fiber glass repair photo heavy tutorial

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Paulioq
KFDU Angler
Posts: 196
Joined: Thu Dec 08, 2016 3:18 pm
Local Fishing Region: Wynnum
Kayaks: pa14 profiha525

fiber glass repair photo heavy tutorial

#1 Post by Paulioq » Sun Nov 18, 2018 8:55 am

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what a beauty. woo hoo got my stealth. but it was second hand and need'd a couple of small repairs. one being where a light post was in the stern and inside the fish hatch to cover the old sounder portal because the bottom screw holes had torn into the floor and would have let water out of the fish hatch.
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I started with stern hole removing the plastic bracket thingy and left with a big hole I need to patch. I was installing a sounder at the time also so I used the cut out piece from the hatch but will show how to make patch pieces further in the post.
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now to get the patch in there is a little trick where first drill 2 holes in the middle to feed some fishing line or string through this will let you retrieve the patch if you drop it in side and also to pull it up when you use epoxy glue(marine epoxy mixed with fillet/glue powder) to secure it in place. now to get it in place you turn it 90degrees and flip it up and start it through the hole you are repairing. I had to clean up screw holes cut out a little access for the patch piece.
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push it through and with the string you have attached flip it horizontally and spin it back 90 degrees wala
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now prepare the surface by giving it a light sand inside the hole on the under side and clean with acetone to prepare the surface for a strong bond and mix up some glue buy following the directions I recommend using epoxy because it has superior adhesion and strength characteristics and is recommended for use in any fiberglass repairs. add glue/fillet powder to reach the desired consistency, I like smooth peanut butter it doesn't sag but will squish out into crevices and irregular surface shapes.
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now pull up the line and secure it some how with a stick under it to take up the slack or retying it or both but it needs to keep it in place till the epoxy dries over night

the next day I mixed some epoxy clear gell coat with pigment(should have got the pigment a closer match) and filled the hole to be just proud of the surface so I could sand/faire it flat and then polish out the job
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Paulioq
KFDU Angler
Posts: 196
Joined: Thu Dec 08, 2016 3:18 pm
Local Fishing Region: Wynnum
Kayaks: pa14 profiha525

Re: fiber glass repair photo heavy tutorial

#2 Post by Paulioq » Sun Nov 18, 2018 9:30 am

part 2 the fish hatch
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the internal repairs were not cosmetic and only structural so I took a little different approach. I made a piece to span the old acess port hole and cable grommet that was installed.
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I also made a battery box for myself to hold a 12v sla battery more on that later

this technique I am using can be used to repair any large hole in a kayak it could be a rock punching through the hole etc but there you would use the befor inside out technique so you could faire it flat for a factory looking repair. being inside the fish hatch I just wanted to know it was water proof and strong.

I started by making up my patch piece on a flat surface away from the yak
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this is called a composite lay up and you are building up and weting out your cloth here because it is easier then trying to do it in a tight confined place and creating a mess. we don't want that we want repairs that build confidence when scene not make you second guess the seaworthiness of your craft. also maintaing resale value. now back to layup

there is a thing called a "lay up scheduale" this is what fiberglass was used in its construction you can contact the manufacturer asking advice or take a guess by measureing the thickness of the exsisting fiber glass. its thing in this area and the screws had torn out tearing down into the floor. I need'd a patch to cover all this damage because I was mounting the tranceducer behind the original battery battery box on the other side any way.

I used 6 layers of 200 gsm cloth weave to make up my schedule this was a little thicker then original so not being an enginer I knew it would be strong enough. the reason for multiple layers of light cloth and not one or 2 of heavy chop mat is for weight to strength. multiple light layers are stronger and thiner then thicker layers adding up to the same amount eg 6 layers of 200gsm cloth = 1200gsm total 2mm thick or 2 layers of 600gsm chop strand mat = 1200gsm total but will be 3.5mm thick. this uses more resin adding unneccisary weight for no strength bonus

best wet out technique is to lay out some kitchen grease proof paper (it doesn't stick to epoxy or fiberglass) and mix your marine epoxy painting it straight onto the paper weting out an area the size of your patch pieces you have precut and ready to go. now lay a piece onto the wet area wet out again and add another piece etc follow this until you have lay up schedual completed and put another piece of grease paper on top the use a roller to push out the air from the center out as well as remove excess epoxy. you only need enough to wet out the fabric you want 50%mat 50%resin this is a good technique for pieces up to 30cm square and produces thin strong composites.

now your ready to just lay your wet patch piece between the 2 grease papers over the area with the hole you want to repair
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leave it there till it dries over night and into shape. it should be a fairly good fit if not perfectly following the contours. once drie it can be glued in with epoxy glue
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Paulioq
KFDU Angler
Posts: 196
Joined: Thu Dec 08, 2016 3:18 pm
Local Fishing Region: Wynnum
Kayaks: pa14 profiha525

Re: fiber glass repair photo heavy tutorial

#3 Post by Paulioq » Sun Nov 18, 2018 9:37 am

part 3 diy battery box. now I'm just boasting
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it is possible to make custome acesories for your self like tackle pockets and holders etc by laying your wet layup over a shape maybe like a sla battery wraped in card box and grease proof paper and held in place with bricks to hold the form I wanted
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