Hi there,
I’m new here and 1[SUP]st[/SUP] time boat owner. Bought a “lake ready” 1984 20ft cuddy cabin this February and slowly discovered all the little things that make that boat quite not so lake ready
. (Most likely paid way too much but I’ll book it as a pricey “lessons learned”). I was already in the process of restoring the stringer outboard after finding water in the gear oil ( upper + lower seal kit, new water pump, new ball gear kit, new drive shaft ) and the V8 engine ( this one runs great once its started but needs new exhaust manifolds, electric fuel pump, starter, plugs, hydraulic hoses)
After first taking her out I discovered that the engine mount bolts came out and then after gradually digging here and there and removing more and more of the old floor, the status was:
Transom ( 3 x ¾ ply sandwiched ): 1st layer rotten 2[SUP]nd[/SUP] layer invested with worms, 3[SUP]rd[/SUP] ( outermost) layer fine
Stringer/Engine mounts: back of the boat (everything close to bilge) rotten, front fine, cabin wood + fiberglass in good condition
I already removed all the floor and 2 layers of the transom. I watched a lot of videos about stringer repair and fiber glassing (and got some surf board glassing experience) and I kind of have an idea what to do, but I’m not sure if this is the best way. Also is the boat build a bit different than most designs I found online and I’m a bit indecisive between restoring it 100% original ( that’s recommended on a couple posts) or the way I found in tutorials ( which is simply different from the build).
Although it wouldn’t make big difference in time and material at that point, I don’t want to touch the last transom layer and the cabin. I’m mainly concerned that the cabin somehow falls apart / warps if I remove all stingers and the old material there seems pretty good ( I drilled several 2” holes, fiberglass is thick, wood dry and solid, foam not soaked) so that I think I’d do more damage than good touching it. For the transom it looks like the outer side is part of the fiberglass hull and I don’t want to cut into it.
Transom:
I want to sandwich 2 new marine ply layers to the remaining layer of the transom:
Grind down old glass, soak old ply, then CSM + 2x 1708 + 2[SUP]nd[/SUP] ply + CSM +2x 1708 + 3[SUP]rd[/SUP] ply + CSM +2x1708.
I don’t know what’s the best way of making sure that there’s no air between the ply layers. I can clamp them fairly good where the hole for the outboard is. For the rest I’d drill a couple holes and press them together with screws. I don’t know if there’s a better way of doing this and how many screws I should use. I want to drill as little holes as possible but also don’t want any air bubbles between the layers.
Also the 2[SUP]nd[/SUP] layer had wood worms in there and I was wondering how they got in there at all and how to prevent it from happening again. Isn’t marine ply treated in a way that kills bugs? I’d also assume a completely resin sealed piece of wood doesn’t let any air in so they should suffocate.
Stringers:
So that’s what’s puzzling me a bit. What I found in tutorials are stringers on PBJ or similar, glassed and tabbed from both sides and completely sealed. What I found in my boat looks like they build the floor stringers + bulk heads in 2 pieces ( 2 halves of the boat) and then they flipped it into the boat and tabbed it only on the inside and filled the other side with foam. I attached some pictures to illustrate this. The tabbing is only on the “inside”( there where the tank sits). The underside of the floor is tabbed to the stringers and there is no glass on top of the stringers. The tank side is glassed pretty strong and good, but the side where the foam is, is poorly glassed and therefore started rotting quickly once water got in. I think the idea was that water never leaves the bilge / tank section. Well unfortunately it happened. Also those stringers are only 0.5inch thick but there runs some reinforcement bar in parallel and the whole floor + foam seems to give pretty good structural integrity.
For restoring I was wondering: Should I use 3/4inch stringers instead or stick to the original 0.5 ? Should I tab them from both sides ? They are pretty tall (1ft), do I need to wrap them in all layers all around or is one layer enough to make them water proof and then use only all schedule layers on the bottom for tabbing ? I don’t want to leave the top of the stringers unglassed like the original design. The floor there was screwed on and had no fiberglass on the bottom, except where it was tabbed to the stringers. I would glass the floor on both sides and then PBJ it to the stringers if that makes sense? I also read several times that ppl sand down layers or the filleting area before tabbing. From board glassing I know that poly stays tacky, I would just add another layer of laminating resin, even a couple days after. Is sanding necessary?
For connecting it to the old stringers I attached a drawing. I don’t know if that’s a good way to do it and if I should somehow reinforce the joint.
Depending on your recommendations I like to figure out how much glass and resin I need.
Schedules I found are: Transom/Stringer CSM (1.5oz) +1708+1708, Deck 6OZ cloth both sides + gel coating top, Filler: Cabosil + Poly resin 1:1
I found a hint on how much resin per sqft to use here: https://www.lbifiberglass.com/how-much-resin-glass-do-i-need/
If I stick to the schedule above I’d need 58sqft CSM, 117sft 1708, 95sqft 6oz sloth + 8Gal resin
Is that realistic?
Thanks for your help. Hope my mix of thoughts and questions is not too hard to read.
I’m new here and 1[SUP]st[/SUP] time boat owner. Bought a “lake ready” 1984 20ft cuddy cabin this February and slowly discovered all the little things that make that boat quite not so lake ready
After first taking her out I discovered that the engine mount bolts came out and then after gradually digging here and there and removing more and more of the old floor, the status was:
Transom ( 3 x ¾ ply sandwiched ): 1st layer rotten 2[SUP]nd[/SUP] layer invested with worms, 3[SUP]rd[/SUP] ( outermost) layer fine
Stringer/Engine mounts: back of the boat (everything close to bilge) rotten, front fine, cabin wood + fiberglass in good condition
I already removed all the floor and 2 layers of the transom. I watched a lot of videos about stringer repair and fiber glassing (and got some surf board glassing experience) and I kind of have an idea what to do, but I’m not sure if this is the best way. Also is the boat build a bit different than most designs I found online and I’m a bit indecisive between restoring it 100% original ( that’s recommended on a couple posts) or the way I found in tutorials ( which is simply different from the build).
Although it wouldn’t make big difference in time and material at that point, I don’t want to touch the last transom layer and the cabin. I’m mainly concerned that the cabin somehow falls apart / warps if I remove all stingers and the old material there seems pretty good ( I drilled several 2” holes, fiberglass is thick, wood dry and solid, foam not soaked) so that I think I’d do more damage than good touching it. For the transom it looks like the outer side is part of the fiberglass hull and I don’t want to cut into it.
Transom:
I want to sandwich 2 new marine ply layers to the remaining layer of the transom:
Grind down old glass, soak old ply, then CSM + 2x 1708 + 2[SUP]nd[/SUP] ply + CSM +2x 1708 + 3[SUP]rd[/SUP] ply + CSM +2x1708.
I don’t know what’s the best way of making sure that there’s no air between the ply layers. I can clamp them fairly good where the hole for the outboard is. For the rest I’d drill a couple holes and press them together with screws. I don’t know if there’s a better way of doing this and how many screws I should use. I want to drill as little holes as possible but also don’t want any air bubbles between the layers.
Also the 2[SUP]nd[/SUP] layer had wood worms in there and I was wondering how they got in there at all and how to prevent it from happening again. Isn’t marine ply treated in a way that kills bugs? I’d also assume a completely resin sealed piece of wood doesn’t let any air in so they should suffocate.
Stringers:
So that’s what’s puzzling me a bit. What I found in tutorials are stringers on PBJ or similar, glassed and tabbed from both sides and completely sealed. What I found in my boat looks like they build the floor stringers + bulk heads in 2 pieces ( 2 halves of the boat) and then they flipped it into the boat and tabbed it only on the inside and filled the other side with foam. I attached some pictures to illustrate this. The tabbing is only on the “inside”( there where the tank sits). The underside of the floor is tabbed to the stringers and there is no glass on top of the stringers. The tank side is glassed pretty strong and good, but the side where the foam is, is poorly glassed and therefore started rotting quickly once water got in. I think the idea was that water never leaves the bilge / tank section. Well unfortunately it happened. Also those stringers are only 0.5inch thick but there runs some reinforcement bar in parallel and the whole floor + foam seems to give pretty good structural integrity.
For restoring I was wondering: Should I use 3/4inch stringers instead or stick to the original 0.5 ? Should I tab them from both sides ? They are pretty tall (1ft), do I need to wrap them in all layers all around or is one layer enough to make them water proof and then use only all schedule layers on the bottom for tabbing ? I don’t want to leave the top of the stringers unglassed like the original design. The floor there was screwed on and had no fiberglass on the bottom, except where it was tabbed to the stringers. I would glass the floor on both sides and then PBJ it to the stringers if that makes sense? I also read several times that ppl sand down layers or the filleting area before tabbing. From board glassing I know that poly stays tacky, I would just add another layer of laminating resin, even a couple days after. Is sanding necessary?
For connecting it to the old stringers I attached a drawing. I don’t know if that’s a good way to do it and if I should somehow reinforce the joint.
Depending on your recommendations I like to figure out how much glass and resin I need.
Schedules I found are: Transom/Stringer CSM (1.5oz) +1708+1708, Deck 6OZ cloth both sides + gel coating top, Filler: Cabosil + Poly resin 1:1
I found a hint on how much resin per sqft to use here: https://www.lbifiberglass.com/how-much-resin-glass-do-i-need/
If I stick to the schedule above I’d need 58sqft CSM, 117sft 1708, 95sqft 6oz sloth + 8Gal resin
Is that realistic?
Thanks for your help. Hope my mix of thoughts and questions is not too hard to read.