Too_Many_Tools wrote:
On Feb 2, 1:16*am, RS at work wrote:
Stuart Wheaton wrote:
Here's the question, how do you clean steel for painting and so forth?

We were buying a product called Kleen-Kote, it was a pre-primed,
weldable tube, we could get it in 16 ga. 1x1 box and 1x2 box, and it met
more than 75% of our steel needs. *About a year ago out supplier began
to have trouble finding it, and as far as we can tell, the supply is now
gone.

The nearest substitute they can find for us now is a product that
appears to be made from pre-painted coil, which is then formed and
welded into box tube. *The paint is scuffed off in the forming and the
welding seam area is not painted either. *And we have found some
problems with the adhesion of the original paint to the steel as well..

We are trying to decide on our other options,

We can start either with plain tube, or we can clean the poorly painted
stuff we are now buying. *then we are thinking about:

1. Build or buy some kind of solvent based steel tube carwash.
2. Some kind of acid based pickling process.
3. Some kind of sand blasting process.
4. Finding a new source for pre-primed 16 ga. box tube.

We are talking about 300 - 2500 linear feet a week, sometimes more.

Once the tube is cleaned and cut it will be assembled into many
different sized and shaped objects, so cleaning is easiest to do before
cutting.

If you have a quick and effective technique, or a good source for a
machine or a steel supplier (midwest USA) Cincinnati area. * Please tell
me about it.

Thanks,

Stuart

How about building yourself a tube washer?

Load as many tubes into a 6"? PVC pipe as will fit and then mix lye
and hot water and pump it in one end and out the other. *This should
take off all the paint and grease. *Then a fresh water rinse followed
by warm air to dry, and then immediatly prime.

You might need sime kind of fixturing to keep the tubes separate in
the plastic pipe.

This concept can easily be tested on a small scale to see if it would
work.

You might also ask someone in the plating or galvinizing business for
some suggestions, I am sure they deal with this kind of problem all
the time.

The reason I suggested lye is that once you neutralize the solution it
can go down the drain without getting the water treatment folks
upset. *Large vats of solvent would probably be considered haz waste
and need $pecial permit$ and $pecial dispo$al contractor$ to take it
off your hands.

Roger Shoaf- Hide quoted text -

- Show quoted text -

The lye may not be HAZ but the paint residue will be.

TMT

Since it is not lead based paint we are talking about here, and any
VOC's are long evaporated, what about the paint residue is a probem?
Think about the millions of paint brushes and rollers that are cleaned
up with soap and water every day.

I suspect that the solids left settle out in the sludge and the oils
softened by the lye float off as scum at the water treatment plant
like soap scum does. After the bugs get done not much is left in the
water.

Roger Shoaf