Hi All, Between availability and the small amount needed and the desire to not use balsa again I am ordering a sheet of diviney foam, scored on a scrim. The repair will take about four square feet above my v-berth in the M 17. Has anybody used this particular product? I am looking for personal knowledge hints on problems I might encounter with this stuff. I have read all the literature on installing it. Fair winds, Tom B M-17, #258, 77'
Tom: You may want to reconsider the balsa option. I wouldn't be too quick to eliminate it. The reason you have what you have is the bolt holes that pass through it were likely not sealed on the inside. What was protecting the balsa was nothing more than the bedding compound the fixture was resting upon. Over time, that hardens, cracks, etc and water manages to weep past it, then through the bolt holes and into the balsa. Yes, balsa is more likely to soak up water and rot, but even with foam, the water will still be there doing damage (and adding weight) unless you completely seal the hole. The way to seal the hole is to enlarge the bolt hole from the inside (larger hole inside on bottom of cabin top). Then tape off the inside bottom hole, and backfill the bolt hole with slightly thickened epoxy. What you are essentially doing is pouring an epoxy compression bushing between the outer and inner sandwich layers, which not only seals the hole, but any water that gets past the bedding compound enters the bolt hole.......and drips straight on through to the inside of the cabin. It never reaches the balsa, which can't get wet if it is fully encapsulated with no chance of exposure. Balsa is relatively low tech, but still one of the best, and least expensive choices for glass sandwich core. Also, with the epoxy bushing into place, you can crank your bolts down without having to worry about compressing the inner core. To those wondering how to tell if your balsa core is wet, take a good sized plastic handled screwdriver, use the handle end and gently tap/rap the outside. If the core remains solid and dry, you get a solid ring/ping. If the core is wet and rotten, it is a dull thud/thunk. If you are trying to sound it out, keep moving around in a grid pattern and map it out. Start near the bolt holes and work your way out. And whatever you do, make sure you use epoxy resin to make your repairs. Do not use a polyester. It was right to build the boat with, but not to repair it with. I would also double/triple check the thickness of the core. I had to redo my chain plate backing. That was half inch as I recall. Didn't think so until I got into making the repair. Had to buy core materials twice. On Apr 14, 2014, at 2:07 PM, Thomas Buzzi wrote:
Hi All, Between availability and the small amount needed and the desire to not use balsa again I am ordering a sheet of diviney foam, scored on a scrim. The repair will take about four square feet above my v-berth in the M 17. Has anybody used this particular product? I am looking for personal knowledge hints on problems I might encounter with this stuff. I have read all the literature on installing it. Fair winds, Tom B M-17, #258, 77'
Thanks, Howard, That's about what I was looking for. Did you repair your deck from the top down or the bottom up, like I am? Tom B On Mon, Apr 14, 2014 at 2:34 PM, Howard Audsley <haudsley@tranquility.net>wrote:
Tom:
You may want to reconsider the balsa option. I wouldn't be too quick to eliminate it. The reason you have what you have is the bolt holes that pass through it were likely not sealed on the inside. What was protecting the balsa was nothing more than the bedding compound the fixture was resting upon. Over time, that hardens, cracks, etc and water manages to weep past it, then through the bolt holes and into the balsa. Yes, balsa is more likely to soak up water and rot, but even with foam, the water will still be there doing damage (and adding weight) unless you completely seal the hole.
The way to seal the hole is to enlarge the bolt hole from the inside (larger hole inside on bottom of cabin top). Then tape off the inside bottom hole, and backfill the bolt hole with slightly thickened epoxy. What you are essentially doing is pouring an epoxy compression bushing between the outer and inner sandwich layers, which not only seals the hole, but any water that gets past the bedding compound enters the bolt hole.......and drips straight on through to the inside of the cabin. It never reaches the balsa, which can't get wet if it is fully encapsulated with no chance of exposure. Balsa is relatively low tech, but still one of the best, and least expensive choices for glass sandwich core. Also, with the epoxy bushing into place, you can crank your bolts down without having to worry about compressing the inner core.
To those wondering how to tell if your balsa core is wet, take a good sized plastic handled screwdriver, use the handle end and gently tap/rap the outside. If the core remains solid and dry, you get a solid ring/ping. If the core is wet and rotten, it is a dull thud/thunk. If you are trying to sound it out, keep moving around in a grid pattern and map it out. Start near the bolt holes and work your way out.
And whatever you do, make sure you use epoxy resin to make your repairs. Do not use a polyester. It was right to build the boat with, but not to repair it with.
I would also double/triple check the thickness of the core. I had to redo my chain plate backing. That was half inch as I recall. Didn't think so until I got into making the repair. Had to buy core materials twice.
On Apr 14, 2014, at 2:07 PM, Thomas Buzzi wrote:
Hi All, Between availability and the small amount needed and the desire to not use balsa again I am ordering a sheet of diviney foam, scored on a scrim. The repair will take about four square feet above my v-berth in the M 17. Has anybody used this particular product? I am looking for personal knowledge hints on problems I might encounter with this stuff. I have read all the literature on installing it. Fair winds, Tom B M-17, #258, 77'
I just had to do the core area behind the chain plates on both sides. Mine were full of water and black mush. Since they only hold the entire rigging up I figured it might be a good idea and was getting tired of wet cushions beneath them after every rain. I did my repairs from the inside, but those are vertical sides, not working from beneath like you would have to do with a cabin top. Decided to save the cabin deck while I was at it, as it was still sound and I didn't want to have a core issue like yours. Not many, if any, production boats I've seen drill out and back fill the enlarged boat holes through core areas. If you don't want to do that, plan on periodically stripping off all the hardware and rebedding them. Caulk doesn't last forever. While the cabins on most boats are built while upside down in the molds, most repairs on the cabin tops, cored side decks, etc. are done from the outside in. Always easier to work with gravity than fight it. Best plan is usually to sound it out or use a moisture meter to find where the damaged areas are, cut out the exterior around the damage, saving the exterior piece. Clean out the damaged core and sand the inside surfaces back to flush, which will also give the epoxy some tooth to hang on to. Then replace the rotted core, then epoxy the original exterior glass piece back into place. With a little care and practice, it may be possible to fair the repair edges well enough most people would have to be shown where the repair was made to notice it. The hard part is matching the gelcoat back. If it is an older boat, you may want to take the occasion of your repair as an opportunity to repaint the entire boat. You can get expensive epoxy from West Marine, but MAS and some of the other places like RAKA and Progressive Epoxy Polymers offer very good 2:1 products for less money. Use fumed silica as your thickening agent. There is a learning curve, but must not be too steep. I figured out how to do it. On Apr 14, 2014, at 3:45 PM, Thomas Buzzi wrote:
Thanks, Howard, That's about what I was looking for. Did you repair your deck from the top down or the bottom up, like I am? Tom B
On Mon, Apr 14, 2014 at 2:34 PM, Howard Audsley <haudsley@tranquility.net>wrote:
Tom:
You may want to reconsider the balsa option. I wouldn't be too quick to eliminate it. The reason you have what you have is the bolt holes that pass through it were likely not sealed on the inside. What was protecting the balsa was nothing more than the bedding compound the fixture was resting upon. Over time, that hardens, cracks, etc and water manages to weep past it, then through the bolt holes and into the balsa. Yes, balsa is more likely to soak up water and rot, but even with foam, the water will still be there doing damage (and adding weight) unless you completely seal the hole.
The way to seal the hole is to enlarge the bolt hole from the inside (larger hole inside on bottom of cabin top). Then tape off the inside bottom hole, and backfill the bolt hole with slightly thickened epoxy. What you are essentially doing is pouring an epoxy compression bushing between the outer and inner sandwich layers, which not only seals the hole, but any water that gets past the bedding compound enters the bolt hole.......and drips straight on through to the inside of the cabin. It never reaches the balsa, which can't get wet if it is fully encapsulated with no chance of exposure. Balsa is relatively low tech, but still one of the best, and least expensive choices for glass sandwich core. Also, with the epoxy bushing into place, you can crank your bolts down without having to worry about compressing the inner core.
To those wondering how to tell if your balsa core is wet, take a good sized plastic handled screwdriver, use the handle end and gently tap/rap the outside. If the core remains solid and dry, you get a solid ring/ping. If the core is wet and rotten, it is a dull thud/thunk. If you are trying to sound it out, keep moving around in a grid pattern and map it out. Start near the bolt holes and work your way out.
And whatever you do, make sure you use epoxy resin to make your repairs. Do not use a polyester. It was right to build the boat with, but not to repair it with.
I would also double/triple check the thickness of the core. I had to redo my chain plate backing. That was half inch as I recall. Didn't think so until I got into making the repair. Had to buy core materials twice.
On Apr 14, 2014, at 2:07 PM, Thomas Buzzi wrote:
Hi All, Between availability and the small amount needed and the desire to not use balsa again I am ordering a sheet of diviney foam, scored on a scrim. The repair will take about four square feet above my v-berth in the M 17. Has anybody used this particular product? I am looking for personal knowledge hints on problems I might encounter with this stuff. I have read all the literature on installing it. Fair winds, Tom B M-17, #258, 77'
Hi Howard, Thanks for the info. I looked at RAKA and their prices are much better than West. I wondered about the quality of their product due to the price difference but with your suggestions I will give more weight to the costs. Also found some separation of the cabin liner where it joins the hull in the keel/mast step area. Gotta take care of that too. For those sprucing up their hulls this spring, I had an unnerving experience yesterday while spraying straight bleach on the cabin interior and cockpit sides and coamings. Some of the overspray ran down behind the toerail (mine is the metal perforated kind) and down the hull. My hull is bright yellow. Soon discovered that where the bleach had run down the side of the hull it had reacted with the gelcoat and leached some rust red coloring out of the gelcoat and left that behind as the bleach evaporated. Had to resort to wet sanding it off. Was thankful I was able to remove the stains. My whole transom had to be done the same way. "And so it goes". [" The learning curve"] Fair winds, Tom B On Mon, Apr 14, 2014 at 10:12 PM, Howard Audsley <haudsley@tranquility.net>wrote:
I just had to do the core area behind the chain plates on both sides. Mine were full of water and black mush. Since they only hold the entire rigging up I figured it might be a good idea and was getting tired of wet cushions beneath them after every rain. I did my repairs from the inside, but those are vertical sides, not working from beneath like you would have to do with a cabin top. Decided to save the cabin deck while I was at it, as it was still sound and I didn't want to have a core issue like yours. Not many, if any, production boats I've seen drill out and back fill the enlarged boat holes through core areas. If you don't want to do that, plan on periodically stripping off all the hardware and rebedding them. Caulk doesn't last forever.
While the cabins on most boats are built while upside down in the molds, most repairs on the cabin tops, cored side decks, etc. are done from the outside in. Always easier to work with gravity than fight it. Best plan is usually to sound it out or use a moisture meter to find where the damaged areas are, cut out the exterior around the damage, saving the exterior piece. Clean out the damaged core and sand the inside surfaces back to flush, which will also give the epoxy some tooth to hang on to. Then replace the rotted core, then epoxy the original exterior glass piece back into place. With a little care and practice, it may be possible to fair the repair edges well enough most people would have to be shown where the repair was made to notice it. The hard part is matching the gelcoat back. If it is an older boat, you may want to take the occasion of your repair as an opportunity to repaint the entire boat.
You can get expensive epoxy from West Marine, but MAS and some of the other places like RAKA and Progressive Epoxy Polymers offer very good 2:1 products for less money. Use fumed silica as your thickening agent. There is a learning curve, but must not be too steep. I figured out how to do it.
On Apr 14, 2014, at 3:45 PM, Thomas Buzzi wrote:
Thanks, Howard, That's about what I was looking for. Did you repair your deck from the top down or the bottom up, like I am? Tom B
On Mon, Apr 14, 2014 at 2:34 PM, Howard Audsley < haudsley@tranquility.net>wrote:
Tom:
You may want to reconsider the balsa option. I wouldn't be too quick to eliminate it. The reason you have what you have is the bolt holes that pass through it were likely not sealed on the inside. What was protecting the balsa was nothing more than the bedding compound the fixture was resting upon. Over time, that hardens, cracks, etc and water manages to weep past it, then through the bolt holes and into the balsa. Yes, balsa is more likely to soak up water and rot, but even with foam, the water will still be there doing damage (and adding weight) unless you completely seal the hole.
The way to seal the hole is to enlarge the bolt hole from the inside (larger hole inside on bottom of cabin top). Then tape off the inside bottom hole, and backfill the bolt hole with slightly thickened epoxy. What you are essentially doing is pouring an epoxy compression bushing between the outer and inner sandwich layers, which not only seals the hole, but any water that gets past the bedding compound enters the bolt hole.......and drips straight on through to the inside of the cabin. It never reaches the balsa, which can't get wet if it is fully encapsulated with no chance of exposure. Balsa is relatively low tech, but still one of the best, and least expensive choices for glass sandwich core. Also, with the epoxy bushing into place, you can crank your bolts down without having to worry about compressing the inner core.
To those wondering how to tell if your balsa core is wet, take a good sized plastic handled screwdriver, use the handle end and gently tap/rap the outside. If the core remains solid and dry, you get a solid ring/ping. If the core is wet and rotten, it is a dull thud/thunk. If you are trying to sound it out, keep moving around in a grid pattern and map it out. Start near the bolt holes and work your way out.
And whatever you do, make sure you use epoxy resin to make your repairs. Do not use a polyester. It was right to build the boat with, but not to repair it with.
I would also double/triple check the thickness of the core. I had to redo my chain plate backing. That was half inch as I recall. Didn't think so until I got into making the repair. Had to buy core materials twice.
On Apr 14, 2014, at 2:07 PM, Thomas Buzzi wrote:
Hi All, Between availability and the small amount needed and the desire to not use balsa again I am ordering a sheet of diviney foam, scored on a scrim. The repair will take about four square feet above my v-berth in the M 17. Has anybody used this particular product? I am looking for personal knowledge hints on problems I might encounter with this stuff. I have read all the literature on installing it. Fair winds, Tom B M-17, #258, 77'
Hi Tom, I have not used diviney foam but I stayed at a Holiday Inn Express last night. I looked on the Jamestown distributors web site along with a bunch of other sites then ordered double cut (scored) A500 foam. I think this or balsa would work very well from a compression and core laminate stand point. And since I plan on making all the holes solid epoxy on anything in the repair area water intrusion is not an issue going forward. I went with the foam since the repair area is small and the foam is very consistent density. But it looked to me like any foam would work well and the balsa would as well. The A500 was convenient. I would feel just as good about balsa. The whole idea that the laminated core is an I beam structure appeals to my brain and I reason that any of the core materials used for this purpose by marine and automotive users is going to be sufficient for our boats. Thanks, Robbin On 4/14/2014 3:07 PM, Thomas Buzzi wrote:
Hi All, Between availability and the small amount needed and the desire to not use balsa again I am ordering a sheet of diviney foam, scored on a scrim. The repair will take about four square feet above my v-berth in the M 17. Has anybody used this particular product? I am looking for personal knowledge hints on problems I might encounter with this stuff. I have read all the literature on installing it. Fair winds, Tom B M-17, #258, 77'
My thinking as well, Robbin. I have stayed at Holiday Inn Express as well but it hasn't helped me a bit yet about anything except getting a good night's sleep. [?] On Mon, Apr 14, 2014 at 6:14 PM, Robbin Roddewig < robbin.roddewig@verizon.net> wrote:
Hi Tom, I have not used diviney foam but I stayed at a Holiday Inn Express last night. I looked on the Jamestown distributors web site along with a bunch of other sites then ordered double cut (scored) A500 foam. I think this or balsa would work very well from a compression and core laminate stand point. And since I plan on making all the holes solid epoxy on anything in the repair area water intrusion is not an issue going forward. I went with the foam since the repair area is small and the foam is very consistent density. But it looked to me like any foam would work well and the balsa would as well. The A500 was convenient. I would feel just as good about balsa. The whole idea that the laminated core is an I beam structure appeals to my brain and I reason that any of the core materials used for this purpose by marine and automotive users is going to be sufficient for our boats.
Thanks, Robbin
On 4/14/2014 3:07 PM, Thomas Buzzi wrote:
Hi All, Between availability and the small amount needed and the desire to not use balsa again I am ordering a sheet of diviney foam, scored on a scrim. The repair will take about four square feet above my v-berth in the M 17. Has anybody used this particular product? I am looking for personal knowledge hints on problems I might encounter with this stuff. I have read all the literature on installing it. Fair winds, Tom B M-17, #258, 77'
participants (3)
-
Howard Audsley -
Robbin Roddewig -
Thomas Buzzi