I have NEVER had this happen before. Casting labels and playing cards with Silmar 41 Polyester Resin. Opened up a brand new can. Casting in vertical tubes with 5 drops of catalyst per ounce. Put in pressure pot with 44 psi and let it sit for 24 hours. Totally shocked as all of the tubes were surrounded by tiny bubbles and all completely ruined. Ughhhh!!!! Any ideas why this happened today and NEVER in the past???? Could it be a bad can of resin? Would appreciate any help. Thanks.
HELP! Bubbles!!!
- Thread starter saffron
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Mortalis
Member
Without pictures it is tough to identify any issue. I am not a caster but only thing I could say would be you needed higher pressure (like 60psi). That is only a guess from what I have read and observed from online information. Were the tubes open to the pressure? Obviously, if the tubes were capped on both ends the pressure would not be able to condense the bubbles.
Curly
Member
My wife's setup when she cast feather blanks used only 10 or 15 psi. She degassed all the resin in an ultrasound cleaner that also warmed it a little. Then she very gently mixed in the MEKP. They were horizontal moulds but I don't see how that would make a difference. Your bubbles might be because it was a new can and had been agitated a bunch before you got it.
JohnU
Member
Have you successfully cast those exact cards in this exact resin and procedure before with success or is this the first try? I ask because not all cards are made the same. Some are paper, some are vinyl, some bleed ink in certain resins if they cure too slow, others don't bond well if they cure too quick.
Sometimes a sealer is needed before casting to close the pours of the material, or create a surface the resin can stick to. Also, I always warm up the blanks before pouring the resin.
Porous materials will soak up humidity moisture and need to be warmed to burn it off. This usually results in a white foam and bubbly surface.
Clear Bubbles with no foam can mean there's not enough pressure or the resin was too hot and thick when poured.
And then there's those times when "sh*t happens" even when you do everything the same every time and sometimes they just don't turn out. I find this happens usually in late September (here in IL) with the changing of the weather/season. I cast most everything around 40 lbs - 50lbs in the pressure pot. I always stay around 10lbs under the maximum rated tank pressure. I use 3-4 drops of MEKP per ounce with Silmar but I dont think I've cast cards with it.
Like stated above, If you can post a picture of the blanks we might be able to give a little more specific advice.
Sometimes a sealer is needed before casting to close the pours of the material, or create a surface the resin can stick to. Also, I always warm up the blanks before pouring the resin.
Porous materials will soak up humidity moisture and need to be warmed to burn it off. This usually results in a white foam and bubbly surface.
Clear Bubbles with no foam can mean there's not enough pressure or the resin was too hot and thick when poured.
And then there's those times when "sh*t happens" even when you do everything the same every time and sometimes they just don't turn out. I find this happens usually in late September (here in IL) with the changing of the weather/season. I cast most everything around 40 lbs - 50lbs in the pressure pot. I always stay around 10lbs under the maximum rated tank pressure. I use 3-4 drops of MEKP per ounce with Silmar but I dont think I've cast cards with it.
Like stated above, If you can post a picture of the blanks we might be able to give a little more specific advice.