Hi Everybody! My name is Alexander Kuznetsov, I'm professional body worker (my specialisation is thermoplastics repair). I'm new here
And i would like to share my experience in auto body work and maybe learn something new from You.
I will give you information about technique where the high quality planar connectors Bamperus can help you to repair the plastic expansion tank in automobile, truck, and tractor. All expansion tanks can be classified by the plastic type: PA6 or PA66 and copolymers on the basis of PP. Now we will show you the example of repair of two expansion PP tanks. PA6 repair is approximately the same. So what is the reason when the expansion auxiliary tanks suddenly crack and break without significant reasons (accidents)?
As usual the reason is the same in all cases. Hot gases systematically enter into cooling system. As example they enter through clearance leakage between cylinder head and cylinder block.
Usually we can see this situation when we speak about big diesels of trucks and tractors. Gases going through the cooling system and radiator enter to the expansion tank. Gases beat the tank walls opposite the tube leading from the radiator. The wall is broken in this area – the plastic is dry, it becomes brashy and cracked. Also the plastic is broken when the gases are concentrated in tank creating bubbles. The tank can be safe and completely new because the plastic doesn’t contact directly with hot exhausted gases.
This damage repair can be performed with use of heat sealing and good welding rod. All the rest methods (wire rods, glues, cool welding, composite resins, and brand chemical compositions) are short time because this area is under inner pressure within the constant critical differential temperature (up to 150 degrees) + chemically corrosive atmosphere: tosol cooling agent, antifreeze and gases. As a rule repair that is alternative to the heat sealing can be hold only prior to the place of repair but it is not enough.
New tanks usually cost a lot of money (including equipment) but if you buy secondhand goods you have the tank with similar damages. When you have this like tank to repair a small break or empty piece you need to define the volume of the works because it is useless to weld to the destroyed plastic – it will crack the surface. It becomes brashy and cracked in place where it lost its properties.
That’s why you cut all by flat-nose pliers. When plastic is in usual condition and normal, it will bend, crease but not crash. It is important to find out the edges of original break and its square. Usually the break is significantly bigger than that was shown to you for repair. It should be taken into account so you perform the repair quick and at a high quality level. Also it depends on the pricing.
Then we take a piece of bumper with thick wall. The marking of the plastic should be started with PP. You can take appropriate piece of bumper with a big wall and acceptable quality of the plastic. Cut the piece in shape, heat it, band in shape of tank.
Tack the break all round by soldering-copper making V-shape groove on the break.
Closely apply the planar connector of group A without gaps and bubbles.
Then cut the odds of the planar connector of group A by the abrasive tool making a gliding transition from place to place without sharp levels and grooves. It will allow applying the connector of group C closely to surface.
The connectors of group C will be applied leaving the distance of 2 – 3 sm around the break. The planar connectors are applied overlapping to each other. You need to spread the last connector before, making the shape and gliding transition by the next connector.
One more example:
Ask me if You have any questions!