Anti Foaming Agent

[rattrap]

Apoligies if there are previous posts on this question, I have tried to find some without success.

I was recommended it by a very experienced caster who swears by it. Smooth- On do an equivalant called Doxy 5.

I have bought Bentleys own brand which is considerably cheaper.The amount to use in resin is very minimal, and my question is what results do you guys out there get from it?


Cheers, Merry Christmas and Happy New Year to all....

[mangozac]

Thanks for the info Rattrap! RageOfAchilles did some experimenting with the anti-foaming agents but without much success (note however that we have concluded that his problems are environmental). IIRC after enquiring with Bentleys (who are a Smooth-On distributor) he eventually ended up with a sample of their branded anti-foaming additive. Hopefully he will be along shortly to comment...

What were your results like? Noticeable difference? Are you casting at room pressure?

[RageofAchilles]

[rattrap]

Thanks for the replies.

The last cast I did yesterday, I added about 10 drops to an open mould to assist in getting rid of surface bubbles. The results were slightly better, but I think more agent is needed because it is a rather large mould.

To answer your question zac, I am casting at room temperature.

Interesting to see the pics of the casts at different agent strengths too.

I will be doing more this weekend, so I will let you guys know the results.

[rattrap]

Well, I promised to reply back on my results, and sorry for the late reply.

So far I have to admit using it on small casts, it makes no difference at all. However, using it on large open mould casts, I have had very slightly better results, but I think I may not be adding enough of it.

I spoke to Bentleys who told me to use it the same as Doxy 5 which I have tried. I think it is not quite as concentrated as Doxy 5, probably why it is so much cheaper. I have some more open mould casting to do very soon, so I will post back with further results.

[rattrap]

A further update on this.

I have used it this weekend on open moulds adding a lot more than instructed, and it does work quite well.
If anyone out here is thinking of getting some to use for casting big open moulds, I would say go for it.

Also, I was given a really good tip from the great guys at Bentleys. If when doing open moulds and you are having problems with bubbling at the surface of the cast after degassing. After pouring the resin into the mould, add a light spray of mould release, the bubbles just disappear.

Hope this is helpful.

[RageofAchilles]

Glad to hear that you got some good results

Was it used in conjunction with a Vacuum chamber or normal atmosphere? As the main issue I had was foaming during degasing.

[rattrap]

I added it to the resin then vacuumed normally, then add pressure.
When mixing the resin parts A and B the bubbling occurs as it normally does,once the agent is added, it almost eliminates the bubbling.