PC test #8 + I have a ?

[benherr]

OK, here's my latest PC job and as you can see from the photo I have quite a few craters and some minor OP. I cleaned this with acetone then degreaser, then acetone again before coating. Still haven't got it right.
Now for another question. How long do I have to let this cure before I can use my CNC machine to engrave a graphic into the PC?

Ben

[CarWiz]

Wow. Not to dis ya or anything but I wouldn't do any CNC on it until you striped it and started over. I've been tied up on other projects for a while and away from the forum so some background is necessary. What's the base metal? What are you using as a degreaser? What is the environment like in your shop?

It looks like you have contamination as well as powder too thick. As far as curing, it's cured when it comes out of the oven.

[benherr]

Originally Posted by CarWiz

Wow. Not to dis ya or anything but I wouldn't do any CNC on it until you striped it and started over. I've been tied up on other projects for a while and away from the forum so some background is necessary. What's the base metal? What are you using as a degreaser? What is the environment like in your shop?

It looks like you have contamination as well as powder too thick. As far as curing, it's cured when it comes out of the oven.

CarWiz, (No offense Taken, I'm learning and welcome the input)
The piece in the photo is only a test piece. It's billet T-6061 aluminum 1/2 inch thick. I'm using a product called Purple Power, which is supposed to be a industrial strength cleaner/degreaser. I've checked the air and there's no water or dirt in the system. I've tried various combinations to get rid of the craters and the OP(orange Peel) Tried less powder, more powder, double and triple cleaned, still same effect. Used Acetone twice on it and the degreaser. I'm not sure what you want to know about the shop. Its in my 2-car garage. Use a gas ceiling heater, air compressor is a Farmland up to 135 PSi max. Have water filter and the filter on the Caswell hobby gun. Using a regular electric oven to bake. i even tried pre-heating the piece before cleaning.
any suggestions would be greatly appreciated.

Ben

[Popeye]

Do you hang the part or is it laid flat when you powder it?

What temp are you curing it?

Have you tried powdering a piece of anything else besides the 6061?.. Pop can, piece of steel... anything?

[46Ford]

Try cleaning your oven out really good, you would be amazed at what you will find. I had some similar issues when i started and this made a huge difference.

[mikmj]

Still looks like too much powder...........

[benherr]

Originally Posted by Popeye

Do you hang the part or is it laid flat when you powder it?

What temp are you curing it?

Have you tried powdering a piece of anything else besides the 6061?.. Pop can, piece of steel... anything?

popeye,
this last piece I laid flat. I'm curing at around 400 degrees. I haven't tried anything besides the 6061.
I give a piece of steel a shot and see what happens.

Thanks,
Ben

[benherr]

Originally Posted by 46Ford

Try cleaning your oven out really good, you would be amazed at what you will find. I had some similar issues when i started and this made a huge difference.

46Ford,

hadn't thought about that. I did clean the racks, but not the inside of the oven. did you use a regular oven cleaner? The oven I have is a self cleaning one,will that work?

thanks for the info.
ben

[benherr]

Originally Posted by mikmj

Still looks like too much powder...........

mikmj,

One guy told me he thought I hasn't putting enough powder! Maybe somewhere in the middle!!!

thanks,

Ben

[46Ford]

The self cleaning cycle is a good place to start. After it is done it will be easier to wipe out what is remaining. Good luck