Can I use this for making parts?
#1
Posted 08 September 2012 - 07:36 PM
Does anyone know anything about it? If it is useable for casting parts, what would I use to make the molds? I've never done this before but would like to try.
Thanks in advance for any help.
Later-
#2
Posted 09 September 2012 - 07:08 AM
1) If it's branded "Hexcel", it's out of date. Structural epoxy ststems like this have a recommended shelf life, usually six-to-12 months. Hexcel sold off their resin division in 1996. As old as it is, it may not harden at all.
2) Structural resin systems require specific mixing ratios to cure properly. I BELIEVE this to be 100 to 44 (resin to hardener by weight) for this resin system. It needs to be mixed on a gram scale. Sloppy mixing will NOT provide consistent hardening.
3) Even if it will still harden, it's a laminating resin, not a casting resin. Because it's intended for laminating, it MAY exotherm excessively if used in a mass-casting application. What this means is that if mixed in sufficient quantities and not spread out on a laminated surface (poured into a mold, for instance) the heat generated by the normal exothermic-reaction of curing resin may develop what is best understood as a feedback loop. Bubbling, smoking and even fire can result from mass-casting with a resin intended solely for laminating.
The MGS resins I use most will exotherm in quantities as small as a thimblefull on a hot day.
I recommend: 1) Carefully research the SPECIFIC mixing ratio for the products. 2) Use a gram scale to mix about a 20gram total weight of mixed resin-hardener in an un-waxed Dixie cup and observe the results. Do it outside. Exothermic reaction products can be toxic. 3) If it hardens fully and doesn't bubble, smoke or expand strangely, you should be able to cast small parts with it.
#3
Posted 09 September 2012 - 12:45 PM
WOW!!!! you are the resin guru.I've been heavily involved in the composite-aircraft industry, both experimental and production (Cirrus, etc.) for many years. Your Hexcel Epolite resin system presents some problems that make it less than ideal for casting parts.
1) If it's branded "Hexcel", it's out of date. Structural epoxy ststems like this have a recommended shelf life, usually six-to-12 months. Hexcel sold off their resin division in 1996. As old as it is, it may not harden at all.
2) Structural resin systems require specific mixing ratios to cure properly. I BELIEVE this to be 100 to 44 (resin to hardener by weight) for this resin system. It needs to be mixed on a gram scale. Sloppy mixing will NOT provide consistent hardening.
3) Even if it will still harden, it's a laminating resin, not a casting resin. Because it's intended for laminating, it MAY exotherm excessively if used in a mass-casting application. What this means is that if mixed in sufficient quantities and not spread out on a laminated surface (poured into a mold, for instance) the heat generated by the normal exothermic-reaction of curing resin may develop what is best understood as a feedback loop. Bubbling, smoking and even fire can result from mass-casting with a resin intended solely for laminating.
The MGS resins I use most will exotherm in quantities as small as a thimblefull on a hot day.
I recommend: 1) Carefully research the SPECIFIC mixing ratio for the products. 2) Use a gram scale to mix about a 20gram total weight of mixed resin-hardener in an un-waxed Dixie cup and observe the results. Do it outside. Exothermic reaction products can be toxic. 3) If it hardens fully and doesn't bubble, smoke or expand strangely, you should be able to cast small parts with it.
#4
Posted 10 September 2012 - 02:30 AM
Thanks for the great response. That was exactly what I was looking for and confirmed my suspicions. I guess I'll just pitch it.
Later-












