I have a sensor housing that is used for winter plow trucks. I have
my fabricator of the housing powder coat it. It seems to have good
integrity, but some tests I have been doing with thermo-shock from
about 0 degrees F to 170 degrees F have shown some flaking problems.
The material is flaking in sheets, like the metal may not have been
prepared properly.

Can someone give me a quick prep course so that I can talk
intelligently to the powder coat supplyer? What prep questions
should
I ask? Are there different types of powder coat that may be better
for the harsh environments seen by a winter plow truck?


rec.crafts.metalworking

It is called clean, clean and very clean. The surface must be degreased
thoroughly and sand blasted to a oo finish. For longevity there should be no
sharp edges. Every edge should be radiused.
Steve

"Eric Anderson" wrote in message
...
I have a sensor housing that is used for winter plow trucks. I have
my fabricator of the housing powder coat it. It seems to have good
integrity, but some tests I have been doing with thermo-shock from
about 0 degrees F to 170 degrees F have shown some flaking problems.
The material is flaking in sheets, like the metal may not have been
prepared properly.

Can someone give me a quick prep course so that I can talk
intelligently to the powder coat supplyer? What prep questions
should
I ask? Are there different types of powder coat that may be better
for the harsh environments seen by a winter plow truck?


rec.crafts.metalworking

Eric Anderson wrote:
I have a sensor housing that is used for winter plow trucks. I have
my fabricator of the housing powder coat it. It seems to have good
integrity, but some tests I have been doing with thermo-shock from
about 0 degrees F to 170 degrees F have shown some flaking problems.
The material is flaking in sheets, like the metal may not have been
prepared properly.

Can someone give me a quick prep course so that I can talk
intelligently to the powder coat supplyer? What prep questions
should
I ask? Are there different types of powder coat that may be better
for the harsh environments seen by a winter plow truck?


rec.crafts.metalworking

Umm, tell him not to powdercoat it?
Seriously though, it's a cheap and effective coating in the short term,
but I don't trust it to last more than a year or two outdoors before
delamination becomes apparent. Sometimes even newly-delivered items show
chipping on corners. It's not easy to deal with by brush-touching
either. I think the older "baked enamel" paints held up better, and were
easy to do touch up repairs on. But alas it's no longer cheap or easy to
find someone to do it.
Some say better prep is the answer, but how to know how well it's been
done soon enough to stop the payment?
What about galvanising, possibly followed by paint?

Jordan

Eric Anderson wrote:
I have a sensor housing that is used for winter plow trucks. I have
my fabricator of the housing powder coat it. It seems to have good
integrity, but some tests I have been doing with thermo-shock from
about 0 degrees F to 170 degrees F have shown some flaking problems.
The material is flaking in sheets, like the metal may not have been
prepared properly.

Can someone give me a quick prep course so that I can talk
intelligently to the powder coat supplyer? What prep questions
should
I ask? Are there different types of powder coat that may be better
for the harsh environments seen by a winter plow truck?



I'll assume this is a steel housing?
In that case you want the steel fabricated. Degrease it with a good
solvent. Then for prep you can sandblast it with 100 grit. Once blasted
a run through a chromate bath and then coating with a polyester blended
powder should do the job.

Powders come in a LOT of formulations. They are not a one size fit's all
solution. The proper powder on a properly prepped substrate should last
at least 5 years with NO degradation of finish quality. Explain what the
problem is and they will likely change the formulation.

We did that a lot at the powder plant I worked at.

--
Steve W.

All the major snowmobile mfg's use an e-cote dip for corrosion
resistance and UV stabilized powder coat over the top for impact
resistance. The e-cote has the advantage of a slight roughness that
gives 'bite' for the powder coat.

Eric Anderson wrote:
I have a sensor housing that is used for winter plow trucks. I have
my fabricator of the housing powder coat it. It seems to have good
integrity, but some tests I have been doing with thermo-shock from
about 0 degrees F to 170 degrees F have shown some flaking problems.
The material is flaking in sheets, like the metal may not have been
prepared properly.

Can someone give me a quick prep course so that I can talk
intelligently to the powder coat supplyer? What prep questions
should
I ask? Are there different types of powder coat that may be better
for the harsh environments seen by a winter plow truck?


rec.crafts.metalworking