Phase 3. NiKaSillen, honing and finishing the cylinder
After your cylinder has been pre-treated at PowerSeal as described in previous articles, we will start the actual application of the NiKaSil coating. The cylinder is cleaned in the preliminary stage and the old layer is chemically removed. After this, the cylinder is prehoned to start, when applying the layer, with a round and straight cylinder as also described in the previous article.
The cylinder is now measured to determine the correct layer thickness of the NiKaSil coating.
After this, the cylinder is further cleaned in the pre-treatment tanks. Using ultrasonic degreasing and other chemical degreasing methods, the cylinder is cleaned deep into the pores to ensure that the NiKaSil coating has a perfect adhesion. After this pre-treatment, the cylinder is put in a specially designed rack and an anode is applied. In this rack, the cylinder is placed in the NiKaSil bath. The layer is applied electrolytically under the constant control of an advanced in-house designed computer system.
When the desired layer thickness is plated to the cylinder, a signal is given and the cylinder is taken out of the NiKaSil bath and rinsed thoroughly. The cylinder will be chemically purified again. After this action, the cylinder is blasted clean in our glass bead cabin and is sent to the honing department.
In the honing department the applied layer thickness is checked and on the work card we check if there are any special wishes with regard to the final size. It is possible that a piston has been supplied or purchased and the size of the piston together with the desired or prescribed tolerance determines the final size. Or it is possible that we use the standard size as specified by the factory.
The cylinder is now initially pre-honed with special honing stones to remove the possible sharp edges. After this, the cylinder is honed with finer honing stones at one of our automatic Sunnen honing machines until the final size is almost achieved.
It is very important that the cylinder is round and straight. During this honing process, the dimensions are checked constantly with micrometers. The final phase of the honing process is carried out with extremely fine stones to create maximum performance. This way of honing is also called plateau honing because there are three phases of honing in which the scratches are laid crosswise over each other. This is a requirement to create enough oil channels to provide the necessary lubrication between the piston(ring) and cylinder wall during the use of the cylinder.
Despite the fact that this hone process takes place in an air-conditioned room of 20 degrees, the honed cylinders are measured again the next day by our quality inspector. If okay, the cylinder will be thoroughly degreased again and goes to the end-control department.
In the end-control department all cylinders are checked and the ports are polished. Also the top and bottom are checked here. With two-stroke cylinders with have a bridge in the exhaust port, it is polisched back as it is done at the factory. This is to prevent possible cylinder jamming. After this process, the cylinders are cleaned for the last time and are sent back to the customer.
Again, a broken cylinder has been given a new life.