Resin Quotes last updated 13 October 2008:
ATL Composites - Southport, Gold Coast http://www.atlcomposites.com/
R246 Kinetix 18Kgs $281.90 inc GST
H128 Fast Hardener 4.5Kgs $148.63 inc GST
Datasheet : http://www.atlcomposites.com/products/epoxy-resins/laminating/index.htm
CG Composites - Hendra, Brisbane http://www.cgcomposites.com.au/
Ampreg 22 20kgs $433.25 plus GST (Ampreg 22 they use in Germany for Gliders.)
Hardener Extra Slow 5.6kgs $227.00 plus GST
DataSheet : Ampreg 21/22/26 http://www.gurit.com/downloads.asp?section=000100010037&itemTitle=Brochure+Downloads
CG Composites - Hendra, Brisbane http://www.cgcomposites.com.au/
Araldite LC3600 20kgs $310.00 plus GST (Jabiru use the Araldite LC3600.)
Hardener 6.7kgs $241.00 plus GST
Datasheet: Araldite LC3600 http://www.kirkside.com.au/Uploads/Images/aralditekitk3600.pdf
IronBark Composites, 7B Baines Court, Torquay Vic 3228, http://www.ironbarkcomposites.com.au
L285 epoxy resin 5 Kgs $250.00 plus GST
H285 amino hardener 1Kg $56.50 plus GST
H287 amino hardener 1Kg $56.50 plus GST
Delivery to Brisbane by Fastway (7kgs) $45.00 plus GST
Resin Certification Notes
For resins to be approved for aircraft construction by the LBA (German FAA equivalent) they need to exhibit, among a whole bunch of other (mechanical) requirements a certain glass transition temperature. For gliders I think this is around 55°C, while for "real" powered aircraft that temperature is around 80°C. That L20 resin is only approved for glider construction due to its Tg. Same is true for MGS L335, btw! (*)
For repairs the rule here is the following: Use the original resin… if that one is not known or unavailable, use L285. So most professionals use L285 almost exclusively.
The somewhat higher price isn't really a factor considering the lack of hazmat fees. Makes sense to have only one resin in stock and not having to order from abroad.
(*) Edit/correction:
From the MGS 285 datasheet:
"After heat treatment at 50 - 55 °C (122-131 °F), the system meets the standards for
gliders and motor gliders (operational temperatures -60°C (-76°F) to +54°C (129 °F).
In order to meet the standards for motor planes (operational temperatures -60°C
(-76 °F) to +72 °C (161 °F), heat treatment at 80 °C (176 °F) is necessary."
The temperatures which can develop within an airframe structure when parked and exposed to solar radiation are very high; see the table below for surface coatings and finishes. Post-curing is necessary; it can be seen that even with a white finish (the norm for all composite aircraft) the 68° C temperature reached is well above the initial room temperature curing Tg.
Quite a few years ago the Australian Department of Civil Aviation released a document which included temperature readings on fibreglass reinforced polymer panels with various colour surface finishes. The ambient atmospheric temperature was a high summer 40° C and the table following records the surface temperatures of the panels.
Surface colour Temperature reached
White 68° C
Yellow / pink 72° C
Light blue / aluminium 76° C
Blue / purple 80° C
Light green 84° C
Orange / tan 88° C
Green / red 100° C
Black 110° C
Heat soaking can have a deleterious effect on composite structures; the problem is related to the glass transition temperature. White is the only suitable overall finish for composite aircraft and care must be taken in the choice of trim colours to minimise differential heating of the structure.