Old school stain block

[michealangelo]

Oil based undercoat best , if you have the time

Zinser Cover Stain ....3 hour dry ....but not a 100 percent stain blocker

Next up oil based spray can .....quicker dry

Zinser Bin Red .....I find it too thin

I don't think the newer water based ones are good stain blockers

 

[Wayners]

Zinsser BIN maybe thin but one coat and all good. The go to for water stains.
Can't be used outside.

Coverstain is very good but needs 12 plus hours to fully work I've found. On some surfaces it needs 7 days to fully cure. Can denib it with 320 grade sandpaper unlike BIN so a good high build.
Coverstain can be used outside and probably the best primer for exterior wood.

Bin aqua is also good where the smell is an issue but I've heard it can fail. Might be user error though. No strong smells and great opacity. I use it now as an adhesion primer.

Aluminium primer is amazing but can take 3 plus days to cure. Very gray though.

Standard oil based undercoat used to be good over water stains back in the 90s but not now, although years since I've used it.

Johnstons stainaway emulsion has worked well for me over nicotine and water stains. Leave for 12 hours between coats though.

 

[michealangelo]

Cheers

I am doing some of my own tests on spare walls in a house I have just moved into

I found wickes oil undercoat and zinser coverstain on water stains from an old leaking window very good .....but needed two coats ...and of course that means delay

I really like Crown PX4 as an adhesion primer and it's got good cover so might try that over Bin red

Now Crown PX4 is around I don't see Zinser blue 123 being of much use to me

Zinser Bin Aqua and Zinser 123 Plus seems a bit pricey compared to Crown PX4 ?

 

[Wayners]

Stick with acrilic primer over BIN.
Sticking something like PX4 over BIN can cause a reaction. It's an unknown and the chemicals can react.
You can always test first but I don't see any point in it. Just wasting a quality product.

 

[michealangelo]

I have been away from the trade a long time lol

I have just coated a few different stains ....tea , permanent marker , gloss brush marks ....so very obvious shiny ....and some margarine from the fridge all of which have been there for 2 days and have left obvious stains

Those I am testing are Bin red , Zinser Cover Stain, Wickes stain block undercoat , Zinser bullseye 123 , Crown PX4 , Bedec All Prime

I already know oil based thinned slightly is good on water stains and Zinser bullseye 123 isn't....in fact I have tried most stains and it fails .....but it's a good sort of acrylic undercoat ?

I am almost certain Bin Red X2 if necessary followed by acrylic for opacity and coverage like you suggest is going to be the best all round approach