Sandy looking PC....

[jagboy69]

I am still new to this whole PC thing... SO far my results have been for the most part excellent.. I am amazed at how easy it is to do and do well.
BUT, every now and then, I'll end up with a part that appears to have had sand sprinkled on it Could it be due to overheating?? I am running the oven at 400F for about 15-20 mins depending on the thickness of the material. The steel part I particularly had the problem with was a fairly thin piece of steel that took up every inch of the oven. ( I have a sneaky feeling it was too close to the heating element. )

[jagboy69]

hmm.. 36 views and no-one knows why my PC is turing out sandy looking?

[jtagger19]

well if you are ussing the same powder it can be the powder
I got some real cheap powder that had even hair in it .
on my expirience a part too close to the element will turn darker in that area but it won't turn sand like
is it just a few spots or is it like sand paper ?
all I can think about is outgassing or a bad powder

[mkewl]

First time here.

Hey jagboy69. This is my first post. I am really excited to learn powder coating. I have purchased my system here from caswell and it should be here sometime next week. I am going to start with black. Are you using a conventional oven?? I think that you are suppose to have the temp set at 375 and you also have to allow the part additinoal time for it to get to the needed curring temp. I am a newbie here but I would think that the part would have some kind of contamintaion. Mabey. Keep this post open and I would like to know if a correction to this problem has been identified.

[jagboy69]

I have to confess... I was using black powder .. Now before everyone goes.. EWWWW//// Some of the parts I have done with the stuff has turned out perfect. While other parts using powder from the same container get this sandy looking spots on it.. (not like sandpaper)

I am using a normal electric kitchen oven. and the temp has been either at or slightly below what is recommended by HF..

I just cant help but to think I over heated the stuff..

Post edited due to violation of the Terms of Use

http://www.caswellplating.com/bbs/viewtopic.php?t=1482

customandsound

[Noob2PC]

I have to confess... I was using black powder .. Now before everyone goes.. EWWWW//// Some of the parts I have done with the stuff has turned out perfect. While other parts using powder from the same container get this sandy looking spots on it.. (not like sandpaper)

I am using a normal electric kitchen oven. and the temp has been either at or slightly below what is recommended by HF..

I just cant help but to think I over heated the stuff..

I have used the Same powder from HF and I get the same results you're posting. I have yet to have any issues with Caswell Powders on parts I have done.

[DALE]

Ok, first blow out the oven and under it,kitchen ovens usually have an air intake hole in the bottom, it may be drawing in shop dust from the floor.
Next buy the same powder from a different supplier.Occasionally you get particles in the powder that won't melt when its manufactured, these are powder that won't melt, they are screened out but cheap manufacturers will often skip this step.For the tiny amount you saved in price, was it worth it? Order from here and avoid this in the future.Caswell's powder comes from very highly respected powder manufacturers in the country.

Wow, did I just sound like a salesman?

[customandsound]

Ok, first blow out the oven and under it,kitchen ovens usually have an air intake hole in the bottom, it may be drawing in shop dust from the floor.
Next buy the same powder from a different supplier.Occasionally you get particles in the powder that won't melt when its manufactured, these are powder that won't melt, they are screened out but cheap manufacturers will often skip this step.For the tiny amount you saved in price, was it worth it? Order from here and avoid this in the future.Caswell's powder comes from very highly respected powder manufacturers in the country.

Wow, did I just sound like a salesman?

i will take 10 of them you talked me in to it !!!!!! cheap powder is not what you want use caswell's it is better and like deal said it comes from a repected company and this is Caswell's Site so show some support in the product's you get what you pay for !!!! and you get more than your money's worth with caswell plus you are buing from a company that know all about the product they are selling and they use there onw product's or they would not sell it !!!!!

[bar_acres]

Hmmm don't get offended

but is anyone getting anything for plugging certain brand powders?

Hey, I'm just kidding...so don't get touchy.

On the sandy powder coat finish...is there any dust or airborn particles where you are spraying the powder coat?

Or, dusty conditions between the spray booth and the oven?

I'd evaluate those things first, then look at the oven. Maybe even give it a thorough cleaning.

What about attaching a air cleaner snorkel for the air intake...similar to that of an after market auto air cleaner?

[11111111]

snorkel? air cleaner? lets not get too over kill here.

[Hemi-T]

The other Companies powder is way more expen$ive than Caswell's. You also don't know where it came from. HF buys absolute bottom dollar stuff. Try the same project with Caswell powder, and I'll bet it turns out better. Just my opinion...

Hemi-T

Post edited due to violation of the Terms of Use

http://www.caswellplating.com/bbs/viewtopic.php?t=1482

customandsound

[BlindUmpire]

I had to comment...I've been attempting to coat a large part and it has been a pain! I'm thinking it doesn't heat up fast enough. Any comments on this? The part takes a good 45 minutes to come up to temp while smaller parts with the same color/temp schedule that come up to temperature sooner, cure nice and smooth. I'm also wondering if maybe the heat isn't circulating in my oven, causing uneven temp distribution? As a side note, The last time I tried to coat it, it had little black dots in the white. After reading this thread, I cleaned the oven really good and whallah! No more black spots. Caswell, you've got a great thing going here!

[DALE]

Ahhhh, another satisfied customer.

[sdold]

Jagboy69, I have the same effect on some cast aluminum yard lights that I am doing. I am using the same powder as you since I bought a can with the gun to see how it worked before I ordered any more.

I have only had this problem on the cast aluminum pieces, these are old and porous and had surface corrosion, and looked like they were getting maybe some intergrannular corrosion too.

The effect was as if there was sand on the part before coating. It was more apparent on the underside of the piece, where I didn't blast it as well.

I think it is outgassing.

[Heavykote]

I may have an answer: I did a car computer cover and have the same thing. Sand or small particles. I sandblasted the part and I don't think I cleaned it properly. Try blowing off the part really good, then wiping it down with a dry rag, I use cotton tee shirts. Then, blow it off again and also blow out your oven before every use.
I betcha you won't see any more sand or dust...