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MG MGB Technical - BGT door drain holes.

Wondering why my roughly 6 year old doorskins had shown signs of rust already, I checked on Paul's website and found the reference to drain holes being ideally located at the rightangle between the inner skin and the "carcass". In the pic you can see where my drain holes were - almost completely useless. The arrows show where they should be - is this the conventional wisdom?
I just hadn't woken up to the significance when my body/spraypaint guy fitted new door bottoms and skins back in 2017. So it's off to a different repair shop next week to excise the damage - and to put the bleepin' drain holes in the right place!
John.


J P Hall

The holes don't seem quite in line, as if the installer realised there were none and thought he was doing the right thing.

Of course as arrowed only help if the bottom of the carcass isn't tilted the wrong way! Which could happen as the flange if a new skin is tapped down over the edge of the carcass. But when cornering any lying water will be moving from side to side anyway.
paulh4

Thanks Paul. I'm thinking maybe make the new holes elongated to maybe 1cm, for better water egress. Any thoughts? I'm in tropical North Queensland, so evaporation is good!
John.
J P Hall

Yes, or bow the holes down a bit. After either a good coat of Waxoyl ("other products are available ... ") in the lower part of the door should help.
paulh4

Hi John
I've never seen drain holes where yours are, they should be where your arrows are but the end ones need to be right out the end where the carcuss starts to turn upwards. The holes need to go down round onto the vertical part of the carcass so the water can drain out of the trough between the carcass and the skin.
pic of a std mgb hole--upside down door

William Revit

Sorry Willy but your pictures come out as thumbnails on my screen. As with cornering any 'loose' water will run back and fore with acceleration and braking. There will always be some left in the join, duration dependant on ambient temperature and humidity!

paulh4

Hmm That's a bit weird, it works ok here--maybe right click on it, open it in a new tab and use Ctrl and + to blow it up if you want but basically it's just a pic showing the original holes as in your blue door--
Thanks for the heads up Paul, I'll check out what's happened there-
William Revit

Right-click and new tab shows 'blocked', and copying and pasting into a graphics program shows it has a width of 120 pixels i.e. thumbnail.

I wonder if uploading defaults to a minimal resolution/size? Some other apps offer me a choice when inserting an image, but not this site using Chrome which uses the original size. What browser do you use?
paulh4

Sorry Paul it was my security system blocking it from being able to be opened.

William Revit

Good stuff Willy, thanks for the clarification. I couldn't find much about this in the archives, yet it's surely important. Thankfully Paul had it referenced. John.
J P Hall

This thread was discussed between 25/01/2025 and 31/01/2025

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