Stringers using Coosa

Im restoring an 83 and decided on Coosa.   using 3/4 x2 for main stringers 3/4 for secondary.   Not using foam. Im going to be using system of cross braces to give lateral support.   Im trying to verify if there is a need to use a flex beading compound for coosa such as PL or simply use thickened resins.   

Also Im using the current CC resin which is a epoxy/vinyl ester type..   

Deck will be 3/4 Coosa and likely bonded with thickened resin or PL.   possibly use ss deck screws to hold in place instead of using weights to hold down.   

Any thoughts?

Joes will be a better reference since he did a 2001 as well. Gary's right, long to do lists this time of year!

shierh wrote: I possibly use ss deck screws to hold in place instead of using weights to hold down.   Any thoughts?

Steve,
Screws are simply a stress point that is prone to fracture. Stick with the bonding. BTW, leave the SS deck screws for the deck. If they see water from a stress fracture, they will rust especially the 400 series deck screws.

Don't forget we want plenty of pictures!

ok found it.   

Joe looks like he beefed it up quite a bit for the high hp engine.   

Dont see the need for glass on top of floor as the coosa is strong enough.   Im going to roll on coat of the resin to seal it on top since carpet holds water.

Im going as light as possible.   

One thing im still not sure of is the need to bed the stringers since not wood.   looks like the ply and fir need beding using foam spacers but not clear on the coosa.   I would guess that beding using thickened resin direct to hull is all thats needed. see no reason to have any significant space.   any thoughts?

I also have some 3/4 nida core board that i got for a steal. 4x8 sheet that is already laminated on both sides.    this will be used for the removable part of the deck and also where driver seat and spotter seat are..   going to install round deck plate under spotter seat to access the through bolts and also give a place to vent the hull sides since not going to use any foam.   , going to notch top of all cross members to allow it to breath. and of course notch bottom corner to drain.   

I start this friday.   

Understand monolithic structure. if deck is bonded to stringer and support system and to sides then it will stiffen the entire structure. However i doubt it adds much if anything to the sides of the boat since it sits only 6" or so from the bottom edge and the top of the hull is surrounded by the upper shell.   Upper shell gives support to sides.   If this was a very thin hull boat then i would agree floor would provide extra support for sides.   

Origninal lay up on floor was thin sheet of chop mat that ran up sides about 6".   chop mat has no real strength by itself..   Dont believe the original floor added anything to side strength on these boats.

I dont plan to cover entire floor in mat, will however back cut outer edge on top so that i can fill with peanut butter with some chop strand in it.   possibly one transition layer up the side and out on floor.   

shierh wrote: Dont see the need for glass on top of floor as the coosa is strong enough.

You had better look at the modulus specs in the horizontal.

Heads were cracked between valves, both sides. overheated.   got replacement e7 heads and machined them.    
block bored 30 over .   

sadly this was a new engine 12 years ago only used one summer then boat was left to rot was not pickled.   risers cracked and leaked into cylinders from freeze and the boat was covered on an off with plastic and left outside. in fl this makes a green house. ruined everything..

trans was good , i took it apart myself, it had no wear, signs of prior rebuild. installed new seal kit and its good.   

engine is almost done, had to wait for a reverse rotation rear seal, was able to find a supplier with an one piece reverse rotation seal.   now have to wait until mid august as the friend doing the engine is in bahamas until then.   so im starting stringers this weekend and will have them ready to install the engine at end of next month   

Looking good

Fun began over weekend. removed port outboard stringer and ripped up the chop strand that held it.   Decided it was easier and less mess than grinding.   used air hammer and ran it under edge and then pried with a thin wide pry bar.   going to do same with main stringers.   

removed prop shaft ,strut, rudder and rudder housing.   shaft in good shape, Cutlass bearing shot but thats easy especially since strut has been removed.   Sending prop to shop to have it scanned, looks good but may as well make it perfect.

i have NO wood left,   yours were in way better shape. I will have nothing to template with.

took out port out board stringer broke in half but can sort of use as template.   i pulled off all the mat/chop strand holding it to hull by using air chisel and then power washer with spinner head, its pretty clean. will finish off with grinder to have proper media to bond to.   

the rudder backing plate was full of water and rotted, took it out and found the chop strand under it was soaked to the base hull, same goes for the center backer plate on transom.   all the filler glass and bonding glass has been removed from both areas.   

plan to cut the last 6" of the main stringers off to allow me to smooth the whole transom and bond one sheet of structural mat. I want it behind the main stringers.
Then build up the center 10" of the curve transom with chop and bi ax.   same goes for rudder mounting area. make the rudder mount area flat glass.   Will then bond in the outboard stringer then cut out port main stringer and so on.   

also this boat was damaged about 12 years ago, the rear lifting ring pulled out when hanging in a boat house and rear of the boat went under water.   Correct Craft did the repair and claimed to do it out of warranty just because.   Well you should see what South East Correct Craft did to repair,   they slapped on some glass on transom interior. then covered the torn up rear gunnel with teak wood,,, they did not even fix the torn up gunnel, it was ripped in 4 directions about 10" out from the center where ring fits.   the sub structure is not completely rotted away.. im repairing from underneath,   not fun.   

Great story, keep it coming!

apopka,

installed the new port side stringer, bedded it with vinyl ester-cabosil. Did not glass it yet.   Removed port main stringer and am prepping surface. Will make that one this week and bed it. then glass them together.

Keeping the hull clean with power washer and spinner head.   rips up the loose fibers , reduces the glass in the air and on me. Also the bonding surfaces will be very clean.