The Best Putty Knife

I spent ten years in construction as a carpenter, foreman, and supervisor working on high-end homes in the Boston area. I’ve also been writing about tools since 2007 with articles appearing in Fine Homebuilding, This Old House, Popular Science, Popular Mechanics, The Journal of Light Construction, and Tools of the Trade, where I’m a contributing editor. Over the past few years I’ve also completely painted the interior of my 100-year-old farmhouse as part of a full gut and remodel. During that process, I applied putty to what felt like an infinite number of nail holes.

For more insight into putty knives, we turned to Jeff Young of Young Ideas Painting based out of Concord, Massachusetts. Jeff has been a painter for 30 years and has appeared on Ask This Old House, where he shared his expertise on paint brushes.

If you’re only going to get one putty knife, Young suggests one with a 1½-inch wide blade because they’re “good for filling holes and removing tape on walls.” When you go bigger, you lose precision and the ability to get into tight corners. Smaller widths are too narrow to fill wider cracks.

Young also recommends getting one with a flexible blade. The traditional putty knife has a stiff blade, but as Young explained, those “are for removing window glazing (as well as putting glazing in) but you can do that with a flexible blade too.” He continued by saying that, “not many people have true divided lights anymore, so you don’t need a real putty knife.”

There is a slight upcharge for the stainless steel blade, but Young says “it’s worth spending the extra few bucks” because you don’t have to worry about rusting. I have a few old putty knives that aren’t stainless, and if I’m patching a small hole in the wall, the rust from the blade actually stains the wood putty as I’m putting it on.

I’ve also found that it’s worth seeking out a knife that has a metal cap at the base of the handle. It just makes it a lot easier to bang the lid back on a paint can or a putty container.

If you’re doing more advanced projects at your house, you may need to add some larger knives to your tool box. A 3½-inch angled putty knife like this Craftsman is useful for larger holes, and if you’re going to be taping drywall joints, a 6-inch knife is helpful as well.

We also tested the Hyde 06108 Pro 1½-inch Flexible Putty Knife, but the handle is quite a bit shorter than the others and not as comfortable. The leading edge of the blade isn’t as crisp as either the Craftsman or the Husky.

During our research, we discounted a lot of models because they were missing a feature or two. Warner doesn’t offer a metal cap at the end. The Goldblatt has a simple plastic handle with no ergonomic considerations. The Stanley and Purdy aren’t stainless.

In the end, we got our hands on three putty knives; the Craftsman, the Husky and the Hyde. All three companies have solid reputations and are widely available. For testing, I simply used them as I prepped and painted a number of rooms in my house. The tools were used for filling nail holes, patching some plaster cracks, minor scraping, and mixing two-part wood epoxies. It didn’t take long for me to decide on the Craftsman. It’s just the most comfortable to use.

We found that the best general purpose putty knife is the Craftsman 1½-inch Flex Stainless Putty Knife. It’s the best size for filling small holes and cracks, it has an easy-to-clean stainless steel blade, and it has a long, ergonomic handle that makes the tool comfortable to hold and use for extended periods of time.

Tip: When most joint compound and putties dry, they shrink a little, so when you fill a hole or crack, you want to leave the putty a little proud of the surface. If you don’t, it will likely cave into the hole a little and you’ll have to add a second application. It’s much easier to lightly sand off excess putty than to apply it again and wait for it to dry.