Living in California, weird/wonderful, does have its drawbacks. One of which is that air pollution controls have greatly curtailed do it yourself spray painting. In most instances I'm trying to make do with rattle can paint jobs. But this has seen the comeback of an old issue "fisheyes". For anyone not familiar, fisheyes are blemishes in a paint job which causes round spots where the paint because of contamination doesn't cover the target/metal. Here is a small part, the top of the throttle body from the right hand grip displaying fisheyes. The paint being used is rustoleum in a spray can. For anyone not familiar Rust-o-leum is a decent quality commercial enamel paint.

You will notice the small white dots scattered around. My understanding is that these are caused by contamination principally from silicone. When I was shooting paint from my own gun I would compensate for this by adding a small amount of fisheye compound to the paint. Basically contaminating the paint before spraying. But when shooting from a spray can it's no longer possible to add the fisheye material to the paint. BTW, the painted piece was wire brushed till all paint was gone, and then cleaned with acetone followed by lacquer thinner.
So my question does any have suggestions as to how to either clean a piece before painting or how to compensate for silicone contamination. Silicone is often a component of polishes as well as lubricants.
best regards
J.Jefferies

Did you use primer?

A couple of very light coats first up will often work and I always use Prepsol to clean any wax or silicone away before I paint.

Laitch wrote:Did you use primer?

yes, but a light one. Didn't seem to matter.

RicK G wrote:A couple of very light coats first up will often work and I always use Prepsol to clean any wax or silicone away before I paint.

Hmm, the product name doesn't ring a bell. Any idea what it is? or is there a generic name?
thanks

jjefferies wrote:Hmm, the product name doesn't ring a bell. Any idea what it is? or is there a generic name?
thanks

Maybe your bell is down for servicing.    Prepsol.

Laitch wrote:

jjefferies wrote:Hmm, the product name doesn't ring a bell. Any idea what it is? or is there a generic name?
thanks

Maybe your bell is down for servicing.    Prepsol.

Ok, I'll go looking for it at my local auto paint store tomorrow. On my ride to pickup some braided brake lines. So many new things to learn about.
Or maybe not. Amazon and ebay aren't showing it. Better I call and see if the shop carries it.

jjefferies wrote: BTW, the painted piece was wire brushed till all paint was gone, and then cleaned with acetone followed by lacquer thinner.

J.Jefferies

Clean the part with Prep-All BEFORE any sanding or abrasive activity, and again when you are done.  Use paper towels changing them frequently.  If you use a tack rag to remove dust before shooting(you should) just let it float over the part. Never use a tack rag on a part that feels warm to the touch.

Sanding or wire brushing will drive the wax and silicone into microscopic scratches in the surface where it's very difficult to remove.  Because wire brushes will hold a lot of crap in the wires(and new ones will have oil), I never use them for anything beyond loose rust removal.

The heat from machine abrasion helps work the wax and silicone into the surface as well.  I prefer to wet sand with 320 to prepare a surface using water with a squirt of Dawn dish detergent in it to keep the dust and contaminents in suspension.  Then when I'm done I will wash the part with S-100 which is a fantastic grease remover and shoot my primer.

A note on primer: I put down a light coat of Self-Etching primer on bare metal followed by High Build Sanding primer to fill all the scratches.  For plastic parts just go to the High Build.

Hey point seven five,
thanks for the details. I'll be trying that.
J.