I. Provisional fixing:
After the bending Bendywood®-handrails should only be fixed provisionally to the banister, so that they can shrink along their length.
Handrails that are bent at a moisture content of 12% will shrink up to 0,5 cm per meter along their length until the moisture content is reduced to about 8%.
II. Final assembly:
Only after this the handrail can be taken off, sanded (if necessary), finished and permanently fixed.
Start with a fix mounting point halfway its length and mount the handrail from there towards the ends in such a way that it can still shrink a bit along its length, especially in the case of long handrails.
Please consider that a 6 m long handrail, for instance, will further shrink up to 1 cm (on its total length) within the first year after final assembly, especially when the place is well heated.
III. Mitre joints:
Mitre joints at the ends should be avoided: the risk that they will „open up“ in the long term is high.
In case mitre joints cannot be avoided, there are 2 options:
- Mitre joints with synthetic resin glue and a threaded rod:
- Drill sufficiently big and profound holes into the handrail ends that need to be jointed;
- Fill these drill holes at both ends with a synthetic resin glue and insert a threaded rod, which diameter should be a bit smaller than the one of the drill hole;
- Press both handrail ends together with clamps and keep them in position until the glue has dried.
The use of a threaded rod as well as the use of synthetic resin glue are both absolutely necessary to prevent the joints from opening up.
- "Open" mitre joints or "open" butt joints:
Such joints are secure and in certain cases also decorative (when combined with glass elements, for instance).
Only in the following cases this problem doesn’t occur:
- In case the handrail is bolted down to a continuous metal rail (from below) at small intervals of about 10-20 cm;
- In case the mitre joint is under tension: this occurs when bent parts (which always open up a little) exert pressure on the mitre joint.