Repair Performed by Special Welding
Parish of St. John the Baptist, Carona (BG), October 2015
The first bell, having 123 cm diameter and weight of 990 kg was cast in the year 1951 from Foundry Angelo Ottolina of Bergamo in the year 1951.
The bell itself presented asymmetrical bevels on the whole length of the lower lip, up to the proximity of the abutment point of the clapper. These grindings we believe have been made by the mother foundry for groped to stem a bad merger.
Being carried out in the year 2014 maintenance by our company, it was found an acoustic level of intonation lacking adequate normal intonation features. We therefore spoke first carrying out a thorough examination by the use of special dye penetrant from which it was found that grinding cracks were presented in an important way as to completely cross the thickness of the same bell.
In order to contain the costs of a new bell recast it proceeded to the complete disassembly of the bell and its transportation to our company.
The cracks present initially presenting with a length of about 20 cm for the first clique, and of about 42 cm for the second.
REPAIRS BY SPECIAL WELDING
The first bell of the repair operations (main bell) were held as briefly indicated:
- Disassembly of the clapper;
- Finding the end of the bell break;
- Check for any possible extensions of breaks;
- Cleaning the interested party;
- Preheating with special oven at varying temperatures with achieving the desired temperatures by dedicated control software;
- Welding with proprietary technique, for which were used approximately 37 kg of filler material;
- bell cooling through dedicated software;
- Grinding of the section concerned with appropriate instrumentation and grinding finishing;
- Final verification penetrant;
- Cleaning the bell with sweet blasting;
- Repositioning of the bell in the bell tower with rotation of the striking point of the same amount to 45 °.
In addition to the transactions described above, after the intervention of welding it proceeded to replace the clapper and telebattente to the sound of the hour.