On Fri, 6 Oct 2017 11:25:27 +0100, David Billington
wrote:

On 06/10/17 01:10, Christopher Tidy wrote:
Am Freitag, 6. Oktober 2017 02:00:24 UTC+2 schrieb David Billington:

Items that are hot dip galvanised have to be vented in order to prevent
dangerous pressure build-up, I've had many items dipped and it is a good
process* but the* sections need to be vented to relieve the pressure
build up.
Makes sense. Not what I guessed, though. I was guessing it was to prevent stagnant water from building up inside the tubes and causing corrosion.

Here is a venting guidance video from Wedge Galvanising
http://www.youtube.com/watch?v=C8EGUlerwVg , it include brief footage of
what can happen when an unvented items is dipped and it bursts.

I hope they had the customer sign that he had drilled vent holes, so
he can pay for it instead of them. Messy! 840F/449C expands air a
bit, I'm guessing.

--
However beautiful the strategy, you should occasionally look at the results.
-- Sir Winston Churchill