Hi all , I seem to be getting a lot of tiny air bubbles appearing when I apply the clear coat, I am carbon skinning parts , I thoroughly clean and prep the parts, No problems with resin when applying, all seems to go very well , I spend a lot of time wet flatting the parts down and to be fair they look perfect ie nice and even , smooth and no visible signs of any holes or bubbles, I use a heat gun during resin coats making sure all bubbles are gone. I use acetone to clean the parts before clear coats, I really can't see why I am getting so many , although I am fairly new to carbon skinning ,I am not a noob when it comes to car painting ,I've been painting for 25+ years now.
Is there anything i am missing here.
Thankyou.

Since you have been painting for so many years I wont go into what I originally was going to when I first read the topic. Just a question, how long do you wait after its cured to clear it? Maybe when you sand to prep it for clear, it isnt entirely dry and is still releasing some vapors and you now reopend the surface for it to release. Any reason you use acetone for a cleaner vs a panel prep type cleaner? 

You have a good point there , I leave it for a full 24 hours to cure , should I leave it a bit longer ?, how long would you advise,  I usually always use panel cleaner, I read somewhere else when doing some research into carbon skinning that acetone was used prior clear coating , thanks for your reply , much appreciated.

The reason I asked about acetone is that its pretty aggressive. I have used it in a pinch when I run out of my usual cleaner, but I have had some issues with it from time to time and it always makes me nervous. 

Can I start by saying that I am not a paint sprayer and this is based on trial and error

Carbon can be a tricky one to clear coat compared to say a steel panel. Good point made about the resin not being fully cured, presuming you have access to a booth/oven I would put the part in there for a good few hours to fully cure first.
 
I use Infusion but often clear coat parts to give UV protection, but this should also apply to skinned parts.

Wet Sand with 320's
Wash part thoroughly with warm water.
Dry in oven or use hot air gun on smaller parts.
Panel Wipe
This is the part I have found to be the key one. Wipe over with Plastic Primer (twice) spray applied on larger parts.
I use 2k clear starting of with 4 or 5 very very light mist coats, just to seal the surface. Allowing 15 minutes between coats to flash off.
Once the surface is sealed I then apply heavier coats until the required gloss is achieved.
I know this may not be "text book" but it works for me


Regards Warren

Carbon Copies Ltd

Warren, what do you mean by plastic primer? Do you mean an adhesion promoter?

Not familiar with that term but sounds similar. Used to prep plastic car panels prior to paint. Basically an etch primer for plastics and it is clear.
I use a couple of different types, one is a Mipa product, not sure if you have that in the States but I can't remember the other. Will have a look today.

Warren

Carbon Copies Ltd

Adhesion promoter is plastic primer, same stuff. 

I've had exactly this problem too.  The key is how you spray.  One option is like warren says by spraying a few dust coats and let the dry before the next.  You can end up with a full layer of dust coats.  This seems to seal the surface and it takes a spray coat just fine afterwards.  The other way I've found that works is to brush a coat on to seal the surface, let that dry and then spray.  IME sealing the surface is the key step.  I'm not sure why this is but its essential.

Ok thanks for the replies , things I've tried so far are , wet flatting back leave for 24/36/72 hours before applying 2k clear coat , various ways of clear coating, ie: dust coating then heavy coats, also putting wetter coats with more thinners to try and get it to seal anything, flatten it back then reapplying another 2 or 3 clear coats .



here's a piece i finished yesterday really pleased with how it came out apart from these damn pinholes. this is after wet flatting back and re coating.

2nd pic is first application of clearcoat as you can see the pinholes were really bad, and i will add you couldn't see any defects or pin holes before i clear coated , I would say this part looked perfect




I will persevere however and will try wiping a clear coat by hand to see how that turns out and will report back. Once again thankyou to all who replied.