Dear colleagues! In the last time we figured out how to remove old coatings, anti-gravity and cleaned welds. Now we are ready for spackling.
Today you will learn:
- how to align the surface before the filler;
- how to prepare the surface for spackling;
- on the surface which can be applied to filler, and which can not be;
- in what proportions to mix the filler and hardener; what should be the movement, with stirring;
- how to apply putty;
- as the filler to dry.
Substrate Preparation puttying reduced to two mandatory requirements: The surface must be clean, and on it with the help of an abrasive material coated risks specific configuration and size. Only the joint implementation of these two conditions will provide reliable adhesion of putty layer.
Questions surface cleaning and polishing we discussed in the last article.
When grinding pay attention to the old paintwork border around the defect to the maximum smoothed sloping state. This is important because it affects shrinkage fillings. For more information, you will also find in the last article.
Smoothing old paintwork borders
After graduating from the grinding, the surface should be blow the compressed air and degrease more times.
On metal or on the ground?
We often hear the question of whether it is possible and necessary to prime the metal before Shpatlevanie. Response - it is possible and necessary, provided that it is an epoxy primer. Although the application of epoxy primer layer to bare metal before Shpatlevanie - operation in most cases ignored by the masters, let's see what this gives us.
First, we get 100 to metal corrosion protection. It is not necessary to forget that in the process of refinishing, we must endeavor to provide maximum protection for the metal, which is comparable in quality with the factory.
Also keep in mind that in the repair putty mass layers are sometimes quite thick, so the coating must have good adhesion. When we put putty on the bare metal, the chemical adhesion is not necessary to hope - putty in this case holds only created by the grinding material risks. In the case of the filler is applied on top of the soil, in addition to the physical adhesion (due to risks), we get more and chemical (adhesion fillings with the ground).
So that the use of epoxy primer before Shpatlevanie clearly justified. On the increase in the cost of the repair will be affected minimally because the soil flow is not great - it is enough to put just one thin layer. But the durability of the coating increases significantly.
Meanwhile, there are situations in which it is not necessary to select and pre-coating is optional. This includes work on aluminum and galvanized surfaces. The fact that these types of surfaces to have a relatively high adhesion only certain special types of fillers. However, these fillers can be made, not all types of work. For example, large dents, through-hole is recommended to plug the putty with glass fibers. But the problem is that not all fiberglass putty firms have sufficient adhesion to aluminum. And here comes to the aid of epoxy primer. Apply a thin layer of metal, and the top of it - any polyester putty.
Do not apply the putty on the old paintwork. The fact that ethers produced during drying putty - most aggressive solvents of all. And their interaction with the old paintwork, especially where it rasshlifovki, can turn very dire consequences, starting with delineating the filled area and sagging / swollen scratches, finishing with a total loss of adhesion.
But in fairness I must say that avoid completely the filler is applied to the old paintwork is not always possible, especially in the areas of transition. Often this happens when clearing the defect to the metal, we have not calculated and "cleared" the area is too small, and when Shpatlevanie, layer by layer, gradually "overtook" the old paintwork. With factory coated, which had not previously been subjected to repairs, problems usually does not happen.
In this case, again, the pre-coated metal epoxy primer with a stop at the old paintwork we will be able to play it safe, and while the putty will be in the ground area, we have nothing to fear. Neutral to all epoxy primers is, perhaps, the only material that is not dissolved ethers.
For the above reasons, putty, under any circumstances, be applied to the primary acidic soil (also known as acid, etching, reactive), as there is an active chemical reaction in the process of drying putty, which destroys the primary primer film.
To sum up a little on surfaces that can / can not be putty.
Thus, the conventional filler is recommended to apply three types of surfaces:
- bare metal;
- other polyester putty;
- dried epoxy primer.
If you are working with aluminum or galvanized surface, it is necessary to use a special putty for working on these surfaces (usually a universal putty) or primed surface epoxy primer and only then apply any polyester putty.
When repairing plastic parts need to apply a special filler for plastics.
Do not apply the putty on old paintwork, and even more so on the one-component material (1K-soil, alkyds, "the base"). It is strictly forbidden to put putty on acidic soils.
With this sorted out. We proceed to the preparation of fillings.
Preparation of fillings
For mixing filler with a hardener is necessary to prepare two blade spatula. When mixing large amounts of useful "easels" - small metal plates, plexiglass, plywood and so on. Organic glass, unlike other materials, can be easily cleaned from the hardened putty (with a spatula or a knife). Do not forget to thoroughly clean the entire working tool after each operation shpatlevanija.
With regard to the volume, it is desirable to mix an amount of filler, which will be enough to work for 3-4 minutes. Then putty begins to grasp and process of applying complicated and shpatlevanija quality decreases.
The proportions of the hardener
The percentage of hardener depends on the temperature and varies between 1.5-3% by weight of the filler. Thus, at 13-24 ° C in a filler is added 2% hardener. At high temperatures (25 ° C and above) are allowed to add slightly less hardener (1.5%) at low temperatures (12 ° C and below) - slightly larger (3%). But to go beyond these limits can not be.
Quite often, the master, especially during the cold season, add the hardener more put, expecting from this putty quickly grabbed. But it was not there. In fact, the reaction takes exactly as much hardener, as necessary, and its surplus (the part that exceeds the three percent barrier) is stored in pure form. And as the hardener (peroxide), - chemically very aggressive substance, its residue can "leak" through all the layers of the coating down to the paint and react with its pigments that discolor them. As a result, shpatlevanija spot will be seen on the finished paintwork! This is particularly evident in the blue tones. These are the "miracles" ...
Therefore, if taken too much hardener and filler mass when mixed becomes pink hue, such filler is better not to use it and throw it away immediately.
If you add too little hardener, putty is fragile. When grinding abrasive will clog and scratch the surface.
How not to lose the proportions? To do this, a couple of times to take advantage of electronic scales to train the eye.
Spatula which will stir, put on the scales and reset them. The second spatula put 100 g of filler. Therefore, we have to add the curing agent 2 g (2% from 100 g). Thus we get the right balance - 100: 2. If 100 grams a lot for you, put 50 grams of putty and squeeze 1 g hardener (2% of 50 g).
Visually remember this relationship in the future will be able to easily do without weights. If some error has been made, it is in any case fall within the range of 1.5-3%.
Visually, the ratio of 100: 2 corresponds to the volume of a tablespoon and a pea. This will help you in the absence of scales.
Get putty from banks better separate clean spatula. It is undesirable for this use the spatula, which is involved in stirring filler and hardener, otherwise the bank will "be recorded" peroxide and putty will gradually lose its elasticity.
Mixing technique putty with hardener
At first glance, the mixing technique fillings may seem something not very important, but in fact this is a very important moment, because ineptly blended mixture, due to the large amount of air in it, leads to the formation of voids, large pores and craters subsequently cause drawdown and even local delamination of the coating.
Mixing putty hardener is done with cutting, pressed movements (step 1 and 2). The exception is the putty with glass - it should be mixed in a circular motion to avoid damage to the fiber.
To test the uniformity of a little smudge on the putty spatula (step 3). This technique of mixing putty is correct and allows you to not "chase" in her reverse air traffic.
Stir until completely disappear until the traces of red hardener. Remains of fillings on one spatula try to trim other. Solid color fillings talks about her readiness to deliver.
The curing agent (peroxide) - this substance turbid milky. The bright red color of its paint specifically for the control of the mixing uniformity.
Shuffle? Excellent! From this moment begins a chemical reaction and our putty cures in 4-7 minutes (harden). So let us go.
Technique of putty
Great minds have considered that in order to completely push the filler into the risks left abrasive, and squeeze the air out of them, you need to apply a force of 2-4 tons per square centimeter.
Therefore, the first layer, we need to be applied with maximum force, and only a thin layer, holding a spatula entire area intended shpatlevanija. If the force applied at the first layer is insufficient, then the coating may shrink, "falling" in unfilled voids and surface grinding LPC manifest risk.
So that the first layer (also called adhesive) must be "rubbed" with all the enthusiasm. And already it is possible to apply thicker layers of fillings.
A metal spatula during application must be held at an angle of 45-60 ° relative to the surface. This tilt provides maximum indentation fillings in the risks and the best way of replacing the air layer.
Before drawing each stroke to be done subsequent steps 1 and 2 for the mixing circuit. In this way we clean spatula and turn smoothing compound, slightly prolongs its viability (it cools down a little).
If you are working with fiberglass putty, we must remember that after drying it becomes very hard and difficult to grinding. Therefore, it is recommended that no sanding block melokozernistoy putty. You do not need to wait long - after 10-15 minutes, it can be applied to the other filler.
Thus, firstly, we will not have to suffer and grind coarse fiberglass putty (it will need to do, if it will have time to dry completely). Sand will have only a layer of fine-grained filler, which is much easier. And secondly, the adhesion between the layers of filler is more powerful, because the chemical interaction nedosushennoy and fresh fillings contributes to this.
Generally, any filler is able to take the next layer without grinding for one hour. But if more time has passed, then the applied layer must be sanded before applying the next, otherwise proper adhesion will not be.
When removing large defects is not necessary to seek to align all in one go. It is better to apply several thin coats than one thick. Too thick layer may not be sufficiently tight in the future may putty to sink and crack. In addition, in a thick layer to be concluded a large number of air bubbles, which in turn polishing in the craters requiring additional shpatlevanija.
When applying putty remember that the more accurate will be the stopper surface, the easier it will be to grind. So try to make each layer is beautiful. To this end, smooth movements straighten putty, removing "step" and giving details of the desired shape. Borders also filled area to try to smooth out the maximum soft state, propped on one edge trowel Beacon surface (undeformed portion).
For shpatlevanija convex and concave surfaces is convenient to use special flexible rubber spatula.
After 4-7 minutes after mixing the filler starts to set. You will feel this time to increase efforts at drawing. This is a signal that it's time to call it a day and clean spatula.
Since the filler is cured at a very different circuit than all the other paints and varnishes (her reaction with a hardener accompanied by a sharp release of heat), to its grinding can begin relatively soon - after 20-30 minutes after application (at 20 ° C).
At low temperatures, the putty dries longer, so the polymerization process can be accelerated by using infrared drying or hair dryer.
It should be remembered that the polyester putty sensitive to high temperatures and overheating, they can crack and swell. Therefore, when warming up the item, watch the degree of heat to the touch. Putty can be moderately hot, but in no case should not burn your fingers. If possible, the item can be heated from the inside.
The maximum temperature that can withstand polyester putty - 60-80 ° C. Although to this rule there are exceptions - the putty with aluminum filler. It withstands heat up as much as 135 ° C!
But the best for drying putty without doubt the shortwave infrared lamp, which gives a full guarantee that the filler will not shrink in the future. A surface in this method of drying is ready to sand after 5-7 minutes. Only in this way it is not recommended to place the transmitter close to 60 cm of the repaired site.
Summary of spackling
- Keep container tightly closed with putty, or from eroding the banks will be solvent and putty will lose its elasticity.
- Stick to the right proportion hardener - 2% by weight of the filler. In cold weather this share increased slightly (3%), in the heat - lower (1.5%).
- Mix the putty and hardener chopping motion.
- The exception is the putty with glass - it should be mixed in a circular motion to avoid damage to the fiber.
- Apply putty to the pre-sanded and degreased surface. Graduations sandpaper: P80 in the main zone, P150 in the peripheral zones. When repairing plastic items for both areas quite P150.
- Putty is applied only on bare metal or dried epoxy primer. In no case can not be applied to the filler acidic soils.
- The first filler layer should be thin, and the maximum force applied.
- Lifetime putty after mixing is 4-7 minutes. During this time, you need to have time to apply it.
- Putty is able to accept the next layer without grinding for one hour.
- Do not apply too thick layers. It is better to apply several thin, than one thick.
- After each operation, thoroughly clean the spatula scraping against each other. Each new layer is applied to a clean spatula. To clean spatula solvent may also be used.
- By grinding fillings can begin after 20-30 minutes after application (at 20 ° C).
So, our surface Stopper and dried, you can now proceed to the grinding fillings. It will talk in the next article. And for today. Till!