The Moerman probably isnāt the ideal starter squeegee, needs more pressure, more soap (more slip)ā¦ one reason I ditched it & to bootā¦ Iām not keen on their rubber that comes with it.
Start with a new rubber - always. Itās not worth even trying to get it to work & youāll lose so much time backwards & forwards to your work vehicle trying to figure it out. Work it out later when you have more time if need be.
Is your channel bent? Eye it from the end, just to make sure.
Make sure you have decent slip so the rubber glides, any lines shows you have a problem with the rubber, itās either got muck on it or a hair, or nicked (change it or flip it) & it needs cleaning with a sponge or cloth.
Straight pulling you need to remove the liquid behind the rubber. Some people use their finger, edge of rubber, a towel so that they can place the rubber in a short dry space on the window before pulling. Personally I tap the rubber on the glass, you need to get rid of the excess water behind the rubber before you pull the squeegee across.
Do not touch the any sides of the window, this will cause dragging/skipping or lines.
The reason you are getting more lines on the downstroke is because of the change of angle of the squeegee, look at how near the handle angle changes pulling left to right or up & down. Usually you hold the handle out more when pulling down as opposed to left to right.
Make sure youāre soap make-up gives you lots of slip. Put neat soap on your applicator then try it with your normal mix & see the difference. One reason GG4 is not liked by manyā¦ but with experience you learn to work with it.
Do not put too much pressure on the squeegee, beginners mistake, hold the handle with the same pressure you would to grip a 5 yr olds hand.
When you learn to fan, most of these issues go away.