see the demonstration at youtube: https://www.youtube.com/edit?video_id=3twhOEMN8M4&video_referrer=watch

This project is not yet complete, and I will update alot with images etc. -So I found this instruction on hydrofoils and did a 3d model - scaled up in size but correct ratios. https://www.seabreeze.com.au/News/Kitesurfing/How-to-make-your-own-Hydrofoil_8649403.aspx

I figured I could print a plastic copy, make a mould and cast it in glassfiber and epoxy.. There is so far just the main wing, but I suppose it would be easy to scale and print a rear rudder and attach them to a center axis somehow.. Btw the 'fill elements' are for inside the epoxy and glass just for filling and saving redundant material.

Here it is for everyone if you think you can use it :)

Update 4th June 2017: new file: frontFoilLeft.stl is the file I printed on an ultimaker Extended (for the height) -to make the other half, just mirror the stl in your slicer software..

Instructions: Some weeks ago I got the Silver Crest Vacuum sealer for about 35 euro in Lidl. It is as the name indicates, a vacuum packer and plastic sealer in one, meant for vegetables sealings. I am using it for vacuum sealing and compressing the composite (glass and epoxy) on the outside of my 3d print.. The model has to have its surface offset inwards with the distance of the intended composite thickness. (that is done for the file frontFoilLeft.stl)

1: Printing my left and right wing at about 70% infill and gluing it together,

2: cut out two pieces for each side of the wing such that they get diagonal directions of fibers overlapping.

3: paint one layer of epoxy out on the plastic shape, lay on a glass layer and soak additional epoxy on top, distributing epoxy untill soaking all glass thats over the shape.

4: repeat with all layers, both top and bottom of the wing.

5: very carefully put the whole thing inside the vacuum plastic bag ( I did not do so well) avoid any epoxy or glass on the sealing surfaces(inside of opening of the bag.

6: place bag in vacuum sealer, and arrange the bag such that it will fit while vacuuming, and not tare itself on corners and edges of the shape.

7: vacuum little by little (use the stop button, and arrange the bag along the way) 8: vacuum until the vacuum pump stops, press stop to avoid sealing, and do another few rounds like that to vacuum all extra air out. 9: you are done, now wait 10 min and check the bag for air tightness - in my case I had a bad seal both due to holes in the bag, and glass fiber and epoxy residue in the opening seal. -One trick to avoid this could be to fold the edge inward while bringing the object into the bag, then it may stay clean before the sealing process.