Dip painting

[Paddy]

I'm building a hand rail and will be painting a bunch of the parts before I assemble. I'd like to dip paint for several reasons, quickly paint and to get the inside of the hollow parts as well.

There are some tricks like filling a container with water and then pouring the oil based paint on top. The paint floats. Then as you lower the part in, it gets coated in paint. As it goes lower, the painted section enters the water layer. When you pull the part back up, it passes through the paint once again. My parts are 6 ft long so I'd use a pc of PVC pipe as my vessel.

I'm sure the paint would need to be thinned to get a less drippy coat. Not sure if it would need to be as thin as for spray painting,

Anyone do this?

 

[davesl708]

I have not tried it but my concern would be water getting trapped inside and start a rust point.
I know the auto industry does dip painting on a large scale (at least they did at one time).
Controlling sags and runs may be an issue as well.

If no trap points should work ok.

 

[Paddy]

Dave,

I can skip the water because all my parts are 1" square tube, so filling a pc of PVC will not take much paint. But yes, controlling the sag is controlling the viscosity. For handrails it's more about durability than fine finish.

 

[JRobyn]

I used to do this with handmade arrows. Worked well! You do have to thin to the correct viscosity.

 

[Paddy]

JRobyn,

Can you shed light on how much you thin? I know I should experiment but having a good starting point would be great. Do you the paint floating on water, or straight paint?

 

[JRobyn]

Too long ago for me to remember! Being small diameter arrows, I just used a section of 3/4" dia copper pipe for my "tank". IIRC, the paint was lacquer, and cut maybe 9 parts lacquer to 1 part lacquer thinner. Or slightly thinner. I was looking for a thick enough coat for good color, but with minimum added weight. No floating.