Only twenty-one overs were possible on another rain-hit day but that was sufficient for the Irish to move towards a first innings lead.
Resuming on 35-0, William Porterfield and Paul Stirling had added another 14 runs before the Scots got their only success of the second day. Home captain Porterfield had made fluent 30 with six boundaries when he was trapped in front by Yorkshire's Iain Wardlaw. Paul Stirling, though, joined by John Anderson, guided Ireland to 99-1 - just 39 runs behind Scotland's poor first innings tally - before rain set in.
Middlesex one-day specialist Stirling proved he also has the temperament and technique for the longer game by moving to a patient half-century. His effort came from 73 deliveries, included eight boundaries and allowed Anderson to play second fiddle with a pain-staking 46-ball 17 as the Scottish bowlers exercised a degree of control.
The time lost from the match has at least increased Scotland's hopes of escaping with a draw but, with two days remaining, the Irish, already through to the I-Cup final, will be confident of establishing a substantial first innings lead and bowling their rivals out for a second time.
Meanwhile, there was a little more joy for Scotland's Development XI who restricted Gloucestershire's second string to 165-9 in their second innings at Bristol. The county had rattled-up 365-7 in their first knock before dismissing the Scots for 176.
Debutant Ryan Brown of Largo was the pick of the bowlers with 3-19, matching fellow new boy Chris Sole's haul in the first innings.