The reparation of deposits by filler rod is a relatively cheap work and that it is not difficult to do but which, at the same time, requires to perfectly know the process and to have the proper material.
The experience will contribute to do a good work. The aim of this article is not to explain the reparation process, which has been explained in other articles, but to give some advice which contributes to improve the reparation where it is possible.
Firstly, we must remember that the resistance to the chemical agents is the main reason why the thermoplastic materials are chosen to store all kind of liquids, from flammable chemical products to water, going through several fuels.
In the sea water desalination plants, tanks, neutralizing plants, as well as wastewater recovery plants and all type of deposits it is exploited the advantages of the thermoplastics, whose extrusion welding is used for many basis and lids.
Advice not to make mistakes in the welding
Prestar especial atención a la elección de la tobera adecuada
There are five different extrusion welding; with join by overlap (film weld), and with V-shaped welding or ‘v weld’, T-shaped welding or ‘fillet weld’, with the shape of an outside corner or ‘corner weld’ and X-shaped welding or ‘x weld’.
The weldings V and X have the same nozzle, but the rest has a different nozzle. Not using the correct one in each case doesn’t suppose not placing the rod in the necessary place.
Keeping the speed of the constant extrusion
Not too quick, but not too slow. In the first case, we will not get the welding of the pieces, and in the second case, the welding iron can be burned.
>>> IMPORTANT: Doing correctly this process will take you some time… as the speed must go hand in hand with the temperature, if at the beginning you find it hard to do and you go slower than the normal average, slow down the temperature to avoid burning the plastic.
Never forget the scratching phase.
The typical mistake due to the inexperience. With the scratching it is removed the external layer of oxidation and the characteristic bright which acquires the external layer during its fabrication.
Proving always that the nozzle has no worn-out Teflon.
If we aren’t sure of its right state, we take the risk that the Teflon could produce malformations in the join and spoil all the work. Especially we must pay attention if the nozzle is old, as the damage can make it lose its original shape.
Collocation and adjust of the pieces to weld.
Before welding by filler rod it is essential that the main requirement is fulfilled: the perfect alignment between the pieces. Tracing them with a manual welder where we are going to join them will help us. In the case of being two workers, one could assure that the pieces are joined while the other welds them with the extruder machine. Always increase the attention in the case of joining parts of the deposit which make a corner.
Using the igniter to prove the welding.
It is a non-destructive method which checks the possible leaks which have been produced due to high frequency.