Hey everyone,

I have been infusing parts using a two mould method to reproduce a curved piece with smooth surfaces on both sides. Unfortunately, during my infusion, once the epoxy reaches the vacuum line side and it starts spurting bubbles into the catch pot (see the middle-right circle), small bubbles started to climb back up the resin line, which is connected to the resin feed pot (see bottom circle). I can't seem to get it to stop. During my first infusion of this part it did not have any adverse effects, but it still concerns me that air is:

a) apparently not all the air is moving towards the flow of vacuum - ie. towards the vacuum pump
b) there shouldn't be bubbles in there regardless. The only bubbles I could think of are ones that get mixed in with the epoxy and do not have a chance to off-gas out of the mixture before they are sucked into the part. I realized that a degassing chamber would help fix this, so I am going to build one.



And yes I just realized that you can't read the print so ignore that part of the picture haha.

Anyways, if anyone else has experience this, or knows what it may be, that would be a big help. It is unfortunate that it is a closed mould, as I cannot see the details of where these bubbles are coming from. Any help would be greatly appreciated.

-Mike-

Thanks for the tips guys. I like the idea of warming everything up for better flow characteristics, plus the workshop I work in can get a bit chilly (17 degrees celsius at times).

I have attached some photos of the piece out of the mould after being post cured. The pinholes appeared as I had thought they would, but oddly enough, there are two "fronts" of bubbles on the underside on both the vacuum side and resin feed side. Any ideas as to why this happened? Or has anyone experienced this kind of problem before? I think this may have been linked somehow to the bubbles I saw rising back up the resin feed line.

-Mike-

That is exactly how every piece I have ever done looked as far as pin holes.

Try again using my advice for sealing your bag, heating the mold. After you have infused  close off the vacuum side first then wait 15 seconds or so and then close off the resin feed. (also make sure your resin is up to temperature. and infuse with full vac)

This worked for me.

Hope it works for you. let us know.