I thought Ethanol was an 'octane boosting solvent'? TK
On 18 July 2012 11:27, Chris Gardner <cgardn...@rogers.com> wrote: > Sid > I had a similar occurrence years ago with my KR wing tanks made of Dow > Derakane vinyl ester resin and Sunoco 94 octane gas. > At the time I didn't think Ethanol was the problem but rather some kind of > octane boosting solvent. > Luckily I noticed it before running the fuel into the header tank or > engine. > Draining the tanks and letting it re-cure also worked for me. > I now use Shell V Power 92 and test every load for ethanol with a simple > water absorption test > Works fine > Regards > Chris Gardiner > kR2S 230 hours VW2180 > > > Sent from my iPad > > On 2012-07-12, at 10:52 AM, "Sid Wood" <smw...@md.metrocast.net> wrote: > > > I remember Mark Langford saying that public confessions were good for the > > soul or something like that. That also makes it more difficult to get > > elected to political office. I am looking for neither of those concerns. > > I once recommended building fiber glass fuel tanks using Vinyl Ester > Resin. > > All sources that I could find did say that Vinyl Ester was compatible > with > > the Ethanol found in most automobile fuels today. Conversely, Epoxy was > not > > compatible with Ethanol. I built the wing tanks in my Diehl wing skins > > using Vinyl Ester Resin per the Diehl instructions. When I put in > 92-octane > > auto fuel containing 10 percent Ethanol, I got the same reaction as if > the > > tanks were made with Epoxy. Surfaces slowly started to dissolve, fuel > > turned yellowish brown and a sticky brown goo starting clogging the > sumps. > > I researched my sources on the internet and all still confirmed my > previous > > conclusion. Looking a little further on solvency chemistry, I found > > internet sites that address ways to enhance solvent action. Pure > Ethanol, > > gasoline and water are excellent solvents by themselves, but none of > these > > alone will effect cured Vinyl Ester. Adding 6 percent water to Ethanol > will > > produce a solvent that will slowly dissolve Vinyl Ester. So, how much > water > > would that actually be in auto fuel containing 10 percent Ethanol? The > math > > is easy: 10 percent of 6 percent is 0.6 percent. That's less than 1 > ounce > > per gallon. Where does the water come from? From the moisture in the > air, > > the Ethanol will readily adsorb the water in half full tanks, especially > if > > there is a vent like most aircraft tanks (like mine). > > I now have drained the tanks and left the caps off. After 2 weeks the > goo > > on the inside surfaces has "re-cured" hard just like the original. The > > quick-drains had become clogged and have been replaced. One concern is > the > > integrity of the tank walls; there is an imprint of the foam layer > > sandwiched between the inner and outer wing surface, top and bottom, that > > outlines the wing tanks. This imprint pattern appeared when the drying > out > > process was started. Any ideas what is going on with that? > > Long term plan now is to use 100LL. > > > > Sid Wood > > Tri-gear KR-2 N6242 > > Mechanicsville, MD, USA > > smw...@md.metrocast.net > > > > > > > > > > _______________________________________ > > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > > To UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > > please see other KRnet info at http://www.krnet.org/info.html > > _______________________________________ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html >
