My first real boat.... upgrade from 10ft jon boat.

[Studduck]

First there is a lot of great info in this forum and every one seems very helpful (I have yet to come across an insult.) I just bought a 1982 Cobia Sunskiff 160 w/1984 Johnson 90hp. I am told "motor runs" ignition parts look newish but that don't mean anything. I picked the boat motor and trailer up for $900! the bad is the deck of course. looks like someone did a really bad job replacing stuff once before. had 3/8th ply as deck.. wtf. wiring was hacked. so i find it worth (spending more money) redoing the deck since the hull is shallow. transom seems in good shape haven't looked close cause i just got it to the house yesterday and spent today ripping out that sorry excuse for a deck. now the question i could not find an answer to is how to tell what kind of resin epoxy or poly-e to use, I've heard that one wont stick very well to the other and not sure. I've done lay ups on new projects (non-marine) but never had to bond old to new. just wanted to be sure before wasting time and money. I will get pics posted once i put them on the comp from the camera. I am mechanically and carpentry inclined so I'm not afraid of any kind of work this boat might need. also i want to thank friscoboater for all the info on boat construction vids. very helpful and also let me know what i have in store and what techniques work best.

 

[Bomber Goober]

Re: My first real boat.... upgrade from 10ft jon boat.

epoxy will stick to about anything, polyester doesnt like to stick to epoxy. Polyester will be just fine and more cost effective to use and done properly(proper prep) will be fine for this project. Make sure you check your stringers as well, more than likely they are just as bad as the deck. Your boat should have flotation foam and if the deck was as shabby as you mentioned it probably has allowed water to get to your foam and more than likely trashed that as well.

 

[Jimmy H.]

Re: My first real boat.... upgrade from 10ft jon boat.

Welcome. Looking forward to some pictures!!

 

[Studduck]

Re: My first real boat.... upgrade from 10ft jon boat.

ok so I went back out to look as some stuff. ply was 1/2 not 3/8 just had a lot of soft spots. no foam 10-12 inches from deck to keel slopes up really quick. not sure to foam when im done. seems pointless for so little cubes. tapped around the transom and sounds solid and looks unmolested. I already ripped out the center stringer before my first post. to enforce the crappy job. i found exposed ply on the stringer where the spliced fg didnt even meet. it was glassed w/roven then capped with chop strand that wasn't even smooth. looked like crap. I'll take a pic later to show you the crap. ALSO i was able to remove the stringer by kicking it. I guess it makes my life easier. I tried to post pics but the files are too large and I'm not familar with editing on macs. any pointers on that. :facepalm: Ill update later. thanks

 

[jigngrub]

Re: My first real boat.... upgrade from 10ft jon boat.

That 16 footer is required to have floatation foam per USCG regs. I'm sure the previous owner ripped out the wet foam that was there and just didn't replace it.

1/2" decking is the norm in most fiberglass and aluminum boats. The manufacturers use the 1/2" and support it with the expanding urethane floatation foam, the foam also adds support to the hull.

Hack jobs on boats by previous owners are common on this site, it's amazing what those nincompoops will do sometimes.

Get a photobucket account for posting your pics, much easier for you and for us to see. The pics post nice and big like this:

 

[Studduck]

Re: My first real boat.... upgrade from 10ft jon boat.

looks like i need to do all the interior. the rot stops at the bilge and under the bow platform. but since there is crap work and I already have its guts spilled, I'm gonna do it my way

today I'll brace the hull and start cutting out the bow platform. also the underside of the top of the platform is not glassed so it will rot soon if not replaced. and I'm going to try to get into the habit of taking pictures before I rip things apart. no promises cause I get excited and will start going to town.

 

[carribbean soul]

Re: My first real boat.... upgrade from 10ft jon boat.

pull the wires up and get them out of your way, and pull the motor i bet the transom is gone too.

 

[rickryder]

Re: My first real boat.... upgrade from 10ft jon boat.

Welcome to the Dry Dock! Yes take lots of pictures and measurements
so you have something to look back on later! Looks like a good start

 

[Studduck]

Re: My first real boat.... upgrade from 10ft jon boat.

I found foam!!! and it is wet of course. and also found more half @$$ work. and I did the math and I only need about 10 cubes of #2 foam to be more than enough positive floatation. now I have 2 cubes on each side of the transom plus whats below deck will be plenty. Which means that I can take advantage of the entire cavity of the rebuilt bow platform. hull weighs 800 pounds per mani. plus outboard (300lb) and misc acc's (50lb attached to boat). and the #2 from aeromarine products recomends 1 cf per 200 pounds of hull weight and 1 cf per 60 pounds of dead weight. now most of what i plan on storing in the bow any ways is my bulky extra life jackets (little more flotation). but........ I'm not a certified ship wright. Input?

that was how i spent my sunday.

 

[Studduck]

Re: My first real boat.... upgrade from 10ft jon boat.

 

[carribbean soul]

Re: My first real boat.... upgrade from 10ft jon boat.

doing good

 

[Woodonglass]

Re: My first real boat.... upgrade from 10ft jon boat.

The USCG requires Boat MFG to install floatation foam. NOT DIY'ers. You are NOT required to put floatation in a boat that you are restoring. The USCG will never check to ensure that you have installed it. Having said that, It's a really good idea to do it and Your insurance may be null and void in the chance that your boat sinks due to not having the foam.

But it's your boat, Your Risk and you can do with it as you see fit.

 

[jigngrub]

Re: My first real boat.... upgrade from 10ft jon boat.

Check the prices at USComposites for 2# foam, even with shipping it may be cheaper than the aero marine.
Urethane Foam , Expanding Marine Polyurethane Foam

Most boats that size take 12-14 cubes of foam so your figuring isn't too far off... but depending on the ambient temperatures when you pour you may need more because of a reduced expansion rate due to pouring below optimum expansion temperatures. The ideal temp for full expansion of urethane foam is 85*F+ and at lower temps 10 cubes of foam may only expand to 7 or 8 so you may want to take that into consideration when you make your purchase (buy extra).

 

[Studduck]

Re: My first real boat.... upgrade from 10ft jon boat.

Thanks for the tip on uscomposites. What about the best deal for fg? I've been looking around but havn't found a place that really seems like a great deal. And for wood I'll probably go with the 3/4in aruco ply from Home Depot then give it a good treatment. I plan on being ready to pour foam by late spring/start of summer which should have a hot day in there somewhere so I should be able to get atleast a decent yeld. so ill get 16 cubes and go to town when the time comes.

 

[jigngrub]

Re: My first real boat.... upgrade from 10ft jon boat.

USComposites sell glass cloth, mat, and polyester resin too... and epoxy resin if you should need any of that

 

[Trooper82]

Re: My first real boat.... upgrade from 10ft jon boat.

Those pics look hauntingly familiar.....

welcome to the dry dock!

 

[carribbean soul]

Re: My first real boat.... upgrade from 10ft jon boat.

take lots of photos cause I want to do one of those boats next.

 

[Studduck]

Re: My first real boat.... upgrade from 10ft jon boat.

Ok, so I don't have the time to get much done during the work week. But while I was outside pouring a beer I sucked it up and just had to core the transom.

Not sure what to think about it. I think it looks like 29 year old wood, not really rotten. Like I mentioned before, I tapped around with the handle of a screwdriver and all sounded solid. So I'm going to make a personal choice to leave the transom like it is for the argument of it was a $900 boat. When the time comes ill cut the transom out from the outside and that is when ill gelcoat the outside of the hull. The carpenter in me says go ahead and replace it while everything is apart but I'll just save it for the outside resto. Forgive me if someone disagrees.

@carib I am making sure the process is well documented. I probably won't do videos but you never know. Are you lookin at a similar boat or one of the same brand and style? The issues I have with this boat (that I'm changing) is the bow foam boxes have no way to drain to the hull and ultimately the bilge. Also I don't like the idea of a stringer down in the keel always in water. My fixes are drain holes for the boxes and I'll probably waterproof the keel and stringers the way frisco did with that red membrane. That is some cool stuff.

Wednesday's are my fridays. I hope to get at least some more demo done but I'm supposed to go out of town. We'll see