Composite Panels

[Hooty]

Well, I've broke the transom in the Katcando and it's necessary I do some major repairs to it. My original plan was to remove the deck in order to gain access to the transom area but that ain't gonna happen. What I've got to do instead is cut out the whole aft section of the deck. Rather then try putting that section back in, I'm gonna build a large hatch (approx 2'X6') that will give access to the space behind the rear seat (battery, fuel tank, hydraulic pump, etc). My original plan was to make it out of plywood but I've decided to try my hand at composite panels. I'm gonna build the hatch out 3/8" R45 Klegecell, fiberglass and epoxy. I'm also gonna build two gussets to tie the transom to the floor. I'm building those out of 3/4" Klegecell, fiberglass and epoxy.<br />If any of ya'll have any experience with light weight composite structures or any kind of input, for that matter, I'd sure like ta hear from ya.<br /><br />Thx & c/6<br />Hooty

 

[Hooty]

Re: Composite Panels

Here's the project.<br /><br />

<br /><br />c/6<br />Hooty

 

[snapperbait]

Re: Composite Panels

Hooty.. Don't know much about klegecell but, I've done a little work with other composite core materials like urethane foam, pvc foam, styrofoam, and divinacell... <br /><br />Some of the composites will have a tendancy to "pucker" or bow up from the heat and shrinkage durring the resins cure... Something to consider when your trying to achive a smooth flat surface...<br /><br />If the hatch is fairly flat and simple, why not make a simple disposable mold out of particle board, then line the inside of the mold with aluminum foil and lay up your glass against that.. Makes for a pretty true surface...

 

[CTD]

Re: Composite Panels

I think its a good idea to reinforce the transom for that motor bracket, it adds a little leverage on the transom. With your motor sitting back and up like that you can probably use most of the motor well area for your hatch but you need to be sure to add some extra bracing. Where did it break?

 

[Hooty]

Re: Composite Panels

Yo Sb,<br />The Klegecel is closed cell vinyl foam much like the Divinylcel. My plan was to use a 30-35 min. geltime epoxy reinforced with 3oz. mat and a layer of woven roving on each side of the hatch. I didn't think that mass would create that much exotherm to warp the foam but maybe I'm wrong. What do you think?<br /><br />Howdy CTD,<br />The distance from the top of the transom to the floor is 15" so I planned to build the gussets from the top of the transom forward about 30" or just to the back of the rear seat.<br />The break is in the area (both sides) shown in the foto below. It was caused by a previous bogus repair to the transom.<br /><br />Thanks for the help and advise.<br /><br />c/6<br />Hooty<br /><br />

 

[Hooty]

Re: Composite Panels

^Bump^

 

[BillP]

Re: Composite Panels

Hooty,<br />Now I see. Couldn't you just use the cutout and hinge it to make an access hatch? A lip for it to rest on would make a good bearing surface.<br /><br />About the Klegecell...Many, many years ago I helped a friend build a lightweight dingy with the stuff. If memeory serves right it weight 40lbs vs 100lbs. We used 3/4oz surfacing mat with polyester resin on each side and it was VERY tough and strong. He later added more glass on the bottom to make it more durable for pulling up on the beach. It seems to me the KCell was only 1/4" thick. Warping wasn't a problem but it was over a temporary mold

 

[Hooty]

Re: Composite Panels

Here's a foto update on the composite hatch for the Katcando.<br />Nr.1 is the Klegecel without any laminate. The black stripe is carbon fiber tape.<br /><br />Nr.2 is the top laminate in place.<br /><br />Nrs. 3&4 are the first fitting after trimming.<br /><br />Wood inserts are for the latches and hoses for the fuel line, electrical cable, water pressure line, shift and throttle cables. I'll put two more wood inserets in the aft edge for the hinges and then the bottom laminate. <br /><br />

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<br /><br />c/6<br />Hooty