2-ethanediol and Proseal

[bobmarkert]

Cliff note question.

Does 2-ethanediol react with proseal and will it soften it over time?

Will it screw up paint?

The saga
I think I outsmarted myself?.. Tanks built, time to test them. I hooked up a Vans test kit, used the manometer method and pressurized the tanks to 1 psi. I grabbed this



and found this



I used a camera to locate the offending area





I shaped a thin dowel wrapped the tip with a paper towel and used MEK to clean the area. I then used the bare dowel to apply proseal through the fuel filler opening to the offending area; Luckily I plan my leak locations well??



next brilliant idea,?. I?ll pressurize the tank to 1 psi to force the proseal into the gaps. Success, kinda. The tank held pressure for about 30 minutes then began to leak. I found this (you can see the hole in the corner)



the pressure did not force the proseal into the gap, it made a hole in the new proseal. I repaired that and will now let the proseal set up a few days while I go fly a trip.

Here are my concerns:

1) When I was applying the proseal I noticed some of the leak detect fluid had weeped inside the tank. I put enough on to ?burry it? and the tank holds pressure.

2) From a test I?m doing it appears that 2-ethanediol does not evaporate, or at least not quickly (a test patch on scrap aluminum overnight).

3.) I believe a lot of 2-ethanediol weeped up against the proseal along the entire back baffle. Will this react with the ?good? prosealed areas and possibly cause leaks in the future? This is especially bothering as this stuff does not appear to evaporate quickly.

Lesson learned on this ?. Use soapy water for the test?.. I battle building an experimental airplane and experimenting and following Vans directions like a drone ant. In this case Vans directions would reduce the level of stomach acid burned.... use soapy water!

Off to Korea

[Ted Johns]

2-ethanediol is another name for ethylene glycol. Yup, the main ingredient in antifreeze. I don't believe it will hurt cured proseal, but I wouldn't expect freshly applied proseal to form a good bond to a surface coated with it.

[bobmarkert]

Im hoping the cleaning I did with MEK will be enough to let the proseal bond to the existing cured seal and the surrounding metal. I'll know in a week when it sets up some and I test it.
Bob

[rv7charlie]

If you don't have good luck with the MEK, try toluene; it's the solvent in 'proseal'.

When I fixed a leak in a back corner (I used a compatible pourable product from Flamemaster), I discovered that I couldn't leave the pressure on for very long at all (just a few seconds, if memory serves). If I left it longer, it would 'blow a hole' through the new sealant & I'd still have the leak. Realistically, if you can get to it to fully coat the corner, do you really need to pressurize & push it into the joint?. The proseal is pretty rugged stuff. Spanning a gap of a few thousandths of an inch shouldn't be a problem.

FWIW, Charlie