First off, I had to take some time to let my 'professional ego' simmer down. And then I needed to do some research to make sure that I was actually following industry best practices. After 35 years in the business - which included an apprenticeship with a master painter - I had never heard of disposing of brushes at the end of a job. Not unless you actually were using disposable brushes with some sort of finish that was difficult to clean up.
So I did plenty of investigating. And while we probably could have taken better care of this customer and asked if cleanup at his house was fine with him (or else taken the brushes back to clean at our shop, as we most often do), I would like to address his two points.
Which brings me to my next point regarding disposing of paint brushes. It's my belief that a painter who regularly does this ends up spending a lot more money on tools than he needs to, and his costs he passes along to his customers by way of the prices he charges are going to be excessive. In short, he's wasting the customer's money. Now, while we know we're not the cheapest painting contractor in town, we believe in giving our clients great value for their dollar. And judging from the reviews we get, they agree that we do.
So why do we wash brushes on-site at times? Periodically it's because we're changing paint colors. Or perhaps we didn't have the materials available to wrap up the brushes for storage for use the next day. (Most painters will do this with latex brushes, and it is an accepted industry practice.)
Does latex paint damage plumbing? Absolutely not. Household cleaning products and chemicals like Draino can be harder on your pipes than latex paint. (Never put oil-based paint down the drain, but that's a moot point because it's not water-cleanup anyway.) You should never wash brushes used with latex paint where it could get into ground water - such as in your yard - but water treatment plants can easily processing highly diluted latex paint residue.
The belief may be based on the prohibition against washing latex paint brushes in a home that has a NEW septic system. Unless the septic is well established, latex paint can inhibit development of the bacteria necessary to break things down in the septic tank. And because of that, contractors working on new construction will often arrange to have a tank pumped when they are finished.
Yes, it's fine to re-use paint brushes. In fact, we're highly in favor of it. If that were not a good industry practice, there wouldn't be so many articles and video tutorials for PROFESSIONAL painters showing them how to do it properly. And we try not to waste our customers' money, so we watch our costs and try to avoid unnecessary spending.
Yes, it's fine to rinse off latex paint from brushes and let it run down your drain. There won't be an issue with your plumbing, and you won't have trouble with your sewer. People put far worse things down their drains than a trace amount of latex paint, and their water pipes seem to do just fine.
Apologies to the customer for not asking first, but we will have to agree to disagree about best industry practices when it comes to re-using and cleaning paint brushes.
- John Schweiss