Oil paint

[whatsreallygoingon]

I used some OB1 last weekend where I had some cracks between windowsill and wall (and did quite well with the application, given it was my first time as a homeowner. Pat on the back for me!)

I, potentially foolishly, painted over it with oil based paint. I did this because the sill's are painted in oil, but I'm still not sure it was a wise move.

72 hours on - the paint still hasn't dried/cured correctly. Certain bits are sticky to touch and do leave a little bit on my finger, if I touch.

Is this just going to need some patience - don't touch and check in a week, for example? or have I completely messed up here?

It was two coats (again, maybe overkill) and, as someone not experienced with painting, I may have applied a little thick - for context.

Thanks!

 

[opps]

The paint will "never" dry. Just hit it with water based primer. Then recoat with oil based paint.

OB1 is a MS polymer. I have painted MS polymers a year after they were applied. The oil based paint would still not cure. I do not understand the chemical reaction.

I have come across a brand which required two coats of water based primer (from memory the product was called the Dogs *******s- or something like that).

Don't worry about the fact that the oil based paint is still slightly tacky. The above definitely works. I am a decorator.

 

[whatsreallygoingon]

The paint will "never" dry. Just hit it with water based primer. Then recoat with oil based paint.

OB1 is a MS polymer. I have painted MS polymers a year after they were applied. The oil based paint would still not cure. I do not understand the chemical reaction.

I have come across a brand which required two coats of water based primer (from memory the product was called the Dogs *******s- or something like that).

Don't worry about the fact that the oil based paint is still slightly tacky. The above definitely works. I am a decorator.

Cheers. Two questions, if I may (one of which is likely stupid, so please accept my apology!)

1) any particular water based primer you'd recommend? I do actually have a 'Leyland acrylic primer undercoat', if that would do the job? (this one)

2) after applying the above - would there be any benefit to using a water based paint over that, or should I just stick with oil, given where I'm up to?

 

[opps]

Cheers. Two questions, if I may (one of which is likely stupid, so please accept my apology!)

1) any particular water based primer you'd recommend? I do actually have a 'Leyland acrylic primer undercoat', if that would do the job? (this one)

2) after applying the above - would there be any benefit to using a water based paint over that, or should I just stick with oil, given where I'm up to?

That is my go to waterbased primer/undercoat. I found it when I used to specialise in painting (raw) MDF cabinets. It was the only one that I could sand flat without clogging my abrasives. It is not particularly good at obliterating dark colours, but that never bothered me because I let the oil based coats do the "heavy lifting" colour wise. Oil based paints in dark rooms will yellow. Water based paints are far, far less likely to. Many water based paints become soft over time because of the oils in our skin, so much so that a year down the line the areas of high (hand) contact will not pass the fingernail test. Additionally, many, but not all, will leave black marks when they come into contact with ferrous materials. A regular customer once asked me to use waterbased eggshell on a window sill in his hallway. I tried, and failed, to nudge him towards oil based eggshell. After a week or two he noticed that when he put his keys and loose change on the sill, it/they would leave dark marks. "Copper" coins now have iron in them. He got me to repaint it with oil based eggshell.

It is also worth noting that some waterbased paints when applied over recently applied oil based undercoats will "fisheye"- I have first hand experience of Farrow and Ball water based eggshell doing that four days after I have painted the the oil based paint on and around the door architraves and windows. I applied the F&B, it pulled away from the oil based paint. Dulux Trade emulsion is normally ok after a day or so.

Personally, I prefer oil based finish coats, I find they are superior with regards to both durability and levelling (minimum brush mark/tramlines). Many of the other decorators here prefer using waterbased finishes though- horses for courses.