View Full Version : layers of fibreglass needed for hull

Horus - n/a
28-Sep-06, 10:44 AM
Hello I hope to start building a fibregalss challenger as per HCGB constructors manual, and to at least turn up with next season in f3, but not sure on how many fibreglass layers for hull and duct, a lot of good build sites but none say how many layers and what weight they should be the manual suggests one layer of mat and one of woven roving, the only stuff I can find on ebay is 450g mat and 800g woven is this good enough ?

tonybroad - n/a
28-Sep-06, 12:17 PM

i'm assuming you are going to be making flat fibreglass panels for the challenger

two layers of 450 mat should be adequate for the hull and planing surfaces

duct needs 6 layers of 450 100mm either side of the line of the fan to conform to build regs

the 800 woven stuff sounds heavy - try glasplies in Southport, they do 300g 450g and 600g in mat and woven

good luck - keep the weight down - speak to Pest who has some postings on the board - he'll have some good challengar tips having built one !!!


Sean Atterbury - n/a
29-Sep-06, 07:11 AM
Yip 2 is good, I however went for 3 being inexperienced and wanting a realy strong hull, I however on top I used only one layer, with no reinforcing on the bends, this was a mistake and I seem to have to patch it every now and again.

Lesson learnt. The next one will be better. http://hovercraft.org.uk/images/icons/smiley_icons/icon_biggrin.gif

Remember to do it in an open area, otherwise we get sick quick. http://hovercraft.org.uk/images/icons/smiley_icons/icon_cry.gif

Horus - n/a
29-Sep-06, 12:00 PM
Hello, Many thanks for reply I will be building a wooden shell then using that as a mould to make a fibreglass hull. I hope to make the duct as well, not to save any money as Im sure it is just a cheap to buy ! You have a great website I have learnt a lot from looking at it ! Thanks again. Richard.

tonybroad - n/a
29-Sep-06, 01:23 PM
get a good sander and a respirator - my guess is that your workshop/shed/garage will be as dusty as a dusty duster that's been in the 'too dusty' pile for a long time and gathered more dust

p.s.(i'm in a strange mood today)

hovercad - n/a
29-Sep-06, 01:42 PM
Im thinking of getting started on patching up the flying Pig ready for next season.

Has anyone written any tutorials on this type of work on hovercrafts.

Ive never done any fibreglassing aprt from the odd hole patching thats been out of site.

Is it better to make panels and replace that damaged area or cut out the damaged area and rebuild.????

At the moment not too sure which way to go.


ugglas - n/a
15-Oct-06, 06:34 PM
Is realy 2-3 layers of 450 enough for the hull, does it not get flimsy? How do people fiberglass around their engine mounts?

tonybroad - n/a
16-Oct-06, 07:44 AM
put more layers around engine mounts and stressed/impact areas, the original posting was for fibreglass panels for a challenger which has a wooden sub-structure and two layers 450 is ample


Horus - n/a
16-Oct-06, 02:32 PM
I hope my hovercraft will be all fibreglass once complete, I only intend to use the wood to make a mold and then to use fibreglass to make a nice light racing craft. I didnt make that clear in my original post, apologies for that.

so my question should be once I have made the wooden shell which will be the mold and will be discarded once made how many layers of fibreglass should i use.

Don83000 - n/a
16-Oct-06, 04:43 PM
You can use hardboard instead of ply for your plug as its cheaper and because of the finish you have less prep work before you lay up.

tonybroad - n/a
16-Oct-06, 06:32 PM
i agree - white sheet hardboard is excellent - i used it to make a mould for a prototype hull bottom (see pic) - made the mould in a day, next day laid up the prototype bottom - when it was fitted and everything worked OK i took a mould off the protoype bottom


no spraying,sanding etc. and you can apply release agent directly onto the white surface which gives a decent surface finish - i was going to fill and sand a nice radius where the panels met but ended up just sealing them with brown parcel tape - worked a treat


ugglas - n/a
16-Oct-06, 08:18 PM
Tony, how many layers of fiberglass did you use on the bottom hull?

tonybroad - n/a
17-Oct-06, 07:53 AM
mostly 2 layers - i overlap the layers at the bottom edge to give me 4 layers where contact with the ground is possible

i put a few extra bits around the front and rear corners and an extra layer around the air holes and outer edges

hope that helps