Cobia CB175 Full Restoration

[ZTCollins]

Hello to all. I am new to the forums, but i have been reading a good bit of post that are already here on the forums. I am looking to do a full restoration on a 81 Cobia CB 175 Bass Boat.

I have already begun the process of removing the upper portion of the boat and inspecting the hull. Which has got to be gutted and redone. All the wood is like dirt. The transom will have to be replaced, good news there is the outer hull is not cracked at the transom. Also from what i have been able to see the hull has no stress cracks visible. From the information i have gotten so far i am at the point of trying to determine if its cost effective to restore this boat.

Any input would be greatly appreciated.

 

[Scott Danforth]

Assume $2-3k for the hull restoration. YMMV

Ad $1500 for interior

 

[tpenfield]

It will be a labor of love. Not a money maker though

 

[ZTCollins]

Here is some photos of the demo I have gotten done to this point.

One question is when i put the new plywood in on top of the stringers the mat that covers the plywood. Does that need to be the 1708 or just the CSM?

 

[sphelps]

The 1708 would be stronger but you could probably be ok with a couple layers of just csm ..
At least tab the sides in with the 1708

 

[Dennischaves]

I did 2 layers of csm (tabbed with 2 layers of 1708 seams too) as that seems to be the norm Just make sure you have PLENTY of resin on hand
once you start you want to keep going with glassing the deck

 

[AShipShow]

I originally did 2 layers of CSM on top with 1708 tabbing, but I then went back after the fact and read the sticky in the resto forum on re-decking and it said that a deck should have at least 6-8 oz of glass on top so that kinda freaked me out and I did a layer of 10oz cloth on top... I'm also told CSM has very little strength so I was worried about it cracking over time...

Dunno, probably overkill, but I don't feel like doing this again.

 

[Woodonglass]

For stringers, I recommend two layers of 1708 tabbing and two layers of torn HAIRY CSM to waterproof the tops For a deck IMHO 1 layer of CSM and 1 layer of 8oz glass on top and one layer of CSM on the bottom. Remember that it's very important to precoat both sides of the plywood and the edges with a coat of Resin Prior to applying more resin to lay the CSM. Also Fill any voids in the plywood that you can see Prior to coating with resin.

 

[ZTCollins]

At this point im just not sure about continuing. I am looking at over 2k just to get the hull and transom back ready to put the top on. Then the top needs about 1k work to it plus the motor..... was thinking 2k max for the whole boat... but then again this is my first boat so all the prices are sorta sticker shock for me... when there are 3k to 4k boats being sold everyday.

The resin is outrageous. 25 to 100 a gallon is expensive to me.

 

[sphelps]

Do you have a motor ?
‘You could probably make it seaworthy for less than 3 grand .. There are ways of saving money use poly instead of epoxy and a good ext grade plywood for the structure would save some dough .. The outboard and electronics can get pricey . Some of that you can add as you go along .
Chances are the boats you find for 3 grand for sale have there own set of demons hiding under the glass ..
Unless ya get lucky and find one that was well cared for ...

 

[ZTCollins]

This is using poly. its gonna take 25 to 30 gallons to get the hull back including the transom. thats 1500 in resin alone. and thats about 30 yards of 1708 and CSM..... The plywood is actually the cheaper of most of it.. I have a 1994 75 HP Mercury i was gonna put on it if i could get it fixed reasonably. it has 125 PSI on 2 cylinders and 30 on the top. So I assume there are some stuck rings or a stuck or warped valve. good thing is i can to the motor work. Not really sure the 75 would push that boat more than 30mph on the water .... but was thinking i may be able to sell the motor once i got it running and be able to upgrade. Good thing im not out much money on this i got the boat motor and trailer for $400.00

 

[ZTCollins]

OK. so i go back over my math again tonight and i realized i was not dividing my resin by 4 sqyd.


So i am going to break it down here and let you all correct me if its not enough.


Breakdown:
*= HBS (Hull between Stringers)


Stringer

1 - Stringer 12' x 8"(avg) - 16 sqft
*HBS - 12' x 12"x 2 (avg) - 24 sqft
2 - Stringer 10.33' - 7"(avg) - 24 sqft
*HBS - 10.33x(10"+6") (avg) - 14 sqft
2 - Stringer 6.83' x 6" (avg) - 14 sqft
*HBS - 6.83' x (6"+6") - 7 sqft

Total Sqft - 99 SQFT

Floor:

6' (avg) x 8' long - 48 Sqft
2.5'(avg) x 4' long - 10 sqft

Total Sqft - 58 SQFT

Transom:

10 SQFT


99 + 58 +10 = 167 SQFT x 15% waste = 192 SQFT = 21.34 yds of material

That being said i was thinking it was gonna take 20 gallons of resin for that and it should only take 10 even at a 3sqyd covereage.

My question is will one mat of csm and a mat or 1708 be enough.

My thought is to get a 50"x30yard roll of each. and 10 gallons of resin would be about the max i could put into it...

Will that work?

 

[Woodonglass]

Well I don't think you considered that Stringers decks and transoms have TWO sides and you'll need extra resin for PB.
Also, the amount needed to wet out a yard of fabric is calculated on proper techniques. It's been my experience that almost all newb's use WAY to much resin at first. They do get better as they go. IMHO 20 gallons is the minimum you'll use for your project. 20 yards of 1708 should be close and since you don't need that much CSM when using 1708 5-10 yards of 1.5oz should be close. If you read the 2nd link in my signature line below, it will have some helpful info for you. Remember you must PreCoat ALL the wood for your boat prior to applying more resin for the Fabric. This takes more resin as well. All voids in the plywood must be filled with PB an the edges must be Soaked really well with resin. You'll need about 4 gallons of Cabosil and 1 lb of 1/4" chopped milled fibers as well.

 

[Woodonglass]

At this point im just not sure about continuing. I am looking at over 2k just to get the hull and transom back ready to put the top on. Then the top needs about 1k work to it plus the motor..... was thinking 2k max for the whole boat... but then again this is my first boat so all the prices are sorta sticker shock for me... when there are 3k to 4k boats being sold everyday.

The resin is outrageous. 25 to 100 a gallon is expensive to me.

Remember, There's NO GAURANTEE that those $4K boats won't have the exact same issues. We've had several Members take that approach only to find that they would have to do a full restoration on a more expensive boat. New boats of similar characteristics Sell for $20K +. Sooo for some blood, sweat, and tears you can have a boat that's like or better than new for $3-4 K. If the boat fits your needs, and you like it's style then it's probably worth it. But...Your money...Your Choice.

 

[tpenfield]

This is using poly. its gonna take 25 to 30 gallons to get the hull back including the transom. thats 1500 in resin alone. and thats about 30 yards of 1708 and CSM..... The plywood is actually the cheaper of most of it.. I have a 1994 75 HP Mercury i was gonna put on it if i could get it fixed reasonably. it has 125 PSI on 2 cylinders and 30 on the top. So I assume there are some stuck rings or a stuck or warped valve. good thing is i can to the motor work. Not really sure the 75 would push that boat more than 30mph on the water .... but was thinking i may be able to sell the motor once i got it running and be able to upgrade. Good thing im not out much money on this i got the boat motor and trailer for $400.00

I don't see it taking more than 10-15 gallons of resin. Not sure how you are figuring up to 30.

 

[sphelps]

I would just get 5 or 10 gal to start and see how far that gets you . Careful not to mix big batches up until you get used to how fast it kicks . That way you don’t have a lot of waste . Try and have an extra spot available that you can wet out if you have too much mixed in your pail .

 

[ZTCollins]

Anyone know a good source of resin in South Carolina.....

 

[mickyryan]

I know it looks painful budget wise , but i can assure you just about any boat 5 years or older left outside is going to be in rough shape and it is even more painful when you buy a 4k boat and still need to dump 4 more into it to bring it back to sea worthy things i have learned about buying used boats, self bailing hulls tend to be in better shape carpet hides everything

 

[kcassells]

Hey Iboats sells the resin and so does uscomposite out of fla. What I do see is alot guys go and overbuy the goods needed. Start with basics. Get used to the feel of the goods and make orders up from there. Believe it or not a project is just what it says..... TIME....Money...TIME...MONEY.
The only person I ever saw burn thru a boat in 3 days was mickyryan . He's a machine. He's done 3 boats to my 1 not completed yet. And there all sweet.
Also poly has a shelf life. Get a feel then blow out a next order.
Typically things just don't fly out that fast. When they do they not so hot/safe.

 

[mickyryan]

yeah try to buy from somone who moves a ton of it or you might get almost out of date product, that's not usually a problem for me because i use it quick but if you are a weekend here and there 3 months goes by and its gelled up.