How to make Oru Kayak with - PP Solid - No Corrugated Sheet

I am living in istanbul and there is no corrugated polypropylene sheet seller anywhere in the country.
I found 2 to 5 mm thick solid - not corrugated - polypropylene sheets 3.5 X 1.5 Meters and 0.9 density. AFAIK , 2MM solid sheet and 5mm corrugated sheet are at the same weight.

How can I make oru kayak out of solid pp sheet ? Can pizza cutter make the folding lines on to solid pp ? I cant find torch. Show me few ways ? What would be needed the thickness of solid to withstand coastal sea or more distance ?

Umut
Istanbul

use plywood for your kayak. It is lighter and probably stiffer than polypopylene sheet stock. No torch needed. Describe the kayak that you wish to make. Is it a sea kayak, cruising kayak, recreational kayak, or .....? length. width, etcetra............

messabout said:

use plywood for your kayak. It is lighter and probably stiffer than polypopylene sheet stock. No torch needed. Describe the kayak that you wish to make. Is it a sea kayak, cruising kayak, recreational kayak, or .....? length. width, etcetra............

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I want to fold the pp sheet in to small package which I could carry on my shoulder. Its a 350 cms boat and with around 60 cms. I must use pp solid sheet.

Here's a different boat made out of 5-6 mm polypropylene sheets,

The specifications for boat you need | Models | Porta-Bote https://www.portabote.ca/models

The porta-bote waterproof folding line hinges are made by melting along the lines by using industrial machinery. Maybe a soldering iron with melting tip might work instead, you will have to try it and practice so you don't melt it too far and weaken the hinge.

The polypropylene is much more flexible and much heavier than corrugated sheets, it might be kind of heavy to carry on your shoulder. I don't think plywood would work if any of the folding lines are underwater, because some other leakproof material would have to be used between pieces, to keep any submerged folding lines from leaking under pressure.

I used a porta boat decades ago for several years, and it was worse than a low pressure inflatable- like rowing a jelly boat because the underwater panels would Flex and absorb/ lose energy with every stroke. But the porta boat was great for stability because it would twist and flex adjusting itself according to different loading positions, and also twist and slide when hitting rocks in shallow water.

If MtUmucSarac wants to build a boat with pp, he should do it. Probably his pp is marine grade.

YES!

MtUmutSarac said:

I am living in istanbul and there is no corrugated polypropylene sheet seller anywhere in the country.
I found 2 to 5 mm thick solid - not corrugated - polypropylene sheets 3.5 X 1.5 Meters and 0.9 density. AFAIK , 2MM solid sheet and 5mm corrugated sheet are at the same weight.

How can I make oru kayak out of solid pp sheet ? Can pizza cutter make the folding lines on to solid pp ? I cant find torch. Show me few ways for acft calculator? What would be needed the thickness of solid to withstand coastal sea or more distance ?

Umut
Istanbul

Click to expand...

Yes, you can make an oru-style kayak from solid polypropylene sheet, but it’s more difficult than using corrugated PP. A pizza cutter won’t work for folding lines—use a utility knife or V-groove cutter to carefully score the surface. Without a torch, you can crease by scoring halfway through and folding over an edge, or by clamping and slowly bending. For sea or coastal use, 3–4 mm solid PP is better than 2 mm for strength and durability. Reinforce folds with tape or straps if needed.