Cobia Rebuild

Hello great site here and I can't wait for the help and suggestions you all may have for this project.  This is my second rebuild project and a little bigger than my first one which was a Gheenoe rebuild.  It turned out fairly well as you can see from the last couple of pics.  So I'm going to build a front deck about 4' and a rear deck with baitwell but I can't decide if I should enclose the side walls once I build a gunnel walkway around the boat.  And since this is a small boat would it be ok to use polyester resin instead of epoxy?  Thanks in advance for any help or suggestions.  P.S. the tearout and grinding stinks!

[quote="PRomeo"]Hello great site here and I can't wait for the help and suggestions you all may have for this project.  This is my second rebuild project and a little bigger than my first one which was a Gheenoe rebuild.  It turned out fairly well as you can see from the last couple of pics.  So I'm going to build a front deck about 4' and a rear deck with baitwell but I can't decide if I should enclose the side walls once I build a gunnel walkway around the boat.  And since this is a small boat would it be ok to use polyester resin instead of epoxy?  Thanks in advance for any help or suggestions.  P.S. the tearout and grinding stinks!

Welcome, You have certainly completed the worst part.

So I'm going to build a front deck about 4' and a rear deck with baitwell but I can't decide if I should enclose the side walls once I build a gunnel walkway around the boat.

The only issue in making a gunnel would be the loss of some cockpit space, but gunnels will stiffen up the boat quite a bit. Those rolled edge designs will flex (I had a 21' baystealth for a few years). You dont need super wide gunnels either, 5" or so would work, but I would make them wide enough to walk on, because you know people will a couple of little frame under the gunnel between the decks are all you need.

And since this is a small boat would it be ok to use polyester resin instead of epoxy? Thanks in advance for any help or suggestions.

the reason to use epoxy is not the size of the boat. Epoxy has far superior bonding ability to older fiberglass. Because a rebuild is almost all secondary bonding (bonding new to old) epoxy is far superior and the only thing I would use. You can make pieces from polyester (baitwell, stringer parts, etc) but they should all be glassed to the hull with epoxy.

I would not personally enclose the sides under the gunnel as it is really nice to have that space for your feet/knees when you are leaning over the gunnels I did a 17 mako recently and the main goal was to not enclose the gunnels.

Here is another skiff I did maybe to give you some ideas

TY Daytrip for the reply! I like your design here on the flats boat. DEf. will do at least 5" and I guess now use the epoxy. Also I would love to see your pics of the outside motor mount for I was wanting to make one for this boat as well. And if I may would aloso like to know how you molded the hatches for the boat as well as how you made the hatch doors. Do you think I should do something with the gunnel outside overhangs on the boat? Like cut them off or will the gunnel walk help with support? Thanks so much Daytrip. Do you live in the South Florida area?

Hey Promeo,

Not sure what you are asking about with the motor mount.

I like the deck overhanging the hull actually as it makes a great place to hold onto. the red boat had that same configuration. Personally I would work with it. I also like wide gunnels as you can guess from the pics. At least 9" wide for my taste.

I do live in SF. I am in North Palm Beach. Where are you?

Made the gutters and the hatch mold using MDF and Malamine as the building material. These are the ones I did for the Mako project I finished last year. The gutters on these are 1.25" wide and 2.25" deep. The gutters on the Bertram are currently designed to be a bit narrower as I was incorporating a o-ring gasket recess. I will post a drawing of the cross section.






The hatch mold itself is simply a shallow box made of melamine. The part releases right off that stuff. You can see little "inserts" that create recesses for the hinges along the edge as well.

Hey Daytrip thanks for the great info.....BTW My name is Patrick Romeo and I live in Stuart. Would love to come down there one day and pick your brain a little in person. About the motor mount. I was thinking about building a n external mount for a motor on this boat to give me more interior room. So hopefully we can meet up sometime and I can get your input on that if you don't mind.

Also Daytrip I noticed no foam in that boat. Did you put any in there? My Cobia was loaded with foam and I was wondering how much I need to put back in there? ty Pat

You are welcome to come by and check it out for sure. Not sure I would do a bracket on a boat that size but I am happy to share anything I can. I did do foam in the mako but not tons. It is down the outside stringers and in the bow. If you are trying to be unsinkable as they say take the weight of the boat and motor and divide that by 60. That will be the cubic feet of foam required