Rookie questions

[dekebell]

I tried posting this previously, but I guess I did something wrong.
I am using a cheapie Chicago Electric system.
My air system is top-notch though, lots of clean, dry air available.

a) While sandblasting (aluminum oxide) an aluminum intake, I noticed many, many black dots being penetrated into the material. Why did this happen, how do I avoid it and can I repair the intake?
b) After blasting two steel brackets, cleaning with dish soap, pre-heating, coating and letting cool in the kitchen style oven until back at room temperature I now have tons of tiny black dots visible throughout the brackets. Please advise on what you think may have caused this and how to prevent it.
c) I researched outgassing and understand how to avoid it, but I can't figure out what "faraday" means.
d) Please recommend a gun system around $1500 (or less ), I plan on strapping a pound or so of TNT to my Chicago Electric system when I get the new system! One of you guys recommended the Caswell portable system, I would love some more input on other guns and reasons.
e) How are you guys getting oil out of engine parts like valve covers after power washing at the local car-wash (not that I would ever do that )? I wouldn't mind spending some money on a good system, as I plan on focusing on engine parts.
f) I have purchased 10 or so different colors and types of powder off e-bay and unfortunately don't know how to determine if they are of good quality. Please recommend type and supplier for engine parts. I also have some motorcycle parts that will be exposed to UV and fuel, grease and grime- what do you recommend for these type parts?

I truly appreciate all your help. I have read everything I can get my hands on and want to do well with this. I have built a nice paint booth, spent some money on my air system and bought different types of abrasives. I have succeeded with a few parts thus far, but don't want to continue doing things wrong. Thank you thank you thank you!

Regards,
Deke

[KZjim]

Originally Posted by dekebell

c) I researched outgassing and understand how to avoid it, but I can't figure out what "faraday" means.

e) How are you guys getting oil out of engine parts like valve covers after power washing at the local car-wash (not that I would ever do that )? I wouldn't mind spending some money on a good system, as I plan on focusing on engine parts.
f) I have purchased 10 or so different colors and types of powder off e-bay and unfortunately don't know how to determine if they are of good quality. Please recommend type and supplier for engine parts. I also have some motorcycle parts that will be exposed to UV and fuel, grease and grime- what do you recommend for these type parts?

i can cover 3 of your questions.

Question C;
Faraday is when you get into a tight corner and the neg charge 'field' on the part dosent allow the powder into the corner.
I will either 1) remove the tip of my gun and increase my air pressure. 2) turn off the box, discharg and remove the tip.

Question E;
pre-bake to out gas the part, especially aluminum. i will pre bake a set of v-covers to 15-20 min at 300. aluminum i will do at least 3 pre-bake cycles.

Question F;
do yourself a favor stay away from powder on EBeh, I have bought powder of EBeh but it was from a supplier i usually buy from directly and it was fine. I bought powder one other time and it was a waste of time, read my post 'Brutal Effency'

[bzer1]

A&B: You might want to check to see if your blast media is contaminated. Also give us the color, cure temp and time.
C: Faraday cage effect is when you spray charged powder into a corner and the charge repells back because you have two positives in contact with each other resulting in no coverage in that area. Think of it like this...oposites attract.
D: Looking to purchase pro type gun from caswell have questions
I like this system alot as you can tell. I have an early released system which is not as good as the current system, but it's still a great system. There are other pro-level cup guns out there but for a small shop looking for a good gun at a reasonable cost I recommend the Alpha.
E: I degrease them then bake em or send them to a local parts store to have them hot tanked.
F: I do not ever buy powder from ebay. If you buy from a reputable supplier like Caswell your purchase is garanteed. Powder will last a long time...If it's stored properly. If you buy it from ebay how do you know who is selling you powder or where it comes from? As for type it really depends on the task at hand. I suggest you go to the home page and hit the powder coating link and check the lower right of the page and read the write ups on the powder types. The advantages and disadvantages should give you the info you need.

[dekebell]

Thanks for the replies and suggestions guys.
Concerning A and B, the aluminum oxide is new and I cleaned the cabinet before adding the abrasive. Could the air pressure be too high impaling the abrasives into the substrate? The color is orange; cure time is 15 minutes at 375.
C) Thanks for explaing, makes great sense.
D) Looks like you really do like that gun! I believe that's the one I will get, but can I get a couple more recommendations on guns. I would like to compare features and see what else works great.
E) Please tell me if I'm reading this right: Power wash the part, use paint stripper, blast the part and pre-bake a few times? When I pre-baked the part, the oil stood up all over the valve cover. Should I continue to pre-bake and clean until it is all gone, or degrease with something else? What do you guys use to degrease?
F) Thanks for the recommendations on e-bay powder. I will heed your advice.

Thanks again guys! I will use Caswell for my next purchases. How could I not, after they facilitated my learning all this great information? I hope that I may help some new guys in the future, as you guys are doing. Thanks again!

Regards,
Deke

[KZjim]

i have had to run some aluminum v-covers thru 2 pre-bake cycles and thru the bead blaster inbetween... besides.. if someone brings me something really greasy.. i charge 'em extra...

[dekebell]

How about some more input from you more experienced guys?
Thanks,
Deke