Mogas

[BH1166]

Anyone have any issues they can directly correlate Mogas use concerning the tank/paint issues? Two builder/ friends have some quarter size paint blisters over a few random rivets. One runs 100ll in one tank , mogas in other...only Mogas tanks has a few blisters. Blisters are not fluid filled . One plane, RV 4 ,10+ years old, other 6 year old RV 3.

Thanks

[Larry DeCamp]

MR STEWART, at Kosh told me years ago that auto fuel has injector cleaners in the recipe that 100LL does not. That is why my paint peeled off when the primer was accessible due to lack of protection ( read rivets, edge of surfaces ) from the 2k finish system whether urethane or acrylic.

So, the question to investigate is how robust is the primer ? Is there a difference between epoxy vs self etching vs other ?

[alcladrv]

I run 91UL in my -7A on occasion. When I had a leaky fuel drain, the occasional drip of fuel would land on the gear leg fairing painted with Acry-Glo. Over a period of a few months the mogas discolored the paint. Then one time, the drain didn't seal because of some crud in the tank and within a week, the paint looked so bad on the gear leg fairing that it had to be re-painted

[swisseagle]

Originally Posted by BH1166

Anyone have any issues they can directly correlate Mogas use concerning the tank/paint issues? Two builder/ friends have some quarter size paint blisters over a few random rivets. One runs 100ll in one tank , mogas in other...only Mogas tanks has a few blisters. Blisters are not fluid filled . One plane, RV 4 ,10+ years old, other 6 year old RV 3.

Thanks

Normally you get blister on QB kits, because in the past they where not following the industrial standards, covering each seam at least 1/2" into the material.

[RV8Squaz]

Blisters have occurred on tanks with MOGAS or 100LL, QB or standard build, freshly painted or flown for 5 years without, g’s or no g’s, grass or no grass, nose wheel or tail dragger, primer or no primer, and glass panel or steam gauge panel. No one has solved the mystery!

[sailvi767]

When shopping years ago for a RV6/7 I did look at one aircraft that had at least a dozen blisters on the tank using auto fuel and none on the 100LL side. He ran the highest quality auto fuel available. This thread makes me wonder if the higher quality auto fuel which normally has more additives could be at fault.

[lr172]

Originally Posted by sailvi767

When shopping years ago for a RV6/7 I did look at one aircraft that had at least a dozen blisters on the tank using auto fuel and none on the 100LL side. He ran the highest quality auto fuel available. This thread makes me wonder if the higher quality auto fuel which normally has more additives could be at fault.

It is quite debatable that auto fuel is better. However, the additive packages are very different and it's not surprising that there are additives in the auto fuel that can either break down the proseal or simply allow migration past compromised sealing that the 100LL additives cannot.

[DeeCee 57]

my 2005 ride has been running AVGAS on one, and MOGAS on the other tank, for the whole time. Neither leaks nor blisters

[abwaldal@gmail.com]

I have been running Costco premium for the last 3 years in my 19 year old tanks, and had zero problems in my RV-6A. I have a 110 gallon tank/transfer situation in my truck so works great. But no blisters anywhere.
Art