Welding pores
1. Preparation
Depending on the size of the pore, various methods can be used to remove it.
An important prerequisite is that the weld or pore is clean.
No dirt such as polishing agent or investment material must be embedded in it!
2. Use a fresh electrode
Small, pinprick-shaped pores can often be closed quickly and easily. Use a pointed electrode and a low welding power.
Hold the handpiece perpendicular to the workpiece surface and place the electrode
precisely in the pore.
3. Soldered joints
Be careful with pores in solder joints! Solder can vaporize due to the lower melting temperature and thus tear a larger hole. It is therefore better to work with a lower welding power and a short pulse duration.
4. Reaming for larger pores
Larger pores that cannot be closed in the manner described above should be drilled out and a pin inserted. Chamfer the edge of the hole slightly with a scraper or milling cutter and shorten the pin so that it protrudes about 0.5 mm from the hole.
Then melt the edge of the pen into the joint all around.
5. Use a riveting wheel / cutter
To improve the homogeneity of the freshly melted metal, process it with a riveting wheel, for example, or forge it lightly. Sometimes it is advisable to cut a recess with a ball cutter in order to weld in a ball. Place a welding spot vertically on the end of a wire to melt a ball. This should be slightly smaller than the milled recess.
6. Use welding wire
For larger porous areas, it is advisable to remove the entire upper metal layer with a milling cutter and fill the area with welding wire (see workshop 2.1 and 2.2). If the porosity is too deep to mill it out completely, you should apply a few spot welds without adding metal before filling. The porous area is compacted by this melting.
7 Correct welding
Always hold the electrode tip in such a way that the electrode moves across the indentation during welding. You pull the supplied welding wire into the direction of the indentation. The molten metal always flows together where the electrode was placed! If the electrode has a flat angle of attack, the metal also flows from the point of contact in the direction of the electrode movement. Deep and steep pores can be made shallower and wider with a spot weld (possibly with a longer pulse) at the deepest point so that they can then be filled better.
8. Shrink hole
Shrink holes that are larger under the surface than can be seen from the outside are particularly annoying. The thin edge around the opening melts away and the hole becomes larger instead of smaller when
is welded.
In this case, it is advisable to mill out the shrink hole or widen it slightly with several individual welding spots and then fill it with metal afterwards.
