Vapor holes?

[T. Cotten]

It has been brought to my attention that chromed crashbars have vapor holes (see attachment), where enamelled ones do not.

These holes appear upon later Pan saddlebag rails and bumpers as well.

Was this necessary for the chroming process?

Thanks in advance,


...Cotten

[Pete Gagan]

Most of those items you mention have flattened ends or similar, so could allow acid to enter the inside during plating. The "vapor holes" allow the draining or evaporation of these nasties afterwards. There would be no particular need for this on items that are not intended for plating.
Pete

[T. Cotten]

Pete!
When these pieces were brought to me with this question, I immediately inspected the pressed ends. Both were welded shut the length of their seams, although the top mount (as shown in the previous attachment) had only been "tacked" before sweat-brazed (or "speltered").
Still, all seams seem thoroughly sealed

Ordinarily I would have assumed that the holes were for equilibrating gas expansion pressures of welding or oven-sweating, but the enamelled example with no holes still wears the yellow stamps and remnants of an NOS tag.

So the question was raised: Was it only necessary for the plating process?
By experience, my first reaction was declare that they were intended to make the pieces rust out from the inside!

The placement of the holes (on trim items as well) are in no way appropriate for efficient drainage, of either chroming solutions, condensate, or water from a stream crossing.

My conclusion is not a new one: chrome is evil.

...Cotten

[mmoore]

but your conclusion is true

[Kojack]

Holes would have allowed a thorough rinse, just in case some solution got in, and also eliminate any problems that buoyancy could cause in the plating tank. I talked to a plater a few weeks ago. I took in a few old Indian parts for stripping, among them the rear fender braces for a skirted fender chief. (I plan to just paint the parts later). He told me that he recommends that holes be drilled in an inconspicuous place to make sure that any stripping or plating solutions that may seep in can be drained, otherwise, corrosion will result. I balked at the idea so he baked them for me. The result was a nasty looking crust that formed at the pinched ends as the solution was forced out and dried.