What are the yellow spot that came through the wood after I put two coats of paint on deck. All of sudden there they were
It's sap from the wood around the knots. That happens all the time if you don't use a primer first. You need to sand those areas at least and prime then paint. Should always use primer before you paint.
And a stain blocking primer at that.
Cheap primer won’t work.
These videos will give you some information to help you on this project! Good luck.
Probably wood resin bleeding through, especially if you have knots, use a stain blocking primer like Kilz first.
Hi Diane, here is another link for you to check out