During the operation of heating systems, and chimneys in particular, periodically there is a need to get rid of the cracks, gaps and cracks that have appeared. Similar problems are often faced by owners of brick structures - fireplaces or stoves.
In such cases, you risk not only an increase in fuel consumption, but also the penetration of combustion products into the living room. Which, in turn, can cause severe poisoning, and sometimes even cause death. Therefore, the maintenance of heating systems must be approached with all seriousness.
Chimney features
If you put high-quality ceramics or a sandwich in the chimney, then these problems are minimized. But not everyone can afford such expensive equipment, as well as expensive installation, so many have to use what they have.
Normal operation of the chimney is possible in the absence of gaps, that is, the system must be airtight. Very often, soot accumulates on the walls, and if it gets access toair, it can easily ignite. Considering the local temperature of 1500 degrees, the fire will easily spread to the partitions and the roof. What will happen next is clear to everyone.
It is also worth noting that the cracks in the chimneys are the cause of the attenuation of the flame in the gas boiler. In winter, when the winds are strong and unpredictable, you run the risk of being left with the heating turned off. In the daytime, this is a completely solvable problem, but waking up at night from the cold and going to kindle the boiler is still a pleasure.
What to do?
Special sealants for chimney pipes act as a panacea in this matter. This is, as a rule, a consistency that is already ready and poured into tubes, resembling ordinary toothpaste. Sealants for chimneys are different both in composition and in the method of application. Therefore, it is very easy for the average consumer to get confused in all this diversity.
We will try to understand this issue and consider the features of sealants for chimneys: characteristics, application and the feasibility of buying in a particular case. Similar compositions are sold in any hardware store, so there should be no problems with the purchase.
Types of sealants
The main component of the sealant is polymers. Moreover, different compositions are used, fillers are added, and the main qualities of the final product depend on this. The packaging of sealants for chimneys is also different: in tubes like toothpaste, under a mounting gun, or in very modest portions for one-time use.
Also foundtwo-component formulations that must be mixed before use. Due to the strict requirements and the finicky of the product as a whole, such chimney sealants are recommended to be used only by professionals in their field. Yes, they are cheaper, and they have more returns, but for one-time and small jobs, there is a lot of hassle.
Specifically for chimneys, special compounds are used that can withstand high temperatures. But even here there is a gradation, which you must definitely pay attention to before buying. On sale you can find two categories of sealants - heat-resistant and heat-resistant. Depending on the temperature and type of work, the appropriate category is selected with its own specific characteristics. Let's take a closer look at them.
Heat resistant compounds
Heat-resistant sealants for the chimney are made on the basis of silicones. The specific temperature regime can vary greatly and depends on the selected composition. For example, when iron oxide is added, the sealant perfectly tolerates heat up to 250 degrees with short-term peaks up to 315 ° C. Similar compositions have a reddish-brown color and are great for stoves and fireplaces with a similar range.
It should also be noted that silicone sealants can be neutral or acidic. The latter are much cheaper and give off acetic acid when hardened. Therefore, it is better to exclude such compositions when working with metals that are not resistant to corrosion, as well as concrete and cement. Such sealant for stainless steel chimneycome in handy.
Neutral Lineups
Neutral compositions, when dried, emit only water and alcohols, so they can be used almost everywhere, of course, with an eye to the maximum temperature. They are resistant to direct sunlight, impervious to water and have good adhesion to brick, concrete, ceramics, wood and glass. You can also use a similar sealant for a stainless chimney.
Features of heat-resistant compounds
The curing speed of silicone sealants can vary from several hours to several days. Here, again, everything depends on polymers and fillers. In addition, the date of manufacture of the product also plays a significant role. That is, the fresher the sealant, the faster it cures.
Approximate curing speed should be indicated on the packaging. The optimal parameters for silicone products are temperature around 25 degrees and humidity within 50%. Everything that is out of these limits, one way or another affects the rate of hardening. Low temperature and high humidity - long curing, and vice versa.
Heat resistant compounds
Heat-resistant sealants for chimneys, or, as they are also called, heat-resistant, are produced on the basis of silicate. Such compounds can tolerate very high temperatures. For them, the normal working environment fluctuates around 1200-1300 degrees. Some heat resistant chimney sealants can withstand peak temperatures of 1600°C. In this case, another characteristic is indicated on the packaging -"refractory".
This composition is used where there is direct contact with fire. That is, inside the chimney, and not outside, as is the case with synthetic sealants. Silicate compounds are excellent for filling gaps in kiln-cast masonry, sealing fireclay bricks, and sandwich and stainless steel chimneys.
Heat-resistant compositions are recommended in all cases for the internal processing of chimneys. An exception can only be condensing or pyrolysis boilers, in which the temperature of combustible materials at the outlet does not exceed a temperature threshold of 150 degrees. Here it is much more practical to use a regular heat-resistant sealant.
Features of heat-resistant compounds
It is also worth noting that heat-resistant compounds are very well combined in an impressive list of building materials: stone, concrete, cement, metals, including stainless steel. Perhaps the only critical drawback is associated with smooth surfaces. Heat-resistant sealants do not adhere very well to them, unlike heat-resistant counterparts, so additional abrasive preparation is needed here.
In addition, the composition is picky about the temperature during application. The best option is the upper limit of 40 degrees and the lower limit of 20. Otherwise, the stability and quality of solidification is difficult to guarantee.
After hardening, the consistency of heat resistant sealant becomes rigid and inelastic. Therefore, this composition is best used in places where vibration is excluded or at least minimized. Otherwise, the sealant will simply crack. But this nuance also has its advantages. A solid compound is much easier to apply paint, which will adhere noticeably better than flexible heat-resistant sealants.
Stamps
Almost all popular and sought-after manufacturers write on their products that the sealant is intended for chimneys, so in a good half of cases there should be no problems. In addition, detailed information on the label will allow you to navigate the temperature regimes, as well as the belonging of the composition to a particular resistance class.
Among the manufacturers, there are several of the most popular and well-established brands. Their products are enviably popular and have a lot of positive feedback on specialized forums from consumers.
Best Manufacturers of Chimney Sealants
- Penosil.
- Soudal.
- "Titan".
Penosil boasts the production of extremely high quality heat-resistant sealants that can easily withstand temperatures of 1500 degrees. Soudal, as they say, ate the dog on heat-resistant compounds, and on its shelves you can see a huge assortment of silicone fillers for any chimney.
Titan offers generic products for the most part. Its sealants withstand temperatures up to 1300degrees and are attractively priced compared to the formulations of the two previous brands.
