Ethanol and Proseal

Morning all,

Preparing myself for the innevitable addition of ETOH into Oregon's road fuel in January.

I have not worked through all the issues yet but one potential stumbling block was a fellow who claimed to have dropped soem hard proseal into some ethanol laced gas (10%) and it turned into a gooey mess after several months.

I seriously doubt it was a mogas issue...I mean 100LL is almost all mogas anyway so one can assume it must be an ethanol problem.

This is the first I had heard of this as I thought the new formulation of proseal was compatible with etoh.

Anyone shed any light here?

Thanks

Frank

Hey Frank,
That was my experiment I did last fall. I live up here in central washington and from what I've heard, am doomed to the same ethanol problem you are. In the experiment, the proseal didn't turn to a goo, just softened it more than the 100ll. During the last 6 months or so of building I left both tanks about half full of 92 oct. from the local shell station. I've noticed only 2 rivits so far that have started to leak. Recently I stuck a screwdriver (universal tool) down into the tank and pushed at some of the proseal and found it wasn't very hard to scrape it off the aluminum. Will ethanol work with proseal? My conclusion after the experiment (and now) was/is yes, but you better have done a dang good job sealing the inside of your tanks. Doesn't need to be pretty in there, goop that stuff on!

Leak Pix?

Joe,
Do you have pix of the leaking rivets? Where are they. Great idea - filling the tanks off wing!

I don't have any pictures, both leaks were in the left tank in areas that wern't absolutly plastered with proseal. As "pro auto fuel in airplanes" as I am... I'm burnin' 100ll for now.

I have been burning 92Oct

For about 9 months and have notice the slightest of bubbling under the paint over the heads of the rivets, mainly on warm days.

I can't put it down to being due to the mogas however. I have not been testing the fuel either. I believe so far it has all been ethanol free (bought from Chevron or 76 and I tested samples from both before I started using them).

Mine are prebuilt tanks. As I painted the tanks seperate from the wing it would be easy to remove them and repaint if I ever had to.

I have the website for Flamemaster so as soon as I get the product number off the can I'll call 'em and get their opinion.

Frank

When I was building the Velocity aircraft, I used a product called Jeffco 9700. I created some test batches and had them immersed in both Gas, Avgas, and Diesel for over 2 years without any changes to the test batches and the material underneath. From their website:

System SKU: sp9700-FCR
System Category: Specialty
DESCRIPTION:
Jeffco 9700-FCR is a high quality epoxy novolac coating system with chemical, high temperature, and abrasion resistance superior to Bis-A type epoxy resins. This tightly crosslinked system cures in the presence of moisture and humidity with excellent mechanical properties. It contains no solvents (100% solids, zero VOC) or carcinogens and has minimal odor and toxicity that assures ease of application. 9700FCR?s viscosity is well suited for vertical applications. Jeffco 9700FCR is typically stocked in gray and ships DOT non-corrosive.
APPLICATIONS:
- Tank Lining
- Secondary Containment Coating
- Floor Coatings

Is it a slosh or a proseal replacement?

BobK said:

When I was building the Velocity aircraft, I used a product called Jeffco 9700. I created some test batches and had them immersed in both Gas, Avgas, and Diesel for over 2 years without any changes to the test batches and the material underneath. From their website:

System SKU: sp9700-FCR
System Category: Specialty
DESCRIPTION:
Jeffco 9700-FCR is a high quality epoxy novolac coating system with chemical, high temperature, and abrasion resistance superior to Bis-A type epoxy resins. This tightly crosslinked system cures in the presence of moisture and humidity with excellent mechanical properties. It contains no solvents (100% solids, zero VOC) or carcinogens and has minimal odor and toxicity that assures ease of application. 9700FCR?s viscosity is well suited for vertical applications. Jeffco 9700FCR is typically stocked in gray and ships DOT non-corrosive.
APPLICATIONS:
- Tank Lining
- Secondary Containment Coating
- Floor Coatings

Click to expand...

Sounds interesting, but is it a direct replacement for proseal? From your post is sounds more like something you'd slosh the tanks with.

<<Sounds interesting, but is it a direct replacement for proseal? From your post is sounds more like something you'd slosh the tanks with.>>

FWIW

The product is a tank sealant. I have no knowledge of what proseal does, but from what I have read, it is used to seal the tank. Jeffco is an epoxy based product and is spread on. It is rather thick. In a velocity, with it being a fiberglass plane and very porous, those instructions said to use straight builder's epoxy, but it was unclear if that epoxy would handle diesel let alone auto fuel. You would use a spreader/scraper to spread this stuff. The kit maker now uses jeffco as part of their kit. After you spread Jeffco it dries to a hard gloss but not slippery surface, thus why they say it can be used on garage floors.

So if the primary reason is to seal the tank form leaking, this might be a good choice. I have heard that Jeffco also sells a structural coating, but I am not familiar with that.

Bob