It’s been a fair while since i last posted, but i finally got to make a little progress now,
right now it’s holding a good vacuum, so i’ve left it for a while before i mix up some resin, hopefully there are no leaks.
The part pulled from the mould ok, but there is an area where the carbon hasn’t gone right into the corner of the mould and it’s filled with resin.
Any ideas as to how i can avoid this happening on my next attempt?
HELP:confused:
Are you using infusion resin?
Yes, It’s infusion resin.
Here’s a close up of what the rest of the piece is like, there are very fine pin holes, will a varnish top coat be needed or is there some way to polish it out?
I’ve never infused before but to me it looks like your flow media may be the problem. Going around the corner it won’t want to make a sharp 90deg and it will want to curve at some radius. This would hold the bag back from pushing hard at the edge. Maybe cut the media so it come just to the edge or a bit back. If you have to you could use two pieces, one for the concave portion and one for the flat top. Just my zero experience observation. 
I always spray a few coats of UV gel coat in my molds let it get tacky then I lay the carbon fiber down.
Be more accurate when laying the cloth. Every layer should be perfectly in shape. Vacuum does not move fabric.
After vacuuming, check and re adjust the fabric untill it is OK.
As for the bubbles: degass your resin before infusing, make sure your infusion speed is low, not fast, and use as high a vacuum as you can get. Way at least 30 minutes before infusion, to let moisture escape.
For this part, there is a product called “carbon pore filler” from MAP Yachting, France. A great product for this.
Next time you might to make the flanges for your mold a about 4-6 inches, it makes things a lot easier.
Thanks! How do I slow down the infusion speed?
Also how do I degass? Just leave it to settle in the pot?
Noted! Definatly need a bit more room
You could cover only 50-75% of the part with flow media instead.
Did you put in pleats, that helps with the bag bridging.
Yes there were pleats.
For small parts like this it is a lot easier to put the whole thing inside the bag instead sealing around the edges and you don’t need to make a big flange that way.
Slowing down infusion:
-different mesh
-no mesh
-thicker resin
-smaller inlet tube
-smaller runners round the part
Degassing: put the resin in a bucket in a vacuum vessel. Pull as deep a vacuum as you can. Bubbles and foam will form on the surface of the resin. Wat for it to settle. (takes 3-4 minutes). Let air into the vessel (carefully) and you are done. A small piece of scotchbrite dumped in the resin can help with degassing.
Thanks! I think i’ll try slowing the infusion by just partially opening the hose clamp on the resin feed tube.
I don’t have a degassing chamber / Vacuum vessel? is it necessary to get one?
Would this type of bagging tube be suitable?
http://www.ecfibreglasssupplies.co.uk/p-1661-50-micron-vacuum-bag-film-06-mt-wide-tube.aspx
that or just a double width sheet of film, tacky tape on 3 sides, and fold over in half. Envelope bagging.