Hey guys i vacuum bagged CF , using gelcoat as first layer, then brush resin and bagged, its undercover for cross bike, check the picture , there is unsaturated fiber, how do you think :
What was the reason of fail? what did wrong ?
Can I repair it now in anyway ?
pics:
Bad fiber placement.
Pay more attention to fiber placement, and the whole stack that goes behind (perf film, breather, vacuum film). Make sure no bridging is possible.
I also see quite some air bubbles in the rest of the part. Make sure your epoxy is well degassed after mixing, and work carefully, to prevent introducing airbubbles.
Ok I see… but how to degass it? I leave it for around 5 min’s to let bubbles out.
Btw… Herman , do you think in infusion it will be exactlly the same? because of problem with fiber placement, or infusion will do the job?
If you do not get better at placing fibers, things will not be better.
Wet bagging is about placing fiber, and laminating skills.
Infusion is about fiber placing skills only.
Its because fibers “dont listen to me” , I dont know what I can do to improve placing them, usually CF dont stick to mould when I use mould which are not flat…
I guess maybe with infusion would be better ? cause I can use a spray glue there
Is it possible the vacuum is to weak ?
Vacuum will not move fiber.
Do you use a gelcoat?
When lightly sprayed, you can use Airtac2 to glue the fabric to the mould, and will not see it afterwards. This works with infusion, I have no idea if it will work in wetbagging.
On fibers not listening: Most carbon is Japanese, so try talking in Japanese, not Polish… 
I mean more vakuum will put more pressure on fibers to stick them to mould, I guess…but not sure.
Yes i used gelcoat, why you asking?
sasasasa 
so this is the secret of carbon fiber…
I tried next day, i minimise little bubbles by turning off the pump after about 4 hours…
But some delaminated places still appear… Maybe I should put less resin on muld and wet out from top ?
A tacky gelcoat can help sticking the fiber to the mould and stay put.
The vacuum film will not move the fiber into the corners. What you could do is pull a very light vacuum, and push it in the corners then.
You mean to put firstly fiber on tacky gelcoat? instead of first layer resin?
So wetting out from top not from under
If the fiber does not stay down otherwise, yes.