This is a testing site only. See the live Public Lab site here »

Public Lab Research note

watercraft from reused and recycled components

by nikete | April 30, 2018 01:47 30 Apr 01:47 | #16268 | #16268

We are planning to build a watercraft to be used as a platform for water quality measurements. The aim of the craft is to serve both those taking the measurements and

The boat structure is based on two hulls made of used truck tarp that encloses closed PET bottles and construction scaffolding bridging the two hulls, providing a mounting for the floor and box as well as the engine.

This is extremely early work at this stage. The initial objectives of the platform seeks to support are:

  • timed samples for archiving, eventually having this be automated completely.

  • spectrophotometry

  • bench space for hacking sensors / cabins for the crew to be able to spend multiple days on board. Ideally a workbench where one could assemble or diagnose problems in something like

The current planed sizing is 12m long and 5 m wide, with the tarp filled with bottles having a maximum diameter of 80cm, given by using the 2.7m width of the truck tarp as the skin of a cylinder. Attempts at having the trips of the hulls smoothly curve to a point. One of the collaborators has experience building a sailing catamaran in a similar sizing, also using constructing scaffolding for the bridge structure (in that case the hulls are made of wood and have interior space, and it is much more of a seaworthy vessel, while this is meant strictly for calm waterways. You can learn more about her )

The material resources are committed, and the human resources seem to be coming together. The aim is to have the hulls and a first iteration of the lab/shelter structure in the water by end of September. One possibility that is tempting for the intial setup is

We have some success obtaining almost pristine discarded MDF for free. There is a desire to minimize the use of epoxy, so much thought is being placed on how to protect it from the water. The current best thinking involves tarps and the use a heat source inside the shelter to evaporate humidity. We are very keen on other designs. Structurally above the floor of the craft we are considering wether to initially use a pair of geodomes since they are light and relatively fast to setup up. 5 meters being a natural diameter.

We are very keen to hear feedback from others who have attempted related projects, or those who would like to collaborate in its co-creation.


Very cool! Where is this project located? I especially like the use of recycled/scavenged building materials, but am a little concerned that working with MDF, which is simply laminated paper, may be more trouble than it's worth if you're planning to use it in or near water... it my experience it distorts and dissolves pretty quickly in the presence of moisture, so you might find yourself spending more time on waterproofing/maintenance/replacement than you'd like, but I'm really excited to see where this goes. I'm also a fabricator, so I would love to hear more about your construction ideas and challenges, and am excited to see where this goes!

Is this a question? Click here to post it to the Questions page.

Reply to this comment...

Hi @bronwen. Thanks for the helpful comment. We are currently building the first one in Berlin, with the goal of learning and providing some monitoring of the canals and the spree. I expect to build at least one more after that in the upper paraguay river, and quite happy to help support others in doing the same.

Agree that MDF is very very far from ideal, it is however thrown out in incredible amounts by convention centers in a way that does make it rather inexpensive. Note it plays no structural role in the craft at all (that is all the scaffolding.) I am running some tests of the MDF wrapped in truck tarp as a roof of a shed. Right now after about a year and a bit in it seems to be holding up. I am super keen to hear of other materials that could substitute in for it.

Reply to this comment...

Is there a reason you are using spectrophotometry instead of spectrometry?

Spectrometry would be much less expensive. Is your application sensitive enough that it requires the extra resolution, both in wavelength and abstinence or transmittance?

Thanks for your help.

Is this a question? Click here to post it to the Questions page.

Reply to this comment...

That was supposed to be absorbance , not abstinence. Darned autocorrect.

Reply to this comment...

A small note on the MDF: we have used it in combination with the tarp for a shed in our garden for about two years and it is holding up rather well.



Reply to this comment...

@Ag8n there is nothing else that i know to measure nitrate or the carbon concentration in situ and without chemicals. You need the UV-light in addition to the visible light to measure these parameters. Here is a short description of the principle:


Reply to this comment...

Thank you for the reply. What are you using for your UV source? The deuterium lamp from the spectrophotometer? Thank you.

Is this a question? Click here to post it to the Questions page.

Reply to this comment...

Love it! Ever hear of the adventures of the ?

Is this a question? Click here to post it to the Questions page.

Reply to this comment...

@liz , I had not heard of it before, that is so awesome! The design continues to evolve, and I picked up a few lesson from reading about the neutrinos, thank you.

Reply to this comment...

Login to comment.