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Trying to mold my doors...:((((
Trying to mold my doors...:((((
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Trying to mold my doors...:((((
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BlackNDecker
BlackNDecker
posted 11 Years Ago
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Greetings all,
I just discovered this website and it looks like a great resource for novices like myself. I've been trying to mold my doors but have run into repeated failures.
I've posted this previously on
compositescentral.com
, but was hoping to get some feedback from you all.
I cleaned my door and flanged it, then sprayed several coats of PVA (next time I will use mold release). I then applied gel coat with a roller and brush. The temps were low when I applied the gel coat (approx. 49* F but I mixed extra MEKP and have had success even when allowed to set at -10* F).
Here is a pic of the door after the gel coat was laid down:
So I when I checked on it this afternoon (approx. 16 hrs later) I noticed a new problem I've never seen before with gel coat...it pulled away cleanly from the plug in some areas. Would this be due to nonuniform thickness??
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11 Years Ago by
BlackNDecker
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BlackNDecker
BlackNDecker
posted 11 Years Ago
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I don't understand why the pics aren't showing? I'm using photobucket and posting the IMG links just like I would on any other forum....???
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ajb100
ajb100
posted 11 Years Ago
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What % MEKP did you use?
One picture looks like the flanking has moved causing the crack, but that may be down to too much MEKP. I does also look very thick in places
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BlackNDecker
BlackNDecker
posted 11 Years Ago
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ajb100 (02/05/2014)
What % MEKP did you use?
I used 1.5% MEKP in 1 gallon of gel coat...so going by the spec sheet (1% = 1 oz MEKP per 1 gallon gel coat), I used 1.5 oz of MEKP since it was a pretty chilly day. The spec sheet says you can add up to 2.0% or more depending on the temp.
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Matthieu Libeert
Matthieu Libeert
posted 11 Years Ago
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As I would make a guess, you have some places that are thicker than other... when curing there will be an exothermal reaction. The more material you use the faster it wil cure, the more heat will be created, I think this formed some shrinkage causing it to be ripped apart in the thinner spots. your pictures are a bit difficicult to understand btw
Matthieu Libeert
Founder MAT2 Composites X Sports
website:
www.mat2composites.com
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Brian_s
Brian_s
posted 11 Years Ago
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You used a gallon for a door?
Unless it was for a barn I would have thought that was rather a lot.
Brian.
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TomDesign
TomDesign
posted 11 Years Ago
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same here those places that not enough gelcoat get same thing like you got or wrinkles.
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BlackNDecker
BlackNDecker
posted 11 Years Ago
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Thanks for the help everyone.
I agree that the uneven layers was likely responsible for the cracks and pull away, HOWEVER, I used
100% silicone caulk
in all the small crevices between the glass and the weather stripping. I have read that silicone can contaminate gel coat?? The area of lifting is in the same areas as the silicone. I have ordered soft fillet wax for a future attempt.
I am so tired of failing at this...I'm also doing this in my garage and I am at the mercy of the weather
((((
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BlackNDecker
BlackNDecker
posted 11 Years Ago
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Here is a pic of my door flanged prior to gel coat...you can see the silicone caulk all around the seams. I'm worried now about silicone contamination and if this will cause future problems.
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brainfart
brainfart
posted 11 Years Ago
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Silicone is very very bad! It's like teflon, no liquid resin will adhere to it and it wants to creep away from the silicone due to its surface tension.
Hit your reset button, watch the excellent instruction videos on youtube again and start over. There's really no point wasting lots of money and material on full sized car doors, take a small worthless object and make a mold of it, testing ALL your materials and procedures. If you fail, start over and correct what went wrong. You will learn more from 10 failed small trials than from one failed big attempt. And maybe the eleventh attempt will result in a perfect result. Only then should you consider bigger projects which might cost you lots of invested money and time.
This is a journey. Every journey starts with a few small steps. If you fail only one of them you won't reach your destination. So make sure you take those first steps properly. And on't take shortcuts because you might end up in a dead end. Others have walked this path before you, follow in their footsteps. Don't try to build a bigger, better mousetrap, just use one that is proven to work.
Yoda - out...
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