Painting wall, rainbow brush strokes

[DiyNutJob]

I need to paint walls and came across this video where the guy is using rainbow brush strokes. Can anyone explain why? I painted walls in the past using vertical brush strokes and the result wasn't satisfactory. Although at the time I knew nothing about maintaining a wet edge. With the summer temperatures, it would be rather difficult to keep the edge wet. Is it better to paint in the winter?

I have not used a roller before and a bit intimidated by it. I imaging splattering the paint everywhere, wasting a lot of paint, and a big job for cleaning the roller. Am I unnecessarily scaring myself silly?

Any views on taking radiator off to paint behind it, is this a thing people do?

 

[Wayners]

Brush and finish with mini roller tight to edge around all the room wall edges.
Then roller the entire room 2 coats.

Better to take rad off but that depends if you're confident to do so

 

[foxhole]

If there is any “give” in the radiator pipes you can loosen them slightly at valve to rad nut and then lift them of the wall enough to clear brackets and lay them forwards gently onto a brick or pile of books for support . Tighten nuts to prevent any weeping while you decorate .
Essential to isolated both valves and release any pressure in rad via bleed screw before attempting this .
Consider paint rollers as disposable though there are a number of easy cleaning methods .
Adding a cup of water to a tin of paint helps it roller easily without it skidding across the surface , splashing is down to the speed you move the roller, slow is best .
Some like paint pads , I have found them good over wood chip wall paper .

 

[DiyNutJob]

Cutting in on the edges is a given. I would do that even if I brush it. Is there absolutely no hope for using a brush? One of the commenters for the above video said he did a big job for a hospital. He rolled on the paint, then brushed it. Why would some jobs demand brushing?

The radiators have 6 inch pipes coming up from the floor with the T mid-line into the radiators at 7 inches . Taking them off should be do-able. Was just curious if people did that because in videos, they don't do that.

 

[foxhole]

Cutting in on the edges is a given. I would do that even if I brush it. Is there absolutely no hope for using a brush? One of the commenters for the above video said he did a big job for a hospital. He rolled on the paint, then brushed it. Why would some jobs demand brushing?

The radiators have 6 inch pipes coming up from the floor with the T mid-line into the radiators at 7 inches . Taking them off should be do-able. Was just curious if people did that because in videos, they don't do that.

Depends how thorough you are , painting behind rads is not essential, but I would do it if the room had not seen paint for a few years.

 

[DiyNutJob]

OK, found my set up: 4 inch brush, bucket, and water. Normal sized bucket helped with quick paint mixing with water using large brush to get the right consistency. I was already using water with interior wood paint. But, I didn't make the connection between water and wall paint until this thread. The wet edge problem was solved because I could use as much water as I wanted. The paint consistency that produced less brush drag was creamy to watery. I didn't bother with rainbow brush strokes, and mainly used vertical storks. The finish was smooth and good.

Brush would be slower than roller, but OK for doing walls one at a time. Brush cleaning wasn't a problem since the paint was already quite watery. So, there was not much to clean.