Refurbishing Antique Radiators





Introduction: Refurbishing Antique Radiators

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In this Instructable I will detail the steps I took to restore a pair of 19th Century Victorian cast iron radiators, and how I got them to work in my 21st Century home!

Why you may ask is this in the Steampunk section? We'll this is the first project I've worked on that actually involves steam. Generally, steampunk objects pay tribute to the Victorian era... Well this radiator was actually manufactured in the Victorian era! And in the steampunk traditions of anti-commercialism, reusing and repurposing, this project certainly meets those criteria. (Plus, there's no Instructables category for radiators;-)

And why steam heat? When my wife and I bought our home, it came with a steam heating system, and a number of very plain radiators. After speaking with a number of people who were very unhappy about removing their cast iron radiators and converting to electric baseboard heaters, I decided to stay with steam, but to replace the plain (lead paint covered) radiators with a fancier upgrade. What I ended up installing are "Rococo" style radiators, manufactured by the National Radiator Company in the late 19th or early 20th Century. (The patent mark indicates that they were patented in 1891, so they were manufactured some time after) And they still work perfectly.I know the phrase is overused, but they just don't make them like they used too!

These radiators were manufactured in an era that could not comprehend the concept of "planned obsolescence!"

A word of caution: This project is not for the faint of heart. These radiators are ridiculously heavy, and required a number of large individuals just to move a few feet. Make sure you've got the "person power," resources and commitment before you decide to install one of these radiators!

Step 1: Finding an Appropriate Radiator

Cast iron radiators were the most popular form of home heating for many generations. They have since fallen out of popularity in newer construction, replaced by electrical baseboard or central heating systems. And many of those cast iron radiators that have survived for over 100 years are covered with over 100 years worth of paint! (Much of which probably includes lead).

I was very fortunate to find these beautiful radiators on the lot of a fantastic local non-profit business called "Build-it-Green" ( Build-it-Green specializes in salvaging building materials from local renovation projects and demolition sites, reducing what goes into landfills, and reselling materials that still have plenty of life left in them, (and in most cases some heart and soul too, as compared to soulless mass produced big box store items).

If you don't have a business like this near you, you might check with your local junkyard or recycling plant. Also check Craigslist, as people are frequently looking to get rid of these old dinosaurs, and will happily give them for free to anyone who can provide the muscle to remove them.

And muscle you will need! These monsters are HEAVY! I never weighed them, but I would guess that the larger radiator is easily 300lbs. (Thanks for the muscle Brendan!;-)

In picking a radiator, you also need to make sure it will be a sufficient size to heat your space. This involves calculating the cubic feet of your space, and determining the amount of BTU's output by the radiator. Radiators vary in height, the number of columns and the number of fins, so make sure to do your research before committing to a particular radiator. Frankly these calculations were beyond me, so I outsourced this part of the job to my wife's cousin the engineer. (Obrigado Primo;-)

But the above chart may be of some use in this endeavor.

Step 2: What NOT to Do!

My first thought was that I could strip the old paint of these radiators by hand, with some chemicals and power tools. With a new baby in the family, I was determined to remove what was likely lead paint, and restore these radiators to their original beauty.

Oh how mistaken I was!

I started by completely taping off a room with plastic drop clothes (think Dexter's kill room;-) to prevent paint particles from spreading throughout the house.

My radiators were salvaged from a public school building and where likely installed inside a wall and covered during construction, and as a result only had one coat of paint on them. But what a coat of paint it was! A painter friend of mine explained to me that a century ago, paint included high levels of linseed oil, which was a hardening agent that left a hard protective shell. And incidentally makes it VERY difficult to strip.

Note: This work was done while the house was still an unoccupied construction site. I would strongly discourage trying to do this in an occupied home. If you do try to strip a radiator using power tools, chemicals, or both, do so outdoors!

I equipped myself with a quality mask, goggles and gloves, and started the project with an old cordless drill and a wire brush attachment. To continue the butchering analogy, this was akin to trying to butcher a cow with a spork. I moved up to a corded drill and this was like trying to cut through a carcass with a plastic knife. Then I graduated to a grinder and a braided iron brush, and this was finally akin to working on a T-bone steak with a butter knife.

I spent the better part of a week, and many trips to the hardware store for replacement wire brushes, and days of pulling wire schrapnel out of my clothes, and finally gave up when I took a chunk out of the skin on my knuckle with the grinder (straight through the leather glove).

I also tried a variety of chemicals, from mild to highly toxic, and none of these really worked well either.

That's when I decided to find a sandblasting service. And then I learned that sandblasting has actually been banned in NYC. But after quite a bit of searching on the internet, and few phone calls, I found a guy (who shall remain anonymous;-)

Step 3: Sandblasting

Sandblasting is definitely the way to go! It costs a bit extra (I paid about $200 per-radiator), but the end result is certainly worth the extra expense.

Sandblasting gets into all the tiny nooks and crannies and underneath, and most importantly inside the fins of the radiator, which are nearly impossible to reach with hand or power tools.

While the sandblasting does remove a slight amount of detail from the cast iron, these radiators were so incredibly ornate and detailed to begin with, that I decided I could sacrifice a bit of detail to have all of the paint removed.

Step 4: Polishing & Varnishing

The look I was going for was a polished gun-metal look, or a bikini clad beauty emerging from the ocean, but when they came back from sandblasting, they had more of a powder coating effect, (more like my bikini beauties had been rolling around in the sand;-)

But this was easily corrected with a light once-over with the grinder and braided wire brush attachment.

While trying to strip the paint using this method was tremendously arduous and largely ineffective, this was quite an easy and efficient process to polish the metal, giving my radiators the desired gun-metal shine.

Once shined, it was important to get them protected from rust quickly. Freshly sandblasted cast iron WILL rust quickly, even from humidity in the air!

Why varnish and not paint?

One problem with radiators and paint is that radiators get hot. Very hot. (And steam radiators get hotter than hot water radiators). And paint tends to crack at high heat. After all the work I put into these radiators, I certainly did not want to ever have to go through this stripping process again. And my goal was to try and restore them to their original form as much as possible, and paint just didn't fit this equation.

So I contacted a professional paint supply store, and I had them mix me a custom batch of clear silicone based high heat resistance enamel varnish, which I'm told wont peel or crack up to 300 degrees. I hope they're right;-)

I applied a thick coat of the varnish with a specially designed paint brush, much like the one picture here on Amazon: "Radiator Paint brush." This worked great for getting inside all the nooks and crannies, particularly the interior areas between the fins.

Step 5: Custom Parts

I hired a professional plumber to do the actual installation, but before he could do his work, there were a few more custom parts required.

Cast iron radiators can be used in two basic systems; hot water or steam. A hot water system has two pipes; one for the hot water to come in, and one for it to go out. A steam radiator uses only one pipe. Hot steam enters the pipe, and then cools, and the water that condenses drains back through the same pipe.

The radiators I bought were originally used in a hot water system, and I had to retrofit them for steam, which meant plugging up one of the holes where a pipe was. Normally this would be a simple mater of a trip to the hardware store or plumbing supply store for a pipe plug. But what my plumber informed me after much head scratching was that for some reason, my radiators, unlike every other right threaded radiator he had ever seen, had left handed pipe threads...

Not so easy to find a left threaded pipe plug!

(Apparently left threaded pipes where common in the Soviet Union, and left threaded pipe parts can still be purchased in the Baltics and some of the 'stans, but I wasn't about to give a plumber in a former Soviet state my credit card number;-)

So what I ended up doing was buying a piece of pipe with a left threads on one end and right threads on the other, and my neighbor the machinist cut the left threads off the pipe and welded them into a cap. (Thanks Joe!)

The final piece that needed to be added was the steam valve. These were easy enough to find at the local big box store, but took a bit of playing with to get them set just right. The valves need to be adjusted such that they will allow air to escape from the radiator, but not hot water bubbling out, which will eventually damage the floors. This is more of a trial and error process than anything else.

Step 6: Installed

We're now into our second winter with the beautiful Victorian behemoths, and I'm very happy with the final result. Not only do these radiators keep my home and family warm, but they are also pieces of iron art from a bygone era, which are now proudly and prominently on display in my living room and dining room. And if anyone expects to get invited to my home a second time, they better comment on the radiators the first time;-)

Step 7: Bonus Section

If you've read this far, then you are REALLY interested in old radiators and will probably enjoy the above PDF, which is a (public domain) copy of book called "Radiation and Decoration," published in 1906 by the American Radiator Company. This book truly captures how this generation viewed "the art" of home heating.

And if you appreciate this Instructable, please consider voting for me in the Winterize Challenge.



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    Hi Winged Fist,

    This is the first I have read about using tinted varnish to refinish radiators. I LIKE IT! LOOKS GREAT!! It seems like mine are the same finish, partially beneath layers of ugly latex, and back in 1920 radiators "dipped" or coated in tinted varnish make much more sense than the very basic paints they had available to use. I am in the process of refinishing (sandblasting in Upstate NY is A-OK) My question to you is where did you purchase the "Clear Silicone Based High Heat Enamel Varnish" you refer to in your post and what is the color mix you used? I'd like to get some for my own radiators to coat before the heating season arrives- quite soon! Thanks for the great article!!! Geronimo- in upstate NY

    I have a 19 fin Victorian, not sure the year yet looks like its in
    perfect condition! looking to find its value. anyone here know the ins
    and outs of this kind of thing??

    I think "value" in the case of a 19 fin Victorian radiator really comes down to the adage "what the market will bear," or put more simply, what somebody is willing to pay for it.

    Unlike many other items, you can't simply drop a 19 fin Victorian radiator off at the local Post Office and and stick a few stamps on it. These things are VERY HEAVY and I'm sure shipping would be EXTREMELY expensive, so you're really limited to selling it to someone within driving distance, which drastically cuts down on your potential market.

    That said, the right person might spend a lot of money on the right radiator, but it's a matter of finding that person, and I don't get the sense that there is a huge market for antique cast iron radiators. Some people actually pay a lot of money to have these beasts of a bygone era removed, and taken to a scrap yard!

    If it's helpful, I spent about US$500 for the two radiators in this Instructable, (at a non-profit local salvage place) and about another US$150 a piece to have them sandblasted for a total of about $800 to get them to the point where I could buff and coat them with poly.

    Hope this helps!

    Thanks! It does! I appreciate the reply!

    You stated that steam is a one pipe system isn't true. You usually have a two pipe system with steam also. The cooler water or condensation drains back to the boiler to be made into steam again. This stops the usage of adding more chemicals & cold water to produce steam. And, you do need chemicals to prevent the rads & the piping from rusting internally.

    Actually he/she may very well be correct. A steam system can be either a 1-pipe OR 2- pipe system. The 1-pipe has both steam and condensate in the pipe whereas the 2-pipe has one pipe to supply steam and the other to return condensate.

    Thanks for the calrification. I should have been clearer on this. You are correct that there are two pipes in the basement; one for the steam and one for the water to return to the boiler. What I was referring to is that there is only one pipe running into the actually radiator, thus the need for the plug. I was unaware that I'll need to introduce chemicals into this system. How would I know when or if my radiators or pipes are rusting internally?

    Okay, let me clear this up. Apparently you are talking about a 1 pipe steam system that has a automatic vent on the rad. Usually radiators that are in a steam system have 2 pipes connected to them. One is for steam going in at the top of the rad & the other pipe is for condensation comming out at the bottom of the rad. And, there is a 1/4" vent port either at the very top or half way up on the rad. It all depends on how the rad is made & ported. Steam goes in high & the water comes out the bottom. Most of all steam systems are of the two (2) pipe design. And, as far as chemicals are concern, you have to go by the specs of the boiler on what kind & type to add and when.

    As you seem to be very familiar with this technology, I'm hoping you will have time to comment on their efficiency. My belief is that things change to make money for someone, somewhere, not simply because it 'may be unsafe', and that ESPECIALLY applies to power generation. (Lead toxicity is usually related to ingesting or inhaling suspended particles, right? That's why we just kept painting over and over.) But a comparison would be nice between steam heat and electric. This is the type of word problems they should be giving kids in school.

    Steam produced by heating water with gas is probably cheaper than electric heat. Electric heat isn't cheap. Trouble with steam it is HOT! For one thing water flashes at 212 degrees F. A hot water boiler is cheaper than a steam boiler, for sure & smaller. I never worked on a steam boiler that wasn't huge. Thing about radiators they take awhile to cool down once the boiler shuts off. But, when the stat on the electric heater shuts off, the heater is cold. Not so with cast iron radiators. By the way you can dis-assemble the radiators really easy if needed. Just loosen & remove the hog rods, then using wooden wedges, pound the wedges in between the sections on both sides & top and bottom. The section will pull out of the push nipple, which is a non threaded tapered pipe nipple. Tapered on both ends, real easy to do. Another thing about steam heat in relation to hot water heat when the rads are being used on hot water while the rads are hot to the touch, when steam is used those rads you can't get to close to them with bare skin. They are just to darn hot to touch.