Pondering... Fiberglass question

[Ageless]

Wes. the honeycomb used in aerospace is either phenolic or nomex; howeer anyone can buy cardboard and paper honeycomb which is not expensive; has been used in pleasure boats for 50 years.

just have the mold, jigs and bagging equiptment

[WesGrimes]

...cardboard and paper honeycomb which is not expensive; has been used in pleasure boats for 50 years...

Hmm... I had not though about that. How does the cardboard react to the resin? How much strength would the cardboard have?

I had thought about looking for 2" tall, large cavity, say 4" x 4", injection molded plastic. Not sure where to start on that search. I thought I could set that up in the wet resin and it would add to the rigidity. Then I could fill the cavities with A/B foam after the laminate cures. The foam was just for insulation.

I think I am going to try some test panels with varies core layups and see what works best for me. I am going to look into that cardboard honeycomb option. Thanks for the tip!

[Ageless]

Most of the small foredecks on ski and fishing boats are made using the cardboard honeycomb. I'e seen some fairly 'hefty' folks walking on that part.

[ktm_2000]

also look at some other foam products divinicell and corecell $$$$ at best. I've seen products made out of nomex and like them but couldn't find a vendor that would sell to a DIYer.

My boat has a fuel tank hatch that a previous owner installed too many accessories and didn't seal the screw holes. Water leaked in and rotted the balsa core and the hatch became quite soft. The hatch measured 4'x6'. I had built a torsion box and covered it in smooth countertop laminate as a mold surface. The mold was prepped by 5 coats of carnuba wax as well as sprayed it with PVA mold release agent. When ready the I sprayed 4 light coats of gelcoat and put down 1.5oz mat and then 2 layers of 1708. The core material was 3/4" corecell and the back was 3 layers of 1708.

I seriously thought of doing a similar item with thinner core material as well as much less glass but the thought of putting the whole thing to gether would be quite tough as a side panel of a standie is much larger than the tank hatch that I made and would require a decent sized shop to do the work in as well as professional equipment or a large crew of helpers to make a decent product.

[WesGrimes]

I've seen products made out of nomex and like them but couldn't find a vendor that would sell to a DIYer.

http://www.fibreglast.com/showproducts-category-Sandwich%20Core-157.html <-- They have it, but it ain't cheap. $174 for a 40" x 100" sheet!

[ktm_2000]

I stated that incorrectly..... I was thinking of nida-core

http://www.nidacore.com/english/nidaprod_honey_h8pp.htm

pretty slick stuff, has the honeycomb and a scrim fabric on each side so it is easier to laminate fabric to it,

[Wolfgang92025]

I build the camper below in the mid 80's.
Used 3/4" Poly Iso insulation panels.
That was all I could find, way before internet.
Had to peel of the aluminum cover from both sides.
From what I remember, it was a real pain.
Used 3/4" pine furring strips were I needed to attach things like lights, windows etc..
Had to scan the pic's to upload.









Whole thing weighed maybe 80 lbs. Could lift it by myself, but it was very awkward being so large. Did not know about CEPS. After about 10 years some of the wood started to rot. Getting a half way good finish took a lot of work. Maybe that's why I don't care a lot for fiberglass.

Wolfgang