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Removing dried epoxy from flanges
Removing dried epoxy from flanges
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Removing dried epoxy from flanges
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FLD
FLD
posted 12 Years Ago
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Great news! Glad its worked for you.
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Philimon
Philimon
posted 12 Years Ago
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Well, I did another layup this weekend. I put a further 8 coats of EC Easy lease on the mould. It released much easier and the resin on the flanges scraped off very easily.
So lesson learnt. 4 coats is the bare minimum and probably only suited to polished moulds. Apply at least 8-10 coats on mould surfaces that are sanded to 1500 grit
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neilb
neilb
posted 12 Years Ago
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silicone sealer on the parting flanges is great, you can also wipe off excess if it enters on to the mould surface quite easily, would sort your problem out
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fgayford
fgayford
posted 12 Years Ago
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Hi Andrew
I infused 2 molds for my airplane panels. You can see the finished panels in the projects section.
I slit the gum tape very thin and then put that in between my mold surfaces that get clamped together to act as a seal. (I did have channels in the flanges for this though.) You may be able to use something like this.
Even a coat of wax release over the release couldn't hurt if your mold is rough.
Fred
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FLD
FLD
posted 12 Years Ago
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Philimon (13/02/2013)
Wow 12 coats!?!?! Okay I'll give that a try
Yeah, bit extreme but mouldings just drop out of the mould that requred a bit of a pull previously! Should sort your problem out.
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Philimon
Philimon
posted 12 Years Ago
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Wow 12 coats!?!?! Okay I'll give that a try
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FLD
FLD
posted 12 Years Ago
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On a non-polished mould I use 10-12 coats of easylease. I find the surface just eats it up! If you polish the surface then 5-6 coats is enough.
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Philimon
Philimon
posted 12 Years Ago
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Hi Fred
Thanks for your help.
I'm using the same release agent over the entire surface of the mold - including the flanges. I've used
EC's EasyLease
and followed the instructions to the letter.
I forgot to add that I'm using a two-part mold to make hollow wing-joiners. My layup is Carbon-Balsa-Carbon using
EL2 Laminating Resin w slow hardener
. I'm putting a partially-inflated balloon inside the layup, joining the two halves and putting it in a vacuum bag. Under vacuum the balloon inflates considerably and puts a nice amount of pressure on the inside of the layup - seems to work very well! Its this pressure, though, that is squeezing epoxy between the two halves of the mold and onto the flanges.
I'll do the tape-test on the flanges next time I'm at home - at the moment its covered in cured epoxy!
There are two possible causes that I can think of, neither of which makes much sense:
1. I'm using
Epoxy Gel Coat
instead of
Tooling Gelcoat
, which is designed for the purpose. But surely this shouldn't make that much of a difference?
2. The epoxy is forming a mechanical lock with the surface of the mold. But surely 1500-grit sanding would be smooth enough? Remember, I didn't polish the surface of the mold.
Of course, there is a third possible answer - I'm just useless...
Cheers
Andrew
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12 Years Ago by
Philimon
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fgayford
fgayford
posted 12 Years Ago
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Hi
Did you put the same release coats on the flanges? If not that is your problem. I use a different release agent that I think is similar to EC ez lease. This is what I do. I apply the release agent on the whole mold and flanges as instructions. I do a masking tape test on the surface of the mold to check and see how active the surface is. By that I mean, how easily does the tape come off in comparison to an untreated surface. Do the same on the flanges. If it comes off very easy you are good to go.
One problem I had was that the release I use is so slick that the bagging tape would not stick very well.(note this is not EC ez lease) So the solution for me was that I took 400 grit sand paper and scuffed the outer inch of the flange where the bagging tape would get applied. (in essence I removed most of the release) I then applied release paste wax on this area as well as half way in on the flange to give a better barrier. Now I can hardly remove the bagging tape which is OK because I don't get any leaks anymore.
Another tip I have learned. Once you are all bagged up and you are about to infuse. I put my mold in the heat box I have and get things real warm. I then pull it out and go over the bagging tape seams and boy does that stuff stick when warm. I now infuse.
This tip might help you guys who are still having trouble getting a perfectly sealed bag.
Hope this helps.
Fred
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Philimon
Philimon
posted 12 Years Ago
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I'm new to this whole composites thing and have started pulling parts from my first mould. It was made using the EC gel coat and I sanded down to 1500 grit. As the finish isn't important I didn't go down the polishing route on the plug or the flanges.
I've created a few parts now.. I used the easylease chemical release agent 5 applications. . During layup and while curing under vacuum I get a thin film of epoxy curing on the flanges. I clean what I can using malt vinegar during layout but there is still some spread during vacuum. When releasing the part this dried epoxy remains on the mould flanges and I have to remove it manually. It hasn't adhered completely to the mould in most places. But in a few no amount of co-ersion with a wooden part or steel blade will get it off. As a result I'm scratching the mould surface while cleaning this off and i'm reducing the life of my mould a lot.
Any ideas or suggestions to prevent this?
Thanks in advance!
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12 Years Ago by
Philimon
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