Mr TP says just leave the foam on.
He has also forced me to drink too much wine (so sorry for tyos) annd he told me this story:
in 19992 on a Lang building site (I can't tell you know more to protect the guilty).
A New plumber started on 2nd fix Mr TP showed him the site and said they meet at lunch time in plot 42 if he wanted a break or he could carry on working.
New plumber said he hadn't worked on new build site for a long time. Mr TP assured him that 2 second fixes a week were possible once he had a routine.
At lunch Mr TP dropped by to the new guy, to see how he was getting on.
New Guy, " I haven't got much done."
Why?
New Guy, "It has taken all morning to get the packing of the cylinder."
Mr TP? "What Packing?"
New Guy, "The Yellow stufff."
Mr TP laughed, " I like your sense of humour, we are going to get on."
No kidding.
Mr TP went with him and half the insulation off the cylinder had been stripped.
Mr TP
Really!
This is so funny we are laughing now.
Mr TP went and told all the p;umbers at lunch and they thought he was joking!
All cylinder s had foam insulation for about 7 years by this time but Mr TP and I are old enough to remember days when the copper cylinders were bare!