Re: [CR]Protecting new paint jobs

(Example: Framebuilders:Pino Morroni)

Date: Mon, 01 Apr 2002 09:31:30 -0800
From: "Brian Baylis" <rocklube@adnc.com>
To: Thomas Rawson <twrawson@worldnet.att.net>
Cc: classicrendezvous@bikelist.org
Subject: Re: [CR]Protecting new paint jobs
References: <002a01c1d742$ed4c52a0$4f42510c@gateway>


Thomas,

There are lots of ins and outs regarding paints and durability. Many of the problems that are encountered with new paint jobs are assocciated with the changes in paint materials on account of air standards controls. If one is fortunate enough to stay small as a restorer the old paints are available for use. My experience has been that the original Imron is still the best bike paint available when used with the proper compatible epoxy primer. Generally speaking; "letting the paint cure" before assembly is not neccessary. Pretty much all professional painters I know force dry their paint. 30 mins. in a 150 degree oven is more than enough to cure Imron and any other typical air drying paint. The problems you are experiencing are due to the material and application methods combined.

Even when using modern paint materials it is possible to do an adequately durable paint job if the layers are kept to a minimum thickness and other steps are taken to insure adhesion. What I have seen as the main problem with some of the modern paint formulations is the bond between the paint and the primer is poor. That is what causes the peeling of fresh paint from contact points. I experienced the same problem you describe on a similar paint job where the primer was too thick (and probably water based) and the paint was also too thick. Every place on the frame where something was clamped (which is everything on a 1970 frame) had the paint "tearing" away from the primer and "smearing" in all directions. The bike hadn't even been completely assembled since the new paint job and already it was a mess when I got ahold of it. I traded the guy for a Masi I had just repainted and had disassembled to make the deal; there wasn't even a mark on the entire frame and I had been riding the bike already. The difference in the two paint jobs was like night and day! Without knowing all of the details of the paints used it's hard to say exactly what went wrong; but it's doing the same thing I saw on the frame I mentioned. Unfortunately the cure is a new paint job; that job will probably end up being a dissappointment in terms of durability. Hope that helps; but that paint job can't be described as "normal". If you have any other paint related questions please ask, I'll do what I can to answer your questions.

Brian Baylis La Mesa, CA


> Think this is on topic though has implications to other bike
> projects as well.
>
> Ive just helped a friend put together a Rossin with beautiful
> restoration and paint by Cyclart.
>
> It broke my heart to have a largish flap of paint roll up and off
> the newly refinshed and painted seat binder bolt area on the seat
> lug - this was a non recessed style binder bolt seat lug and we
> were using a Campy binder bolt. I was also frustrated to see
> paint lifting around the rear dropouts as the quick release was
> carefully (believe me) adjusted and closed.
>
> Is this inevitable when attaching things to painted surfaces?
> Should a newly painted frame be allowed to sit and cure for some
> extended period of time before attempting to build up? Are there
> things one can do to minimize this damage?
>
> Please everyone feel free to join in but I'd sure like to hear
> from Jim, Brian, Richard, David and any other professional frame
> maker - painter out there.

>

> Thanks

>

> Tom Rawson

> Oakland, CA