Painting problem

[billozz]

I have decided to try to renovate my internal doors which I've shown a pic of. I sanded them down and was advised that if I painted with 2 coats of satin wood paint it wasn't necessary to use undercoat?
I went for a water based paint because it dries quite quickly (5 hrs rather than quite a bit longer for oil based paint) but I'm getting yellow streaks showing through even though I've put 3 coats on one of the doors, is this because I didn't undercoat it should I have used oil based paint and put up with the lengthy drying time.
Really appreciate any help.
Btw I'm painting the doors white.

 

[Wayners]

Always use an undercoat for the adhesion and opacity.

I'd of used zinsser BIN one coat and don't worry about opacity. it don't have much but will stick really well. One waterbased undercoat. Two top coats of satin.

Other option if you want to use waterbased paint only, is to use something like bullseye 123 waterbased undercoat. Two coats or satin

 

[billozz]

Thanks for the reply, so does that mean sanding then all down again and basically starting again with undercoat and then to coat?
When you say use zissner bin does that do away with the need for an undercoat? And what do you mean " don't worry about opacity" ?

 

[Wayners]

BIN won't make the surface very white with good coverage unless you apply multiple coats so just go with the one coat. Then use an undercoat to to kill the background colour and make a good surface that's all white.
BIN will stick really well through, so use as an adhesion primer.
Can you get paint off and start again or just sand and undercoat? You can only decide that based on testing and effort your willing to give it.

 

[billozz]

I looked at the different ones available and thought that bullseye 123 would be good as it's a primer sealer and stain blocker, it's ok but I've put 3 coats on each door now and although it's improving I can still see the colour of the door in places. I've attached a pic I have no idea what I'm doing wrong, saved a fortune not replacing the doors but it's costing me loads in paint hope you can see what I mean, really appreciate y your replies

 

[billozz]

I would just add that I am using a roller, I've tried both foam and the other type of it possible I'm rolling too much?

 

[Wayners]

Bullseye 123 is not a good stain blocker. Says it is but you need to read up on what it's good for. It's more for older aged stains . I think you are getting staining coming through. Bullseye 123+ or zinsser BIN aqua would work better but I'd definitely coat with BIN to kill any staining for a sure thing

 

[billozz]

Any idea what could be causing the staining?

 

[Wayners]

Wood colour staining through I guess.