Dull Finish

[fredmc]

I just purchased a HF pc kit and some of thier black powder(which I understand is not the best LOL)

To get a basic feel for how it all works I shot some black powder onto a piece of aluminum after cleaning it with laquer thinner.

I then set up a crude oven using a torpedo heater and a box made of fireproof sheetrock. I watched as the powder started to flow and it appeared shinny at that point. So I let it cook for 10 minutes or so and when I checked the temp had got up to about 450 at which point I reduced it to 400. Due to the crudeness of the "oven" I'm sure the temp fluctuated wildly so I'm not surprised at the result.

Is the likely cause of dullness the cooking process?

Thanks

Fred Mc.

[Harleydad]

Over cure temp as well as curing too long can cause loss of gloss. On a side note, I would lose the laquer thinner and clean with acetone, nothing petroleum based.

[fredmc]

Thanks for the reply.

For the length of cure is it customary to put the part in the oven for a pre determined time(i.e. 15 minutes) or to watch it and take it out when it appears right.


Thanks

Fred Mc.

[nuttyman]

HF's black powder is a matte powder, not a gloss. You will never get a shiny finish with it.

[fredmc]

"HF's black powder is a matte powder, not a gloss. You will never get a shiny finish with it."

Umm, that certainly would explain it. LOL

Thanks

Fred Mc.

[Harleydad]

Originally Posted by fredmc

Thanks for the reply.

For the length of cure is it customary to put the part in the oven for a pre determined time(i.e. 15 minutes) or to watch it and take it out when it appears right.


Thanks

Fred Mc.

Did not know that about the HF powder, that would explain it.
Follow the powder manufacturers recomendations for cure time and temp. If it says 400 degrees for 10 minutes, you start the clock when the part temp reaches 400 degrees not the oven temp. It would be wise to get yourself an I.R. temp gun.

[nuttyman]

in the future remember that u can over-cure matte finish powders without issue. I do that all the time when I am doing different colors.

[FigureLLC]

Originally Posted by Harleydad

It would be wise to get yourself an I.R. temp gun.

in the mean time or if an ir thermometer isn't in the budget, start the clock when you see the powder flow out (turn shiny).

[SylantBill]

I have a question about a part I did today. I sprayed Chevy Orange on a test strip of Aluminum and baked for 10 minutes at 400 degrees. I preheated the oven (an old kitchen oven) to 400 but when the timer went off I removed the strip and it had a dark look on it almost looked like it had started to burn. The powder instrucions said 375 for 25 minutes but being the hard head I am I did it my way. If I had left it at 375 for 25 minutes I am afraid it would have been too long. Any thoughts on this one? Thanks for the help guys.

[mikmj]

Originally Posted by SylantBill

I have a question about a part I did today. I sprayed Chevy Orange on a test strip of Aluminum and baked for 10 minutes at 400 degrees. I preheated the oven (an old kitchen oven) to 400 but when the timer went off I removed the strip and it had a dark look on it almost looked like it had started to burn. The powder instrucions said 375 for 25 minutes but being the hard head I am I did it my way. If I had left it at 375 for 25 minutes I am afraid it would have been too long. Any thoughts on this one? Thanks for the help guys.

How did you check the oven tenp?


Mike