Renovation of cast iron radiators - step by step

LIFETIME AND TIMELESS DESIGN

Cast iron radiators are unique products, both due to the material they are made of and their decorative properties. Terma, in addition to ready-made new cast iron radiators, also offers a cast iron radiator renovation service, which allows these functional items to be given a new life.

We provide a five-year warranty on tightness and coating for radiators renovated in our plant.

Cast iron radiators fit not only classic and stylized interiors, they also work great in modern spaces, giving them character and a timeless look. Cast iron combines perfectly with other natural materials, such as wood, stone or high-quality natural textiles, e.g. wool. In addition, it is a long-lasting material, a cast iron radiator after renovation will serve us for several decades. By choosing a cast iron radiator, we also gain certainty that changing fashions and trends in design will not affect its timeless character.

Why renovate cast iron radiators?

Cast iron radiators often have sentimental or even historical value. Terma receives richly decorated pieces from the turn of the 19th and 20th centuries, as well as simple ribs from the era of socialist realism, whose owners who value eclecticism want to preserve the original elements of the interior design of that period. The very wide range of finishes of cast iron radiators that we offer gives you the opportunity to play with color, and also allows you to emphasize decorative elements.

Renovation of cast iron radiators is a craft process that requires an experienced hand and a sensitive eye that will notice and bring out the beauty hidden under a layer of damaged coating. We treat all radiators delivered to us with due respect, after all, they are often objects that remember the youth of our grandparents and great-grandparents. During the renovation process, we do not cut corners, we devote as much time to each rib and detail as needed to achieve the expected effect. Our employees are masters in their craft, devoting themselves to creative work every day, the effect of which are unique, one-of-a-kind products, radiators "with soul". The team works under the supervision of sculptor Krzysztof Michalak, creator of the original Kaszub radiator, who supports the renovation of radiators of historical value with his knowledge, and often with his hand. By entrusting us with renovation of your radiators, you can be sure that they are in the hands of enthusiasts of the subject, with the experience and knowledge necessary to properly carry out the renovation process.

In the following part of the text, we will present the individual stages of the renovation process, so that you know exactly what actions will be taken by Terma employees.

Radiators for renovation after reaching the plant in Czaple near Gdańsk.

STAGE 1. ACCEPTANCE OF AN ORDER FOR RENOVATION SERVICE

We invite those interested in the renovation of cast iron radiators to submit an inquiry using the contact form. Our team will make a preliminary valuation and contact you to present an offer. Submitting an inquiry does not oblige you to accept the offer, you will not incur any costs before the radiators are delivered to us.

If after our team has prepared the offer, you decide to accept it, we will help you deliver the radiators for renovation. We cooperate with experienced carriers, we will also provide you with information on how to prepare the radiators for shipping.

After reaching our plant, the condition of the radiators will be visually assessed and photographic documentation will be prepared. If at this stage damage that is not suitable for repair is detected, we will contact you to determine further actions.

After determining the final price for the service, the renovation service order will be entered into our system. It is the basis for generating a pro forma invoice, which you will receive via e-mail.

I want to ask about the renovation of my cast iron radiator

STAGE 2. Pyrolysis

After completing the inspection stage and making formal arrangements, we first remove old, damaged paint coatings from the radiator. This process is carried out as a result of pyrolysis, which involves the thermal decomposition of successive layers by exposing them to high temperatures, but without the participation of oxygen or other oxidizing agents. Pyrolysis takes place in a special furnace, and during the process, scale deposits inside the radiator fins are also crushed. After the operation is complete, the radiator is set aside to cool down freely, and the effect of this process is to obtain a clean cast iron mold, without coatings and deposits. The pyrolysis service is performed by an experienced external supplier and usually takes no more than one week.

The radiator after the pyrolysis process.

 The radiator after the pyrolysis process and after disassembly.

STAGE 3. DISASSEMBLY RADIATOR

Using a specialist set of wrenches, our employee disassembles the radiator into its component parts: ribs, nipples, reduction plugs, screw connections. Each of these elements is carefully checked for possible damage and surface defects.

The most common imperfections of ribs are damage to the sockets, deep pitting and overflows on the external surface. As a rule, they are the result of poor technical quality of the casting itself.

If elements that cannot be repaired are detected, the defective ribs or nipples are excluded from further process, about which the Customer is informed immediately.

STAGE 4. INTERNAL CLEANING AND TIGHTNESS CHECKING OF INDIVIDUAL RIB

Each rib is subjected to cleaning carried out using a compressed air blower. In addition, if necessary, persistent sediment is removed using a scraper. Then, the ribs are tested for tightness by filling them with water, which additionally allows for rinsing out any remaining dust and sediment. If a leak is detected, the team of employees decides to repair or, if it is not possible, to exclude the rib from further process. Repair of damaged fins is done after shot blasting (stage 6). If an element is excluded from the process, you will be notified immediately.

    Threading holes in a cast iron radiator.

STAGE 5. THREAD RENOVATION

Each thread in the fin is renovated using appropriate tools (taps). Thread regeneration results in precise cleaning of the sockets and sharpening of the threads, thanks to which the ribs adhere to each other as closely and evenly as possible during the screwing process.

STAGE 6. SHOT BLASTING

The surface of the ribs is cleaned of corrosion deposits and other contaminants using a strong stream of steel shot. This process takes place in a special cabin, to which the ribs are delivered after being hung on special hooks.

The effect of this process is to obtain elements whose surface is clean raw cast iron.

STAGE 7. VISUAL INSPECTION AND REPAIR OF DAMAGES AND LOSSES

The ribs prepared for the painting service are carefully inspected for any minor damage that became visible only at this stage. Damage and defects are repaired with specialist cast iron repair compounds from renowned manufacturers, which effectively and permanently bond to the surface.

Repairing defects is a very important stage, requiring the employee to have a sense of form and special care. In the case of very large deformations caused by low casting quality, our employee will consult with you to discuss the scope of repair. You can decide to smooth the surface or leave the fins in their original condition in order to maintain the authenticity of the radiator.

 Painted fins and elements of a cast iron radiator.

STAGE 8. PAINTING

The previously prepared fins are first covered with a layer of an appropriate primer. After the coating dries and hardens, the ribs go back to the painting chamber, where they are painted in the color specified by the Customer.

We offer a choice of RAL palette, special color palette, and decorative finish. All paints and varnishes used in the painting process are appropriately selected for use on cast iron surfaces.

CHECK OUT OUR FINISH PALETTE FOR CAST IRON RADIATORS

Test the radiator for tightness after assembly, the last stage before the packaging process.

STAGE 9. ASSEMBLY OF THE RADIATOR

Dry fins, whose paint coating has been suitably hardened, are sent for assembly. The configuration is previously determined with you, it is possible, for example, to assemble two five-fin radiators from a ten-fin radiator supplied initially. The ribs are connected using original nipples and, if the original connectors were excluded from the process due to damage, using replacement nipples. Each connection has a new fiber gasket, this also applies to the reduction plugs.

STAGE 10. LEAKAGE TEST AFTER ASSEMBLY

The assembled radiator is subjected to a tightness test. The radiator is placed on a special stand, where after screwing the plugs, water is introduced into its interior. After filling, the liquid pressure is increased twice, to 5 bar and to 13 bar respectively. Each increase in radiator pressure is concluded with a thorough inspection, the purpose of which is to detect any leaks. The employee uses a paper towel to check the surface of each fin and each joint. Any leaks are marked and the radiator is returned to the assembly station, where any necessary corrections are made.

STAGE 11. PACKING AND SHIPPING

Finished radiators are professionally prepared for transport by the Packaging Team. Transport takes place on a pallet, which guarantees safe transport conditions for the radiator. After the renovation process, the radiator is ready to be connected to the central heating system, or it can be filled with oil and work in a version powered by an electric heater. We provide our customers with advice on the selection of all accessories.

We will be happy to answer your questions and prepare an individual offer for you. We invite you to contact us.