Alternative to knotting liquid required...

[Jacob]

I'd blame the paint. Knotting has been in use for hundreds of years without being a problem.
Ronseal Weatherproof is water based apparently. I wouldn't touch it with a barge pole!
NB just one coat of Allback Linseed oil paint is just about dense enough to cover almost anything, two coats definitely.

I hear you on the paint. It was the best waterbased I could find. Oil based paint drives my Asthma into overdrive and the clean up on waterbased is much easier.

I suppose I just need to layer up until it has gone.

Sent from my MI 3W using Tapatalk

It's the solvents not the oil.
Another of the many advantages of linseed oil paints - no VOCs. To be realistic there must be a tiny trace of something as you can smell it, but no solvents and/or other VOCs. And you can clean up in soapy water, or leave brushes in oil for a very long time, if well covered.
I wouldn't be surprised if Linseed was good for asthma!

 

[rafezetter]

There's a trick used by scale model makers that might apply for some paints, if it looks like they don't seem to have enough pigment to give you opaque coverage - white and yellow are the two colours most prone to the base colour showing through. Obviously for scale models you can't just keep slapping it on or you'll lose the detail so they add just a few drops of black to the mix though obviously we are talking small volumes here. It hardly changes the colour, but gives enough opaqueness to block out the base.

Some people go as far as grading - from grey prime to 30/70 white grey - 50/50 grey white 70/30 white grey - then just the few drops at the end; this is where spraying really shines.

5 coats - primer, 2 undercoat, 2 topcoat isn't that big of a deal especially for outside wood.

 

[Jacob]

....
5 coats - primer, 2 undercoat, 2 topcoat isn't that big of a deal especially for outside wood.

Linseed paint you can get away with one coat oil followed by one of paint. But two is better. 20 years down the line and you might have 5 coats but it goes on thin so no problem.