Hi folks! This is my 1st post of probably many. I recently aquired an MFG Gypsy 15 Fiberglass Tri-hull circa early 70's that I'll be using as a family run-about and fishing machine. I also have a 1957 Crestliner 16 Ft Aluminum Deep-V. I love the Crestliner but a day of fishing can really put a hurtin' on ya. Figured the MFG would be a lot easier on the back and it was free! Couldn't argue with the price but I knew I had some work ahead of me.
The MFG had been sitting outdoors, uncovered, for many years allowed to fill with rain water, freeze and thaw. The floor, stringers, and transom are totally rotted out of it but the glass itself is in good condition.
Here's what I've done so far. I've ripped out all of the rotten stringers from the back of the boat up to the beginning of the console area. Because of the way the boat was originally constructed, I wasn't able to get to the rest of the wood that's under the console without causing some major re-assembly problems later. The wood under the console isn't totally rotted so I felt I could get away with it as is.
I've also taken out what was left of the old transom, It was mostly intact but terribly wet and swollen, rotten from top to bottom in the center area. Someone had previously tried to do a cheap fix on it by drilling holes in the outer transom glass and injecting some sort of resin into the separation between the plywood and glass. I've ground it all off down to the original rove. I've never seen anything like the stuff. It was nearly as hard as porcelain! If you hit it with a hammer it would chip off just like porcelain or glass.
After I got that all cleaned up, I noticed that the transom fiberglass had a lot of stress cracks and also found some minor interior cracks where the transom meets the sides of the hull (most likely due to freezing and thawing). So I ground out the cracks at the hull/transom corners, prep ground the rest of the transom area, and then reinforced all of the corners with Tiger Hair. I then glassed over the entire transom area and corners with 2 layers of matting for additional strength and sealing.
So that's where I'm at. Essentially i'm ready to start putting things back together. This is where the questions begin...
1.) As I mentioned, the wood under the console up to the bow was not totally rotted and is still fairly solid. I've heard that treatment with Ethelyne Glycol (Anti-freeze) is very effective for killing the bacteria and fungi that promote rot. True or false?
1.a) If true, will the Ethelyne Glycol create bonding problems with other nearby glass work?
2.) It appears that this particular model of boat wasn't very well though out from a water rention point of view, which I'm sure contributed to the rot over the years.
Essentially, if water does get into the hull, it has no place to go until it reaches a certain level and there are areas that it can pool in. In it's current configuration, once water gets into the bottom of the boat much of it will stay there with no chance of the hull below deck ever being truly dry.
The main problem is foam and poor manufacturing engineering. I believe that the manufacturer used foam for two reasons in the stringer area. One for flotation and secondly (where my problem begins) for side support of the stringers. These stringers don't appear to be associated with hull stiffening, just simply floor support. The reason I say that is because there was just a single thin layer of matting applied to their sides to hold them in place.
The foam seems to be in relatively good shape. I know there's a lot of differing opinion on foam in the bottom of a hull. So here's what I feel my options are because I don't want water just laying around in the hull to do it's nastiness to all of my hard work later.
A. Leave the foam as is and coat all of the replacement wood with resin to seal it from the water. (Which I plan on doing regardless)
B. Shape the foam (removing most of it) to still provide support for the stringers and better water flow off and around them.
C. Tear all of the foam out and glass the stringers in. (The least favorite of my options.)
On to the transom.
I will be coating the entire transom with resin when I'm finished making a new one out of 2 pieces of 3/4 ply laminated together. On the laminating, should I use resin and matting or can I get away with something like gorilla glue which is much cheaper?
There is no evidence that the transom was ever laminated to the transom glass at the back of the boat. All that I can see that was really holding it in place was 2 to 3 layers of matting covering the entire transom to the hull from the inside of the boat and not very thick either, 1/8 in. at most. Should I do the same thing or laminate the transom to the glass using resin and matting, then glass over the transom on the inside and beef up the corners with strips of rove? I'm thinking that's probably the best way to go, but obviously a lot more work (and money).
The floor. The floor appears to have been "stuck" to the stringers with a thick fiberglass resin of some sort. I'm wondering if I can get away with using a heavy duty plywood floor or wall adhesive instead. My concern is that the adhesive won't stick to the fiberglass resin that I'm going to be coating all of the wood with.
Here's a pic of the stringer area...
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I know that this was a long 1st post and I appreciate your indulgence. I look forward to everyone's input!
The MFG had been sitting outdoors, uncovered, for many years allowed to fill with rain water, freeze and thaw. The floor, stringers, and transom are totally rotted out of it but the glass itself is in good condition.
Here's what I've done so far. I've ripped out all of the rotten stringers from the back of the boat up to the beginning of the console area. Because of the way the boat was originally constructed, I wasn't able to get to the rest of the wood that's under the console without causing some major re-assembly problems later. The wood under the console isn't totally rotted so I felt I could get away with it as is.
I've also taken out what was left of the old transom, It was mostly intact but terribly wet and swollen, rotten from top to bottom in the center area. Someone had previously tried to do a cheap fix on it by drilling holes in the outer transom glass and injecting some sort of resin into the separation between the plywood and glass. I've ground it all off down to the original rove. I've never seen anything like the stuff. It was nearly as hard as porcelain! If you hit it with a hammer it would chip off just like porcelain or glass.
After I got that all cleaned up, I noticed that the transom fiberglass had a lot of stress cracks and also found some minor interior cracks where the transom meets the sides of the hull (most likely due to freezing and thawing). So I ground out the cracks at the hull/transom corners, prep ground the rest of the transom area, and then reinforced all of the corners with Tiger Hair. I then glassed over the entire transom area and corners with 2 layers of matting for additional strength and sealing.
So that's where I'm at. Essentially i'm ready to start putting things back together. This is where the questions begin...
1.) As I mentioned, the wood under the console up to the bow was not totally rotted and is still fairly solid. I've heard that treatment with Ethelyne Glycol (Anti-freeze) is very effective for killing the bacteria and fungi that promote rot. True or false?
1.a) If true, will the Ethelyne Glycol create bonding problems with other nearby glass work?
2.) It appears that this particular model of boat wasn't very well though out from a water rention point of view, which I'm sure contributed to the rot over the years.
Essentially, if water does get into the hull, it has no place to go until it reaches a certain level and there are areas that it can pool in. In it's current configuration, once water gets into the bottom of the boat much of it will stay there with no chance of the hull below deck ever being truly dry.
The main problem is foam and poor manufacturing engineering. I believe that the manufacturer used foam for two reasons in the stringer area. One for flotation and secondly (where my problem begins) for side support of the stringers. These stringers don't appear to be associated with hull stiffening, just simply floor support. The reason I say that is because there was just a single thin layer of matting applied to their sides to hold them in place.
The foam seems to be in relatively good shape. I know there's a lot of differing opinion on foam in the bottom of a hull. So here's what I feel my options are because I don't want water just laying around in the hull to do it's nastiness to all of my hard work later.
A. Leave the foam as is and coat all of the replacement wood with resin to seal it from the water. (Which I plan on doing regardless)
B. Shape the foam (removing most of it) to still provide support for the stringers and better water flow off and around them.
C. Tear all of the foam out and glass the stringers in. (The least favorite of my options.)
On to the transom.
I will be coating the entire transom with resin when I'm finished making a new one out of 2 pieces of 3/4 ply laminated together. On the laminating, should I use resin and matting or can I get away with something like gorilla glue which is much cheaper?
There is no evidence that the transom was ever laminated to the transom glass at the back of the boat. All that I can see that was really holding it in place was 2 to 3 layers of matting covering the entire transom to the hull from the inside of the boat and not very thick either, 1/8 in. at most. Should I do the same thing or laminate the transom to the glass using resin and matting, then glass over the transom on the inside and beef up the corners with strips of rove? I'm thinking that's probably the best way to go, but obviously a lot more work (and money).
The floor. The floor appears to have been "stuck" to the stringers with a thick fiberglass resin of some sort. I'm wondering if I can get away with using a heavy duty plywood floor or wall adhesive instead. My concern is that the adhesive won't stick to the fiberglass resin that I'm going to be coating all of the wood with.
Here's a pic of the stringer area...
I know that this was a long 1st post and I appreciate your indulgence. I look forward to everyone's input!