clare at snyder.on.ca wrote:
On Thu, 22 Mar 2007 23:29:15 -0400, "Phil" wrote:

Hello
Was watching American Chopper this evening , I see things on that show
that make me cringe but I do enjoy the antics of that family, they always
refer to Pipe if they are building a frame out of Tubing etc. , this evening
they were working on a dragster bike for NAPA and when it came time to paint
the machine they said that powder coat couldn't be used because of the heat
involved would ruin the 4130 tubing , seems like a lot of engine mounts and
other A/C parts will have to be junked , would like to hear some thoughts on
this concept , as an A/C welder it is of interest to me.
Thanks
Phil Lohiser
EAA 12873

Powder coating won't hurt 4130, but is NOT RECOMMENDED for aircraft
use because it can hide developing cracks.At least that's what I've
been told.


Bwhahaha!!

Powder coating is done at what, 275 degree F? I gotten my airframe
hotter than that by cussing at it when members wouldn't meet up
properly. 4130 will see it as a pleasantly warm temperature, suitable
for shorts and maybe a light sweater.

Some people don't recommend powder coating because it may hide
developing cracks. Others swear by it because it give better protection
to keep cracks from ever forming. Truth is, if the only thing you have
to identify developing cracks is a visual inspection, you're not going
to have much luck. Use white powder coat, and linseed oil inside the
tube. A hairline crack will seep the oil and make and ugly black mark.