A bare weld on this island is rust in a fortnight, and the second visit is always dearer than the first.
In a boatyard you learn this quickly because the sea is right there and it is not patient. Bare steel within sight of salt spray does not last a season, and a weld is the most vulnerable part of any steel job.
There are two reasons. Welding burns off whatever coating the steel had for a couple of inches either side of the bead, so a galvanised post welded to a galvanised rail now has a raw band around the joint. And the weld itself, with its mill scale and its heat affected edges, holds moisture in a way that smooth steel does not.
So the finish is part of the job rather than a later visit. The bead is ground back so water runs off it instead of sitting in a groove. The scale is taken off with a wire wheel, which is the step people skip, and primer over scale is simply paint over a layer that is going to flake. Zinc rich primer, then paint, and both thin enough to dry rather than thick enough to look impressive.
This is inside the two hours on a welding visit and it is not an extra. It is also why, when a job can come to the yard, we will always suggest it. A gate on a bench in the yard gets prepared properly with a grinder and a compressor. The same gate welded in place on a footpath in the sun gets a brush and good intentions.
The practical point for anybody who has had welding done elsewhere: go and look at it. If you can see a grey or brown band either side of the weld, that is the coating burned off and nothing put back, and half an hour with a wire brush and a tin of primer now will save the whole rail in three years. We will sell you that half hour and we would rather you did it yourself.