76' 170 Rebuild

[MJB]

Here's the latest pics to date.  Have completed stringer repairs, poured the floation foam in the stringers, added strength to the center/keel with 2 layers of 1708, glassed over the stringers, added 3/4" ext ply to the top of the stringers to account for the 3/4" gap between the sole and the stringer.

Foamed in stringer and trimmed.


Cut the stringer at the transom to fit the trough.


Can't see it, but have two layers 1708 over top of stringer under the ext ply, then have the ext ply wetted and set over top of 1708.  


Another of the same.  I added weights to the ext ply while it cured overnight.


Next day, glassed over the ext ply with 1 layer of 1708.  

I plan to anchor the new deck/sole to the ext ply with a layer of cloth/glass bewtween the top of the stringer and the deck/sole as well as anchoring the deck in place while it cures with recessed ss screws.

Now I'm starting to plan for the deck sole replacement. I'm going back and forth between exterior plywood and marine plywood -- my checkbook says save a few bucks and go with exterior, but I keep thinking marine plywood. Any thoughts?? How about thickness?? Seems like the old deck/sole had 1/2" (might be 3/8") if I remember correctly, any recommendations??

I've been looking through a bunch of different rebuilds and have gotten alot of good information, but haven't yet found (maybe I haven't looked hard enough) a good way to secure the fuel tank in the coffin. The old tank had the straps with screws that went thru the coffin and into the stringers which over time wore bigger holes into each. I want to avoid that problem all together. Should I still go with straps and find a better way to anchor or is there another method??

And finally, I want to do all I can to prevent water from getting into the deck/sole -- anchoring the console -- previously it was anchored to 3/4" trim under the console and that trim was screwed to the deck. Is there a better way??

I know, bunch of questions but I don't want to get too far down the road on the rebuild and wish I did something else. Appreciate any feedback/input and I will get the pics up soon.

Any thoughts on the above questions would be appreciated.

[LilRichard]

Sorry - meant to answer last night.

DO NOT USE Exterior ply... it is not the same quality as marine.  Marine has less flaws - your best bet is a PT Marine.  They pressure treat the marine ply, then kiln dry it again to remove moisture.  If regular PT is usde glass will not bond to it - too moist.  I used 3/4" on mine but 1/2" would be OK too.  Fletch (CM Site) used 1/2" on his I believe.

Foam your tank in the coffin.  I screwed the tabs in to some pads I glassed to the stringers - then poured 4lb foam around the tank.  Take it slow- that stuff expands FAST.

I would either glass a piece of trim to the deck, then screw the console into the trim piece - thereby avoiding holes in the deck.  Either way, you want to overdrill the holes - backfill with thickened resin - and redrill to prevent water from penetrating the wood.

[RickK]

Looking Good :!:  :!:  8)

[aqua70]

MJB shoot me an e mail at aquastriperman@yahoo.com

I will send you some pictures of how we attached the new deck/floor.

[billh1963]

Nice progress!

[MJB]

Need some advice -- I am thinking about eliminating the rigging trough on the starboard side of the deck/sole that runs from the side of the center console aft and replacing it with a rigging tube which would run under the deck/sole and come out on the starboard side just forward of the transom about 6-12 inches above the deck/sole.  This would also eliminate the small trough at the transom where the old drains were located.  

Reasoning -- trying to eliminate a bunch of glass work required to rebuild the trough and also eliminate 2-3 inches of depth required for the cockpit drains (cockpit drains would be slightly higher than original which in "theory" would help out the draining problems).  Any comments??  Recommendations??

[LilRichard]

That sounds like a reasonable approach... Think it would be fine.

[Mad Dog]

Need some advice -- I am thinking about eliminating the rigging trough on the starboard side of the deck/sole that runs from the side of the center console aft and replacing it with a rigging tube which would run under the deck/sole and come out on the starboard side just forward of the transom about 6-12 inches above the deck/sole.  This would also eliminate the small trough at the transom where the old drains were located.  

Reasoning -- trying to eliminate a bunch of glass work required to rebuild the trough and also eliminate 2-3 inches of depth required for the cockpit drains (cockpit drains would be slightly higher than original which in "theory" would help out the draining problems).  Any comments??  Recommendations??

MJB, I am rebuilding a 22-2.  That trough is history. :evil: Besides the extra work to put it back I realized it was a large dirt and debre trap that would be very hard to keep clean.  Second, the trough runs all the controls and wiring together.  That creates an additional risk of damage to electrical wiring and control cables.  

As an alternative I will run at least three chase tubes under the sole.  At the stern they will come up inside the false transom.  Under the console they will rise up into the dry control box (not cut off just above the sole).

Why three? 1) for engine controls and wiring harness, probably 3" PVC electrical conduit 2) power to pumps, lights, bilge, Tabs,  etc. 1 1/2" electrical PVC 3) Electronics leads, fish/depth finder, water temp, etc.  again 1 1/2"  and for good measure on more for the fuel line (my project had a leaky fuel hose into the stringers and bilge.  not gonna happen again).  

BTW Batteries are goin under the console.

[MJB]

Mad Dog,

Concur, my thinking exactly with the trough.  I am not a fan of those cables/fuel lines/wiring etc all laying in the trough left to the elements.  

This weekend I'll do some layout work on the tubes figuring where they will start/end, take some measurements for the deck/sole and remove the old fuel fill and overflow hoses and take measurements to replace.  Also need to replace the forward storage box drain tube which drains forward to starboard.  I'm planning to also put in some drains for the other two boxes to drain water to the topside of the deck forward.  I need to make sure I get everything ready before I close in with the deck/sole.

[Mad Dog]

MJB,
That whole plan everything out before you start is usually my down-fall.  

I likw the idea of draining the forward boxes on to the deck.  Mine has the same drain through the bow.  Why have another hole in the side of the boat?   :)

[MJB]

Update as of this weekend -- I bought a used 2001 2S 90HP Yamaha, light weight 262lbs 2 weeks ago, just what I was looking for.  

This past weekend I grinded around the inside where I will glass the deck in place, finally got a transom drain installed, removed the fuel filler and the remenants of the old fuel lines, cut out an access panel for the fuel fillers/hoses just above the casting deck, grinded the anchor locker so I can replace the floor in that bow compartment, removed the thru hull drain for the center casting deck storage/cooler, glassed in the drain hole on the side of the hull, glassed in the drain in the storage box, removed the hardware on the bow and glassed in the holes, removed the bow eye (glad I checked, the bolts holding it in place had completely rusted/corroded to the point where just tapping on the end it all fell off), and grinded around the outer edge of the tank coffin which I will reglass to the stringers.

Doesn't look like much, all small things which needed to be done before I begin the deck.  

Now I have to order a replacement tank -- any recommendations??  Looking at Florida Marine Tanks, Custom Marine Tanks, and Speedy Tanks (Atlantic Coastal Welding).

OK, I have come full circle on the rigging trough -- I was thinking of a rigging tube under the deck but haven't come up with a good way to bring the rigging up thru the deck at the transom and still be able to make the necessary bends in cables without binding.  Plus, if I come up thru the deck with the tube I still think I will get water in the tube either from spray or rain etc.  

I've been doing work to prep for the deck and the more I look at the old method (trough running down the starboard side of the deck) the simplier it looks especially in this small boat.  Any ideas/comments??

I'll take some pics to update.

[RickK]

Sounds like you're making good progress  8)
I think you're right, the trough is easiest and it will route water back to the drains PLUS your sole will completely seal the topside of the boat from the bilge.  While you're at this point I think I would figure out a way to route a bilge pump exhaust pipe/tube out the top rear side of the hull somewhere (need a bilge pump just in case - I don't have one in my bilge but wish I did now - if I ever redo my floor again I will do what I'm suggesting).
You'll probably want to put an access plate in the rear floor to get at the bilge pump too.

[MJB]

Rick,

That's my thinking, trying to keep water out of the bilge.  I do plan on a deck plate/access panel in the sole with a bilge pump for inspection and peace of mind.

[RickK]

If you remember back before you removed the floor there was a trough going not only along the starboard side for the wiring & control cables but also across 2/3-3/4 of the transom and this is where you had the 2 drains right below the engine mount.  The trough could fill the entire length with water (all the way to the console and the drains being in the trough allowed for draining everything.  Looks like you've allowed for this rear trough in your stringer design as well as limber holes to allow water from the outward side of the stringers to the center (don't know how water would get there but just in case).  It also looks like the limber holes are big enough(?) for the bilge pump pipe to snake through to an outside thru-hull.
The problem with the older boats is they were designed for 70hp engines that didn't weigh too much so the original drains stayed above the water line at rest and weren't covered by the engine mounts.  The engine mounts changed sometime in the 70's and newer motors covered the drains (both of mine are 3/4 covered) now.  You have the flexibility now to make the drains wider than  the engine mounts but have you planned them so they will be above the waterline with the motor you'll be using?  I've seen some rebuilds that accomplished this and although they knew the trough would fill up if they walked to the back, it drained back out when they walked to center or was underway.  The main thing is that if it rained, the water would drain out while the boat was at rest.

[DavzBoat]

Great info here, guys, thanks!  It's given me some ideas on what I want to do to my '81 19-6 FF someday!

Dave