Hi All,
I hope that this is the correct forum for the following topic: fiberglass repairs.
I have picked up a new-to-me but clearly 'old but hope springs eternal' Supercat 17. (I'm struggling to find the HIN. Were those on the transoms? Mine are redone.)
The hollows/semi-tunnels that accept the cross-beams (akas?) of the catamaran are in need of being redone. In one of the four joints, one of the metal pieces that was threaded to receive the bolt from above has popped out. In another of the joints, there is a large crack that one shouldn't trust vessel integrity to.
As a relative newbie to working with fiberglass, I'm wondering whether there are clear indications as to whether I should be working with epoxy vs. polyester resin, for the SC17 case in particular.
For each joint in question, I'm going to start with a dremel tool and cut back everything I should to see what I'm working with. I'm contemplating going whole hog, and making 4 new saddle-like inserts, and trying to glass them in... establishing as strong and complete a connection to the hulls as possible. I'm also considering building in glass arches that go above and around the cross beams to capture them entirely. I'm also considering adding new chain plates (metal brackets) to the outboard and inboard sides of the hull, so that I can try holding the cross beams down, via a tensionable connection to those chain plates.
Has anyone done anything similar to their hulls?
My main question is about the kind of resin to use.
thanks!
Supercat 17 fiberglass repair: Epoxy vs. Polyester Resin?
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Matt Haberman
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Re: Supercat 17 fiberglass repair: Epoxy vs. Polyester Resin?
Hello,
The HIN was historically engraved into the transom or a metal plate on the transom. There was also a hull number molded into the hull, either on the transom on just adjacent to the beam saddle on the inside of the hull. If you share some pictures of the saddles, transoms, rudder assembly, etc, I can probably tell you the approximate vintage.
Epoxy would be the most versatile choice as it would be compatible with whatever resin your boat was built with. Earlier builds used polyester or vinylester resins. Epoxy was used in the mid-late 90's and beyond.
My suggestion would be to just rebuild the saddle as it was originally designed and avoid any of the other complex directions you proposed. If you search the forum there are some well documented repairs similar to what your going to be doing that should be helpful and provide some inspiration.
The HIN was historically engraved into the transom or a metal plate on the transom. There was also a hull number molded into the hull, either on the transom on just adjacent to the beam saddle on the inside of the hull. If you share some pictures of the saddles, transoms, rudder assembly, etc, I can probably tell you the approximate vintage.
Epoxy would be the most versatile choice as it would be compatible with whatever resin your boat was built with. Earlier builds used polyester or vinylester resins. Epoxy was used in the mid-late 90's and beyond.
My suggestion would be to just rebuild the saddle as it was originally designed and avoid any of the other complex directions you proposed. If you search the forum there are some well documented repairs similar to what your going to be doing that should be helpful and provide some inspiration.
Re: Supercat 17 fiberglass repair: Epoxy vs. Polyester Resin?
Thank you for the response Matt!
Here's a Google Photo Album, "Cat Plus Dog for Scale": https://photos.app.goo.gl/u4gjA95j4JHYGHYz6
Some other questions:
1) Are the hulls symmetric by reflection through each hulls individual fore and aft centerline? (i.e. could you theoretically repurpose a starboard hull as a port hull, and vice versa?) [I'm asking this because I'm wondering whether the port forward saddle mold could double as a starboard forward saddle mold]
2) Are forward saddles identical to the aft saddles? [I'm asking this to see whether I need to build 1, 2 or 4 molds for saddles.]
Beyond that, I can see foam core between outer and inner layers of glass. For my new saddles, would I be hoping to have new foam core in them, and try to bind that new foam core to old foam core? (Is that even foam that I'm seeing?)
In service to those that come by this way, I'll build a list of links to previous posts that have relevant info about repairing hulls, and post them here.
Thanks again!
Here's a Google Photo Album, "Cat Plus Dog for Scale": https://photos.app.goo.gl/u4gjA95j4JHYGHYz6
Some other questions:
1) Are the hulls symmetric by reflection through each hulls individual fore and aft centerline? (i.e. could you theoretically repurpose a starboard hull as a port hull, and vice versa?) [I'm asking this because I'm wondering whether the port forward saddle mold could double as a starboard forward saddle mold]
2) Are forward saddles identical to the aft saddles? [I'm asking this to see whether I need to build 1, 2 or 4 molds for saddles.]
Beyond that, I can see foam core between outer and inner layers of glass. For my new saddles, would I be hoping to have new foam core in them, and try to bind that new foam core to old foam core? (Is that even foam that I'm seeing?)
In service to those that come by this way, I'll build a list of links to previous posts that have relevant info about repairing hulls, and post them here.
Thanks again!
-
Matt Haberman
- Administrator
- Posts: 620
- Joined: November 10th, 2003, 8:22 pm
- Location: Minnesota
- Contact:
Re: Supercat 17 fiberglass repair: Epoxy vs. Polyester Resin?
Hello,
Based on the photos I believe the boat is early 1980's, nothing newer then 1982.
Regarding your questions:
1) The hulls are symmetrical from the standpoint of shape, so yes you could use one hull to make a saddle mold for the other hill. Structurally the hulls are not symmetrical so to cannot swap a starboard for a Port hull if that makes sense.
2) Both fore and aft saddles fit the 4.5" diameter beam, however the overall saddle geometry is not the same.
3) There is foam core in the hull, however in high stress areas like the beam saddle the foam core was removed and the laminate was solid glass.
Based on the photos I believe the boat is early 1980's, nothing newer then 1982.
Regarding your questions:
1) The hulls are symmetrical from the standpoint of shape, so yes you could use one hull to make a saddle mold for the other hill. Structurally the hulls are not symmetrical so to cannot swap a starboard for a Port hull if that makes sense.
2) Both fore and aft saddles fit the 4.5" diameter beam, however the overall saddle geometry is not the same.
3) There is foam core in the hull, however in high stress areas like the beam saddle the foam core was removed and the laminate was solid glass.