[T3] Undervoat question

[Keith Park]

The late fenders got undercoat, and when it cracked, especially along the
back seam the salt got in and they rotted real bad, worse than the un
undercoated ones.

I strip or sandblast the fenders (careful sandblasting the sheetmetal)and
then use POR 15 with a 3M undercoat over that, the POR 15 is a nice tough
coat and lasts well as long as you don't actually paint it over any rust
(ironicially!)and the undercoat keeps gravel and such from chipping it
anyway.  I also rest the fender on its back edge and apply roofing tar to
the back seam, just enough to seal it AFTER the POR 15 and then undercoat
over the whole shebang.

The real problem is making sure you get ALL of the rust out of that seam on
used fenders, your never going to get 100% but if you make sure water cant
get back in there then your OK.

Keith


Top Notch Restorations
topnotch at nycap.rr.com 
http://www.a383ina68.addr.com/radiorest/main.htm
71 Squareback "Hothe"
65 Notchback "El Baja Rojo"
65 Squareback "Eggcrate"
87 golf "Winterat"
93 RX7 "Redstur"


-----Original Message-----
From: type3-vwtype3.org-bounces at lists.vwtype3.org
[mailto:type3-vwtype3.org-bounces at lists.vwtype3.org] On Behalf Of David
Sanderson
Sent: Saturday, October 29, 2011 9:03 PM
To: type3
Subject: [T3] Undervoat question

Hi All
I have been working on my fenders, repairing where necessary and   
getting them ready for paint.

http://www.thesamba.com/vw/forum/viewtopic.php?p=5648228#5648228

One of the fenders has some undercoat. What is curious is that some of  
the undercoat obviously did not stick well because I was able to  
simply scrape it away and it came off in flat sections. On other  
spots, however, it was stuck firmly and I had to use a heat gun to  
soften it before I could scrape it off. I am wondering what the  
consensus is on spraying undercoat on these cars. I live in the  
Pacific Northwest where we have lots of rain. Also, I wondered why the  
stuff did not stick so well in some spots. Was undercoat something the  
factory sprayed on or would it have been done by the dealer?

Thanks in advance.

Dave
1977 911S
1965 Sunroof Notch
http://www.sandersonmotorsports.com/
Notch build here:
http://www.thesamba.com/vw/forum/viewtopic.php?p=5600139&highlight=#5600139 
  
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