Best fabrication method for one off kayak catch bin

[IronPrice]

I could use some advice on the best way of fabricating a one off catch bin for my new kayak.

Purpose designed fishing kayaks often come with removable catch bins that fit neatly into the rear well (example). This keeps the mass of fish and ice down low and reduces windage. People in wider kayaks on calm waters use ice-boxes, but that isn't an option for me. My kayak is narrow and I use it in coastal waters.

You can get chill bags to fit rear wells but they don't seal well and fish spines soon make holes in the internal lining. After that they start to smell bad. Been there, done that.

Catch-bins are specific to each kayak model and there is no catch-bin available for my kayak (pictured here). I would like to make one.

Requirements are: -
- light
- thermally insulated
- hatch for stowing fish
- rugged

There is a compromise to be struck - thicker insulation means less internal volume.

My thinking so far has been to build from closed cell foam sheathed inside and out with resin and cloth. The bottom half will need to fit nicely into the well.

I'm not sure what the best choice of materials would be or the best way to go about getting the shape correct.

I have few ideas but I'd rather hear from people with experience.

 

[rwatson]

High IronPrice

I have "done " a few kayaks, so perhaps can help a bit.

A few bits of info -

whats your Kayak made of Fibreglass, Plastic, Plywood, etc

Is it sit on or sit in ?

Any photos ?

meanwhile ..

The method you are thinking of sounds practical, but what sort of foam is available close to you ? - high density, home insulating foam, polystyrene etc

Finally, how much experience have you had in fibreglassing, both with Polyester Resin and/or Epoxy ?

Catch you later ..

 

[fallguy]

I would recommend using 2" polystyrene foam; blue or pink from Home Depot. It has great R value and shapes easily. Glue it up with PL200? (The glue in a caulk tube for foam).

It is easy to shape and form and will work great for you.

The lid could be made from the same stuff; just seal the basin to the hull deck and allow the catch basin to be a wet locker. You'll want to make a positive hook or string safety for the lid or the wind will surely take it.

I have used it for building outrigger floats and I really like working with it.

The top of the box is where the heating happens; so keep it thick.

You might want a drain unless you don't mind the tip method.

Only works with epoxy.

 

[fallguy]

You probably need a coaming. I would incorporate the coaming and lid into each other. Like the lid could go over the coaming to avoid water entering.

 

[BlueBell]

The "Best" way is the way that works best for you in design, construction and building ( and possibly modifying ).
If it was my dilemma, I 'd study the short comings of commercially made boxes.
Then, get a large cardboard box, cut off each side and make templates for all four sides.
Tape or glue them together, install, trace the bottom on the remaining piece of cardboard and attach.
Trim as necessary and there's your dimensions to cut 1" polystyrene ( Home Depot, Lowes...) foam.
Cut with a knife, band saw, hot wire ( the best - ventilate well )
Dome your lid(s) if you like. Hinge it.
Then lay up 6 oz fiber-epoxy.
Paint it and shazam!!
You may consider installing a lock for multi-purpose.
Post pics when you're done?
Good luck!

 

[IronPrice]

High IronPrice

whats your Kayak made of Fibreglass, Plastic, Plywood, etc

Is it sit on or sit in ?

The method you are thinking of sounds practical, but what sort of foam is available close to you ? - high density, home insulating foam, polystyrene etc

Finally, how much experience have you had in fibreglassing, both with Polyester Resin and/or Epoxy ?

The kayak is sit-on-top made from thermo-formed plastic: PVC with an acrylic outer layer. I can't get my photo to upload but here is a link to the manufactures website https://hurricaneaquasports.com/our-kayaks/sit-on-tops/skimmer-128-2/

I can easily access
- Flexible closed cell EVA foam board in 5mm, 10mm or 20mm thickness;
- Closed cell sem rigid polyethlene foam in 10mm, 25mm or 50mm;
- EPS board, in a variety of thicknesses from 10mm to 60mm

I have some limited experience with epoxy. On an old 16ft fi-glass boat boat I owned I reinforced the hull plates; fitted new stringers, bulkheads, and deck; reinforced the transom and added an outboard pod. I used plywood, thickened epoxy adhesive, DB cloth, epoxy resin, fairing compound and flow-coat to do this. Mostly interior work that didn't have to be pretty. The finish on the transom and pod (flow-coat) was OK.

All of that^^ was working with a retired friend who is an experienced composite fabricator (also was an importer and distributor). Working independently I have made a cylindrical drinks ice-box/ottoman with the same construction methods. It was structurally sound but the finish wasn't anywhere near perfect.

I have zero experience with molds. I'm generally handy but I tend to let myself down on most projects in the fine finishing detail of painting etc.

 

[IronPrice]

The lid could be made from the same stuff; just seal the basin to the hull deck and allow the catch basin to be a wet locker.

Needs to be removable so the kayak can go on the roof-rack

 

[IronPrice]

If it was my dilemma, I 'd study the short comings of commercially made boxes.

The commercial boxes are great. They tend to be roto-moulded polyethylene. But they are specific to individual models of kayak and none are made for my kayak.

 

[IronPrice]

The "Best" way is the way that works best for you in design, construction and building ( and possibly modifying ).
Then, get a large cardboard box, cut off each side and make templates for all four sides.
Tape or glue them together, install, trace the bottom on the remaining piece of cardboard and attach.
Trim as necessary and there's your dimensions to cut 1" polystyrene ( Home Depot, Lowes...) foam.
Cut with a knife, band saw, hot wire ( the best - ventilate well )
Dome your lid(s) if you like. Hinge it.
Then lay up 6 oz fiber-epoxy.
Paint it and shazam!!

Thank that's very helpful. The rear well has three separate curved sides and one straight side and the method you suggest will work well for getting the shapes right.

 

[rwatson]

Needs to be removable so the kayak can go on the roof-rack

Thanks for the details.

We can probably ignore polyester and epoxy resin then for the actual kayak, and look at techniques like welding systems
Kayak and Canoe Repair Kit https://www.polyvance.com/kcwelder.php

or some stuff like West Systems GFlex

Personally, I would start by making a sealed off permanent bin by welding/gluing vertical polyethylene or polypropylene sides and ends, from the edges of a square cut deck hole, onto the hull. Make sure the vertical panels extend an inch or two above the deck This gives you a waterproof compartment that prevents the stern of the hull from filling up with water in case a tight seal on a fish box fails, as well as adding extra rigidity to the hull itself. You can probably get sheets of polyethylene or polypropylene in your part of the world.

Once this is done, you have the "pattern" for the outside of the fish box, and you can use relatively cheap foam board because you don't need the structural strength.

Just cut sections of foam, and fit them in the well with some cardboard spacers to get a 3-4 mm gap on the outside. Hot glue them to get a temporary box, take the bottom half of the box out, and epoxy with 6oz cloth, all on the inside to make a permanent armature.

No you are free to epoxy the outside ( checking for fit as you go) until you have a removable box. Once the box itself is complete, you can make a lid of fiberglass to fit snugly on top.

 

[IronPrice]

Thanks for the details.

We can probably ignore polyester and epoxy resin then, and look at techni

I'm slightly confused by your post.

I'm not clear why removing the catch bin from the kayak while the kayak is transported on the roof-racks negates the use of epoxy? I will still need the bin to be rugged as it will get knocked about a bit - sinkers, rods, gaff, beach etc

What is techni?

 

[rwatson]

I'm slightly confused by your post.

I'm not clear why removing the catch bin from the kayak while the kayak is transported on the roof-racks negates the use of epoxy? I will still need the bin to be rugged as it will get knocked about a bit - sinkers, rods, gaff, beach etc

What is techni?

I hit SAVE by accident - full test should be there by now

 

[DGreenwood]

First...I have to commend you on asking a question intelligently and providing good pictures to give us an idea what you are after.
This is a complex mold best left to an experienced mold builder. However you seem game, so lets try and work through this.
Something in your favor is that roto-molded plastic does not stick to anything...or rather nothing sticks to it. (well almost nothing)
So you can use your Kayak as a mold. I would still put mold release on it.
Once I had molded the bottom of the container, I would use that shape filled with foam to mold the lid.
Once my lid shell was built I would install my insulation foam in both parts and give them a proper inner shell.
There are a 100 ways to go about this. The fact that you are only making one of these cuts it down to about 20 or so.
Most of it involves common stuff available to everyone (builders foam, kids modelling clay, car body filler, bent sticks, hot melt glue etc...etc.)
What you are taking on takes an inordinate amount of patience and willingness to back out of disastrous mistakes. This ain't gonna happen over a weekend.
I would do it with epoxy if I had the money, it will flatten the learning curve slightly and produce a better part.
The reality is that if there were a commercially available option, it would be , by far, the smart way to go.
There are a lot of people here that can help you with this if you are still game.
I will contribute as much as I have time for.

 

[IronPrice]

Something in your favor is that roto-molded plastic does not stick to anything...or rather nothing sticks to it. (well almost nothing)
So you can use your Kayak as a mold. I would still put mold release on it.

Its not roto-molded polyethylene - it's thermo-formed PVC with an outer skin of acrylic. Very shiny (see picture in subsequent post)

Stuff sticks to it.

 

[IronPrice]

Thanks for the details.

We can probably ignore polyester and epoxy resin then for the actual kayak, and look at techniques like welding systems
Kayak and Canoe Repair Kit https://www.polyvance.com/kcwelder.php
....
Personally, I would start by making a sealed off permanent bin by welding/gluing vertical polyethylene or polypropylene sides and ends, from the edges of a square cut deck hole, onto the hull. Make sure the vertical panels extend an inch or two above the deck This gives you a waterproof compartment that prevents the stern of the hull from filling up with water in case a tight seal on a fish box fails, as well as adding extra rigidity to the hull itself. You can probably get sheets of polyethylene or polypropylene in your part of the world.

Once this is done, you have the "pattern" for the outside of the fish box, and you can use relatively cheap foam board because you don't need the structural strength.

Just cut sections of foam, and fit them in the well with some cardboard spacers to get a 3-4 mm gap on the outside. Hot glue them to get a temporary box, take the bottom half of the box out, and epoxy with 6oz cloth, all on the inside to make a permanent armature.

No you are free to epoxy the outside ( checking for fit as you go) until you have a removable box. Once the box itself is complete, you can make a lid of fiberglass to fit snugly on top.

I think you have misunderstood what I want to do.

My kayak is sit on top with a rear well

It's not polyethylene it's a two layered (PVC & acylic) thermo-formed plastic, and can't be welded.
I don't want to cut holes in the kayak deck.
I want to make a removable bin to fit in the rear well - like this black and yellow catch bin on my previous kayak (it all got stolen ).