How much do you need to sand on Oil base paint before you can prime and paint with latex?

Question

My front door is wood and was originally painted with oil base paint. The previous home owners painted over it with fresh latex paint when they put the house on the market. but shortly after we moved in it all pealed off . I'd like to paint it again but I'm not sure how much I'm suppose to sand before I prime it.

Answer 1

sand to remove the sheen of the old oil finish and then wipe clean with a tack cloth.
Any chips should be sanded out to eliminate any rough edges.

Also, the improperly applied latex shoul dbe completely removed.


An oil primer over the old oil finish and then the latex will provide better grip into the old oil finish but can be avoided by proper sanding and cleaning.


DO NOT USE KILZ for this. The latex primer provides no benefit here and the oil base version is quick frying which means brittle which means it typically lasts less on front doors - particularly the exterior.

Latex on the exterior is FINE. In fact since oil is not what it used to be - latex will look better longer. Latex WILL adhere to oil if you sand and use a high grade latex.


80 or 100 grit paper will make your door look horrible !!! Use a very fine paper. You are looking to remove the sheen - that is all.

Stripping to bare wood is awesom eif you have the time, space and energy but it isnt required to have a good, long lasting finish here.

I like the fact that the oil is on the bare wood. But for best and long lasting color USE LATEX FINISH on the exterior. (unless we are talking about a bridge where we can stil bust out lead based paint!!)

Answer 2

Sanding Oil Based Paint

Answer 3

You will hate to hear this, but you are royally screwed. Do Again But now you have more work in front of you because you need to take off the paint that does not stick. However paint is not really hard until 72 hours. Proper Preparation matters, and you did not do any. So go buy a 2 1/2 inch steel flexible putty knife. Not the stiff ones. Also get a 4" spackle knife of the same flexible steel. These tools are more useful than the thick ones, Also you are going to need sandpaper around 80 grit Garnet and 100 Grit Garnet(orange) the tan colored flint stuff is garbage from the beginning. Now I have never had to do this (because I knew the job would become a JOB) So, I am shooting from the hip. But grab the putty knife by the blade and hold the edge against the wall so it is like your (fingernail against the wall) and pull the edge downward or sideways so you get a scrape on the wall. Paint comes off? You are doing it right. Use spackle knife the same way. They can also be used like a snow shovel but I have an idea the scrape method is the way to go. What can't be scraped off, will be attacked with the sandpaper later. If the paint is that loose you cannot prime it because the paint does not stick so the primer will be fastened to "air" and it all will come off. No use having a fit about it. You screwed up. See, there is more to painting than just grabbing a brush.

Answer 4

Remove all the new Latex, which should be easy, then Prime the door with Flat oil base Paint- you can then repaint with Oil or latex. High gloss does not look good, so use some Flat mixed in to dull the high gloss a bit.

Answer 5

Sand all the latex off and buy some enamel paint anything oil base and repaint you dont want to use latex paint outside thats bad news. If all the latex is removed just rough the door up with 100 or 80 grit and paint.

Answer 6

The purpose of sanding is to get the old paint and dirt off so that the primer can adhere properly. Therefore, only sand until the surface is free of most of the paint and it is smooth to the touch (if you can feel bumps that means that paint has clumped up in that area --be sure to smooth that out or it will be visable when you repaint)
It is essential that you primer the area as the door because as you have found out, latex paint doesn't adhere very well on oil painted surfaces.

Answer 7

Sand until all loose paint is off wipe clean I have always gotten good results using Gripper primmer this is a latex bonding primmer which bonds to anything including ceramic tile Home Depot sells it then I would use a good exterior latex semi-gloss

Answer 8

pritty much down to the door itself (the wood) or intil the glossy like finish is all sanded down or get a chemical called stripper. this chemical should peel that oilbased paint right off. do not use in a plastic bottle this chemical also slowly eats plastic. it may be found at any paint store. this stuff can be dangerous if not used in a proper area such as in a room with no ventalation.

Answer 9

Sand until the gloss is off and until any loose paint is gone. Then prime and paint.

Answer 10

Just sand it until you see the latex gone in most areas. Scuff along the areas that cant be removed or strip it and you then paint over it.