latex over oil base primer

[akuntz [OP]]

I built a small boot rack out of MDF and sprayed it with Rustouleum oil base primer. Is it safe to paint over it with a latex paint
Al

[Stephan in BC]

Did you end up trying it out? What happened?

[Kayak Jim]

Oil based primer used to be THE primer for unpainted wood, for topcoating with oil or latex.

[davezedlee]

Any paint can go over any primer

[stotto]

You may not get very good adhesion with latex over oil.

Oil over latex is no problem.

[Greg from K/W]

Any paint can go over any primer

Not true. I will show you 100 paints that can't. Normal PVA latex cannot Acrylic Latex can.

[Julian]

So sorry.
This is an annoying post and the answers are not helpful whatsoever.
The OP asks a simple question and every one waffles on with a bunch of simplistic data or irrelevant info that does nothing to inform the answer or educate the reader.
That is not the purpose of this forum.

Nothing wrong with his question.
Painting however is a technical issue and must be addressed from a technical viewpoint if good (and helpful) results are intended.

Let me give you a quick overview.

First of all....no "latex" that I know of is really a good idea to be used on a boot rack...as a generic category of coating "they" are not very abrasion resistant and do not like prolonged or repetitive contact with water......that means that while you may be able to use it....its probably not a good choice if you want the paint to standup to usage for any length of time.

2ndly.....READ THE DATA SHEET....for the primer and also for the proposed topcoat...that is your first step....this is your best (and standard) source for factual information about what the paints can tolerate. If you do not have the data sheet ....then down load it and read it carefully ....it should tell you what you need to know and it is the definitive and standard recourse ....that's why manufacturers make them and why they are called "Data Sheets".....because they contain data!

Now, the OP does not tell us what primer he is using (other than it is Rustoleum...which is a brand, not a specific type.....and Rustoleum make more then one "oil primer"....and they are not in fact all the same and they have different uses and characteristics.......which is why they name them differently eh.
Nor does he tell us what "latex" he is using...........well, SW for example make 38 different "latex paints"...ranging from cheap and nasty flat garbage latex to high performance acrylics or urethane modified versions....some dry quick, some dry hard, some have tremendous adhesion, some stand up to UV, scrubbing, children or abrasion, some are simply cheap rubbish designed to fill a spurious niche in the market. (None that I know of say "good for boot racks" by the way....and I am in the coating business)

So actually.....insufficient info has been provided right off the bat to make a really useful reply.

One can however generalize (if you have an actual understanding of the technology involved......and I do not mean "guess" or "provide fatuous opinion" that does nothing to further the information).

It can be factually stated that "many oil primers ,when fully cured can accept a waterbased topcoat"....and this is true...but the end user better understand what "fully cured" means (hint..it does NOT simply mean "dry")....and much depends on what topcoat he is intending to apply.

To further complicate the matter "latex" is a poorly understood term that has come to mean " any water borne coating or an emulsion (British term) ....of PVA (poly vinyl acrylic) or acrylic."
There are HUGE differences between the two....don't mistake a cheap PVA product for a modern high-tech acrylic.
"Latex is NOT Acrylic Latex"....they are very different in terms of performance

Its sort of like saying.
"I want cheese on my toast!".....OK, will that be Kraft slices, aged Stilton or Camembert?
Or "I want a car"......that's nice ..will that be a 2004 Ford or a 2019 BMW?
See what I mean.
Not simple eh.

OK...I digress, back to to the original question.

The answer is: ..there is a high probability that you can apply your unspecified waterbased topcoat over the fully cured oil primer....but you would be better served to apply an oil paint or a waterbased epoxy as they will stand up far better for longer.

Caveat emptor.

Good luck.
Julian