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Puzzled by Bondo

jjbunn

Jedi Knight
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There were some cracks in Harold's paintwork just in front of the windscreen, in between it and the seam of the front wing. I started sanding away with my Dremel sanding disk and eventually went through about 1/2" of what appeared to be Bondo, down to rust, which I cleaned most of to bare metal. Here's a photo:

364245345_48825078fe.jpg


Detailed version here: https://farm1.static.flickr.com/187/364245345_48825078fe_o.jpg

Any ideas what this is? It looks like a bad repair. But I'm puzzled as to how this area should look, undamaged, since there is such a thickness of filler there.
 

Keoke

Great Pumpkin
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Julian, Look on the underside of the metal if it is accessible and you will see how it has been distorted. Alternatively, that area will require raising up by the amount of the Bondo's thickness. Looking at the picture I can see that the Bondo extends over quite a large area--Fwiw---Keoke
 

tony barnhill

Great Pumpkin - R.I.P
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Or, if not distorted, look to see if there's a patch that's been put in from the underside.....the metal should be high enough that a thin coat of paint is all it takes....I'm guessing patch.
 
OP
jjbunn

jjbunn

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I can't see anything abnormal underneath. Perhaps the wing was replaced at some point, inexpertly, and sat proud at the seam, so this repair was done to bring it flush?

I don't think I have much choice but to sand it down to the bare metal, POR15 it, and then rebuild the Bondo. It will be a challenge to make it look good, because that region is all curves and small areas to work on. Ugh!
 

tony barnhill

Great Pumpkin - R.I.P
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Windshield will probably have to come out based on those cracks coming from under the weatherstripping.
 

vping

Yoda
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Maybe something hit or fell onto the bottom of the windshield and the bondo was to bring that area up to meet the moulding?
 

DrEntropy

Great Pumpkin
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Really hard to say just WHY it's that built up. Possibly a wing replacement, maybe after a shunt that deformed it there. Looks a pain inna butt to fix. You siad it: all compound curves and scant area to work within. Tony's right about the windscreen/seal removal too. It is likely extended right to the lip of the glass opening. Looks like a fair bit of corrosion, too. YUCK.
 

100DashSix

Jedi Trainee
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I came across the following advice on windshield replacement while looking for information about V6 MG conversions. Perhaps it'll help if you decide to put the windshield back on, after having decided to take it off.. https://www.rc-tech.net/MGB/window/windown.htm

The site with frames is: https://www.rc-tech.net/MGB/

Not sure if this advice is directly applicable, because I don't know if the components covered in that article are dismantled when the windshield itself is removed.

In any event, it scares the willies out of me.
 

Bugeye58

Yoda
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Julian, if it were mine, I'd remove the windshield frame, strip the affected area, and properly assess the damage.
Probably not what you wanted to hear, I know, but the only way to do it right.
Jeff
 

tony barnhill

Great Pumpkin - R.I.P
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When you do remove the windshield, be very careful not to damage the stainless...take a utility knife & cut the weatherstripping away from it to lift it off....then, you can remove the little round black rubber retainer under the weatherstriping & lift the window out - then toss the old weatherstripping.
 
OP
jjbunn

jjbunn

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Bugeye58 said:
Julian, if it were mine, I'd remove the windshield frame, strip the affected area, and properly assess the damage.
Probably not what you wanted to hear, I know, but the only way to do it right.
Jeff

Jeff, and everyone, thanks for the advice. This is a GT, so I cannot easily remove the windshield frame without removing the roof!

I have all new rubber seals on hand for replacement around the windscreen, as I had foreseen having to do that anyway. What I don't want to do is make any repairs to the area around the windscreen while it is out, because I know what the end result would be: the windscreen wont go back in!

What I am trying to understand is why there is rust down there. If I understood that, I'd be more confident about a repair. It seems the existing repair was made, and then somehow water got in, and spread under the filler. Is that possible? Or is it possible somebody filled *over* rust?!
 

tony barnhill

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Julian - its one of those places that does rust on a GT...water gets trapped behind old or damaged weatherstripping & slowly eats away....I've seen several GT's with rust in that area...have you pulled the fender to look behind it?
 

Keoke

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Well Julian, very politely its the Bondo that caused the majority of the rust it absorbs moisture like a sponge.---Keoke

P.S. Initially, Lack of a good seal at the window rubber cause by old age allowed water to collect in the window channel and promote rusting.

Now Doc just work on which ever end you please cuz I fissed it!-Keoke-- /bcforum/images/%%GRAEMLIN_URL%%/laugh.gif
 

DrEntropy

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Keoke said:
Well Julian, very politely its the Bondo that caused the majority of the rust it absorbs moisture like a sponge.---Keoke

P.S. Initially, Lack of a good seal at the rear window rubber cause by old age allowed water to collect in the window channel and promote rusting.

REAR window?!?! 'splain that if ya will there, Keoke. This is an MGB-GT front port wing seam the rest of us are seein'... You in L.A. "proper"?!?!

..that could explain a lot.


Not that I find argument with Bondo as a water-avid agent. I just wonder which 'end' you're workin' on.

<Obligatory Idiotic Smiley Face Here>

The seams at that point are notorious for this damage, BTW.
 
OP
jjbunn

jjbunn

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Ha ha ... yes I think Keoke mean the front window /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

In fact what everyone is saying makes a lot of sense. Harold is missing the vertical chrome trim piece on the driver's side. The rubber seal underneath is damaged. I have no idea how long it has been like that, but you can actually see the edge of the glass!

One of the first things I ordered from Moss was replacement window seals etc., but just haven't got around to doing the job yet.
 
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jjbunn, id be interested to know how far the bondo extends to the left and right of the effected area, bondo can be a a great filler if used correctly to me it looks more then 1/2" deep but you got the ruller,if it was mine id remove all the filler clean out the rust pop rivet some new metal in its place to fill that large gap then apply as thin a layer of "bondo" as needed. prime the area before applying the bondo,for kicks and giggles id go over the entire car with a magnet see what else went south.
 

tony barnhill

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<div class="ubbcode-block"><div class="ubbcode-header">Quote:]if it was mine id remove all the filler clean out the rust pop rivet some new metal in its place to fill that large gap then apply as thin a layer of "bondo" as need[/QUOTE]

But not until after you've got it running & ave enjoyed for a bit!!

Then, we'll discuss the proper way to repair it...I
ve got a GT we can whack the offending panel off to weld onto yours.
 

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