Help! Paint streaky / patchy (Wagner paint sprayer)

[claire_diy]

Hello everyone

I had a builder install new walls and ceilings as old walls and ceilings were lath and plaster, and really cold. The builder installed the plasterboard but I wanted to try to paint it as I bought a paint sprayer last year to repaint my shed.

I bought this paint from Screwfix: https://www.screwfix.com/p/leyland-trade-contract-10ltr-mercury-grey-matt-emulsion-paint/422pj

I am new to using it but in the FAQ on the webpage, someone called Leyland expert said all of Leyland emulsion paint could be applied direct and it is not recommended to do a mist coat. So I sprayed it using the sprayer but it looks terrible and I’m not sure why and how to fix it.

 

[Wayners]

Airless sprayer?
If Hvlp isn't very good on large areas as you need a bigger tip and thin the paint alot. Also slow going

 

[claire_diy]

Hi Wayners

There are 2 tips which come with it - there is a 311 and a 517 tip. I used the 517 tip which a video I watched said I should use for wall paint.

I didn’t thin the paint though. How much should I thin it? The paint is 10L, would it be good to use 5L and thin it 50%?

 

[Wayners]

517 tip.
About 15% water. You can weigh paint to get ratio.
Cross hatch spray. Might help Vs just got one way.
I don't know how well that paint sprays though.

If you can't adjust pressure on machine you need to adjust the amount of water in paint.