List,
I intended to sent this to Kelvin and the list but forgot to delete the
trailers. It only made it to Kelvin
-------- Original Message --------
Subject: Re: Replacement Panel Primer
Date: Thu, 26 Jun 2003 19:33:52 -0400
From: Don Malling <dmallin@attglobal.net>
To: "Dodd, Kelvin" <doddk@mossmotors.com>, "mgs@autox.team.net"
<mgs@autox.team.net>
References: <2DEF596095A60F4981A459678583AE83EE3EC3@MOSSEX1>
Hi Kelvin and list,
I have a similar question relating to my "new" BMH MGB Body Shell which
is still in it's crate and has been waiting for me in the garage since 1991.
My understanding was that these new body shells were dipped in modern
primers during manufacturing. On close inspection it appears there are
two primers on this shell. A darker gray which appears to be "thinner"
and can only been seen inside the shell members, where it was hard to
reach with spray, and an outer lighter gray, and thicker, primer which
appears to have been sprayed over the darker coat.
I have two questions:
1. Can these two primers be used as a base coat after proper sanding and
surface prep?
2. What if anything was done to the inner sills during manufacturing?
After or before welding were these protected in any way? Would the dip
primer reach them, or are they unprotected and have been rusting away
while sitting in the crate these 12 years?
Thanks,
Don Malling
Dodd, Kelvin wrote:
> Chris:
>
> You got a general answer from Moss because frankly no-one here new
any real
> specifics. Over the weekend at MG2003 I got to attend an excellent
> presentation by John Mangles of Hi Tech Collision in St. Louis. He
showed
> how to remove minor dents in an MGB door, and was a wealth of
information.
> I took the chance to ask him the same question you have just posed,
as you
> are not the first to ask. This type of coating is typically found on MGB
> bonnets and fenders.
>
>
>>From his comments: The shipping coating is designed to prevent oxidation
> during shipment and storage, and is not a paint primed surface. This
means
> it is not a suitable surface for top coating. Cut through the coating
> surface glaze with wet & dri sandpaper, just the same way you would a top
> coated surface. Then use a professional quality self etching primer as a
> base coat. By scuffing the surface, the primer has a chance to bond
to the
> underlying paint/metal, rather than lying on top of the water
resistant top
> surface.
>
> As stated though, be sure that the self etch primer you are using is
> compatible with your finish products.
>
>
> Anything you can do to prepare the back surfaces of the panels is
going to
> improve longevity. I've seen some weld through primers, but so far I
have
> had good luck coating the back of panels with a product called
"Extend" by
> Permatex. This material takes a lot of heat and does not blister.
Coating
> the inside of the body sections with Rustoyl or equivalent is going to be
> the only real way to get protection inside repaired panels though.
>
>
> hope this helps.
>
>
> Kelvin.
>
>
>>I'm about to do a lot of rust repair on my early B. I wrote to Moss
>>asking what kind of primer manufacturers put on replacement body
>>panels. The answer I got was very general, to the effect that I
>>should make sure it was compatible with the paint I was going to
>>use...
>>
>>The second part of my question was whether I should be
>>priming/painting the backsides of parts (like sills and doglegs)
>>prior to installation as a rust proofing step. No answer on that
>>one. I've seen parts with only primer (rattle-can grey mostly) rust
>>through, and many primers aren't meant to be exposed to moisture, so
>>I'm concerned.
>>
>>So my question is, what sort of prep/painting, if any, should be
>>done to black-primered replacement sheet metal?
>>--
>>Chris Attias
>>Aptos, CA
>>'64 MGB
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