Less orange peel

[NXGHOST]

I have been getting a bit of peel using the 50KV gun. I have found a way to almost eliminate it completely. I don't know if this is common knowledge but hopefully it helps somebody.

Either,

A. Apply powder at lowest voltage. I still think the lowest voltage on this gun is too high. I didnt get any peel with a lower voltage gun.

or

B. This is what I find works real well. If the part is powdered on high voltage just before you think you are done give it a quick dust at low voltage. I have even got good results with the gun off! Just give a light dusting.

I would like to open my gun one day and look at the voltage selector switch. I would love to mod it or add a switch that can drop the gun to about 10-12K. The lowest setting of 35K is just too high for many situations.

[jeffford15]

I'll try this out today and let you know how it goes..

Do you have any photos.. of these takeing place

[bzer1]

I would NOT recommend playing with the internals of your gun. I use a pro gun and generally never get below 35KV. In fact Most of the time I shoot at 50-60KV. In my experience I have found that there are two factors that lead to most orange peel. The first is application thickness. If you spray it too thin you increase your chances of getting job ruining orange peel. Getting the thickness correct takes practice and a good eye, especially when shooting candys. The second factor is time to flow out and crosslink. If the coating is allowed to begin to crosslink before it has sufficiently flowed out you will end up with orange peel and fisheyes. The same can happen if it crosslinks too slowly. Practice and patience can eliminate or at least reduce the occurance of orange peel and several other issues as well.

[NXGHOST]

Originally Posted by bzer1

I would NOT recommend playing with the internals of your gun. .

Why the heck not. This is the same place that has people building ovens from scratch! LOL. If I wasnt experienced in electronics I likely would not but I am very qualified to modify things. Its not like I have to worry about warranty (The whole 30 days of it). My findings are I get less orange peel using a lower voltage. I have an Eastwood gun that is much less voltage than my Caswell and I find am using it more now cause it never gave me peel problems.

[DocMartin]

There may be a difference between back-ionization and orange peel. If your part is not grounded properly to dissipate the electrical charge, or if you are holding the gun too close to the part you will commonly see defects in the coating. Back-ionization usually presents as star-shaped craters, and it occurs because the part is actually too charged, and the powder particles are being repelled from the surface during application. Most guns operate at 30-60 kV and would be recommended to run at 100% voltage for optimum transfer efficiency.

Re-check your grounding, and your gun-to-part distance. Check film thickness as well, since higher film build can lead to orange peel. Maybe your lower voltage is preventing you from depositing too thick of a layer over your parts. Low voltage is good for faraday cage areas, but is not good for building much film thickness, and it's terrible for most metallic powders.