3 meter HDPE sailing dinghy

Hi, i will be uploading pictures of the progress of the building.
The boat is being build entirely in welded HDPE sheets of 15, 8 and 6mm of thickness, mast will be Ø50mm hardware aluminium tube.








Saludos desde Chile.

 

Welcome Sebastian, interesting project, will follow you carefully. Good luck!

Btw, what is your cost per m2 or kg for the panel material?

 

Hard to tell but a 2.000 x 4000 x 15mm HDPE sheet cost me 566 euros plus shipping 2 years ago, where you can fit 2 complete kits of the ribs.

 

Interesting project.
Isn't the HDPE is near impossible to glue?
You wrote about weld, how do you weld this?
Do you have an idea of the final weight?
Thanks

 

HDPE is a thermoplastic that can be welded with a special heatgun, there are many boats made of HDPE just google tideman boats or skarsvaag boats.
I´m not really sure about the weight, once finished i will post it.

 

Beautiful, clean design. At only 3 meters LOA, you probably don't need the ribs. I'm thinking the transom, thwart, deck, a keel board and chine stringers, should keep her stiff enough with less weight then the frames. The real benefits will be in crew comfort and ease of movement while working the sails. Plus, drainage will go better.

-Will

 

Hi Will, good observation.
Actually the original design it´s made in plywood the way you say but since i changed to plastic, which bends with heat, i prefered to add those ribs for extra stiffness, since it will be black the plastic gets hot in no time.

Also to show off the cnc cuts.

Pictures attached are not mine.

 

So it has passed some time but better late than never, here are some pictures of 1 day of plastic welding.









More to come...

 

Very cool!

 

An interesting project,and it looks good so far.Will you be incorporating flotation bags for safety?

 

yes, i was thinking to use these cheap swimming pool foam tubes all along, also some straps will be necessary and maybe a floor to not step on the hull.

 

How was the learning curve learning to weld it? Did the tool you uses seem sufficient or is there a different model welder you would have preferred? With the stringer arraingment how rigid does it feel?

 

An experienced welder is doing the job, not his first hdpe boat, but his first sailboat!
The welding gun that you see in the pictures is only for sticking the parts together, after that comes the extruder which is a bigger gun that makes the strong welding for most of all joints.
You have to be carefull welding these thin hdpe sheets (the 6mm ones) because if you take too long welding it will show on the outside so yes, if you want to make your boat look pretty just pay someone to do it, i don´t have the 15+ years of experience that the guy that i hired has.

 

I occasionally weld plastic to fix parts in my dishwasher, vacuum cleaner tubing, etc. But I just use a soldering iron and some discarded piece of plastic like the cap of a discarded mayonnaise jar. I also have use a clothes iron to make a fitted plastic cover for my outdoors cutoff saw out of the emptied pellet bags from my pellet stove.

Nothing like what you're doing here.

-Will

 

Very nice project!
I think it might be quite heavy, but that's unavoidable with this type of build (no rotomoulding and no double shell).
The black hdpe will make it problem free and UV resistant.