My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website ( https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa...). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it. The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels. Does the M17 have a cored hull or should this finder just work? Thanks, Rob
I bought one of those depth finders and tried a lot of different mounts. It "kinda" worked at first and then Itried various ways to put it in (silly putty,wax,and eventually epoxy) it worked most of the time then1/2 the time then pretty much not at all over 3 years. I was determined to figure it out and brought out an oscilloscope and researched these things. Kind of interestingactually. the "transducer" is an oscillator that has a natural period of oscillation at 200khz and the devicesends it a signal that is about 150 volts peak/peak for about 100 oscillations and then uses the same wires tolook for an echo that is just a few millvolts but at roughly the same freq. ( That actually makes it challenging froma probe problem to look at the same signal with 4-5 orders of magnitude of variation) What happens (or I should say happened to me) is that the transducer basically blew it self out and couldn't receive the sensitiveecho. So I would NOT recommend gluing the thing in. I found a bunch on ebay for $10 and took a risk buying them. They worked fine and I put in an RCA jack so that I could easily replace them. It seems to work pretty good just in a pool of water (held down with a spring) on the hull. Works pretty good now on the first replacement. My advice...Do NOT glue them in. They seem to have a limited life and you will probably need to replace them. On Friday, June 19, 2020, 1:47:50 PM PDT, Rob Bultman <rob.bultman@gmail.com> wrote: My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website ( https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa...). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it. The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels. Does the M17 have a cored hull or should this finder just work? Thanks, Rob
Thanks, Lawrence, for the input. That is so weird regarding "blowing out" periodically. It seems like a fault of the system design (I'm an EE by training and an embedded firmware developer by vocation). I wonder if it could be an energy coupling problem where the system design assumes a certain amount of absorption via the hull/water interface. If the absorption is not there, energy is absorbed by the electronics in the transducer, thereby causing failure. My transducer appeared to be held in place with a big RTV blob, and was popped out of the blob when I looked under the v-berth. The installation video says to only use slow-cure 2-part epoxy. Regards, Rob On Fri, Jun 19, 2020 at 5:06 PM Lawrence Winiarski via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
I bought one of those depth finders and tried a lot of different mounts. It "kinda" worked at first and then Itried various ways to put it in (silly putty,wax,and eventually epoxy) it worked most of the time then1/2 the time then pretty much not at all over 3 years.
I was determined to figure it out and brought out an oscilloscope and researched these things. Kind of interestingactually. the "transducer" is an oscillator that has a natural period of oscillation at 200khz and the devicesends it a signal that is about 150 volts peak/peak for about 100 oscillations and then uses the same wires tolook for an echo that is just a few millvolts but at roughly the same freq. ( That actually makes it challenging froma probe problem to look at the same signal with 4-5 orders of magnitude of variation)
What happens (or I should say happened to me) is that the transducer basically blew it self out and couldn't receive the sensitiveecho. So I would NOT recommend gluing the thing in.
I found a bunch on ebay for $10 and took a risk buying them. They worked fine and I put in an RCA jack so that I could easily replace them. It seems to work pretty good just in a pool of water (held down with a spring) on the hull. Works pretty good now on the first replacement. My advice...Do NOT glue them in. They seem to have a limited life and you will probably need to replace them.
On Friday, June 19, 2020, 1:47:50 PM PDT, Rob Bultman < rob.bultman@gmail.com> wrote:
My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website (
https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa... ). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it.
The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels.
Does the M17 have a cored hull or should this finder just work?
Thanks, Rob
Another Electrical Engineer here.... My M17 is 1982 (one of the first of the v2 M17), I also have the Hawkeye, depth sounder, which I rely on pretty heavily up here in the Pacific Northwest.. The Hawkeye transducer in my M17 is mounted dead center on the V hull in front of the keel where the hull thickness fairs out flat to its thinnest point before shaping into the re-enforced ridge of the keel which is much thicker and narrower. The two challenges of getting good performance with a thru hull include positioning it at a "clear spot on the hull" & making sure a solid acoustic connection is maintained over time. Once epoxied in place, over the years if the hull is repeatedly bounced in the water (rip tides, standing waves etc ) the transducer with its smooth surfaces can become very slightly dislodged which can cause the sensor to quit working. To address these issues I found the following worked well; 1. Selected the most reliable spot by temporarily mounting it with a vaseline layer on the bottom of the transducer to provide a consistent acoustic medium and a little duck tape over top to hold it in place, and sailing about in a variety of depths and adjusting the position for best results. (did this for a few trips ) 2. Once the best position is found, a permanent mount was constructed using slow cure 2 part epoxy with enough epoxy to get a well defined "mounting shoe" created when the excess epoxy formed around the outside of the transducer. 3. Carefully dislodge the transducer from epoxy mount by gently tapping it out horizontally per the instructions in the Hawkeye documentation.. 4. Fill the formed epoxy shoe with a thin layer of vaseline and refit the transducer into the shoe. The surface tension of the vaseline holds the transducer in place and presents a good acoustic medium. 5. Every year I just pop the transducer out of the epoxy mounting shoe and reapply vaseline at the start of the season. I have found the performance to be very reliable with this setup. Cheers, Keith *Keith R. Martin P.Eng.* *Vancouver/Burnaby B.C.* *Serenity M17, #353* *http://www.msogphotosite.com/Scripts/Boats/boatsdetail.php?id=105 <http://www.msogphotosite.com/Scripts/Boats/boatsdetail.php?id=105>* On Fri, 19 Jun 2020 at 14:38, Rob Bultman <rob.bultman@gmail.com> wrote:
Thanks, Lawrence, for the input. That is so weird regarding "blowing out" periodically. It seems like a fault of the system design (I'm an EE by training and an embedded firmware developer by vocation). I wonder if it could be an energy coupling problem where the system design assumes a certain amount of absorption via the hull/water interface. If the absorption is not there, energy is absorbed by the electronics in the transducer, thereby causing failure.
My transducer appeared to be held in place with a big RTV blob, and was popped out of the blob when I looked under the v-berth. The installation video says to only use slow-cure 2-part epoxy.
Regards, Rob
On Fri, Jun 19, 2020 at 5:06 PM Lawrence Winiarski via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
I bought one of those depth finders and tried a lot of different mounts. It "kinda" worked at first and then Itried various ways to put it in (silly putty,wax,and eventually epoxy) it worked most of the time then1/2 the time then pretty much not at all over 3 years.
I was determined to figure it out and brought out an oscilloscope and researched these things. Kind of interestingactually. the "transducer" is an oscillator that has a natural period of oscillation at 200khz and the devicesends it a signal that is about 150 volts peak/peak for about 100 oscillations and then uses the same wires tolook for an echo that is just a few millvolts but at roughly the same freq. ( That actually makes it challenging froma probe problem to look at the same signal with 4-5 orders of magnitude of variation)
What happens (or I should say happened to me) is that the transducer basically blew it self out and couldn't receive the sensitiveecho. So I would NOT recommend gluing the thing in.
I found a bunch on ebay for $10 and took a risk buying them. They worked fine and I put in an RCA jack so that I could easily replace them. It seems to work pretty good just in a pool of water (held down with a spring) on the hull. Works pretty good now on the first replacement. My advice...Do NOT glue them in. They seem to have a limited life and you will probably need to replace them.
On Friday, June 19, 2020, 1:47:50 PM PDT, Rob Bultman < rob.bultman@gmail.com> wrote:
My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website (
https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa...
). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it.
The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels.
Does the M17 have a cored hull or should this finder just work?
Thanks, Rob
I think the transducer is passive, and I think mine wasn't "completely dead" either, it just was less sensitive and sometimesin the end it worked sporadically near the dock in shallow water. I didn't replace the electronics. Just bought another totally differenttransducer and wired it in. Apparently 200khz is kind of a standard although there are some others. One thing to think about. At 200khz, the wavelength (which of course depends on the speed of sound through the materials)in water thats going to be something like say 1/5". (pretty small) If different paths were 1/10" different then they would cancel out. Another funny thing. I might be imagining it, but I had a lot of trouble with my depth finder.....as I was passing the submarine base at Indian Island :-) kind of funny... #175 Sonic Weapon Follow Up!! | | | | | | | | | | | #175 Sonic Weapon Follow Up!! This is the follow up to our last episode #174 A SONIC WEAPON ??? It's Driving Us MAD!!! https://youtu.be/bCp3Ln... | | | On Friday, June 19, 2020, 4:23:20 PM PDT, Keith R. Martin <keith.richard.martin@gmail.com> wrote: Another Electrical Engineer here.... My M17 is 1982 (one of the first of the v2 M17), I also have the Hawkeye, depth sounder, which I rely on pretty heavily up here in the Pacific Northwest.. The Hawkeye transducer in my M17 is mounted dead center on the V hull in front of the keel where the hull thickness fairs out flat to its thinnest point before shaping into the re-enforced ridge of the keel which is much thicker and narrower. The two challenges of getting good performance with a thru hull include positioning it at a "clear spot on the hull" & making sure a solid acoustic connection is maintained over time. Once epoxied in place, over the years if the hull is repeatedly bounced in the water (rip tides, standing waves etc ) the transducer with its smooth surfaces can become very slightly dislodged which can cause the sensor to quit working. To address these issues I found the following worked well; 1. Selected the most reliable spot by temporarily mounting it with a vaseline layer on the bottom of the transducer to provide a consistent acoustic medium and a little duck tape over top to hold it in place, and sailing about in a variety of depths and adjusting the position for best results. (did this for a few trips ) 2. Once the best position is found, a permanent mount was constructed using slow cure 2 part epoxy with enough epoxy to get a well defined "mounting shoe" created when the excess epoxy formed around the outside of the transducer. 3. Carefully dislodge the transducer from epoxy mount by gently tapping it out horizontally per the instructions in the Hawkeye documentation.. 4. Fill the formed epoxy shoe with a thin layer of vaseline and refit the transducer into the shoe. The surface tension of the vaseline holds the transducer in place and presents a good acoustic medium. 5. Every year I just pop the transducer out of the epoxy mounting shoe and reapply vaseline at the start of the season. I have found the performance to be very reliable with this setup. Cheers, Keith *Keith R. Martin P.Eng.* *Vancouver/Burnaby B.C.* *Serenity M17, #353* *http://www.msogphotosite.com/Scripts/Boats/boatsdetail.php?id=105 <http://www.msogphotosite.com/Scripts/Boats/boatsdetail.php?id=105>* On Fri, 19 Jun 2020 at 14:38, Rob Bultman <rob.bultman@gmail.com> wrote:
Thanks, Lawrence, for the input. That is so weird regarding "blowing out" periodically. It seems like a fault of the system design (I'm an EE by training and an embedded firmware developer by vocation). I wonder if it could be an energy coupling problem where the system design assumes a certain amount of absorption via the hull/water interface. If the absorption is not there, energy is absorbed by the electronics in the transducer, thereby causing failure.
My transducer appeared to be held in place with a big RTV blob, and was popped out of the blob when I looked under the v-berth. The installation video says to only use slow-cure 2-part epoxy.
Regards, Rob
On Fri, Jun 19, 2020 at 5:06 PM Lawrence Winiarski via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
I bought one of those depth finders and tried a lot of different mounts. It "kinda" worked at first and then Itried various ways to put it in (silly putty,wax,and eventually epoxy) it worked most of the time then1/2 the time then pretty much not at all over 3 years.
I was determined to figure it out and brought out an oscilloscope and researched these things. Kind of interestingactually. the "transducer" is an oscillator that has a natural period of oscillation at 200khz and the devicesends it a signal that is about 150 volts peak/peak for about 100 oscillations and then uses the same wires tolook for an echo that is just a few millvolts but at roughly the same freq. ( That actually makes it challenging froma probe problem to look at the same signal with 4-5 orders of magnitude of variation)
What happens (or I should say happened to me) is that the transducer basically blew it self out and couldn't receive the sensitiveecho. So I would NOT recommend gluing the thing in.
I found a bunch on ebay for $10 and took a risk buying them. They worked fine and I put in an RCA jack so that I could easily replace them. It seems to work pretty good just in a pool of water (held down with a spring) on the hull. Works pretty good now on the first replacement. My advice...Do NOT glue them in. They seem to have a limited life and you will probably need to replace them.
On Friday, June 19, 2020, 1:47:50 PM PDT, Rob Bultman < rob.bultman@gmail.com> wrote:
My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website (
https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa...
). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it.
The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels.
Does the M17 have a cored hull or should this finder just work?
Thanks, Rob
M 17s have a solid glass hull. Same for the 15 and 16. Be well Bob Sent from my iPad
On Jun 19, 2020, at 1:47 PM, Rob Bultman <rob.bultman@gmail.com> wrote:
My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website ( https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa...). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it.
The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels.
Does the M17 have a cored hull or should this finder just work?
Thanks, Rob
When I had my M15 I contemplated having a depth device installed in the hull. But conditions change so rapidly when sailing I really felt that it was not necessary. So, I bought a hand held unit that you just put in the water and fire. That worked just fine. Daniel Rich SCAMP #330 Wildflower M15 #208 Kestrel (sold)
On Jun 19, 2020, at 2:37 PM, Bob Eeg <montgomeryboats@hotmail.com> wrote:
M 17s have a solid glass hull. Same for the 15 and 16. Be well Bob
Sent from my iPad
On Jun 19, 2020, at 1:47 PM, Rob Bultman <rob.bultman@gmail.com> wrote:
My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website ( https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa...). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it.
The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels.
Does the M17 have a cored hull or should this finder just work?
Thanks, Rob
Rob: I've installed a couple dozen of these and in each case used silicone instead of slow cure epoxy. the bonus is if there is a problem with the transducer it doesn't take a jackhammer to get the unit out. I suggest you clean the area where the current transducer was attached and use silicone to re-mount and see if the unit will work. the trick is not to have any bubbles in the silicone (and the epoxy). after placing leave the boat at let it sit for a couple or more days - no sailing! if reattaching the transducer doesn't work either it is dead or the placement is in a location that has a void or other 'contaminant' that interferes with the signals. to clarify all of Jerry's designs have no core in the starboard nor port sides of the hull. the only section of the hull with core is the transom. most of the horizontal portions of the deck and cockpit have balsa core. some of the older M17s also have a thin plywood core on the cabin wall port and starboard of the companionway. :: Dave Scobie :: SV SWALLOW - https://sv-swallow.com :: Montgomery 6'8" #650 :: Truck camper - https://truckpopupcamper.wordpress.com/ :: Ramblings - https://scoobsramblings.wordpress.com/ :: former M17 owner #375 SWEET PEA - https://m17-375.com/ <http://www.m17-375.webs.com/> :: former M15 owner #288 - http://www.freewebs.com/m15-name-scred On Fri, Jun 19, 2020 at 1:48 PM Rob Bultman <rob.bultman@gmail.com> wrote:
My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website (
https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa... ). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it.
The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels.
Does the M17 have a cored hull or should this finder just work?
Thanks, Rob
Thanks for that Dave. I might start with petroleum jelly and duct tape, or a weight, to see if I can get any readings initially. The install instructions from HawkEye mention using petroleum jelly to find the initial position of the transducer on the hull. I understand the comments about bubbles. Regards, Rob On Mon, Jun 22, 2020 at 3:14 PM Dave Scobie <scoobscobie@gmail.com> wrote:
Rob:
I've installed a couple dozen of these and in each case used silicone instead of slow cure epoxy. the bonus is if there is a problem with the transducer it doesn't take a jackhammer to get the unit out.
I suggest you clean the area where the current transducer was attached and use silicone to re-mount and see if the unit will work. the trick is not to have any bubbles in the silicone (and the epoxy). after placing leave the boat at let it sit for a couple or more days - no sailing! if reattaching the transducer doesn't work either it is dead or the placement is in a location that has a void or other 'contaminant' that interferes with the signals.
to clarify all of Jerry's designs have no core in the starboard nor port sides of the hull. the only section of the hull with core is the transom. most of the horizontal portions of the deck and cockpit have balsa core. some of the older M17s also have a thin plywood core on the cabin wall port and starboard of the companionway.
:: Dave Scobie :: SV SWALLOW - https://sv-swallow.com :: Montgomery 6'8" #650 :: Truck camper - https://truckpopupcamper.wordpress.com/ :: Ramblings - https://scoobsramblings.wordpress.com/ :: former M17 owner #375 SWEET PEA - https://m17-375.com/ <http://www.m17-375.webs.com/> :: former M15 owner #288 - http://www.freewebs.com/m15-name-scred
On Fri, Jun 19, 2020 at 1:48 PM Rob Bultman <rob.bultman@gmail.com> wrote:
My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website (
https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa...
). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it.
The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels.
Does the M17 have a cored hull or should this finder just work?
Thanks, Rob
On 6/22/20 12:14 PM, Dave Scobie wrote: ...
most of the horizontal portions of the deck and cockpit have balsa core. some of the older M17s also have a thin plywood core on the cabin wall port and starboard of the companionway.
Seems YMMV a fair bit on some of this with early M17's. My 'early' M17 #38, 1974, has no balsa core anywhere. For which I am quite glad, since I'll never have to deal with rotting balsa core, which would have happened by now on a boat this old, especially given some prior owner used @&#^$%!! silicone to "seal" various things, and, some of the deck fittings appeared to have no OEM bedding at all. Which doesn't cause any problem but possible seepage to the inside, if there's no core to rot or to trap water and cause de-lamination. Anyhow... Cockpit has foam core underneath on some horizontal parts. Cabin sides/top and foredeck have glassed half-tube reinforcement crosswise on the underside. On the cabin top it runs fairly close to fore and aft sides of chainplates and mast step. On the foredeck there are two half-tubes, spaced out what looks like an appropriate distance structurally (my foredeck is plenty solid, anyhow). The cabin layup also gets significantly thicker around the chainplates/mast step area. I could see this when I replaced the window glazing and had the frames out. Aft cabin wall has no core, thin ply or otherwise. Apparently this was a plenty solid layup & reinforcing method, since the boat has had no structural failures in 46 years (though I don't know how much hard use it got with prior owners). Those of you with M17s of similar vintage...same construction, or different? cheers, John
:: Dave Scobie :: SV SWALLOW - https://sv-swallow.com :: Montgomery 6'8" #650 :: Truck camper - https://truckpopupcamper.wordpress.com/ :: Ramblings - https://scoobsramblings.wordpress.com/ :: former M17 owner #375 SWEET PEA - https://m17-375.com/ <http://www.m17-375.webs.com/> :: former M15 owner #288 - http://www.freewebs.com/m15-name-scred
On Fri, Jun 19, 2020 at 1:48 PM Rob Bultman <rob.bultman@gmail.com> wrote:
My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website (
https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa... ). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it.
The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels.
Does the M17 have a cored hull or should this finder just work?
Thanks, Rob
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
Yes John there are many of the very old boats that have foam core and the fiberglass 1/2-rounds for deck strength. I know of some folks that have had issues with the foam core delaminating - the difference is there is no rot like balsa but the repair is the same as the damaged area needs to be rebuilt. Balsa gets a bad rep but the issue is really lack of owner maintenance and incorrect care. :: Dave Scobie :: SV SWALLOW - https://sv-swallow.com :: Montgomery 6'8" #650 :: Truck camper - https://truckpopupcamper.wordpress.com/ :: Ramblings - https://scoobsramblings.wordpress.com/ :: former M17 owner #375 SWEET PEA - https://m17-375.com/ <http://www.m17-375.webs.com/> :: former M15 owner #288 - http://www.freewebs.com/m15-name-scred On Mon, Jun 22, 2020 at 1:02 PM John Schinnerer via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
On 6/22/20 12:14 PM, Dave Scobie wrote: ...
most of the horizontal portions of the deck and cockpit have balsa core. some of the older M17s also have a thin plywood core on the cabin wall port and starboard of the companionway.
Seems YMMV a fair bit on some of this with early M17's.
My 'early' M17 #38, 1974, has no balsa core anywhere. For which I am quite glad, since I'll never have to deal with rotting balsa core, which would have happened by now on a boat this old, especially given some prior owner used @&#^$%!! silicone to "seal" various things, and, some of the deck fittings appeared to have no OEM bedding at all. Which doesn't cause any problem but possible seepage to the inside, if there's no core to rot or to trap water and cause de-lamination. Anyhow...
Cockpit has foam core underneath on some horizontal parts.
Cabin sides/top and foredeck have glassed half-tube reinforcement crosswise on the underside. On the cabin top it runs fairly close to fore and aft sides of chainplates and mast step. On the foredeck there are two half-tubes, spaced out what looks like an appropriate distance structurally (my foredeck is plenty solid, anyhow). The cabin layup also gets significantly thicker around the chainplates/mast step area. I could see this when I replaced the window glazing and had the frames out. Aft cabin wall has no core, thin ply or otherwise.
Apparently this was a plenty solid layup & reinforcing method, since the boat has had no structural failures in 46 years (though I don't know how much hard use it got with prior owners).
Those of you with M17s of similar vintage...same construction, or different?
cheers, John
participants (7)
-
Bob Eeg -
Daniel Rich -
Dave Scobie -
John Schinnerer -
Keith R. Martin -
Lawrence Winiarski -
Rob Bultman