Keystones blowing out of a pin

[TheFlatulentCow]

With the only plastic cask we have I've been using the shives from Barley Bottom and never had an issue. Email them and mention the issue I'm sure they can help.

[Martin G]

Also worth considering forced ferment test so you know where you are in relation to final gravity before casking.

[asd]

i just realised i made a typo in my original post, i didn't mean to put ~2 degrees i meant ~20 degrees, basically room temperature. After doing a bit of searching around, it seems like im storing the cask too warm. This is my normal schedule:

1. Wait for a stable FG for 48 hours
2. Crash to 5 degrees for 2 days
3. Rack and prime at 5 degrees
4. Let the cask come back up to room temp ~20 degrees

I assumed storing it cool would mean the priming sugar wouldn't be eaten up by the residual yeast and therefore wouldnt carbonate, so i thought id bring it into a good temp for the yeast to eat it up, and clean up some of the by-products of primary fermentation. Am i wrong?

I don't see why you'd want to bring the temp back up to 20 degrees. Any clearing up by yeast should be done prior to the crashing. Bringing the temp up to 20 degrees will cause a lot of the CO2 to come out of solution, and build up pressure, plus it will generate more CO2 from the priming sugar - the amount of which is high, anyway -plus I think that the plastic casks are "softer" than steel, so more likely to pop a shive or keystone. Also, I seem to recall that there were machining issues about 18 months ago which caused problems with the fit of the shives, or was it the keystones? How many hammer blows does it take to drive the shive and keystone home?

The fact that all your other containers have no problem gives a clue, though. I guess the steel casks are able to grip the fittings more tightly, and therefore have a greater margin of error with regard to pressure. I'm sure if you drop the priming so as to give a more modest carbonation, and don't warm them up to 20C, you won't have a problem.

[asd]

Id just like to add that the bottles are fine, no bottle rockets, which i thought may rule out over priming as i add the same amount of sugar per volume to them as i do with the pins.

Ahhh.. The carbonation requirements in a bottle are quite different to a cask...... Casks need a lot less, you only want to have about 1 volume of CO2 at 12-13C in a cask.

[asd]

Im priming enough to give 2.3 volumes of co2, do you think this is the problem?

thanks for the advice so far by the way guys

Yes, that is the problem! You need about 1 volume for casks.