Best gloss result out of aluminum mold

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#1

Hello guys…
I am making a 9 piece half half split mold with iner inflating tubing .Actually it is a split mold for hollow carbon fiber sadle rails…that are 7mm width by 9mm height. This thing is supposed to be out of the box ready without any clear coat etc. Because of the cycles this mold is intended i want to get the most out of it. So i am thinking of anodizing the aluminium when it will be finished . First question : does it really make it more durable to scratces ?
2nd question ? Is there any chance that the anodize will come of while i try to take the part out ?

After the anodizing i intend to apply a permanent if that is possible realise agend so 3rd question: if i apply a realise agend maybe i should not anodize at all ?
4th question : what is the best realise agent for aluminium molds ?
The aluminium i use is part 6020 and part 5080 . The cf will unidirectional prepreg cured at 120 degrees

#2

an aluminum mold should be fine… seems to be pretty standard. here are some resluts from Koenigsegg that i just posted in another thread: https://youtu.be/504I_hJDFck

I’ve made parts with aluminum molds, if they’re perfectly polished out, you’ll get an awesome part. Also there are prepregs available now for surface finish quality that have UV inhibitor in the resin. Cytec makes some, i’d imagine others do as well now? With the auto industry using naked carbon parts, there is demand.

as for release, use a semipermanant release. I don’t think you’ll have any need for anodizing but, maybe it helps? I’ve never used a mold with that done to it. The aluminum is durable enough if you never cut on it, are careful in demolding, and have a part that has good draft. I’ve used pretty much mostly freekote but have also used some zyvax release a few times. The freekote works wonderfully and once the mold is seasoned, you only need a refresh wipe for safety, or every few parts as needed.

#3

I have never anodized an aluminum mold but I have plenty of anodized aluminum parts and I can’t stand using them because they are so easy to scratch and so hard to fix.

An anodized surface is the very last thing I would want on a mold for making carbon fiber parts if the plan is to have the part be ready to use straight out the mold. I would go for a polished surface that can be easily repolished when there are light scratches. If it is anodized, you would have to sand the whole surface and reanodize if you scratched it.

Just my opinion. I think anodizing is mainly a cosmetic thing. If you wanted a matte finish on your cf parts, anodizing might be a way of achieving that though.

#4

Wow that video is awesome!

Looks like they don’t use an autoclave though for some parts right? I only guess that because there doesn’t seem to be many safety latches on that door they have. It almost looks like a restaurant walk in cooler.

#5

yah the oven they show is just regular oven. Shows you don’t need the autoclave necessarily. some minor sanding and a coat of clear and those parts look amazing. There are prepregs available for bare carbo finishes now. They supposedly have uv inhibitor in the resin. I’d still spray a coat of clear on though if I could.

there was another video, i can’t find it now, of the redbull car. they were making the nose in the autoclave. I remember how they pulled it from the clave and it looked amazing… and the bag going in wasn’t all super neat and tidy… I guess all that pressure will do wonders.