Hello all,
Ive been using CC10/50 for about a year now and recently been experiencing small micro bubbles appearing in my pours. CC 10/50 1kg pack has been laying for some time and developed crystallizing at the bottom.
Ive put it in hot water and let it cool naturally and got it back to a nice clear consistency.  
Mixing approx 90g in 2:1 ratio
Mixing in small plastic cups for 3mins then pour in to second cup with further 1 min mix.
poured in to 3rd cup slowly at a depth of 35mm
used heat gun to pop top bubbles
left to cure over night
any help would be greatly received, thanks

in the morning i can see tiny bubbles thru the entire 35mm depth of the pour

Hi John, Can I just check; is this GlassCast (You've put Clear Cast) so want to ensure we're talking about the same product; if so, the mix ratio when mixing by weight is 100:45 rather than 2:1, the latter is the ratio when measuring by volume; its worth checking as getting it the wrong way round can give some curing issues.

What temperatures are you working in and what temperature is the resin when you're mixing it? At lower temps, the viscosity increases quite significantly and when it is thicker, it struggles to release air as easily; to avoid this, ensure that both your environment and the resin itself is at least 20'C as this should ensure it naturally degasses without a problem.

+x

 

Rich (Staff) - 1/10/2019 5:53:43 PM

Hi John, Can I just check; is this GlassCast (You've put Clear Cast) so want to ensure we're talking about the same product; if so, the mix ratio when mixing by weight is 100:45 rather than 2:1, the latter is the ratio when measuring by volume; its worth checking as getting it the wrong way round can give some curing issues.

What temperatures are you working in and what temperature is the resin when you're mixing it? At lower temps, the viscosity increases quite significantly and when it is thicker, it struggles to release air as easily; to avoid this, ensure that both your environment and the resin itself is at least 20'C as this should ensure it naturally degasses without a problem.

Update**  Taking the above advice, I slowly heated parts A+B to around 25 Degree C and maintained this room temp for the pour and set. This time correctly measuring weight ratio @ 100:45. Mixed for 3 mins and then poured in to another container and further mixed for 1min then poured in to 3rd container to set. Took heat gun periodically to top to release bubbles over the next hour. The results where again disappointing, less bubbles.I compared this with a double pour I did 1 year ago with the same batch and this has just 3 tiny bubbles, (sorry for the scratches, this was a test piece that has been in my workshop since the pour)

 
Images below are poured 1 year ago, 5 times the amount of resin and virtually no bubbles.

Strange, normally we would expect it to be as per the bottom block, especially if you heat gunned it. A few microbubbles would be normal in a resin that has not been degassed, although they would only be visible very close up and certainly wouldn't look as big as those bubbles look.

It is strange as the only source of bubbles is those already in the resin on mixing, so the bubbles once removed  should not come back if all is going well.  Moisture can cause bubbles in the  resin but it can also make it appear cloudy in bad cases.

How old is the current bottle you have?  You mentioned  a year but  not sure if that is that bottle or a previous one.  The shelf life is 12 months so if it is a little older if may well  be a contributing factor.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

+x

 

Warren (Staff) - 1/17/2019 11:01:23 AM

Strange, normally we would expect it to be as per the bottom block, especially if you heat gunned it. A few microbubbles would be normal in a resin that has not been degassed, although they would only be visible very close up and certainly wouldn't look as big as those bubbles look.

It is strange as the only source of bubbles is those already in the resin on mixing, so the bubbles once removed  should not come back if all is going well.  Moisture can cause bubbles in the  resin but it can also make it appear cloudy in bad cases.

How old is the current bottle you have?  You mentioned  a year but  not sure if that is that bottle or a previous one.  The shelf life is 12 months so if it is a little older if may well  be a contributing factor.

So I did another pour, following the procedure as before, nice warm Part A & B in a warm room 22 Deg C. As I poured slowly, I used a heat gun, so pour about 5mm then used heat gun. In total I poured to a depth of 55mm. This produced a lovely clear mix, I occasionally went over the top with the heat gun. As the mix set, I could see small air bubbles forming in the mix, however as the mix was setting it was not possible to release these bubbles. They increased in side till I was right back at my first picture.
I will try again today with an unopened product and see what happens.

Very strange.  Certainly not something we have seen with new bubbles forming after degassing unless there is moisture present.  Would certainly be interesting to see more feedback from the new batch.  There may well be some deteriation or factor we have yet to see with very old batches.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Hi

I've  been having the same issues.

Is there an update from John as to using a new un-opened product?