It seems that I have not adequately answered this question as it seems to keep coming up.

Both installation methods are available on most of our Your-Door-Knocker.com door knockers so a decision must be made when checking out which one you want.

surface mount door knocker

Lets describe the surface mount first: Simply put the surface mount attaches to the surface of the door, in our case with wood screws. The wood screws pass through the door knocker casting and screw into the door. The screws are visible on the front of the door knocker but are usually finished to match and look quite natural there.

This method works well on wood doors. It can be adapted to other doors using plastic anchors but this is not always satisfactory on non wooden doors.

Through The Door Mounting Method

The other method is the through the door mount. This is the old standard where holes are drilled through the door for hardware to pass through and attach to the back of the door knocker. A decorative nut or machine screw head is visible on the inside of the door.

Your-door-knocker.com supplies a universal mounting kit with our door knockers ordered with this mounting method that eliminates the need to cut the hardware to fit the door. Our unique kit makes mounting using the through the door method quite easy.

Also available on the Your-Door-Knocker.com site are decorative rosettes that are used with the through the door installation method to kind of dress up the inside of the door. Rosettes are also handy when installing a replacement door knocker and the mounting holes do not quite match up. The rosettes act like large washers to cover an elongated hole in through the door to accommodate the new door knocker.

Installation of a door knocker is really quite easy but you must decide which mounting method you will be using before you buy your door knocker. If it is to be a gift and you are not sure which one to get, it is usually the best option to go with the through the door method as it can be used on the majority of doors.

More door knocker installation information can be found on our site on the installation page.

I can see how this can happen. The brass door knocker on the outside would get as cold as the outside air. The through the door mounting hardware is a direct connection from the cold outside to the warm inside. If door knocker gets cold enough it would transfer the cold through the door via the hardware. The exposed inside hardware would then collect moisture from the air and create a layer of frost.

We think we have bad winters here in northern Ohio but I am glad to say we have not had it cold enough to experience this. We are talking climates well north of us.

Any way when asked what to do about this I resisted my first impression to say move south. I thought about using nylon mounting hardware which would not conduct cold as well but I doubt that this would be strong enough.

I have not found a perfect answer for this problem but it seems that the best thing to do to minimize this to fill the holes through the door around the mounting hardware with caulk or putty. You would like to make the hardware in direct contact with the mass of the door which would help to dissipate the cold through the door before it got to the hardware  inside. I also believe that using rosettes would help as the added metal inside would take more cold to overcome the inside temperature.

Thank goodness those of us with who do not see -10F or lower for an extended period of time should not have to worry about this.

Out in the elements a protective coating is needed to prevent the brass from oxidizing or tarnishing. This is the process that happens when oxygen and atmospheric gasses comes into contact with the surface of the brass.

Most manufacturers use a high quality clear lacquer to coat the brass and thus protect it.

When a brass door knocker is engraved the engraving process cuts into the surface of the metal. If it is lacquer coated the engraving will also cut through the coating exposing the metal behind it. The exposed metal in the engraved area will oxidize and tarnish in a short time.

An engraved door knocker should be lacquer coated after the engraving process. This seals the entire door knocker and prevents your investment from deteriorating prematurely.

At our Your Door Knocker studio we dip our products in high quality UV resistant clear lacquer as one of the last steps in the production process. This completely seals the door knocker and ensures a long life.

Brass is a nonferrous metal with good electrical and thermal properties. It also has excellent strength and corrosion resistance. Being an alloy it is available in many varieties. Not all brasses can make good brass door knockers though.

Brass is not a natural element, it is an alloy of copper (Cu) and zinc (Zn). Other elements such as lead, nickel and tin may be added to the mix to achieve certain properties. Depending on the final product to be made the mixture making up the brass can vary. Some brass parts need to be strong while some may need to be resistant to salt water and still others may simply need to look good. The recipe can be changed to accommodate each of theses requirements.

Sometimes the changes cannot be detected just by looking and other times differences are quite apparent. Some of the changes affect the color of the brass which can vary from silver to gold to red depending on the mixture.

A door knocker needs to be made from a bright yellow brass that casts and polishes well. It must also be machinable and engraveable.

The desired properties are achieved by keeping the copper content around 67%-72%, the zinc content around 24%-29% with 1%-3% each of tin and lead. As a general rule the higher the copper and lower the zinc contents, the softer and easier to machine the brass is.

The addition of a small amount of lead makes the brass easier to machine. Tin is added to increase strength and corrosion resistance. Tin will also help prevent the zinc from leaching out of the brass over time.

A quality finished product requires a quality “recipe” for the brass. There are many specifications written for brass that may apply to different industries. Standards are written by such organizations as ASTM, SAE, CDA and MILITARY to name a few.

The elements that make up the brass are mixed in a foundry. They are melted together at temperatures that vary around 1800F – 1950F. When molten the liquid mixture can be poured into a mold to form the product or poured into an ingot for storage for later use. Most product foundries purchase the brass already mixed in ingot form. The ingot is then remelted and poured into a mold to make a product.

After the brass is molded into a shape it is called a casting. The casting is then polished, finished and machined into the completed brass door knocker.

Typically there are three variations of the name. One is to place just the last name on the door knocker. Another is the possessive version with a ‘s on the end. The last variation is a plural version with an s on the end of the name.

Before we go any further let me state that all three methods are correct on engraved door knockers. It just depends on what the you want to say.

The most common method is to place the last name alone in the engraving area of the door knocker. This method is simple and elegant.

The possessive version with the ‘s is also popular. This one is saying that this house belongs to this family. From an engravers standpoint there are a couple issues with this method. One is that the hyphen ‘ does not always stand out as well as the other letters on an engraving. This causes the engraving to be visually off a bit even though it is not. It also adds two characters to the line. This may be beneficial if the name is short. It will help fill the engraving space more efficiently. In the case of a long name it may take up to much space thus forcing the engraving to be smaller to fit into the space available. In the case of a last name ending with an s the plural would be a hyphen without an additional s. I recommend avoiding this. When engraving a name ending with an s with a hyphen following it the finished engraving looks off center. This again is due to the added hyphen not being as visible as the other letters.

The plural version is nice. It says more than one family member lives at this house. An s added to the end of the name only adds one character and will seldom cause a problem. In some instances it could cause confusion as to whether the s is part of the name or is a plural version of the name.

As I mentioned earlier the most common method is to put just the last name on the engraved door knocker. If you are in doubt this is usually the best choice.

Nothing personalizes a house like an engraved door knocker.

Depending on the size of the hardware being used these holes may be up to 3/8 inch in diameter. There are things to think about on both sides of the door before you drill.

Once their exact location is determined the holes must be drilled squarely through the door. The door knocker will lie flat on the outside surface of the door. The mounting lugs are machined into the back of the door knocker so that the hardware must enter at a perpendicular angle. If the holes through the door are not square the hardware will not screw into the door knocker casting.

It is a good practice to have the finished holes large enough so that the mounting hardware fits loosely into them. A very tight fit may do well on the day that the installation is made but if your climate is like ours, there is as much as a 100 degree temperature difference from summer to winter. Changes in temperature causes expansion and contraction. This could cause damage to your door or your door knocker over time if the fit is too tight.

The actual drilling of the holes can damage the door. It is a good practice to first drill holes at the precise mounting locations that are less than half to size of the finished hole. The smaller hole would be drilled all the way through the door. This smaller hole gives you the chance to check your work as well as provides a guide for the finished holes.

With the smaller holes drilled through the door at the exact mounting locations you can drill the finished larger holes. Do not drill the finished holes all the way through. This would have the potential of damaging the surface of the door where the drill exits.

Instead, drill the hole half way from one side and then drill the rest out from the other side of the door. This will provide clean entrance points on both sides of the door.

With a little planning and careful work your door knocker installation will be a pleasing addition to your home for years to come.

A replacement door knocker installation that is a through the door mounting method, the bolt center dimension has added meaning. You will probably want to use the same drilled holes that are already in the door. If so you will have to find a new door knocker with the same bolt center dimension as the previous one.

The bolt center dimension is the measurement from the center of one bolt hole to the center of the other bolt hole. We have shown this dimension on our door knocker comparison page.

The new door knocker must match the old door knocker at this dimension or your new door knocker will not fit the existing holes.

There are no industry standards regarding the bolt center dimension or the size hardware to be used. These are left to the manufacturers discretion. They are usually dependent on the shape and style of the door knocker itself.

At times it can be difficult to find an exact match. Sometimes you have to settle for getting your replacement door knocker as close as you can to the original. Then you may make an adjustment by enlarging the holes in the door or drilling an new hole and using one of the old ones. In these cases something needs to be done with the inside of the door to cover up the old  or enlarged holes.

If the holes are enlarged they may be covered by using larger washers on the inside to cover the larger hole. If a third hole was needed the old one will need to be filled in.

The best bet is to find a replacement door knocker with the same bolt center dimension as the original one if possible.

The phrase Bolt Center references the geometric center of the diameter of the hole that is drilled for a bolt to pass through. Theoretically the center of the bolt will pass through the center of the hole as it goes through the door. In the case of our door knockers this would be the mounting bolts for the through the door mounting.

We refer to this point as the bolt center because this is the exact point that the workman should drill the hole for the bolt so it matches the door knocker. Right in the center.

In the case of our door knockers the bolt center dimension is the same as the distance between the bolts. If you measured from the bottom of one bolt to the bottom of the other the distance would be equal the bolt center dimension. This is true because both holes being drilled are the same size.

Lets imagine for an example that the top hole does not use a bolt. Instead the top hole is an eye viewer that requires a hole 3/4 inch in diameter and the bottom hole is a standard mounting bolt that needs a 3/8 inch diameter hole. In this case you could not drill holes based on the bottom of each. You would need to know where the center of each hole is and drill there.

This is why we use the term bolt center for our through the door mounting instructions.