How to know when you've scraped enough off

Reply

  #1  
Old 04-02-09, 01:32 PM
M
Member
Thread Starter
Join Date: Apr 2009
Posts: 3
Received 0 Votes on 0 Posts
How to know when you've scraped enough off

How do you tell if you've scraped enough paint off for surface prep? I can't tell if I'm over scraping or doing what's required.

I have a 1951 house. The paint is peeling in several places. Although it's not terrible (1 inch wide peeling every 10 feet or so), when it does peel it seems to alligator all the way down to the bare wood. It seems like the problem is that the bottom coat is the brittle oil based kind while the top layers are an elastic latex, and also the house needs gutters installed.

We've been scraping and it's moderately easy to scrape off a lot of paint. It's still hard work, but comes off in big chunks if you just get the knife under an edge. Probably 10% of it is on good and solid, the rest either comes off down to the wood, or down to the first really old layer of brittle oil paint. However, if I hadn't messed with it, it probably would have stayed put for a couple of years without an issue.

Sorry if this has been asked before. It's just not clear what an adequate job is.

Thanks!
 
  #2  
Old 04-02-09, 06:46 PM
M
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 47,918
Received 383 Votes on 339 Posts
Welcome to the forums!

It's always best to get off all you can but that isn't always cost effective. A new paint job [done correctly] over raw wood will always outlast a new paint job over existing paint. The new paint will help the old paint to last longer. Basically it boils done to how much time and energy you have to devote to the paint job.
 
  #3  
Old 04-03-09, 08:13 AM
B
Member
Join Date: Feb 2009
Location: Mass
Posts: 263
Received 0 Votes on 0 Posts
A paint contract would read "Remove all loose and scaling paint" which is what you should do. If it comes off easily with a knife, it isn't worth the effort of painting over it. Generally speaking when paint "alligators" or cracks across the grain it means the is too much paint on the wood and you should strip it off. You could try to lock it in with oil based products, but the cost of paint these days doesn't lend to taking a chance. I have a house that was built in 1895, owned by me for 31 years, and with all the failure symptoms possible in the evolution of paint, over the years I have changed the clapboards on one side at a time, the last side being done last summer. It was about a weeks work for me and $400 for the cedar clapboards, but the house looks new now, free of peeling paint.

Bill
 
  #4  
Old 04-03-09, 02:27 PM
M
Member
Thread Starter
Join Date: Apr 2009
Posts: 3
Received 0 Votes on 0 Posts
We've realized that, at some point in the past, parts of the paint were sanded and painted over, and that those areas are sticking acceptably. The ones that aren't, we're basically scraping down to bare wood and then will go through the whole sand/prime/paint drill from there.

We may end up replacing siding in the future, but our siding is rock hard cedar drop siding. It's hard to find in our area in a good quality wood (the stuff we've found is cheap pine). This project has exploded from "we'll just touch up a few spots" to "we'll be doing this for two months"

Thanks!
 
  #5  
Old 04-06-09, 10:25 AM
B
Member
Join Date: Feb 2009
Location: Mass
Posts: 263
Received 0 Votes on 0 Posts
Just pick the smallest area to start and complete, get your system figured out, and the job will likely move along smoother and faster than anticipated.

Bill
 
  #6  
Old 04-07-09, 12:27 PM
S
Member
Join Date: Mar 2008
Location: Livonia, Michigan
Posts: 203
Received 0 Votes on 0 Posts
mags77,

You need to be aware that the 1951 paint could very well have lead in it.

Use the proper personal protection to avoid breathing the dust (from sanding, scraping or disturbing the paint etc...) and getting the dust on your clothing and transferring that dust into the house etc........

Go to the EPA lead page and download their information and get acquainted with the issues involved with lead and lead safe practices when renovating and painting (if you are not already familiar with these issues).

Beginning next year, even professional painters (as well as other contractors who work on pre-1978 housing) will need to become "certified" in order to contract work on pre-1978 housing, as the government (EPA) wants only competent contractors trained in lead safe practices to work on such housing because of potential lead hazards and the related health issues.
 

Last edited by Slatz; 04-07-09 at 12:45 PM.
  #7  
Old 04-07-09, 02:36 PM
M
Member
Thread Starter
Join Date: Apr 2009
Posts: 3
Received 0 Votes on 0 Posts
lead in check

Thank you for the warning. Lead has to be taken seriously.

We are following all of the recommendations we could find, including the large heavy plastic drop cloths, gloves, coveralls, head coverings, goggles, and P100 lead-safe respirators.

For sanding, we have a system specially designed to trap lead paint dust. It connects to a vacuum with a HEPA filter. We still wear the respirators while we are using it.

At the end of every day we pick up the drop cloth carefully and fold it in on itself and put it in a bin where we will later take it to the hazardous waste facility. We search for rogue paint chips and vacuum them with the HEPA vacuum. We take off our clothes and shoes outside the house and immediately shower.

All of the equipment cost us several hundred dollars, but it's worth it. Afterwards we'll still probably have the soil tested to make sure it's ok and replace it if necessary. We plan to have little ones in the near future (plus we don't know what previous owners have done--we know some sanding occurred int he past).
 
  #8  
Old 04-08-09, 09:41 AM
S
Member
Join Date: Mar 2008
Location: Livonia, Michigan
Posts: 203
Received 0 Votes on 0 Posts
Excellent!!!

I am relieved and glad to see the great precautions and practices you have listed. You've done your home work well.
 
  #9  
Old 04-08-09, 10:06 AM
Gunguy45's Avatar
Super Moderator
Join Date: Dec 2007
Location: USA
Posts: 21,112
Received 4 Votes on 4 Posts
Sounds like you're doing the right things for the paint removal.

Now just watch out for public nudity charges when you strip down outside...lol
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: