge had been flooded with it and it had infiltrated. Two gallons of acetone carefully poured and recovered helped flush the cavity, and about a half inch of glass repairs sealed it back up. I was reluctant to fully seal the metal ballast in epoxy (cost aside) as I am concerned with expansion rates. Little point risking cracking the keel or encapsulation just to water-tight a pig that obviously didnt need it.
I just want to make sure it stays were it is. What concerns me now is the weight of the ballast. Would it come up through the floor if we roll? I have built the floor joists with that in mind :-)
It didn't seem a big deal to clean it out and seal it back up again - is there any additional benefit of encapsulating that I haven't seen yet?
David
None-the-less, next time it rained the bilge was again full of very oily water. For the longest time I couldn't figure out where the oil was coming from - I had made progress with the water intrusion - so eventually it was simply a constant oily ooze that accumulated - finally figured out it was coming from the keel cavity.
I opened it up to find an inch of space each side of the lead, with the rotten remains of balsa ballast padding completely soaked with oil. I guess at some point past, the bilge had been flooded with it and it had infiltrated. Two gallons of acetone carefully poured and recovered helped flush the cavity, and about a half inch of glass repairs sealed it back up. I was reluctant to fully seal the metal ballast in epoxy (cost aside) as I am concerned with expansion rates. Little point risking cracking the keel or encapsulation just to water-tight a pig that obviously didnt need it.
I just want to make sure it stays were it is. What concerns me now is the weight of the ballast. Would it come up through the floor if we roll? I have built the floor joists with that in mind :-)
It didn't seem a big deal to clean it out and seal it back up again - is there any additional benefit of encapsulating that I haven't seen yet?
David
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Dave 397
Keel Deal, Extra 6 feet of stick.
I have an extra (almost) six feet of mast as 397 is a masthead rigged boat.
I have heard from Bill Bell that the masthead boats are a bit more tender, and I can see why that would be.
My thoughts have gone to using a matrix of lead shot and resin...to a specific and as-yet-undetermined addition of weight. Either that, or actually pouring lead in around the existing pig after packing the keel 'round with dry ice. Not sure about how i like that one.
The big question in my mind still is if i dare grind out the 'glass over the gap with the boat standing on the keel... although most of my exploratory drilling would indicate an air gap beneath the ballast pig.
Tim, what do you think? I could reaaly use some guidance on this one!
Thanks,
Dave
I have heard from Bill Bell that the masthead boats are a bit more tender, and I can see why that would be.
My thoughts have gone to using a matrix of lead shot and resin...to a specific and as-yet-undetermined addition of weight. Either that, or actually pouring lead in around the existing pig after packing the keel 'round with dry ice. Not sure about how i like that one.
The big question in my mind still is if i dare grind out the 'glass over the gap with the boat standing on the keel... although most of my exploratory drilling would indicate an air gap beneath the ballast pig.
Tim, what do you think? I could reaaly use some guidance on this one!
Thanks,
Dave
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Tim
- Shipwright Extraordinaire
- Posts: 5708
- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
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- Contact:
Hmm, the masthead rigged Tritons I've seen around here have a shorter rig than the frac, probably by 3 or 4 feet I'd say. There's a couple locally. Typically, fractionals (on any given boat model) are taller than masthead as a larger main is needed to make up for the shorter jib height, and overall smaller size of the jib. Still, even with a shorter rig, I could see the masthead boats being somewhat more tender, what with more sail area up high, and the larger driving force of the genoa. Though the fractional version is certainly tender--more a function of slack bilges and narrow beam than anything.
But, as we know, there are no hard and fast rules with Tritons--exceptions are the rule.
Anyway, that's beside the point--Monday morning rambling, mostly. On to the real question.
I don't see any reason why you should have a problem grinding off the glass covering the lead cavity inside the boat. Is your concern that the keel is suddenly going to collapse when the "restraining" inner cap is removed? hehe No, that won't happen. The glass keel is plenty strong and is carrying the load of the ballast when the boat is in the water--and the weight of the boat when hauled out.
If you go ahead and cut that away, it would be very instructive for all Triton fans if you could document the process with photos. Few people have ever seen into the keel cavity, and it would be nice to have some evidence of what is really going on in there!
Tim
But, as we know, there are no hard and fast rules with Tritons--exceptions are the rule.
Anyway, that's beside the point--Monday morning rambling, mostly. On to the real question.
I don't see any reason why you should have a problem grinding off the glass covering the lead cavity inside the boat. Is your concern that the keel is suddenly going to collapse when the "restraining" inner cap is removed? hehe No, that won't happen. The glass keel is plenty strong and is carrying the load of the ballast when the boat is in the water--and the weight of the boat when hauled out.
If you go ahead and cut that away, it would be very instructive for all Triton fans if you could document the process with photos. Few people have ever seen into the keel cavity, and it would be nice to have some evidence of what is really going on in there!
Tim
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dave 397
keel cavity
I will indeed do just that, in terms of documenting the project with photos and text. The floors are nasty rotten squishy anyway, and need to come out for replacement and for installation of some dividers in the bilge and installation of a water tank, so I might as well make myself a bit of extra work and take care of the keel problem as properly as I can. As mary and I are both on the short side, I am planning to raise the sole a couple of inches as well, to enhance stowage space in the bilge. the chain locker, icebox and cockpit locker drains will be run by hose to a wet sump which is partitoned off from the rest of the bilge area to keep my corned beef hash dry.
Tim, I wonder if you have an opinion on which method would be better for adding ballast weight, the pouring of melted lead, or the use of lead shot and resin? I'm inclined toward the shot myself, but don't mind saving on the resin if I could pour the lead directly without creating problems in the laminate or popping off chunks of gelcoat.
Thank you for sharing your expertise with us all In this forum, Tim, it is truly appreciated.
best,
Dave
Tim, I wonder if you have an opinion on which method would be better for adding ballast weight, the pouring of melted lead, or the use of lead shot and resin? I'm inclined toward the shot myself, but don't mind saving on the resin if I could pour the lead directly without creating problems in the laminate or popping off chunks of gelcoat.
Thank you for sharing your expertise with us all In this forum, Tim, it is truly appreciated.
best,
Dave
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Tim
- Shipwright Extraordinaire
- Posts: 5708
- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
- Location: Whitefield, ME
- Contact:
Dave,
I think I would go with the shot and resin approach. Pouring molten lead into a confined cavity in an already-constructed boat sounds like a recipe for disaster. I think the concerns and dangers are real, running the gamut from blowing the bottom of the keel out to a certain fire hazard and personal safety issues.
Tim
I think I would go with the shot and resin approach. Pouring molten lead into a confined cavity in an already-constructed boat sounds like a recipe for disaster. I think the concerns and dangers are real, running the gamut from blowing the bottom of the keel out to a certain fire hazard and personal safety issues.
Tim