Rebuild 200 Osprey

[seabob4]

Carl, Joel's boat belongs (for the last several years) to one of my long time customers.  Here she is at my house a couple years back...



She lives on a lift on the Hillsborough River in Tampa...

[Callyb]

Pretty sweet Bob! I take it you did the rigging?

There you go Aqua, SB has actually had first hand experience with your benchmark.

Good luck and keep posting pictures.

[Aquasport Commodore]

Will do, but that is the boat that I am shooting for, but do not want a tower along with a few changes of of accessories. I fish Charlotte Harbor and go into the creeks, and with my luck, I'd hit some mangroves going in and smack myself  

[seabob4]

Pretty sweet Bob! I take it you did the rigging?

There you go Aqua, SB has actually had first hand experience with your benchmark.

Good luck and keep posting pictures.

Carl, Mike had bought the boat from Joel, the rigging was an absolute mess!  Seems Joel had paid some shop over on the east coast to rig the boat, gave them a HEALTHY amount of $$...and ended up with basically chit!  But he wanted to boat, so off he went down the road.

Things started crapping out, so Mike called me, dragged her up to my place, I pretty much took apart both lower and upper and re-rigged them properly.  I mean, it really was a joke what Joel paid good money for... :x

[Callyb]

That's a bum deal... Oh well, your work is about the best that I have seen. Beyond first class really, so I'm sure the current owner is better off in the long run having you redo it.

Sorry for the mild digression Aqua.

[Aquasport Commodore]

That's ok, besides learning from my own screw ups, I also lean from others....

I did a lot more grinding and removed more stringer towards the transom to give me more area to tab back the transom core to floor. Located lots of pockets of uncured resin. Made the template for core in paper, transferred to cardboard and put it in the shed for storage. Once the core is in secured with glass, moving the hull to a cradle and moving to replace stringers.

Now here is my new set of questions. I know the boat has to be level side to side and front to back, that is not an issue. My question is how do I make the stringers to be copies of the old but taller? I reviewed Ricks way of building the box for the mold and I like it, but I'm looking at making the stringers a little smaller using 2 2x12's sandwiched together with a cap to get the height where I want it, as a mold and using the outside as the mold.  Laminating over them as one long stringer and trimming to fit the hull. I will fill the inside of the stringer using 8lb foam for strength with a few layers of of glass over the entire hull bottom for strength along with bulkheads attached to the hull side where the deck panels meet. Does anyone see any issue with using this set up or have another way? Would the 8lb be overkill and 4lb a better fit?

The reason I plan on removing the old is due to several locations of delamination and the tops are not level at all and wanting to strengthen hull due to the hole in the hull and the abuse it took. It appears that the deviation on the stringer tops was due to core placement in the hull.

[gran398]

You may consider using foam beams instead of wood. Won't rot and will save weight. For sure avoid treated lumber.

[CLM65]

Aqua,

As someone who is going through the rebuild process and has just passed the stringer phase, allow me to share my thoughts....  I kept the original stringers and cut the caps off to remove the foam.  I then tabbed the insides of the stringers to the hull, and built new caps to increase the height.  A wise man (Carl) suggested that I just remove the old stringers and build new ones, but I was already part way through the process, and my stringers were in pretty good shape, so I figured my way was the easier route.  In retrospect, I wish I had followed his advice, as I probably spent more time and effort rebuilding these stringers than building new ones.  So, I think you are on the right track.  But here is my recommendation for how to do it.  It sounds like you are making a male mold for the stringers, and fiberglassing over them.  I would suggest the opposite.  I would make a female mold out of plywood and glass the inside (l think this is how Rick did it).  My reasoning is that I have had much better experience getting fiberglass to conform to inside corners than outside corners.  I imagine you will be using 1708 or 1808 glass, which does not make a tight outside bend very easily.  Also, one thing I have learned in my rebuild process is that forms/molds allow you to accurately control only one side of the piece you are making.  In other words, it is more critical that the outside of your stringers are straight and level than the inside.  Using a female mold allows you to keep the outside of your stringers as straight and level as the mold itself.  The inside may have thicker areas due to overlap, etc., but you don't really care about that.  I would also incorporate a trapezoid shape to the stringers to help them pop out of the mold easier and also provide a little lateral stability.  I think I have a picture or two of my stringer cap molds on my rebuild thread (flatback fireboat rebuild) if it helps.

As far as the foam, I would go with 4 lb.  8 lb is overkill and twice as expensive for the same volume.  2 lb is a little "soft", unless you have herculean stringers like Rick's.

[CLM65]

You may consider using foam beams instead of wood. Won't rot and will save weight. For sure avoid treated lumber.

My response above assumed he is just using the wood as a form for building stringers.  If I got that wrong, please disregard my post!

[gran398]

You may consider using foam beams instead of wood. Won't rot and will save weight. For sure avoid treated lumber.

My response above assumed he is just using the wood as a form for building stringers.  If I got that wrong, please disregard my post!

Craig, you are right, after re-reading, it is clearly stated the beams were to be used for the mold....so disregard MY post.

Thanks!

[Aquasport Commodore]

I was thinking the male mold, but the female mold makes more sense. I will do it that way. As for Ricks stringers, WOW   what a thickness,  and that transom, 3" on a 17 footer, He needs to change the name to Battleship...

[RickK]

The upper transom is 2 layers of 3/4 marine ply with some glass in between but the portion where it meets the hull bottom is thick

[kaptainkoz]

Craig's (clm65) explanation of the female mold is right on. You can never screw up you dimensions as they are taking the shape of the mold and it doesn't matter how many layers, folds or overlaps, the end product will always stay true to the mold. Great explanation and pretty much the way most fiberglass is done. That's the way to get professional results and appearance. Good luck with those stringers

[Callyb]

I would like to throw this out there too... Keep in mind that while Rick's stringers are strong for sure, (no disrespect Rick) 1/4" thick stringers are about twice what you need if using epoxy and biaxial. The original stringers should have been somewhere in the neighborhood of 1/8" or so. Keep in mind that the stringers are just part of the overall structure. The design of these (and most) boats is a monocoque structure. Accordingly the tie-in to the hull skin, sole and the sole to the hull skin make the stringers just one element of the entire structure. I'm not busting anyone's stones, I just want to offer the advise that you don't need to go too thick with the glass.

What I'm saying becomes tangible as you tear the boat down. Remove the sole, the stringers, hull sides can easily be flexed with your hands. Remove the stringers and you will actually be able to twist the hull, not to mention the stringers themselves will seem like garbage once they are out because they loose a bunch of their rigidity too. Same goes for liners and caps (ring deck, whatever you want to call it).

Moral of the story: i am replicating the original trapezoid stringers system and I am going with 1/8th inch using epoxy and biaxial. However, keep in mind I mix my resin by weight based on the cloth weight the meet the "ideal" 50-50 ratio. Too much or too little resin results in a weaker laminate. Also, I will be filling my stringers with 2 lbs foam. If you are going with 4 lbs foam you will be even more rigid so, in my opinion, you will just be spending more on materials and will not fully realize any benefits from doing so.

Again, I dont mean to insult anyone. I'm just throwing my opinion out there.

[Aquasport Commodore]

None taken at all. I like the feedback as I am new at this and like all newbies we ask questions and listen to the old wise ones..... 8)

I do not plan on going that thick on the stringers, I plan on building 1 layer of 1708 and 1 1200 with no mat as I found source for it and not expensive at all. I will remove the stringers and grind the floor clean. I will also remove the liner and not reuse it. Once done, put 1 layer of new 1708 db on entire inner hull surface for clean new surface and strength, (After I fix the whole in the hull bottom) then make the stringers. Once done fill with foam, if 2lb will work Im good with that as I will only have to buy 1 kit and not 2. Last I will cover the stringers from the hull sides inwards front to back and then center outward towards sides so if I did happen to miss something, at least the inside is a clean 1 piece of glass. So there should be a total of 3 layers of glass on top of the stringers and 3 layers on the inside. 2 layers on the outside all was epoxy.

I tried to find the answer but had no joy, so I will post here.
Does Arjay bonding putty and faring compound stick to epoxy?