ProSeal longevity

[McFly]

File this in your FWIW folder.

A couple of weeks ago I mounted my data plate under the tail. I wanted a barrier between the two naked surfaces that would be more durable than paint. I had RTV and very old ProSeal (Circa 11/2002) on hand, I went with the ProSeal. After a couple of weeks it had set up in a fairly cold environment (temp cycles of 40-60). It may have set up earlier but to be honest, I forgot about it.

My ProSeal had been stored in a semi environmentally controlled area for all four years. The catalyst was harder than the peanut butter consistency when it was new. The ProSeal itself had some slight separation but not much. I did not use a scale to do the 10:1 ratio but rather I just used my eyeball and I purposely used a little more catalyst, so my observation is less than scientific.

I certainly would not use old ProSeal for tanks but it is still useful as a sealant and as an adheasive for non critical applications, years after the expiration date has expired.