I think I may have found the cause of the shrinkage cracks in my finish coats. I normally buy my kiln dried sand from B&Q. It's very fine and flows nicely for the block paving. Having ran out and passing by another B&Q elsewhere I decided to pick up a few bags. These were still sold as kiln dried sand (similar bags) but the contents had a wider range of particle sizes, making it quite gritty.
Having just finished two walls - one with old sand and one with new there is a clear difference in the amount of shrinkage cracks appearing the next day. The grittier sand has virtually no cracks which need to be pushed in but the old sand causes localised crazing which need constant compression over a couple of days before they stop shrinking further.
Anyone else found similar results with the sand they use?, anyone advise a good brand of kiln dried sand? (Hanson's available at the local merchants)
Having just finished two walls - one with old sand and one with new there is a clear difference in the amount of shrinkage cracks appearing the next day. The grittier sand has virtually no cracks which need to be pushed in but the old sand causes localised crazing which need constant compression over a couple of days before they stop shrinking further.
Anyone else found similar results with the sand they use?, anyone advise a good brand of kiln dried sand? (Hanson's available at the local merchants)