What causes air bubbles?

[Lanoline]

Recently startd hand pouring till I get usd to playing around an can afford injectors.

I had some great pours in the beginning, but recently, I get the odd bait with lots of bubbles that appear towards the top of the mold.


Any advice to prevent these?

Thank-you.

[Justin9j]

Moisture is the microwave or cups. Try heating both before you start.  There are some great threads on here about that problem.   

[412BaitCo]

Make sure your cup is free of all moisture before heating your plastic. Sometimes heating the empty cup about 20 seconds in the microwave before putting plastic in it to make sure all the moisture is dried out. Someone else gave me these tips and they helped me a ton a while back. Good luck.

[412BaitCo]

Haha we must have been answering that at the same time Justin.

[Lanoline]

Awesome... Ill try that, and thanks a bunch.


Could too hot of plastic cause bubbles too?

[andrewlamberson]

After I heat my cups for 20 secs or so...I wipe them out with the brown paper that CCM wraps all their stuff in. Seems to make a significant difference!

[412BaitCo]

After I heat my cups for 20 secs or so...I wipe them out with the brown paper that CCM wraps all their stuff in. Seems to make a significant difference!

This was what exactly what I was talking about. Thanks again Andy for this tip I'm pretty sure you game it to me a couple months ago and it solved my problem as best it possibly could working in a humid basement.

[ghostbaits]

Are these aluminum molds? If they are plaster of paris, the coating on the mold has worn somewhere.

Could also be moisture in mold if aluminum. When I keep molds in house and bring outside (cups too), I get a thin layer of condensation inside due to the high humidity and temp difference.

Jim

[Lanoline]

Wow - awesome replies....

They Are in fact Plaster molds that I hand bombed to experament...

I am pouring in my garage, and I dont sti vigorously.. Ill try to attach some pics later, but it seems to only be the first 2 or 3 pursm thn the last two are fine....

[ghostbaits]

Classic problem with mold seal. Reseal mold cavities and you will be good.

Jim

[Lanoline]

Thanks Ghostbaits.

They are one sided open face molds.... Im trying to attach a pic but cant figure out why I cant (no photobucket).

Even up to an hour ago, the first three baits are bubbled, last two perfect (5 baits per mold)

[ghostbaits]

I have hundreds of them. Either after a while or after a few pours, part of the seal is removed from the plastic in corners or edges.

You will get a bunch of bubbles in primarily one area (where seal has breached) but other areas essentially fine.

Recoat area or whole cavity with a few coats of your sealent, paying special attention to that area, and you will be good to go.

Jim

[Lanoline]

...Wow, arent I new.

I never sealed my POP mold.....

Any suggestions of what to use?


You guys are a huge help

[ghostbaits]

Spray on acrylic, 50/50 elmers and water, devcon 2 ton, etc.

Any will work.

Jim

[Lanoline]

Sweet. Thanks Jim!