I see scrim is pretty new in the usa, here in the uk we have been using it for years so here is the correct way to get the best out of scrim!
HOW TO USE SCRIM
The endless comparisons between scrim and microfibre continue to rumble on, with no sign of a conclusion.
One thing which strikes me, though, is that very few people seem to know how to use scrim. Time and again I see references to using “20 or more a day” (well, perhaps not quite that many!). I have been using scrim for 10 years, and rarely possess more than one or two at a time, and NEVER use more than one on any single day.
If you use a scrim for “detailing” edges of squeegeed glass, and for polishing small panes/leaded glass etc.(otherwise known as “ragging”) then you will not need more than one a day. Mopping sills, wiping excess water off frames before squeegeeing, wiping your squeegee blade should all be done with a separate “wet” or “sill” cloth, which you wring out regularly. Doing it this way you will only ever need to carry two cloths with you.
Before using a scrim it needs to be washed out, then wrung out to just the right “dampness” content. To achieve this take hold of opposite corners of the scrim, stretch it out and then “spin” it into a rope. Put the two ends together to halve its length, then the same again. The scrim can now be twisted very tightly, leaving no loose fibres within itself to retain water. As you wring it as tightly as you can, water will firstly run, then drip off the scrim. When you can no longer make water drip, you will see that there is still loose water rising to the surface of the scrim when you really twist hard. Holding the scrim tightly to prevent the surface water retreating back into the fabric, “throw” the water off by bringing the scrim down sharply towards the ground, then stopping dead. You will see water being shaken off the scrim onto the ground. You will create a sizeable puddle from what you had thought to be a well wrung scrim!
Unravelling the scrim can be difficult after this treatment, and this is why “old school” w/c’s crack them like a whip. One good crack and the scrim will unravel easily. The scrim is now in perfect condition to polish, detail - even clean your glasses! During the day the scrim will tend to dry out (NOT get wet!!!) and you will need to dunk it in your bucket and repeat as above.
GOLDEN RULE: Scrim is for polishing, sill cloth for wet wiping - don’t mix them up!!
Ps this comes from a uk forum member! hope you guys find this useful!