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"Print through" residue left on mold surface after demold.
"Print through" residue left on mold surface after demold.
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"Print through" residue left on mold surface after demold.
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seense
seense
posted 8 Years Ago
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Hi!
When molding carbon parts with high Vf (>50%) the fibres touching the mold are leaving a residue on my mold surface. I don't know why this is happening. I just bought easy lease release agent, but it also happened with wax (Partall). In fact I thought the Partall wax had aged so I bought Easy Lease thanks to this forum. But unfortunately no difference. The parts are demolding easy though with easy lease.
I have been using different curing processes: 24h room temp, 48h room temp, 24h 30 degrees C, 48h 30 degrees C. All with the same outcome: a residue on the mold. The molds are machined of PU toolingboard (Renshape) and polished to a mirror surface. Epoxies used are L + GL2 / S / L and EPH161 from R&G. When making a hand layup of one ply of carbon without compaction there is no printthrough and also no residue on the mold surface after demolding just like when using a gelcoat prior to the lay up. So it looks like the problem is related to the compaction of the fibre or it maybe an epoxy problem.
In the video of the small bonnet Easycomposites doesn't use a gelcoat either. Is there also a residue left on the mold? Or is this problem related to the used epoxy? I don't mind a little print through on the part but the problem is that I have to repolish the mold and re apply the easy lease which eliminates the advantage of a semi perm.
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seense
seense
posted 8 Years Ago
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Thanks for pointing me in that direction and good to know you didn't have the problem in the video. I'll contact the supplier and post the outcome.
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8 Years Ago by
seense
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seense
seense
posted 8 Years Ago
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Adding a little heat isn't the problem i guess since the problem also occurs when curing at room temp for 2 days. I also want to point out that I'm not using resin infusion, but RTM (two A sides), so maybe the compression force from the fibre on the mold is a bit higher due to the higher vf.
I contacted several suppliers for a solution. Only 1 replied so far and says the problem is most likely due to the absence of a sealer (micro porosity). Unfortunately not willing or not able to tell if their TR sealer is compatible with the easy lease and only promoting their own release systems.
In the meantime I read on the forum that release properties can differ when applying more coats of Easy Lease. So I took that to the test and applied 12 coats of easy lease. There was a noticeable difference between 12 or 6 coats when doing the tape test and releasing the part. Only a few spots on the mold. I'm not going to repolish the mold this time (the few leftovers I could remove with my nails) but will apply more coats of EL. Hoping the release gets better and better.
Is sealing capability of a single sealer superior to the sealing capability of EL?
I'm also wondering if I want to use a sealer can I use Marbocote sealer with EL? I read on the web that EL is most likely Marbocote 227CE in a different tin. Don't know if this is true, but would love to hear if Marbocote sealer is compatible with EL.
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"Print through" residue left on mold surface after demold.
seense
-
8 Years Ago
My initial thoughts are it might well be a problem with the surface of the board in combination with...
Warren (Staff)
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8 Years Ago
Thanks for your reply. It's renshape 5173 (1200 kg/m3). The supplier told me that this type doesn't...
seense
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8 Years Ago
Unfortunately it's difficult for us to comment on what might be causing this issue because we don't...
Matt (Staff)
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8 Years Ago
Thanks for pointing me in that direction and good to know you didn't have the problem in the video....
seense
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8 Years Ago
Adding a little heat isn't the problem i guess since the problem also occurs when curing at room...
seense
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8 Years Ago
I'm a bit hesitant to post because I don't know if this will help or hinder you, but I'll share my...
Hanaldo
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8 Years Ago
Thanks! Appreciating every input and experience. Semi perms and RTM are new to me. After the last...
seense
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8 Years Ago
My gut feeling is that the issue will be chemical, like Matt was alluding to. I have had similar...
Hanaldo
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8 Years Ago
Problems are gone! I guess my molds needed more coats of Easy Lease during break in time? Anyhow I...
seense
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8 Years Ago
update: Apparently the easy lease tin was already a bit old when I got it. :(. So when I got it I...
seense
-
8 Years Ago
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