primer for cedar siding repainting

[MinnJim]

Hi, I am repainting a 70+ year old cedar siding house. I have done a good job of scraping and cleaning up the loose paint and peeling areas. I don't know if the present paint job is oil base or latex. My question is how do I tell which one it is and what should be used for a primer on the bare spots. As you put primer on it will cover some of the existing paint along with the bare area. My understanding is that putting oil base over latex is a 'nono', so should I use latex primer and forget about determining what the existing paint is. My feeling is that oil base primer is best if I can use it!!! MinnJim

[MinnJim]

I will be repainting with a latex paint

[nailshooter41]

Why? For 100% compatibility, use oil. Never wonder if that flake, bubble or moldy spot is caused by a lack of adhesion. If you use oil and it does that, you would know it was bad prep. If it was latex on top of the old oil paint, I think you would always wonder...

Some of those old resins are nothign but hard plastic after 10 - 20 years of exposure.

A 70 year old house probably has 7 -10 coats of oil based paint on it now if it has been maintained, and you may not get much traction for your latex.

For me it has been 50/50. I buy the best latex I can get and use that when the owners don't want oil, and I am hitting about 80% with no problems. I always test a window trim or something like that though, and give it a couple of weeks or a month before I start. (They usually want test colors anyway on the house).

Good luck!

Robert