Double Holing on Handrails
One of the most common problems encountered is the incorrect positioning of holes in tubular handrails. The principle for hole position is quite simple. All handrails are dipped at an angle that creates a high and low point at the end of each tubular section. The high point is where the heated air will expand to and the low point is where the molten zinc must flow in and out. These points must be diagonally opposite (see illustration).
If you drill right through the ends of each hollow section then this can cover all hanging options.
What is often misunderstood is the importance on how close the hole must be to the end of an enclosed section. If the vent hole is too far away the handrail can float in the molten zinc causing a poor quality finish. If the drain hole is too far away it will trap liquids which can cause potential explosions in the bath. This would also lead to zinc being trapped causing zinc runs and again substandard quality.
For superior quality handrails:
- Holes must be within 10mm of the ends.
- Holes must be diagonally opposite.
- Or if in doubt drill right through the hollow section at each end as this will cover all venting and drainage options.
- The minimum hole size is 10mm but remember as the size and length of the hollow section increases so must the hole size. So the bigger the better!
Should you wish for any further information please do not hesitate to contact one of our experts.