Kon Tiki construction materials

[elton]

I had cause to recall a model hydrofoil I constructed as a child, and sailed on a local lake. I was inspired by reading about Thor Heyerdahl's adventure in Kon Tiki, so I built it out of balsa wood. The vessel was powered by a small electric motor with propeller, mounded on a pylon. I sent it off over the lake, but before it arrived on the other side, it became clear all was not well, as it slowly began to sink, It barely made it to shore, by which time, only the pylon and prop were above the waterline. The balsa wood had absorbed a copious quantity of water, causing my vessel to sink. So what did Heyerdahl know that I didn't? Why didn't Kon Tiki sink?

 

[Ohlin Karcher]

The main construction was of bundles of reeds, which are hollow tubes, and they did absorb a lot of water but not enough to sink her.
Perhaps your balsa wood needed a coat of varnish? I don't think it's anyone's first choice for boatbuilding, the extreme lightness comes with other problems as you have found..
Thor H completed his trip, very well done to them, but his migration hypothesis has since been debunked, I believe.
An inspirational story anyway!

 

[AntarcticPilot]

The main construction was of bundles of reeds, which are hollow tubes, and they did absorb a lot of water but not enough to sink her.
Perhaps your balsa wood needed a coat of varnish? I don't think it's anyone's first choice for boatbuilding, the extreme lightness comes with other problems as you have found..
Thor H completed his trip, very well done to them, but his migration hypothesis has since been debunked, I believe.
An inspirational story anyway!

You're thinking of the Ra boats, which were reed bundles. Ra was an experiment by Heyerdahl to see if Egyptian reed boats could cross the Atlantic.

Kon Tiki was made of balsa logs, but these were green logs full of the natural sap etc. These are much heavier than the dried balsa used in model making, and resist being soaked by water. They don't have as much buoyancy as dry balsa, but they keep it. Further, Kon-Tiki was lashed together using natural fibres, which didn't erode the logs.

Although Heyerdahl made his journey successfully, his theories have been substantially disproved by DNA evidence showing that the inhabitants of the Pacific Islands migrated from SE Asia. Such voyages can only prove the possibility of the mode of migration, not that it happened, and they discount the fact that a voyage that is possible if you know there's something at the other side may not be attempted by people who DON'T know there's anything there! However, there is a possibility that some contact was made that transferred some cultivated plants etc., but that the contact wasn't the source of the population.

 

[elton]

Kon Tiki was made of balsa logs, but these were green logs full of the natural sap etc. These are much heavier than the dried balsa used in model making, and resist being soaked by water. They don't have as much buoyancy as dry balsa, but they keep it. Further, Kon-Tiki was lashed together using natural fibres, which didn't erode the logs.

That answers my query. Thanks :encouragement:

 

[Ohlin Karcher]

You're thinking of the Ra boats, which were reed bundles. Ra was an experiment by Heyerdahl to see if Egyptian reed boats could cross the Atlantic.

Kon Tiki was made of balsa logs, but these were green logs full of the natural sap etc. These are much heavier than the dried balsa used in model making, and resist being soaked by water. They don't have as much buoyancy as dry balsa, but they keep it. Further, Kon-Tiki was lashed together using natural fibres, which didn't erode the logs.

Although Heyerdahl made his journey successfully, his theories have been substantially disproved by DNA evidence showing that the inhabitants of the Pacific Islands migrated from SE Asia. Such voyages can only prove the possibility of the mode of migration, not that it happened, and they discount the fact that a voyage that is possible if you know there's something at the other side may not be attempted by people who DON'T know there's anything there! However, there is a possibility that some contact was made that transferred some cultivated plants etc., but that the contact wasn't the source of the population.

Yes my mistake and thank you for the explanation.