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Old 08-12-2014, 01:21 PM   #1
mjalaly

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Default Better finish from mold

So i laid up one have of my wing and once i removed it the finish wasn't super nice. Some pin holes and it was not super shiny as parts i have seen on the forum come out. Any thoughts??

My Process after polishing and waxing
1) Did a light coating of spray adhesive to hold the dry carbon (2x2 3K) to the mold
2) wet out out the first layer with thin epoxy
2) added another layer and used the same epoxy
4) added subsequent layers and wet out with a ticker epoxy
5) vacuumed

the layup also damaged my mold for some reason

See attached pics

Thoughts on post a post process to remove the pin holes?
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Old 08-12-2014, 01:28 PM   #2
craj1031tx

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If your mold does have a fully gloss finish, the haze you're getting is probably from not properly buffing the wax out. The pinholes are from just doing a wet layup, it's very difficult to get a pinhole free finish using that method. If you're going to stick with wet layups + bagging, you'll want to use an in mold clear or a gel coat application if you want to [try] and get a pinhole free finish straight out of the mold.
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Old 08-12-2014, 08:11 PM   #3
hojo

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Youre best off doing infusion as its very difficult to get a good pinhole free surface with wet lamination.
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Old 08-13-2014, 06:05 AM   #4
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any ideas on how to finish the part from here? How to fill the pin holes?
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Old 08-19-2014, 11:52 AM   #5
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No one??

Should i lay down a 2k or clear coat into the mold first before laying up the carbon?
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Old 08-19-2014, 01:33 PM   #6
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yes ! clearcoat in the mold makes the part super shiney ! it also prevents pinholes

however .. using spray adhesive to hold the cloth is a bad idea ... it makes the carbon have a milky appearance

also, make sure you wet the mold out with epoxy BEFORE you put the cloth down, this also makes a difference

you didnt say if you vacuum bagged ? if you do vacuum bag , you must NOT let the vacuum drop once it has pulled the bag down, if you do, the layup will suck air in and you wont get it out again

all imo ofcourse
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Old 08-19-2014, 01:36 PM   #7
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pffft, sorry didnt see the pictures

your mold is also quite dull ... are you using wax only for release ?
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Old 08-19-2014, 08:40 PM   #8
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Mmmmm I would hold off on doing an in mold clear or gel just yet. Pin holes are a bear but... In mold sometimes traps them too. Then they are shiney little voids in the laminate.

Go ahead and compound your mold with 3m and then hit it with 3m machine polish. Wax twice with meguires then... Buff it off to a nice shine. Go to west marine and buy the purple pva they sell. spray one coat of pva on the mold reducing with a very slightly. Let sit over night and try again.

Brush on a generous even coat and lay your first ply. Then quickly dab the fabric down. Lay the subsequent layers by dabbing it into the carbon.

Peel ply breather and then your vacuum pad like you have. Shield the bottom of the pad with some bagging film so it doesn't wick resin.

You should be good. I get very few pinholes on my simple parts this way. I keep it simple.

The breather should clamp the carbon and draw the bubbles out as it wicks resin. Also..... Full vacuum can generate pin holes.

I stop looking for leaks when I can't barely pull my bag off the stackup when I wet layup.

Also.... I don't know why but a drop of black pigment per 2oz of resin makes my carbon shine much brighter.

Last edited by dallasb84; 08-19-2014 at 09:56 PM.
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Old 08-19-2014, 08:51 PM   #9
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I made a bunch of these covers last night and my only blemish is the print through... But I really don't care about it as these will all be clear coated later. These are all wet layup like I described above and straight out of my mold. I actually brushed my pva on with these as well.

http://s1.postimg.org/z07auxx1b/image.jpg

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Old 08-20-2014, 01:02 AM   #10
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Quote:
Originally Posted by dallasb84 View Post
I made a bunch of these covers last night and my only blemish is the print through... But I really don't care about it as these will all be clear coated later. These are all wet layup like I described above and straight out of my mold. I actually brushed my pva on with these as well.

http://s1.postimg.org/z07auxx1b/image.jpg

Hi Dallas, i always infuse my part but i've been getting this print thru effect on my parts which i thought was due to the tack spray i'm using (Airtac2) but on the last part i infused i tried slowing down the infusion and i got way better results, no fabric print thru but i ended up with a few pin holes which i thinks were as a result of bridging on one of the corners.
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