Glazing Windows

[Peter Aeschliman]

Gary, to reinforce your SARCO purchase, I can definitely recommend against DAP 33. As part of my basement renovation (I'm moving my shop in there), I restored all of the old wood windows. I used DAP 33, and it took about 2 months before the glazing was relatively firm (meaning, it didn't dent when I touched it with light pressure).

I used whiting (chalk powder) to remove excess oils on the surface probably every other day, and kept fans running on them nearly constantly. 65 degrees in the basement were they were drying (curing?). Super frustrating, but they eventually dried enough for paint.

Also, I recommend the small-diamond shaped glazing points. The ones you find at the big box stores (like the ones linked below, which I used) are too long. I found that when I tried to get the glazing putting to line up with the edge of the rabbet on the other side of the glass, I'd hit the glazing points... so I ended up putting on more glazing than necessary just to cover the points. It doesn't look all that great from the inside, and this might be part of the reason why it took so long for for the DAP 33 to harden.

I'm glad I learned these lessons for a project that I never intend to do again!!

Don't use these:
http://www.homedepot.com/p/Glazier-s...P1HD/202284230

[Mel Fulks]

Charles,thanks. I had misinterpreted a couple of things by watching only one clip. And they do bed the glass using the popular latex caulk. Still think they are slow, but old guys are dying off and a lot of us have to find our own methods. The best glaziers I've seen were self employed and worked on job sites and on new stuff in mill shops when needed. They would typically take a long time to set up; endlessly kneading the putty etc. , then do the glazing quickly!

[Rich Engelhardt]

this might be part of the reason why it took so long for for the DAP 33 to harden.

Actually - - no, Dap 33 is formulated for exterior application and it has an extended open time.
For inside - in shop - work, you want a Type "M" - which is what Sarco Multi Glaze is.
Sarco also makes a glaze for exterior application - the Sarco Dual glaze. Dual is the one to use when doing sashes that are already in place outside.
Dual is more "well behaved" than Dap 33 - meaning it's much easier for a novice to work with.

Dap 33 is a great product - - it's just not made for just anyone to apply it.

He does not put the glass on a bed of putty or caulk, just straight in the rabbet, then puts in the points, then does the glazing.

The only thing I've ever seen applied to wood sash before setting the glass is linseed oil or Penetrol.
That's only done so the dry wood won't pull too much oil out of the glazing compound causing it to fail prematurely.

I don't know how "old timey" you consider this. I learned how to glaze back in the late 1960's and early 1970's. A lot of the painters that shared the info were well into their 60's at the time and most were 2nd and 3rd generation, having learned the trade form that father and grandfather.

[Wayne Lomman]

Definitely caulk both sides of the glass. Just because some old windows were done without caulk under the glass doesn't make it right. Cutting corners/laziness is not a new thing. Cheers

[Mel Fulks]

We have had a post or two giving details about sale of company and downgrade in Dap 33. In the last few years I ve seen failures. Not from perhaps an unskilled homeowner but from a skilled guy who runs a pretty prominate mill work company.
He was astounded by the short time before calls on failures. He would have been glad to blame an employee but,alas, he did his own glazing. I seriously doubt he still uses it.

[Paul Girouard]

My Granddad ,born 1894, long since dead, could glaze glass in like no one I've ever met. He was not a professional glazer , but he was a Dough Boy ,(Dough Boy = WW1 era solder / dog face , ) who was shipped to France near the end of WW1 , and he told me that's where he learned to glaze, repairing glass as they "worked" their way to the front. He said the war ended before he GOT to the front , so apperantly a lot of Dough Boy's where used as part of the rebuild , repair France / Europe effort.

He used Dap 33 , he didn't bed the glass in the dap , but he did prime the rabbit before he set the glass in , then the glazing points , then BAM , the glazing part was DONE, smooth as silk , a few quick , really quick, strokes of the putty knife and the glazing was done!

There's a few theory's why they where called Dough Boy's:



Doughboy as applied to the infantry of the U.S. Army first appears in accounts of the Mexican-American War of 1846-48,^[5][6][7] without any precedent that can be documented. A number of theories have been put forward to explain this usage:

• Cavalrymen used the term to deride foot soldiers, because the brass buttons on their uniforms looked like the flour dumplings or dough cakes called "doughboys",^[2][8] or because of the flour or pipe clay which the soldiers used to polish their white belts.^[8][9]
• Observers noticed U.S. infantry forces were constantly covered with chalky dust from marching through the dry terrain of northern Mexico, giving the men the appearance of unbaked dough or the mud bricks of the area known as adobe, with "adobe" transformed into "doughboy".^[9]
• The soldiers' method of cooking field rations of the 1840s and 1850s into doughy flour-and-rice concoctions baked in the ashes of a camp fire. This does not explain why only infantryman received the appellation.^[9]

[Mel Fulks]

Earlier tonight I aluded to a change in Dap 33 glazing putty. I can find no mention of it anywhere and I apoligize for possibly confusing experience with documentation. I stand by my comments about the failures I noted ,but at this point must admit the possibility of simply observing failures due to single bad or out of date product. Would appreciate any new information.

[Gary Viggers]

Before purchasing the Sarco Type M, I spoke to a product specialist at DAP. Mel is correct - it does not contain linseed oil anymore. Check out the MSDS http://www.dap.com/media/52763/00010401001english.pdf

It contains soya oil.

I also spoke with one of the owners of Sarco. According to him, that's what is being used on the window renovation at the White House. He gave me some tips on using their product. He also advised bedding with either the Sarco or caulk. I've got a bunch of DAP Dynaflex 230 that I'm going to use.

Peter, my points' protrusions are just barely in the acceptable range. I may track down some smaller ones.

[Mel Fulks]

Gary,thanks for vindication, I'm ending my self imposed exile on this rocky island! I had been unable to find that information and was starting to doubt my recollection of product change. Wishing you steady hand and smooth glazing!

[Rich Engelhardt]

It's quite possible Dap 33 never did contain linseed oil.
Tall and soya oils go way back - civil war era and before - so it's very possible the Dap formulation was one never based on linseed oil.

[Mel Fulks]

Possible. But SOMETHING is different that is causing early failures.

[Gary Viggers]

It's quite possible Dap 33 never did contain linseed oil.

The rep told me it used to contain linseed oil. I think she said the putty for metal windows still does.

[Steve Schoene]

When energy efficiency becomes an issue on such a house, one reasonably period alternative is to use an wood framed exterior storm window. Some are strictly old fashion but virtually the same look can be a achieved with a moveble lower pane, that allows a screen to be used. Off course the storms can be put in place in fall, and replaced by purely screen windows in the spring. The joys of a 1928 house.

[Rich Engelhardt]

The rep told me it used to contain linseed oil.

Interesting...according to the tech bulletin it still does.

http://www.dap.com/media/73954/33-glazing-tb-2012.pdf

Oh well. Someone is wrong....or someone hasn't updated the web site..

[Sherry Canon]

I would prefer to bed them and use a putty.It will be easier to remove the pane if it is broken, I recently did a casement replacement which I bought from heritage home design windows and doors. It is messy but it is easier to remove smaller pieces from the window frame than one unbroken piece. Sometimes even after you remove the putty and the points the window may not come out. This could be because it could be glued to the place by the old putty that was used to bed the glass.This bedding gives better air seal and allows the air to seat firmly against the frame when you set the points. Heating the glass with a heat gun around the perimeter will soften the old putty allowing you to remove the old glass.If nothing works then you would have to break the glass to remove it.