This question is directed at all Triton owners who have removed, replaced, reinforced, or otherwise observed their arched mast support beams. This is purely for interest and to see what differences there might be.
If you respond, please answer the following:
1. Have you removed your mast beam?
2. Did you replace the beam with new, or reinforce the old somehow?
3. Was/is your original mast beam fiberglassed in, bolted, screwed, or some combination of the three? Or none of the above?
4. Please detail the conditions that led you to replace or otherwise address the beam.
5. Please describe your new beam, or the reinforcement, and how you installed it.
6. Did you address the deck and mast step in any way?
Triton Mast Beam Specifics
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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:
Triton Mast Beam Specifics
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Figment
- Damned Because It's All Connected
- Posts: 2846
- Joined: Tue Apr 08, 2003 9:32 am
- Boat Name: Triton
- Boat Type: Grand Banks 42
- Location: L.I. Sound
1. Yes.
2. Both. Because I'm a sentimental moron, I retained and prettied-up the short forward portion of the beam. The main part of the beam, aft of the bulkhead, I replaced.
3. The original oak beam was secured by screws through the bulkhead from the front with large bronze flatheads, which were in pretty good condition once the paint was removed. It was also through-bolted to the smaller forward chunk, but obviously this was to secure the smaller chunk to the larger, not the other way around. There was no fiberglass connection, except for a few gobs of that blue chalky stuff that Pearson used as "stay there!" putty during assembly.
4. Replacement of this beam was part of my bulkhead replacement project, but the original had deflected enough, and the coachroof above had compressed enough, that replacement was warranted anyway.
5. I made the new part of my beam by epoxy-laminating three layers of 3/4" marine fir plywood. As I recall, this adds up to more wood than the original section. I also sandwiched a 1/4" steel plate between the new plywood beam and the original forward section. This plate doesn't run the full breadth of the beam, but is 6" wider than the passageway, which allows it to bear directly onto the "compression posts" that stiffen the bulkhead at either side of the passage.
I like the look of Nathan's beam a LOT better than my painted plywood beam, but I was kinda pressed for time. Part of me rationalizes it by saying that the plywood beam is stiffer because of the vertical orientation of the laminations, but the other part says "shut up! the steel plate negates that!"
I would've preferred to use bronze for this plate instead of steel, but couldn't arrange it in time, and the assembly is such that replacement will be fairly easy if/when rust develops. All screws were predrilled, waxed, driven soft, removed, rewaxed, and reinserted flush.
The new assembly is a recreation of the old: The outboard portions of the beam are secured with #14 SS screws through the bulkhead. The portions that involve the steel plate are through-bolted. Two bolts at the top of each post, and four bolts in the middle, located per the originals.
To spread the load from the underside of the coachroof to this beam, I injected a thickened epoxy filler into the reigon immediately beneath the mast step. The beam components were heavily waxed before installation to prevent epoxy adhesion so that they can be removed if necessary in the future.
6. The coachroof is fairly rotten, but I elected to address this later, when I recore the rest of the deck. At the time I elected to simply build a solid pad beneath the mast step itself to remedy the compression problem. I cut a circle through the top skin 2" greater in radius than the aluminum mast step, and with a 45-degree router bit I tapered the core. I then epoxied in layer after layer of heavy cloth and mat, (in three stages to avoid excess curing heat) until the buildup was about 1/8" proud of where it looked like the original had been. Fair, prime, paint, drill new holes for mast step bolts. The underside of the aluminum mast step was badly pitted and corroded, so I cleaned it as best I could with a wire wheel, and faired a new flat bottom onto it with thickened epoxy. I don't know if this actually accomplished anything, but I felt better.
2. Both. Because I'm a sentimental moron, I retained and prettied-up the short forward portion of the beam. The main part of the beam, aft of the bulkhead, I replaced.
3. The original oak beam was secured by screws through the bulkhead from the front with large bronze flatheads, which were in pretty good condition once the paint was removed. It was also through-bolted to the smaller forward chunk, but obviously this was to secure the smaller chunk to the larger, not the other way around. There was no fiberglass connection, except for a few gobs of that blue chalky stuff that Pearson used as "stay there!" putty during assembly.
4. Replacement of this beam was part of my bulkhead replacement project, but the original had deflected enough, and the coachroof above had compressed enough, that replacement was warranted anyway.
5. I made the new part of my beam by epoxy-laminating three layers of 3/4" marine fir plywood. As I recall, this adds up to more wood than the original section. I also sandwiched a 1/4" steel plate between the new plywood beam and the original forward section. This plate doesn't run the full breadth of the beam, but is 6" wider than the passageway, which allows it to bear directly onto the "compression posts" that stiffen the bulkhead at either side of the passage.
I like the look of Nathan's beam a LOT better than my painted plywood beam, but I was kinda pressed for time. Part of me rationalizes it by saying that the plywood beam is stiffer because of the vertical orientation of the laminations, but the other part says "shut up! the steel plate negates that!"
I would've preferred to use bronze for this plate instead of steel, but couldn't arrange it in time, and the assembly is such that replacement will be fairly easy if/when rust develops. All screws were predrilled, waxed, driven soft, removed, rewaxed, and reinserted flush.
The new assembly is a recreation of the old: The outboard portions of the beam are secured with #14 SS screws through the bulkhead. The portions that involve the steel plate are through-bolted. Two bolts at the top of each post, and four bolts in the middle, located per the originals.
To spread the load from the underside of the coachroof to this beam, I injected a thickened epoxy filler into the reigon immediately beneath the mast step. The beam components were heavily waxed before installation to prevent epoxy adhesion so that they can be removed if necessary in the future.
6. The coachroof is fairly rotten, but I elected to address this later, when I recore the rest of the deck. At the time I elected to simply build a solid pad beneath the mast step itself to remedy the compression problem. I cut a circle through the top skin 2" greater in radius than the aluminum mast step, and with a 45-degree router bit I tapered the core. I then epoxied in layer after layer of heavy cloth and mat, (in three stages to avoid excess curing heat) until the buildup was about 1/8" proud of where it looked like the original had been. Fair, prime, paint, drill new holes for mast step bolts. The underside of the aluminum mast step was badly pitted and corroded, so I cleaned it as best I could with a wire wheel, and faired a new flat bottom onto it with thickened epoxy. I don't know if this actually accomplished anything, but I felt better.
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dasein668
- Boateg
- Posts: 1637
- Joined: Thu Apr 03, 2003 9:09 am
- Boat Name: Dasein
- Boat Type: Pearson Triton 668
- Location: Portland, Maine
- Contact:
As most of you know, I did replace my mast beam. Most of it is detailed on my website. Specifically at www.dasein668.com/projects/beam.shtml if you want to refresh your memory. I don't have details on the installation there... someday! But I'll summarize here, in the interest of having the info listed with other peoples' experience...
1) Yes.
2) Replaced with new.
3) My beam was through-bolted with bronze flathead machine screws (4, I think...) through the bulkhead from the v-berth. It had also been tabbed in with fiberglass at some point, but most of the tabbing was no longer attached to the beam.
4) The following were the conditions that led to removing the beam? a. The loose tabbing led me to speculate that there had been movement of the beam; b. There was a nasty hole drilled through the center of the beam through which some wiring had been led, and which showed evidence of possible rot; c. There appeared to be inward bulging of the overhead, which I speculated was from flexing of the beam and deck (that later proved to be false).
5) The new beam is laminated from 6 layers of 1/2" thick ash, 3 1/2" wide. This led to a beam which was substantially larger than the old beam in all directions. I also laminated a new short forward section. The laminating process was much easier than I had feared, although it was quite messy. I used West System epoxy. Springback was minimal.
The beam was installed with thickened epoxy. I know this means it'll be next to impossible to remove, but the new structure is so strong that it'll only be coming out in the event of some relatively major disaster. And, of course, it IS possible to remove something installed with epoxy.... The new assembly of oversized beam epoxied to the overhead and bulkhead is pretty much waaaaay overkill.
6) I have not addressed the deck/step. There is no indication of significant deck compression, so I left well enough alone. When I do recore my decks, however, I will replace the core in this area with solid glass.
1) Yes.
2) Replaced with new.
3) My beam was through-bolted with bronze flathead machine screws (4, I think...) through the bulkhead from the v-berth. It had also been tabbed in with fiberglass at some point, but most of the tabbing was no longer attached to the beam.
4) The following were the conditions that led to removing the beam? a. The loose tabbing led me to speculate that there had been movement of the beam; b. There was a nasty hole drilled through the center of the beam through which some wiring had been led, and which showed evidence of possible rot; c. There appeared to be inward bulging of the overhead, which I speculated was from flexing of the beam and deck (that later proved to be false).
5) The new beam is laminated from 6 layers of 1/2" thick ash, 3 1/2" wide. This led to a beam which was substantially larger than the old beam in all directions. I also laminated a new short forward section. The laminating process was much easier than I had feared, although it was quite messy. I used West System epoxy. Springback was minimal.
The beam was installed with thickened epoxy. I know this means it'll be next to impossible to remove, but the new structure is so strong that it'll only be coming out in the event of some relatively major disaster. And, of course, it IS possible to remove something installed with epoxy.... The new assembly of oversized beam epoxied to the overhead and bulkhead is pretty much waaaaay overkill.
6) I have not addressed the deck/step. There is no indication of significant deck compression, so I left well enough alone. When I do recore my decks, however, I will replace the core in this area with solid glass.
Nathan
dasein668.com
dasein668.com
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robertgrayyoga
1.yes i have removed the beam
2. i replaced the beam with a new above deck beam
3. the original beam was machine screwed in through the forward bulk head. there had been an additional beam sistered to the old from the forward bulkhead side. this was but in with what must have been sm 5200. i had to break out the recip. saw.
4.The door to the fore cabin wouldn't close, the boat had been raced hard on SF bay. i had read about how everyone had to deal with their own beams. i may have been under the influence of excessive imagination at the time i ripped everything out.
5. my new beam is a lamination of 6 3/4'" pieces of balou wood, hard as s**t tropical stuff, and a 1/4" / 3" stainless steel plate on edge. the laminations were epoxied and throughbolted together. I bedded the entire thing onto the cabin top with life caulk. my mast had been upgraded to a non tapered anodized alum. section i through bolted the original mast step through the new beam and cabin top, WC boat No core, with two 6" /3/8" SS bolts. i also placed four 3/8" / 4" SS lagbolts up through the cabin top into the beam. I added an aditional layer of 3/4" meranti ply to the existing bulkhead under the new mahogony posts on the aft side of the bulkhead and a layer of 1/2" ply where the chain plates attach to the forward side of the bh. there are two small corbels on the forward part of the bulkhead to support the beam over it/s full width and to eiminate some rocking fore and aft that had been revealed during a sail trail. I have no idea how this works because i have not sailed the boat for a year while i gutted and rebuilt the interior. I used throughout the classic design system of overbuildandpray. i hope i have not created a harbor apartment with a tall flagpole, instead of a sailboat. Sea trials begin in a few weeks.
6. See above
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2. i replaced the beam with a new above deck beam
3. the original beam was machine screwed in through the forward bulk head. there had been an additional beam sistered to the old from the forward bulkhead side. this was but in with what must have been sm 5200. i had to break out the recip. saw.
4.The door to the fore cabin wouldn't close, the boat had been raced hard on SF bay. i had read about how everyone had to deal with their own beams. i may have been under the influence of excessive imagination at the time i ripped everything out.
5. my new beam is a lamination of 6 3/4'" pieces of balou wood, hard as s**t tropical stuff, and a 1/4" / 3" stainless steel plate on edge. the laminations were epoxied and throughbolted together. I bedded the entire thing onto the cabin top with life caulk. my mast had been upgraded to a non tapered anodized alum. section i through bolted the original mast step through the new beam and cabin top, WC boat No core, with two 6" /3/8" SS bolts. i also placed four 3/8" / 4" SS lagbolts up through the cabin top into the beam. I added an aditional layer of 3/4" meranti ply to the existing bulkhead under the new mahogony posts on the aft side of the bulkhead and a layer of 1/2" ply where the chain plates attach to the forward side of the bh. there are two small corbels on the forward part of the bulkhead to support the beam over it/s full width and to eiminate some rocking fore and aft that had been revealed during a sail trail. I have no idea how this works because i have not sailed the boat for a year while i gutted and rebuilt the interior. I used throughout the classic design system of overbuildandpray. i hope i have not created a harbor apartment with a tall flagpole, instead of a sailboat. Sea trials begin in a few weeks.
6. See above
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tikvah59
- Master Varnisher
- Posts: 122
- Joined: Mon Oct 27, 2003 1:12 am
- Boat Name: Emily Hope
- Boat Type: Nimble 30' yawl
- Location: Milton, MA
- Contact:
1. Have you removed your mast beam?
Yes
2. Did you replace the beam with new, or reinforce the old somehow?
The beam (2 parts, forward and aft of the v-berth bulkhead) was in very good shape. I don't plan to replace it, but after grinding off some bondo-like filler on the top of it, I will probably laminate a few layers of oak to fill the space and strengthen it.
3. Was/is your original mast beam fiberglassed in, bolted, screwed, or some combination of the three? Or none of the above?
The beam itself was bolted, not fiberglassed. The mast supports were mostly screwed.
4. Please detail the conditions that led you to replace or otherwise address the beam.
I started poking around the mast beam and supports because of what others had found. In the process, I found the starboard support that (should) go down to the sole had severe rot and had been filled in with bondo or epoxy.
5. Please describe your new beam, or the reinforcement, and how you installed it.
See #2 above. Not installed yet. I will fabricate a new support to the mast beam out of white oak (the rotted one appears to be red oak). I also scarfed in a new piece of oak to the deck support in the head (port side, on the bulkhead between the head and the salon).
I plan to re-install it the way it has been for 40+ years: with bronze carriage bolts. I like the fact that you can take much of this boat apart (although one could argue I might be better off if you couldn't). I don't want to put something in that will be so difficult for the next owner to remove. Might be my kid.
6. Did you address the deck and mast step in any way?
I have an aluminum mast step which had seized to the tang at the bottom of the mast. First I got those two apart, then I removed the mast step from the deck. Both steps were difficult and painstaking.
Under the mast step the deck was depressed and core was compressed. There was a small break in the inside fiberglass skin just aft of the maststep. I removed the old core from the top and put a few layers of glass cloth on the inside (under side) of the bottom fiberglass skin. Then I replaced the core with marine plywood and put the top skin back on.
Yes
2. Did you replace the beam with new, or reinforce the old somehow?
The beam (2 parts, forward and aft of the v-berth bulkhead) was in very good shape. I don't plan to replace it, but after grinding off some bondo-like filler on the top of it, I will probably laminate a few layers of oak to fill the space and strengthen it.
3. Was/is your original mast beam fiberglassed in, bolted, screwed, or some combination of the three? Or none of the above?
The beam itself was bolted, not fiberglassed. The mast supports were mostly screwed.
4. Please detail the conditions that led you to replace or otherwise address the beam.
I started poking around the mast beam and supports because of what others had found. In the process, I found the starboard support that (should) go down to the sole had severe rot and had been filled in with bondo or epoxy.
5. Please describe your new beam, or the reinforcement, and how you installed it.
See #2 above. Not installed yet. I will fabricate a new support to the mast beam out of white oak (the rotted one appears to be red oak). I also scarfed in a new piece of oak to the deck support in the head (port side, on the bulkhead between the head and the salon).
I plan to re-install it the way it has been for 40+ years: with bronze carriage bolts. I like the fact that you can take much of this boat apart (although one could argue I might be better off if you couldn't). I don't want to put something in that will be so difficult for the next owner to remove. Might be my kid.
6. Did you address the deck and mast step in any way?
I have an aluminum mast step which had seized to the tang at the bottom of the mast. First I got those two apart, then I removed the mast step from the deck. Both steps were difficult and painstaking.
Under the mast step the deck was depressed and core was compressed. There was a small break in the inside fiberglass skin just aft of the maststep. I removed the old core from the top and put a few layers of glass cloth on the inside (under side) of the bottom fiberglass skin. Then I replaced the core with marine plywood and put the top skin back on.
Emily Hope
Nimble 30' yawl
Nimble 30' yawl
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bcooke
- Master of the Arcane
- Posts: 2272
- Joined: Sat Oct 04, 2003 10:55 pm
- Boat Name: Jenny
- Boat Type: 1966 Pearson Triton
- Location: Rowley, MA
- Contact:
Oh, what the heck. This thread is ages old but maybe someone will care.
-Britton
Yes.1. Have you removed your mast beam?
Replaced with new.2. Did you replace the beam with new, or reinforce the old somehow?
Screwed with #14 bronze wood screws at six (total) points to the bulkhead. Two #20 (or 24, I can't remember) bronze screws came down from the wooden mast step above. Fiberglass tabbing connecting the beam to the cabin structure was found under the head liner.3. Was/is your original mast beam fiberglassed in, bolted, screwed, or some combination of the three? Or none of the above?
A small amount of cracking was observed directly under the mast step. A PO had drilled a hole down through the mast step and into the beam allowing water to accumulate. Actual condition was unkown but suspect.4. Please detail the conditions that led you to replace or otherwise address the beam.
A new beam was fabricated by laminating with epoxy 1/4 inch strips of oak, increasing the original beams dimensions by about 1/2 inch in width and thickness. The beam was installed with new SS screws and thickened epoxy.5. Please describe your new beam, or the reinforcement, and how you installed it.
Removed the plywood mast step. Cut out top skin and coring in a 12 inch diameter circle under the mast step. Filled cut out with layers of fiberglass cloth and epoxy. Reinstalled rebuilt mast step.6. Did you address the deck and mast step in any way?
-Britton
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jhenson
- Candidate for Boat-Obsession Medal
- Posts: 393
- Joined: Mon Jan 17, 2005 9:59 am
- Location: Marshall, Virginia
Tim,
1. No, I did not remove the mast beam. It was accomplished by a previous owner.
2. The current replacement mast beam is a steel box structure. Two arches were cut out of mild steel and the top and bottom were bent around the edges and welded in place. The box beam is pretty heavy steel by the looks of the threaded holes on top for the mast step. The aluminum mast step is bolted through the deck directly into the beam. The whole thing was primed and painted, and I can find little evidence of rust, despite broken/leaking connecters for the VHF and nav lights that were located nearly on top of it. The whole beam has a L-shaped teak cover that hides the steel beam. With this cover off for interior work, I bang my head on the steel corner just about every week. I should get some foam and tape it to the bottom corner I guess.
3. The assembly is bolted to the bulkheads with four 1/4" carriage bolts.
4. Happily, this is one of the few places on the boat that I will not have to touch.
5. Had I needed to replace this, I would have probably constructed a laminated beam. The teak cover lowers the opening to the V-berth by about an inch. That's really the only minor negative I see so far with this system.
6. I am on this step right now. I did several core sample of the lower coach roor and found not evidence of water intrusion. However, the core around the mast step was badly compressed. I have cut a 12"X12" section of skin around the step and removed the core from below. The core was indeed dry but compressed to less than 1/4" in some sections. I'll be building solid laminations in this area when the weather allows me to do so.
Joe
1. No, I did not remove the mast beam. It was accomplished by a previous owner.
2. The current replacement mast beam is a steel box structure. Two arches were cut out of mild steel and the top and bottom were bent around the edges and welded in place. The box beam is pretty heavy steel by the looks of the threaded holes on top for the mast step. The aluminum mast step is bolted through the deck directly into the beam. The whole thing was primed and painted, and I can find little evidence of rust, despite broken/leaking connecters for the VHF and nav lights that were located nearly on top of it. The whole beam has a L-shaped teak cover that hides the steel beam. With this cover off for interior work, I bang my head on the steel corner just about every week. I should get some foam and tape it to the bottom corner I guess.
3. The assembly is bolted to the bulkheads with four 1/4" carriage bolts.
4. Happily, this is one of the few places on the boat that I will not have to touch.
5. Had I needed to replace this, I would have probably constructed a laminated beam. The teak cover lowers the opening to the V-berth by about an inch. That's really the only minor negative I see so far with this system.
6. I am on this step right now. I did several core sample of the lower coach roor and found not evidence of water intrusion. However, the core around the mast step was badly compressed. I have cut a 12"X12" section of skin around the step and removed the core from below. The core was indeed dry but compressed to less than 1/4" in some sections. I'll be building solid laminations in this area when the weather allows me to do so.
Joe