Powder coating question??

[wheelhouse8]

I am powder coating my engine and had a question for all ya'll. I used matte black; the valve cover turned out good as well as the smaller parts. however the cylinders and head turned out more semi-gloss than matte.
I was wondering if this had to do with thickness or possibly heat time.

Questions:

If I heated them longer will it turn a less glossy?

Is thickness the contributing factor with this since I had to spray a bit more on these pieces to get deep into the fins?

 

[RFLIVES]

Most likely the cylinders did not hit temp are you measuring part temp or using oven temp. If you are not using part temp you need to. looks like that is your issue is the it did not get to temp and the other stuff did. Pick up a IR thermometer if you don't have one yet.

 

[wheelhouse8]

Thanks RFLIVES, do you think I can just put it back in the oven and cook it to temp?

I think that is what I am going to try.

 

[RFLIVES]

I would just dust another coat on and then re-bake. careful with the cylinders the sleeves tend to come loose when heated for a long time. just check to make sure they are fully seated before they cool.

 

[wheelhouse8]

will do thanks!

 

[hotrdd]

When I worked at a powder shop we could get a matt finish if we didn't ahve enough circulation. Not sure if thats here?

 

[wheelhouse8]

So in case anyone was curious...I put the parts back in the oven after preheating it to 415ish and let them sit for 15 minutes for the second time and there you go...the matte finish I was looking for came out good. The first pic is the first bake and the second and third are after the second bake.

Thanks to those who gave pointers

 

[RFLIVES]

Sweet figured it was an under cure situation. Get a IR thermometer I have had wheels take 35 min's just to get up to temp

 

[swbill]

I kinda disagree with releaves about the initial problem but may be wrong. What powder were you using? Is it a flat,gloss,mirror,what? From my experience doing PC bake time doesn't effect the gloss very much. Just curious on the powder your using before I pass judgment on the problem.

 

[wheelhouse8]

I was actually using the powder from harbor freight...Only because I couldn't get anyone local to sell me anything in small quantities. The powder was matte black. I initially baked them for 15 minutes from the time I shut the door. So I am assuming it was real close to 10-12 min bake time at 410ish (oven temp gauge).

The second time around I never used a IR thermometer but didn't start my timer until my oven temp light kicked off at 410ish again. They then baked at that temp for 15 min and came out looking much better.

The oven I made is out of an old medium sized chest freezer...insulated, lined, with one filament in the base, no air circulation via fan.

The parts actually came out looking more matte than in the pic

PS: you were right RFLIVES, the cylinders did slide out a bit...luckily the tape kept them from falling out. I cooked that piece right side up the second time and the cylinders slid back down to seat.

PSS: If that's your bike in your profile pic swbill...It is probably one of the best I have seen... Good work!

Thanks again all for your input.