Hello ,
This is a great forum and I have gained immense knowledge here . Thank you guys !
After getting all supplies from easycomposites
I infused many carbon sheets on glass and a perfect glossy finish.
This is my first part I’m infusing in a mould.
Attempt 1 - pinholes towards the inlet side and relatively very less towards the vacuum side
( pinholes exactly between the fabric weave pattern )
It’s a 26”x 20” mould vacuum spiral was all around the flange of the mould and inlet in the center.
Mesh was right till the edge of the carbon fabric and spiral over the mesh.
This infused very fast approx 8-10 mins
Attempt 2 - pinholes all over the part. This time I infused from the side. Resin inlet spiral along the 26” side. I cut the mesh short and the spiral was over the peelply and carbon fabric. On the opp side I used two layers of the mesh on the flange and silicon connector in the middle.
This took about 20-25 mins to infuse.
Both times it was a perfectly sealed bag leak tested for 30 mins.
Where am I going wrong ? How do I get a pinhole free finish ?
Also which is the ideal way to place the inlet and vacuum on such a mould .
Really appreciate some help, thanks in advance

Thats a brave comment. Physically it is not true what you say. Yes you have a degassing in the flow media during infusion. But not 100%. So some air will travel in the fibers and will stay there. You won't degass anything if the resin is not moving as the air will not move because of friction and surface tension in the fibers.
If you have a degassed resin there is less air, true you can't get it 100% free of air but lets say 90% less air. And thats already 90% less that can go into your laminate.  You are correct with what you say that the "bubbles" shrink to virtually nothing once the part is filled. But thats because the pressure is leveled to ambient in the part after infusion because the resin is pushed in by ambient pressure against the brake zone. BUT once you clamp the feedline you still have the vacuum working on the spiral. And the brake zone is called brake zone because it slows the resin. That means that it just takes a while til the minimized airbubbles will start raising again because they want to expand and push resin into the spiral hose.  And that's what the MTI hose is made for. It is a resin stop, so the resin can't travel anywhere and the laminate will not be affected by the vacuum. and the airbubbles keep as small as they would be at ambient pressure.
Also the MTI hose allows to infuse independent of the flow front.
If you think it's wasted money thats ok, and yes in an ideal world infusions can be good without degassing and MTI hose, but it helps and brings process stability.