Painting over old oil based gloss

[Nik2879]

After some advice please. We have old oil based gloss on all the wood work in the hallway it was done before we moved in. Its now starting to discolour looks more cream now not white.
I want to paint over it only white again but know going over oil based with water based paint can be tricky. When I google it loads of videos come up of people completely stripping the old paint off and it taking days just to do that. Has anyone got experience of just sanding it down instead. Havent got time to trying and get it all off completely.
Would really appreciate any advice. Thanks.

We’ve been painting over oil based since we bought this house 10 years ago, using water based satin wood. No issues whatsoever.

If the paint is sound and not flaking I would wash with sugar soap then apply an undercoat of Zinsser B.I.N. It's not cheap but works brilliantly and you can undercoat and gloss on top.

Just paint oil based products on top…its only a problem if you want a water based products on top

We just do it anyway and it seems fine. As above been here for years.

Bedec acrylic paints over everything! We've used it all over so far!

Was just coming on to recommend Zinsser BIN also. Great stuff for a reset.

I put water based paint over oil based paint on all the woodwork in my house with no problems. Used Zinsser perma white which is great but rubs off on high wear areas like banisters after a few months.
Whoever invents a white paint with the qualities of oil paint but which doesn't go yellow is going to make millions.

Use sugar soap to clean off any grease, lightly sand to give the new paint something to bind onto and you should be OK.

It won't last as long as it would if you stripped all the old paint off and went down to bare wood tho'.

Used Zinsser perma white which is great but rubs off on high wear areas like banisters after a few months.

Yes we had this issue with water based over oil based on our banister. On the bits that got touched a lot (tops of newel posts) eventually the water based wore off leaving the oil based showing.

I’m not sure what the fix is but would imagine thorough sanding to key the old paint and/or some kind of primer.

if the paint is VERY old, be careful about sanding, there could be lead in it. Either use a different method, or mask and glove up when sanding and sand as little as you can get away with, just enough to get a 'key' for an undercoat.
Other than that, if it's glossy but flat, I'd sand lightly by hand, and then either spirit-based undercoat and spirit based topcoat, or acrylic primer/undercoat and water based topcoat. If the first layer isn't sticking, or is not spreading out evenly but acting like water on an oily surface, sand a bit more. If it is full of runs from previous poor paint jobs, I'd get a good power sander on it; I use one with fairly large circular discs, saves time and effort and my knees, as it's much faster, and largish disc helps get the job nice and flat. Always use a mask when sanding,and the best electric ones have an extraction system that you can fit to a hoover if you have a Henry or similar.That saves an awful lot of dust getting about. The one I have gives out next to no dust at all with the Henry on it.