Repainting the exterior of a wood sided house. Old paint is blistering in many places, still tight in others. Told the painter to scrape the loose stuff, then sand to smooth the edges and see if anything else loosens, then apply an exterior primer and paint. He called, said he wants to use a block filler primer, cuz it will fill the tiny holes and make the old paint-to-bare wood transition smoother. Says otherwise he will have to sand the entire house to bare wood to get a smooth finish.
I thought block filler primer was only for concrete blocks and similar. Is he trying to do a shortcut?
Do it right, or do it twice.
Replies
I would contact the manufacturer of the primer to see if it can be used in this way. If you have a problem and the primer was applied on an improper substrate, you won't have any warranty recourse. My guess is that these primers shouldn't be used on wood, which moves a lot more than masonry does, especially if it's lap siding.
Bottom line - if the painter agreed to do the way you want, he/she should do it that way.
I read the instructions on the can of block primer, and it does not list wood as a suitable material. All it says is that it's good for several types of concrete & masonry.
Do it right, or do it twice.
I wouldn't use it then - imagine the problems you'll face if this stuff is falling off in two years.