In message , MrCheerful
writes
On 01/10/2017 19:06, Bill wrote:
I may be about to buy, from a scrapyard, a set of 5 replacement
wheels for the recently purchased car to get a spare wheel, proper
sized tyres and wheels that fit the wheel nuts.
In the past, I've often been told that the reason for a slow
puncture was that the alloy wheels had gone porous.
More recently, I've been told that the cylinder head on a certain
vehicle had gone porous and that was why it chuffed when cold.
I have always wondered whether this is a standard get-rid-of-him
phrase taught as part of the Car Mechanics PhD (Hons) course, or
whether alloy does actually start to leak.
Does anyone know? Is there any sort of standard test, like wheel
tapping, that can detect this sort of rot?

Paint them well before the tyres are fitted, they will probably be
fine. Testing would cost more than a new wheel.

When you say paint, what with and inside or outside the wheel? Or is
this referring to painting the edges, or more, with sealant.

Sorry if this is a stupid question, but I'm just learning how little I
know about wheels and tyres.
--
Bill