FF to CC Rebuild

[RickK]

Another option is to scruff up the outside of the stringers and lam a layer of 1708 (or 2) across the entire stringer.

[captjwteal]

I did a layer of wood, 3/4oz CSM, 1708, 3/4oz CSM, wood and then resin coated the result.  I used poly for the lam of the wood. After beefing up the transom with several lams of 1708, I mixed thickened epoxy and troweled that onto the inside of the transom and stuck the core into place and clamped.  Finally I did 3 layers of 1708 with 4" overlap onto the side and floor to lam the core into the hull.I would recommend putting a piece of PVC into the drain hole and glue it down before you start beefing up the transom otherwise the low point in the boat will not be at the transom anymore but will be about a foot in front of the transom.

RickK could you elaborate more on the pvc and drain plug please? I'm a bit confused on this but that's nothing unusual.

Thanks

[RickK]

Ok, here you go:
If you look at the low spot in a factory hull it is at the transom where the drain hole is (top portion of pic) - As we start to lam in new core and all the layers of the low point moves forward in the hull (lower portion of pic)


I think my low spot is now about a foot in front of the transom - if I would have thought this through earlier I wouldn't have the drain problem (everyone has this problem if they rebuild their transoms "beefy")
So if you glue a 12" length of 1" ID PVC to the hull with it aligned with the hole and cut the core around it and as you lay you lams, include laying it over the PVC, you can eventually grind back the PVC at an angle at the low spot in the hull.


Here is a thread where Hawgleg followed this idea - he says it works great.  I always have a 1/2" of water in my bilge now 
http://classicaquasport.com/smf/index.php?topic=13148.msg134262#msg134262

[ftac03]

It's been 6 weeks since I last posted. Most of the time I've been grinding, removing foam, and the center stringer. Yesterday I got the transom dam up and I can see some progress.





I have gaps at the top of the transom that I'm not exactly sure what to do about?? I'm thinking that I should fill these gaps with modeling clay as a temporary form. Any input would be greatly appreciated. The rest of the transom dam has a really nice tight finish with nothing more than a 1/16" gap all the way around.
 




Finally the scupper drains and bilge drains will get recovered with glass from the new transom. Should I just laminate over these holes, or should I attempt to make a plug that goes in the hold and then laminate over that? What have you guys done in the past? Thanks for the the help. - JLW

[ftac03]

Should I be concerned with the lack of responses to the post above? Is it a total cluster f#$%k??

[Levi]

 So when Luke and I closed in the transom on his 246 we used a sheet of 1/8" thick msg with a light texture on it. In hindsight I would suggest a full sheet of whiteboard MDF because it has a glossy super slick finish which would yeild a nearly perfect part HOWEVER YOU MUST reinforce the back of either one where it is straight or you'll end up cracking the gelcoat and making a mess of it. If you look at my gallery you can see where and how we did his.
You won't like what happens when you put modeling Clay in that gap. You'll grind for days and be itching for months.
Only the osprey style hulls have flat transom the rest curve forward a few inches from the hull sides. Took me and Luke some serious head scratching to figure out how to move forward and our closure came as an afterthought and after our core was back in however except for getting the sammich effect with the skin and the core I'd do it again this way.

[ftac03]

Levi,

That's a 3/4" sheet of Melamine I used for the dam. It wouldn't take much to add some stiffeners. Would you share or PM me how you closed in the gaps? The more I look, I'm thinking I could just leave gap open and fair the corners with thickened epoxy after the dam comes  off??

[ftac03]

Hhhhh

[ftac03]

I’m resurrecting this project and was hoping to get some input on what to do about the keel stringer on this boat. Does it need replacing or can I reinforce the are with 1708?

[ftac03]

[RickK]

The transom looks like it came out nice. How did the upper corners come out that you were concerned about.
As for the center stringer, I as still unsure why they put that in, my 170 didn't have one. So you have a hollow there now that I think I would mix up some thickened resin, thickened with chopped fiber and press that into the hollow and let it harden.  Then you can grind it flush and cover with 1708.
Are the knees against the transom permanent or are you using them to make a template for new composite knees?

[ftac03]

The knees are permanent. There’s 2 layers of 1708 on each side of the brace and tabbed in with 3 layers of 12oz 12”’ 9” & 6”. The transom turned out well. The outside skin is not that great. I had to grind out some fairly large voids but the inside came out as good as I could hope for.  All in all she’s solid as a rock. I like the idea of filling with putty and glassing over. I used aquatec for the transom core and decided to use bcx exterior for bulkheads and floors.