1974 170 CC- refurbishing project

[Redfish Ron]

Got out today, pulled all the cables, controls, etc. and removed the center console...big rascal...pulled the bilge pump, opened up all the pie plate accesses and cleaned up the mess...removed all the screws and pulled the tank coffin lid- the tank looks pretty corroded - flashlight shinning through the pie plate shows the stringers look pretty solid- no de-lamination visible..

[Redfish Ron]

The old fuel tank (56X20X6) was made in 1996 according to the date stamped on the BIAA label...so someone replaced it during the life of this old boat...and the poured foamed in really made removing it a nasty, tedious job.  I had to cut the foam with a knife and pry out chunks...took me three hours yesterday afternoon of digging it out and pulling chunks of the fuel soaked foam to remove the tank...I don't think I will foam mine back in that way when I install my new tank.

[redemn93]

is that corrosion or foam on the tank?  if that corrosion, its the worst ive ever seen.

[Redfish Ron]

That is corrosion- ate through in a dozen or more places on the top...although the sides and bottom don't look that bad- the top of the tank is swiss cheese- gas did not drian out of the coffin- small pool of gas residue and heavy fumes in the coffin after pulling the tank...I plan on repairing all the screw holes on the coffin and over drilling and filling the screw holes in the coffin lid

[redemn93]

wow thats bad.

[Redfish Ron]

Looked at the center console really close today- it doesn't need much of anything, so I am going to clean it up and fill a few holes and reuse it...thought about going with a new smaller Panga console but it is only 30 inches wide and I can't see picking up an inch per side being that big of a deal. I am replacing some of the Gages and not using others- using the GPS for speed...so there are three holes in the dash to patch and a few mounting holes here and there, but nothing major. The seat is firmly attached with factory hinges and looks perfect. I don't plan to touch it.

[Redfish Ron]

Started cutting out the sole today- point of no return is long gone...I was amazed that the wood used to laminate the deck was a bunch of scrap pieces of 1/2 inch marine plywood put together like a puzzle and not a solid one piece of marine plywood...so far the stringers look perfect- other than 40 years of crud and dirt, the inside hull is perfect and shouldn't need much to put this all back together- I have not drilled a one inch hole in the stringer to check the foam, but it all looks nice and dry- the adhesive they used to glue the deck down is some nasty stuff

[gran398]

Ron, not to be the bearer of unwanted news.....but a '74 is pretty much guaranteed to have water in the stringers. When we tore ours down, the top third of the foam was dry...the middle portion damp, then wet...and the bottom third saturated.

You can leave it like it is, drill some holes low on the inside stringers at the back near the transom...cock up the bow and let it drain. Or you could go the full monty and strip them out. Kinda depends on where you want to be on the time/money investment

[Redfish Ron]

I guess the 64 million dollar question here is how long would it take for the new foam to duplicate the 40 year old foam and get soaking wet again- my understanding is the vinyl resins allow water to seep in and the hulls are made with this type of resins. If it is an effort in futility, why not just drain and seal the drain holes with epoxy patches? I have everything I think I need to do a full restoration including the pourable expanding foam from US Composites.  And my floor will definitely be stronger and stiffer than the jigsaw puzzle pieces of plywood laminated together 40 years ago...

[gran398]

You are right. The thing to evaluate is how the foam became soaked to begin with.

We've hit on two theories:

a)  The consoles were screwed through the deck and into the stringers. Over the years...regardless of how well-sealed...the screw holes leaked water into the stringers.

b) The transoms leaked water around the lower garboard drain tube. Transom became wet, stringers became wet.

Throw in delamination of the outer tabbing, bilge water could leak into the stringers. Many potential combinations. Even if just a little every year....40 years is a long time.

So....when you go to rebuild, be aware of stringer piercing, etc. Glue/glass the deck down, console screws away from the stringers, etc

[Redfish Ron]

It appears that the foam is a necessary structural support component in the rigidity of the hull/deck/liner. before I cut any more of the sole away, I am going to put the boat up on blocks and have it perfectly level so as not to induce any stress or flex in the hull. I have cut out some of the stern section decking just to look and see what extent of a rebuild I was looking at. The boat is almost totally 1974 factory stock with very few owner add ons. It has very few issues that need to be addressed- one starboard rod holder (the rear one) is loose and not screwed in, someone put in a Rule 750 bilge pump and did a lousy job plumbing it...when they replaced the aluminum fuel tank in 1999 they put it in bare metal, no paint or preservative, and the wiring under the console looks like a rat's nest...anyway today is getting the boat jacked up and leveled on cinder blocks that I picked up yesterday from Lowes and off the trailer. Then it is "Katy bar the door" full-bore rebuild-

[CLM65]

I guess the 64 million dollar question here is how long would it take for the new foam to duplicate the 40 year old foam and get soaking wet again- my understanding is the vinyl resins allow water to seep in and the hulls are made with this type of resins. If it is an effort in futility, why not just drain and seal the drain holes with epoxy patches? I have everything I think I need to do a full restoration including the pourable expanding foam from US Composites.  And my floor will definitely be stronger and stiffer than the jigsaw puzzle pieces of plywood laminated together 40 years ago...

I believe the closed cell foam used today is much more impervious to water absorption than what they used when these old boats were built.  I would still be judicious about sealing it in and keeping that water away from it, but I don't think it will be in that bad a shape in 40 years.  At least that is what I'm counting on.

[Redfish Ron]

Need some advice on electrical supplies to replace the wiring and circuits in my rebuild- Is there a difference in the wiring for marine use vs. standard Home Depot wiring you can buy in the local hardware stores? What gages of wire will I need or should I just hire an electrician to re-wire and rig the boat? Some of the work I see in the re-builds is fantastic and the experiences of others is a very valuable resource for us amateurs...The navigation lighting will all be replaced with new equipment- I have a Hummingbird 798 ci DI unit to install and a Standard Horizon VHF marine Radio- that will be the extent of my electronics- I will have 2 AGM 12 volt batteries onboard- I have the Optima series 31 900 battery and plan on buying another series 27 AGM battery as a backup- just in case. So a Blue Sea battery switch is on the list- I would welcome a shopping list of essentials and necessary supplies- as well as sources for buying...

[slvrlng]

There is a difference in the wires. Marine wire is tin coated which slows down the corrosion rate of the wire itself. Most lugs are the same and you will need to heat shrink all connections. Well most anyway.

http://gregsmarinewiresupply.com/Zen/

http://www.genuinedealz.com/

Most regular household electricians don't understand 12 volt and rigging. Some may but I think they would be the exception.

[Capt. Bob]

The Resource forum is your friend.

Here's some things to help along the way.
http://classicaquasport.com/smf/index.php?topic=9053.0