how do you repair a doorknob hole?

Been searching over the internet for an answer to this question and so far haven't found much. The doorknob hole of my door is damaged so that when you put the doorknob in there is a gap that you can see through. I have researched the internet and Bondo seems like a possible solution to fill in the space. Since I am doing this work to an interior door, I am concerned about the fumes and I've never worked with Bondo before. Any suggestions.

DIY on the fly:

You can patch the old with Bondo, or you can use an two part epoxy meant for wood repair, or you can replace the door, or you can plug the hole with an old sock. There's a gazillion things you CAN do.

But, if it wuz me, I'd just put an escutcheon plate on both sides of the door.

If it's a common lock like Weiser or Schlage, then you can buy "escutcheon plates" in both square and round styles that you can put on either side (or both sides) of the door knob at your local hardware store or home center. If it's not a Weiser or a Schlage, then you can get other escutcheon plates in other sizes, and your local locksmith would know where to get them from. If push comes to shove, you could probably order a couple of large brass washers from any place in your yellow pages that sells fasteners and have it machined at your local trade school to fit.

Thanks. I never heard of an escutcheon plate before. i failed to mention that this is a white bedroom door. also the gap goes to the wood frame part of the door. will a plate look ok? i could probably put a plate on the door and put some white epoxy at the edge where the veneer got knocked off. I have Devcon 2 ton white epoxy. That's sounds like it would work to cover the area where the plate doesn't and i won't have to paint over it. i have a Penn Reading standard doorknob fits 2-3/8" and 2-3/4" backset. Please comment. Thanks so much for the reply.

I have a similar problem. I was trying to install an actual door knob in some french doors that were 'pop-out' doors. Unfortunately, I didn't measure correctly, and ended up drilling the hole about a quarter inch to the left. Now, when I install the latch, the door knob will not thread through the hole in the latch. So, I have to drill some more to the right, but there will definitely be a gap that I'm not sure how to cover up. Any ideas?

LJohnson:

The Weiser escutcheon plate I referred Diyonthefly to are 2 1/2 inches ID and 3 3/4 inches OD, so they will cover the wood for a full 5/8 inches around the hole. You should have no trouble hiding a 1/4 inch gap with a pair of them. They are Weiser Part # 1639 and you should be able to order them from Weiser at most hardware store, or at any locksmith. So, if you just install a Weiser set, a pair of Weiser 1639 escutcheons should cover the gap if you drill a new hole.

Not sure if I answered your question, but it seems to me that if you use an escutcheon on both sides of the door, the gap will be hidden.

You can also get larger and smaller escutcheons for other brands of locks as well, such as Schlage, Medico, Kwikset, etc. in different styles and finishes.

diyonthefly said:

Thanks. I never heard of an escutcheon plate before. i failed to mention that this is a white bedroom door. also the gap goes to the wood frame part of the door. will a plate look ok? i could probably put a plate on the door and put some white epoxy at the edge where the veneer got knocked off. I have Devcon 2 ton white epoxy. That's sounds like it would work to cover the area where the plate doesn't and i won't have to paint over it. i have a Penn Reading standard doorknob fits 2-3/8" and 2-3/4" backset. Please comment. Thanks so much for the reply.

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You CAN use epoxy to fill a gap in a wood door. However, I think something like water putty (which you can buy at any hardware store) would be a little more user friendly. Basically, you just mix some water putty powder into a bit of water, and then spread it into the gap you want to fill with a putty knife. If you've ever seen plywood, you've seen football shaped voids in it wherever there was a knot or void that have been filled. It's water putty they use to fill those football shaped patches. Water putty is reasonably strong and hard, sandable, paintable, and sticks well to wood.

I would use water putty to fill your gap, sand smooth and paint, and then decide if you need the escutcheon any more.

here's what i tried and how it turned out so far.

tried using epoxy and found the consistency to thin to built up much of a layer. Also left a crappy bumpy finish which didn't exactly feel hard.

then i put some "wood putty" in the hole and it was hard enough to build up a layer to cover the gap when i put the doorknob in. however, after 2 days it stilll hasn't hardened. ie. i can still press my finger into it. The stuff is actually called "painter's putty".

i should be able to tighten up the doorknob so that there will enough grip on the door that it won't slip. the putty covers the hole and maybe i paint it a bit.

next time i will try Bondo or invest in a plate.

I've never heard of either "Wood Putty" or "Painter's Putty", but from their names, I expect they're both what I would call "Glazing Putty".

I've heard of Glazing Putty, Plumber's Putty and Water Putty. Water putty is the only one that you mix with water and it's the only one to dry hard within a day or two. Water putty is the only "putty" I've ever heard of that you mix with water.

Glazing putty is nothing more than clay mixed with linseed oil, and it will eventually harden up, but it takes a long time. Plumber's putty is the same thing, only it's clay mixed with a non-drying oil.

G'Luck with your repair anyhow.

"DAP Painter's Putty 53" is ordinary glazing putty with some titanium dioxide tossed in to make it whiter.

Click on one of the MSDS links and you'll find the stuff is made up mostly of linseed oil and calcium carbonate. When calcium carbonate ("Tums") occurs naturally, it's called "chaulk" or "limestone". The fact that they say that it contains 60 to 100 percent "limestone" means that they ground up natural limestone to make the stuff, rather than use pure food grade calcium carbonate.

It's the same stuff as glazing putty (with the addition of a small amount of titanium oxide to make it whiter) being sold under the name "Painter's Putty". Most people won't know what you mean by "Painter's putty", so just tell them it's glazing putty being sold under a different name.

the glazing putty takes a long time to harden. it's great for nail holes and even anchor holes. i painted over it and it took the paint well. i'll never work with epoxy again. it's messy, leaves a bumpy finish and tends to discolor yellowish. i guess glazing putty is better than spackle in terms of strength. i put the doorknob on and it seemed to hold up ok. i really wanted to use wood putty, the stuff that comes in a cylindrical tube, you cut and roll in your fingers to mix the hardening agent in, but i couldn't find it. also the wood putty i found was only in wood color, the glazing putty was white. guess i wasn't thinking that i could just paint over it. ka duh!:banana:

Maybe buy yourself some water putty. If you don't, you'll forget what it's called next time you need to do a repair like this. The stuff lasts forever in a dry environment, and if you buy some, you'll have it and use it on the next wood repair project. I think you'll like it more than glazing putty for interior wood repairs.

diyonthefly said:

the glazing putty takes a long time to harden.

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That's because glazing putty is just a mixture of clay and linseed oil, and linseed oil takes a long time to solidify when exposed to air.

And, in fact, that's exactly how glazing putty is supposed to work. Wood is a natural material which swells and shrinks with changes in it's moisture content due to seasonal changes in atmospheric temperature and humidity. Glass, on the other hand, is a ceramic material that hardly expands or contracts at all with temperature changes (and is unaffected by humidity). Consequently, you don't want your glazing putty to harden up so that it won't be able to accomodate the relative movement between the wood and glass. You want it to remain a semi-solid for as long as possible SO THAT it can maintain a seal at the joint between the glass and the wood despite there being relative movement between them. Even if the exposed surface of the putty hardens up and cracks during it's lifetime, the still softer putty under that surface will continue to maintain a water tight seal between the wood and the glass. Eventually, however the putty needs to be replaced, but nowadays most people are replacing glazing putty with modern synthetic caulks which weren't available years ago when putty was most commonly used. They still use the glazing points to hold the glass in place, but use modern caulking around the glazing instead of putty.

i painted over it and it took the paint well.

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Only paint over glazing putty with oil based paint. Because it contains linseed oil, I don't think latex paints will stick well to it. If you want to paint the door with a latex paint, then use an oil based primer over the glazing putty, and when that oil based primer is dry, paint over it with the latex paint.

i guess glazing putty is better than spackle in terms of strength. i put the doorknob on and it seemed to hold up ok.

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They'd be about the same, I think. One is a mixture of clay and linseed oil, the other is a mixture of gypsum with a bit of glue. The strongest would have been water putty which is basically a mixture of Plaster of Paris and white wood glue.

i really wanted to use wood putty, the stuff that comes in a cylindrical tube, you cut and roll in your fingers to mix the hardening agent in,

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No, anything that comes in two parts that have to be kneaded or mixed will most often be an epoxy. The stuff you're talking about (where you cut a piece off a tube and knead it to a uniform colour before setting it) is an epoxy.

Next time you want to repair indoor painted wood, try water putty:

DAP Products - Repair Products - DAP® Water Putty (Dry Mix)

Home Depot should sell it.

Or, if your "Painter's Putty" doesn't last, repair it better next time with water putty. (I'm presuming this is an interior door. Glazing putty will stand up better outside than water putty. Glazing putty is more or less water proof, whereas water putty is only for interior applications.)

Water putty dries to a hardness similar to wood. When mixed it's got a consistancy that allows you to shape it well, and it typically comes in a colour that's similar to wood so that it won't stand out like a sore thumb when stained. When hard, it'll be about the same hardness as Plaster of Paris, but it's be a lot tougher (cuz of the glue in it) so it doesn't crumble or crack easily. It can be drilled, but I wouldn't trust it to hold a screw as well as wood. Here's the colour of dry water putty (but it still looks a bit damp near the bottom of the thumb:

that is a very fine thumb mold. speaking of plaster of paris... isn't that the stuff you use in paper mache. what if you added very fine particles of paper mache or other fibrous material to the water putty, wouldn't that make the end product even harder?

Adding paper fibers to water putty might work well because the water putty has white wood glue in it, which bonds extremely well to cellulose.

Maybe give it a try. If no one else has tried doing that before, the idea might make you rich beyond your wildest dreams. And, if and when that happens, try to remember the little people who were nice to you at www.houserepairtalk.com.

PS:
Plaster of Paris and gypsum are chemically kinda similar, but also chemically kinda different. They're both compounds made of calcium sulphate and water. In one form, you have gypsum, which contains two water molecules for each calcium sulphate (CaSO4) molecule. If you heat the gypsum, you drive off the water as water vapour, and the chemical structure of what's left behind changes so that there are now two calcium sulphate molecules per water molecule. The resulting powder is called "Plaster of Paris", whereas the starting material was "gypsum". Gypsum was called "alabaster" in ancient times. In Greek, "alba" means "white", which was probably the root word of alabaster.

That chemical reaction is very important. Since you need to heat gypsum to drive off the water and produce Plaster of Paris powder, when you mix Plaster of Paris powder with water, you get an exothermic reaction that releases that heat again. And, this is exactly why drywall makes a good fire stop. Heating starts to drive the water out of the gypsum core of the drywall at about 80 deg. C. As the water is driven out of the gypsum, the temperature will rise to about 150 deg. C. But, that's still well below the kindling temperature of wood. So, instead of water that boils at 100 deg. C., gypsum converts to Plaster of Paris at a temperature range from 80 degrees C. to about 150 degrees C. Since the heat of the fire goes into converting gypsum into Plaster of Paris, no matter how hot the fire gets, the studs behind the drywall won't get any warmer than 150 degrees Celsius. It's kinda like no matter how high you turn up the ring on your stove, the pot of water will only boil at 100 deg. Celsius. It'll boil faster the higher you turn up the ring, but it'll still only boil at 100 deg. C. It's the same with drywall. That conversion from gypsum to Plaster of Paris happens between 80 and 150 degrees Celsius, so all the heat of the fire will go into converting the gypsum core of the drywall to Plaster of Paris in that temperature range. So, the wood studs behind the drywall will never get hotter than 150 deg. C. as long as there's gypsum between them and the fire, and that protects the studs so they don't burn. (Or, more correctly, don't ignite for long enough that there's time to evacuate the building.)

It's really that chemical reaction of converting gypsum to Plaster of Paris that provides the high fire safety rating of drywall. It's essentially the same as having water in the walls. As long as you have that water chemically bound up in gypsum, the wood studs behind the drywall won't start to burn until all of the gypsum has been converted into Plaster of Paris.

(In real fires, that Plaster of Paris gets hot enough that it undergoes further chemical changes so that even if you were to collect the dust that the gypsum leaves behind, it wouldn't react with water anymore to form gypsum. It forms another compound that doesn't react with water.)

Ya gotta know this stuff to get your DIY'er armbadge in drywall.

The same thing happened to me, I sprayed some expanding foam into the hole and let it cure, once it hardened, I sanded and painted, can't even tell there was ever a hole, also the foam acts as a tough backstop. Might want to cover the new area with one of those rubber doorknob stops.