no drain holes in very old frame

[mr_gumby]

Good morning,

while mounting mudguards on my steel-framed winter bike yesterday, I noticed small holes in several places: BB shell, lower fork blades, and in seat- and chainstay, just before they intersect with the rear dropout.
That most frame manufacturers drill holes in low spots in order to allow water to flow out/condense and thus prevent corrosion in steel frames, is known to me. I also read that they are needed in the welding or brazing process.

When I checked the frame of my recent restoration project, my 1936 New Hudson (viewtopic.php?f=12&t=358124), I coudn't spot such drillings. As I am planning to use the bike on sunny winter days, I wonder if I should retrofit the frame.

Here's what I want to do:

BB shell: M5/ 5mm
insides of lower fork blades, seat- and chainstay: 1.5-2 mm

afterwards I'll flush the tubes (not the BB of course) with penetrating oil/silicone spray.

What are your thoughts?


Have a great day,

-Dan

 

[keithglos]

Re:

Generally gas holes were needed by large manufacturers because of the fierce heat and large areas heated would blow expanded air out through the joints as they were trying to run spelter in to the joints. Most real hand builders did not need them, but some drilled one from the seat lug into the top tube.

If a tube is completely sealed then it does not need ventilation. Corrosion can be caused internally by flux residue, this does need some damp to happen.

Some makers also drilled holes or used the gas holes to introduce rust proofing.

Keith

 

[mr_gumby]

Re:

Thanks Keith - drilled the holes at the bikeshop today and inserted some wd40. Read some horror stories involving rust-eaten frames here (search).