From time to time, I like to do product testing here on the blog because it helps me find the best products out there and share them with you. You can check out my most popular test to date, the Wood Filler Test (Year 1 and Year 2) for some useful testing. Today, I thought it was about time I did some head to head testing on glazing putties.
In my shop, we glaze about 600 LF of putty every week, so making sure we are using the best putty that is not only easy to use but performs better than the other products on the market is of vital importance. I’ve written about Which Glazing Putty is Right For You previously, but have never done head to head testing of multiple products. Plus, I’ve included some additional putties that I don’t have experience with, but are readily available, so I’ll be learning right along side you.
For this test, I have glazed a 3-lite sash with the various putties and left the sash in my shop for approximately 4 weeks before taking it outside and leaving it exposed to the elements unpainted. Here’s what I’ll be looking for in the testing and will rank them on a scale of 1-10 (1 being the worst and 10 being the best)
- Ease of Application
- Clean Up
- Cure Time
- Mildew Resistance
- Long-Term Performance
Below are the products that will be a part of my glazing putty test. I also snuck in my own glazing putty recipe to see how it performs with the rest. Soon we may have some of our own glazing putty available for you readers too! Test points 5 and 6 won’t be evaluated this year, but in the upcoming years we’ll be able to see how the putties perform on these items.
Crawford’s Painter’s Putty
This a new putty to me that I have seen on the shelves at paint stores but never tried until now. This is a linseed and calcium carbonate putty with titanium added. It’s a natural product with no harsh chemicals and very similar to the traditional putties of the old days.
The putty comes in a sealed metal can and has a layer of water on top that needs to be poured off and blotted dry with a rag before digging out some putty. The water keeps the oxygen off the putty and prevents it from developing a skin on top which saves you from loosing a layer of cured putty, which is nice.
Right out of the can, the putty was simple to work in my hands and tools pretty nicely. I didn’t have any problems with the putty sticking or clumping and it was easy to work with my glazing knife. It is oil-based, so clean up really consists wiping it off your hands with a rag and then washing a couple times with soap and water, but in the end, it does come off.
As far as the cure time, I was impressed that after only about 1 week the putty had developed a good enough skin that it was ready for paint.
- Ease of Application – 8
- Clean Up – 6
- Appearance – 8
- Cure Time – 9
This is an old standard for a lot of window glazing. I’m not a big fan of it from past experience, but I decided to give it another try for this test since it had been a few years since I last used it. In my opinion, the greatest strength of DAP 33 is that it is available at almost every hardware and paint store in the country.
The putty was very thick and oily and difficult to work with a putty knife compared to the other putties I tested, but I was still able to get a smooth putty line. The clean up is much like the other oil-based putties, requiring wiping off then washing thoroughly. It took just about 16 days before the putty had a sufficient skin enough for painting, which is on the long side for glazing putties.
One small benefit of DAP is its white color. Since a vast majority of the sashes I paint are white, it is much easier to ensure good coverage of the paint on the putty rather than with the natural tinted putties.
- Ease of Application – 4
- Clean Up – 6
- Appearance – 8
- Cure Time – 5
Sherwin Williams “66” Glazing Compound
I’ve seen this putty on the shelf at my local Sherwin Williams store and have wondered how it performed, so I forked over a few bucks and brought a quart back to the shop for testing. The putty is white in appearance just like DAP 33 and when I dug it out of the container, I found it to be a sticky, gooey mess to work with. It stuck to everything, including my gloves so much so that I had to take them off and use my bare hands.
The stickiness of the putty made it feel more like a paste than a knife grade putty. The stickiness did make it easy to adhere to the glazing rabbet but other than that, I did not enjoy working with this putty one bit. Trying to tool a smooth finish was not an easy task and I’m a pretty darn good glazier.
Cure time was about 13 days before it was ready for painting. Even if this putty performs amazingly, I would not recommend it because it was such a pain to work with.
- Ease of Application – 1
- Clean Up – 3
- Appearance – 6
- Cure Time – 6
At the time of this writing, this is the putty I use everyday in our shop. I included it in this testing even though I am immensely familiar with MultiGlaze because I wanted to have a baseline by which to judge the other putties with. MultiGlaze is a linseed oil putty and has a beige/grey appearance. It is extremely easy to work with and has just the right consistency to stick to the sash and not stick to your hands and tools.
It tools easily and leaves a super smooth bed of putty. Not only that, but it cures in about 3-4 days and is ready for paint at that point. The only down side to it is that it is not meant for on-site application. Sarco recommends that it be glazed in the shop and then painted before it is placed into service.
- Ease of Application – 9
- Clean Up – 6
- Appearance – 9
- Cure Time – 10
For this test, I decided to add my own mixture of putty into the testing. I used a traditional glazing putty recipe of raw linseed oil and whiting. It was a little difficult to find a good mixture, because when I made it thick enough that it wouldn’t sag, it was then very hard to work with my glazing knife. When it was thin enough to glaze easily, it was too thin and would sag.
Clean up was much the same as the other putties, which wasn’t surprising. I knew that by using raw linseed oil instead of boiled linseed oil that the drying time would be extended, but I was surprised by how much slower the skinning over time would be. It took about 26 days before the putty was ready for painting, which is crazy long!
While it was helpful to see how a traditional linseed oil putty performed compared to modern glazing compounds, it was particularly helpful for my testing while I try to develop my own putty. Right now, I would consider this putty a fail, but testing and learning is never a failure in the end.
- Ease of Application – 3
- Clean Up – 6
- Appearance – 5
- Cure Time – 1
This is only the first year of my glazing putty test, so be watching for future posts to show how these putties perform out in the elements.
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I love old houses, working with my hands, and teaching others the excitment of doing it yourself! Everything is teachable if you only give it the chance.
32 thoughts on “The Glazing Putty Test”
Sarco has petroleum distillates in it and can smell in a closed shop. Also fumes might be harmful? It dries like concrete after a few years making removal difficult. I like Crawfords got the non-toxicity Andrade of working. I’ll see how it holds up 5 years from now. That’s another test to do; how it holds up over time.
I have been reglazing some long-neglected windows in my ~100 year old farmhouse using Glazol. I am new to this and it is not clear to me how to know when the product is “set” enough for painting, so I would love any auggestions. Also, it seems to stay soft permanently – is that a good thing? Thanks! Sue
Why is Sarco Type-M recommended only for shop installation? I keep reading that, but there is no explanation as to why.
It cures too quickly when exposed to sunlight so keeping it in the shop until it’s painted is best. Otherwise it will have a shorter lifespan and be more brittle.
I spoke with the owners of Crawford’s Putty, who stated that their putty should not be used to glaze windows because it lacks the long-term flexibility of glazing compounds. It is intended only for nail holes.
I just opened my canister of dual glaze from Sarco. It’s very very sticky to the point that I cannot apply it correctly. Is there something I can add to it to prevent it from being so sticky?
Mix the putty thoroughly and add some whiting to help with the oiliness.
Thanks, just ordered some whiting today.
It also helps to buff your glazing knive to a mirror finish. The protective skin applied to new knives that prevent rust will pull on the glazing.
The last few years I have noticed the Dap 33 get gooier and stickier. In the past I believe I would mix in some corn starch. I think I’ll start doing that again unless someone can suggest a better thickener.
Do you have any updates on this? I haven’t see. Any blog posts showing results.
The client wants the sash primed and painted (intetiorcshd exterior) before the glazing goes in. Is this advisable? Will glazing putty stick to the final boat of exterior paint? Thanks
don’t put the putty over paint. clean to bare wood, smooth, brush with a mix of 2 parts boiled linseed oil, 2 part turpentine, 1 part penetrol. This will prevent the linseed oil in the putty (if you go with Sarco) from absorbing into the wood. Then you can prime and paint over the putty once it skims. Sarco cures the quickest in my experience. they also make a version for rin-place installation. l You can get it from Winn Restorations in New Hampshire.
Can anybody second this recommendation? No paint or paint before putty?
Rebates are to be prepped with linseed oil mix as above, though I think not enough of a barrier, or shellac or oil-based primer before painting. Shellac or primer for rebates, glaze the window, allow the glaze to cure, prime then paint the window.
We have been playing with making our own putty too with reasonable results.
I’ve been priming with slow drying oil base primer for years before glazing with no problems. it seals better than linseed oil. And yes Sarco bonds to it fine.
I live in an 1820s log house that still has the original sash and wavy, bubbled, glass. I recently took on the task of glazing some of them in preparation for the painter. I used an old can of DAP “33” that was pretty stiff but after warming it in my hands, it worked great. Late on a Saturday night I ran out so headed to the local hardware for another can. Ran in, grabbed it, paid, and left but found that I bought Painter’s Putty “53”. Pretty stiff but worked OK once warmed up. In the late 1950s I worked for my Dad, who built custom homes, and I did nearly all of the glazing. I think this was before you could buy ready glazed sash. I used all of the “53”, went to a different store and got Glazing Compound “33”, TERRIBLE, really soft and sticky. So, I came to this page for suggestions but didn’t really find what I needed. So here is my remedy. I think the old painters used white lead to custom mix paints, and also to “stiffen up putty”. I didn’t have that so I went to the grand-children’s chalk board, found some white chalk, and shaved it into a ball of putty until I got a workable consistency. Worked great and this group of windows is finished.
I work with stained glass and have yet been unable to find the “perfect” glazing compound. Since painting is not an option, a true grey color is optimal. Is it possible to tint glazing to the desired shade, or is there a premix the someone has found in a true grey?
David, I know that Sarco will tint their putty to whatever color you want. Might be worth checking.
Heck yea, Tint it with a powder called,” lamp black” to desired shade. Lamp black is a pulverized soot. I’ve even used a pulverized charcoal briquette. A barbecue briquette. Brian
Thanks Brian…great idea!
I think Andy talks hateful to me because I’m popular.
Crawford’s putty isn’t oil. It is waterbased
Crawford’s putty is indeed oil based. Says so right on their website
I’ve not tried any of these but Red Devil; And That was many years ago. I use the Dap 33 and gauge it with whiting powder and linseed oil. Sometimes I blend in zinc chromate for good measure, I will follow up with a final dusting of whiting powder using a soft bristle brush. This enables me to apply oil base primer immediately. Then subsequent coats of paint. I’ve had immense success for the past 44 years in the window business.
Brian Manne Historic Woodwork
So the Sarco can be used on exterior windows? I thought it was for interior glazing. I’m hoping to use it soon.
Exterior is the intended usage.
I wanted to leave an update to my comment about the Sherwin-Williams 66 compound. I used the remainder of my quart on one scrap window sash. In the past, I had been using this outside, in the full sun. I think that’s what did the damage. The heat and sun caused the glazing to basically liquefy and turn into a sticky, gooey mess that was impossible to work with. I checked on a basement window sash that I used some 66 on, but this time I stored it inside, out of the heat and sunlight and it was starting to skin over without the sticky layer of oil on top. This time, I worked in cooler temperatures, and in a shaded area on my back porch, and I must say, the difference was night and day. It was still a little sticky, but considerably easier to work with. The bedding went on smoothly, and the glazing was easily packed into the rabbet and cut smooth with a standard putty knife. One pass down the rabbet with the handle held parallel to the glass (as opposed to holding the knife perpendicular to the glass) yielded an impressively clean and smooth cut. And, the excess on the glass peeled off easily, where before in the heat, it had to be basically scraped off. The corners were cut in and formed very neatly. My opinion of this has changed and I would probably use it before I went back to Dap 33 or Glazol. Just with the understanding that direct exposure to heat and sunlight is counterproductive. I probably wouldn’t think twice about using it now, in a cooler area or in a shop.
I have discovered Red Devil’s brand of glazing compound. I love it in every way. It’s just right. Unfortunately, nobody carries it around me and I have to order it directly from Red Devil. But, it’s worth it.
Have you used Red Devil’s glazing putty? It’s not in any store around here, so I ordered some directly from Red Devil. I just glazed a sash with it and boy is it some nice stuff. Super easy to work with and tools like a dream. It has the exact same smell as the Sherwin-Williams 66. And I was worried that I just got another container of that stuff but this isn’t nearly as gooey and oily. It says it can be painted with oil paint immediately or latex after a few days. Now I wait to see what kind of cure time it has.
I too picked up a container of Sherwin-Williams 66 thinking it may be superior than the other consumer brands. I had been using good old Dap 33 with no problems a few years later, and Glazol which seems to harden in the can even a day after the can is first opened.
My experience with the 66 are exactly the same. It’s like working with a bucket of caulk. Even worse as you keep it in your hands and it gets warm. Tooling was extremely difficult, and 3 weeks later, the glazing is still gooey and sticky and has a layer of oil on it. I tried leaving some of it on cardboard to absorb some of the oil. It may work better in a cooler area, straight out of the bucket instead of having it in your hands. It’s definitely easier to work with using a flexible knife instead of the stiff glazing knives we all use. For the two sashes I used it on, I ended up removing it and reglazing with Dap. I’m somewhat disappointed, I really hoped it would be a superior product.
Sarco’s Dual Glaze is made for in-place use.
Nice to see this head to head. We used SW 66 on the advice of a man who does colored glass restoration since he learned it decades ago as a teen from the originator of the shop he now runs. he said it was much better than DAP, but maybe he had never used sarco.
My daughter did a fine job in spite of using SW. We’ll have to get the sarco.
I am assuming that one can use sarco in place, not in the shop, if one protects from rain before it is painted, or am I missing something??