Repainting wood sheds

I have three "lean to" wood sheds with paint bubbling in various spots. Latex paint the previous owner told me the sheds were put up in 2008 and that's the original latex paint. Doesn't look like it's been primed.

So I used a metal scraper and scarped all the loose and bubbling spots. Did that a few weeks ago. Then after some sun and rain, I found more loose paint. So far I have scraped it three times, and each time I scraped off the loose paint until I couldn't anymore, but a week later I noticed the edges that I previously scraped started to come loose. I thought once you get all the loose paint off I can wash off all debris, then prime then paint, but if more is becoming loose then I can keep going forever.

Here are some pictures.







Should I use a pressure washer instead?

Is it because I waited too long? I should scrap then wash and prime within a short time period?

Should I take a sander and sand the edges of the paint I scraped off?

When I do prime it, what would be a good primer on a partially painted wood surface? Would Benjamin Moore's Fresh Start be a good choice?

 

Dont know how it was preped originally but some how you need to get all that old paint off, pressure washer, scrape, sand, looks like a big job.

But when clean dont use paint , use a solid color stain, will work much better for outdoor wood!

 

I'd scrape again and then prime and paint it or use a solid latex stain. It is common for failing paint to keep failing after scraping if it's left exposed to the elements. The fresh coating generally stops the paint from peeling further. Ideally you'd remove all the paint first .... but they are just sheds.

 

I doubt I would be able to scrap all the paint off. That's impossible. I think if I really want them all off I would just get some new plywood and re-face them.

My goal was to scrap all everything loose then prime/paint. I was only doing stuff on some nights and weekends, several projects so I would scrap and come back a week later ready to prime, only I see more places I could scrap. I thought may be I wasn't very thorough the first time, so I did it again, and decided to wait another week. Same thing. If this is common and a new coat will prevent further peeling, good to know.

Why stain instead of paint? If there is still original latex paint there, plus a coat of primer, why stain? Wouldn't the stain need wood grains to achieve it's purpose?

 

The solid stain soaks into the wood vs pait which tends to sit on the surface. It's great for rough texture wood.

To date I have never had to scrape (nor do I think you could) any surface that was "painted" with solid stain.

 

OK but only if it's bare wood right? In this case I have old latex paint so I have to prime it with a primer. Would the stain still make sense if the stain is going on a primer?

 

An over simplification of what solid latex stain is - a thin paint. While it's best for all the existing paint to be removed it's acceptable to apply latex stain over small amounts of paint. Light colored solid stains over woods with a lot of tannin need a coat of oil base primer first. Personally, I'd either go with primer and house paint or just stain. Normally in central fla unless the paint job goes way to long before repainting - peeling isn't much of an issue.

 

Looking at what I have now I'd say I will have scraped off not more than 20% of the total old paint. So would solid stain still be a good choice in that case? If I could use a stain I only need to do one coat so that's only 50% of the work. But not sure how the stain would perform if I have this much old paint left, as well as these shed walls are 1X8 and there is caulk in between each plank as well. Some I dug out some I didn't.

 

With only 20% of the paint removed a solid stain wouldn't be a great choice .... and it would probably take 2 coats to make it look decent.