Bill Stock wrote:
I've talked (email) to a couple of the guys that have built their own HVLP
turbine from a 3 stage vacuum motor and they both seem quite pleased with
the results.

SNIP

The CV is
fairly powerful though and I've never seen any dust on the car, plus it's
dead quiet compared to my blower or Shop Vac.

I know the purists will hate this idea, but has anyone actually tried it?
Any other problems I've overlooked?

TIA

You would have to have a pretty strong CV to power your HVLP. I am
assuming that you are also talking about hooking up to exhaust, not
reversing the motor.

You should be able to find some specs somewhere to get started, but
again, I don't think you will get enough (but I have been wrong about
other things) to get a good gun going. Find the gun you want first,
then find out what the requirements are for the gun. Make sure you
allow for more since all of the manufacturers of HVLP guns lie like
hell about how little airflow their gun requires.

In understanding HVLP, you should be aware that pressure means very
little to the gun. What you are looking for is HV (high volume) LP so
when you spray you have lots of continuous air. You only need about 5
- 10 pounds of pressure to pressurize the gun so again, airflow is the
key. I am not sure that a well used, dust/hair/dirt would be a good
source of clean air to get you the finishes you want. The filters on a
turbine are very dense and the air that comes out of the is really,
really clean. The air that comes out of a vac has been cleaned by a
paper filter of some sort. If you are spraying latex that would
probably be fine, but for lacquers and polys, I wouldn't.

So I think I would look at either buying some inexpensive unit to goof
with, or something expensive that would last.

Of you could build your own turbine.

Some of the systems are cheap enough for three stage you could hardly
build for the cost when you look at a good gun ($300+), the proper
supply line ($50), and a whip ($25). And still you have no turbine.
But if you are so inclined to build, this is the only book I know of
with detailed plans:

http://tinyurl.com/gznac

Note that the book can be had used for about $5 plus shipping. Whether
you use the plans for an HVLP turbine or not, this book has some good
discussions on spraying in general and also CAS HVLP compared to
turbine HVLP. Good info on general finishing, too.

Good luck!

Robert