View Full Version : Hovercraft Construction Questions

30-Jun-09, 10:00 PM
Hello Everyone :)

Iím currently building a hovercraft at my school with some of my friends. (I appeared on here a few years ago asking some questions, but the club I was with gave up and moved onto a Green Powered Car)

The hull we are using is fibreglass and comes in several pieces. (A Kestral Hull it was though to be) So far we have put some aluminium angles around the edge and attached the planing edge onto these using some bolts, and cut out a bit of plywood for the base. However, we have come across some problems, and Iíd be grateful for any help on these from anyone! :)

1) The skirt we were originally going to use (off an old challenger) is too big it seems (the tags on the bottom of each segment stretch far past the bottom of the hull) and so we are either looking to make a new skirt (I have a copy of the manual for a challenger which explains it in there) or modify the current one. Is it possible to modify the current one easily and if not, where could I get some new skirt material? (Polyurethane coated nylon or similar)

2) Also, we need to make a frame for our 250TZR engine which should be made out of steel I believe. Any idea where I can get the required steel for a low cost, as Iíd rather not spend near £50 buying it from B&Q :(

3) Finally, where can I get some buoyancy for the craft? I was thinking of using expanded polystyrene blocks but Iím not sure whatís the most effective or cheapestÖ

Anyways, thank you for reading this and Iíll be grateful for any help :)


(P.S. I'm situated around Canterbury, Kent if thats any help)

1-Jul-09, 06:35 AM

The Kestrel is a very old type of craft, I owned 2 in the 80s.
The skirt design requires 3 or 4 different types of segment on different parts of the craft. I doubt if anyone still has templates for them and so they'd have to be designed from scratch. You could possibly modify the Challenger skirt for the front and sides but probably not at the rear.

This craft would have originally had a PU foam block on the bottom for buoyancy which made it unstable. It is preferable to have the buoyancy behind the planing surfaces but if you don't have the bottom block then the planing surface moulding won't fit, nor will a standard skirt.
You could use expanded polystyrene for buoyancy and this is readily available from packaging companies in big sheets. I've got some you can have if you like. I live in Gillingham.

I'd be careful abbout putting plywood on the base as it may add too much weight. Try to use a coremat material or similar and add extra fibreglass at the wear points.

A top tip for the steel, if you only need relatively short lengths, find a local metal fabricators and ask them if they've got any offcuts or if they can cut you off a metre or so of whatever profile you want. They'll probably let you have it for free or only charge you a few quid.

1-Jul-09, 09:09 AM
I think I can help out on the skirt templates.
I will be needing them myself soon and will dig them out.

Regards, Kip

Jon Pert
1-Jul-09, 09:12 AM
Hi Benjamin http://www.jonrb.com/emoticons/wavey.gif

May I suggest that you seriously think about joining the club so that you can get access to the members areas. In the members areas there is a Tips forum, a Builders forum and most importantly an archive of the Club Magazine going back 40 odd years!! I'm sure that somewhere in that archive there would be some info you need! http://www.jonrb.com/emoticons/whatever2.gif

Have a look at the Main Menu on the left of the Homepage and look for Renew Membership (it's under Club Shop).

Good luck with your project.

1-Jul-09, 06:01 PM
Thank you all for the help! I've managed to arrange some cheap steel from a steel merchant of sorts, so should get that soon and my school's said I can have some foam they dont need. (I believe its PE foam, the stuff that has foil on both sides, used for lost insulation)

I'll definatly have a go at modifying the skirt, although a heavy material was used to make it, so it weighs more than a normal skirt. Anyone know where I can get extra skirt material, or whether I could buy it from the club? If you can find those templates Kip, I'd love to have a copy as they'd probably be very helpful :)

I'll probably join HCGB soon and look on their forums for more info :)