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MG MGA - Chassis drilling for drainage

I intend to drill holes in the chassis of my roadster for drainage as it rains alot here in the NW. Then fit a rubber grommet type cap. I have waxol'd the inner sections. Are there any reasons not to do this? Careful I'm sensitive. Clive
c allen

Why do you think water will get in,there are no holes for that to happen,and I have heard it rains a bit where they came from ;)
gary starr

There are already drain holes in the original frame in the horizontal tubes below the doors.
Barney Gaylord

Barney, you refer to the sill drains? I think Clive is talking about the frame. I would agree with Gary, keep it sealed.
Art Pearse

No. There are originally a couple of pencil size holes in the bottom of the main frame side tubes.

No matter how good the (production) welding job may be, there will always be a small pin holes somewhere that will admit water, either from breathing with temperature change in high humidity conditions, or from splash or momentary submersion. The small bottom holes allow the frame to drain and eventually dry out.

Long term experience reveals that the frame does not rust much at all inside, except where it would first rust through (perforation from the outside). When you cut one open for rust repair you usually find it to be in very clean condition on the inside surfaces. The frame never had any factory coating inside.

If you omit (seal up) the drain (and vent) holes you will only succeed in trapping moisture inside the frame for long term any time it does get wet inside.
Barney Gaylord

Thank you for your replies. I will take and bow to experience from you all and leave well alone. Clive...
c allen

I recently cut a bunch of rust out of my frame where the wood floor boards met the frame. Moisture apparantly got trapped there by the wood and carpet, and you know the rest. Notably, when I cut the frame open, there was vertually no rust other than at the mentioned spots. Pretty surprising. Thus, I didnt worry about coating the inside.
Tom Going

Barney, Thank you for your information on the location of the drainage holes in the chassis. I found them located as you described. You were spot on thanks again. Clive..
c allen

My experience was just like Tom's. I had major rust through, all along the floorboards. When I cut it out I had a very good view inside the frame and was really surprised that there was very little rust inside.
Jeff Schultz

This thread was discussed between 07/03/2013 and 20/03/2013

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