Author Topic: Glass fibre mould from the slender plug  (Read 1512 times)

Offline vtsteam

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Re: Glass fibre mould from the slender plug
« Reply #50 on: July 09, 2018, 11:21:54 AM »
Looks like you just had adhesion problems -- gel coat was bonded more strongly to the mold (release) than to the laminate. So it broke the particle board mold and also separated off of the laminate.

Maybe it just didn't cure. That would leave it adhered glue-like to the mold, and not firmly attached to the laminate -- that's just a guess. Maybe something inhibited full cure?

For separating parts, have you tried compressed air?

I have to say that I don't use particle board or MDF for patterns of any kind -- I know others do, but I don't like it. I think it's too easily damaged, and also subject to moisture attack. I like wood.

If you're going to stick with particle board or chipboard or MDF, I would guess you really need a deep coating of finish and it needs to be a very glossy and strong finish that is well cured.

Just another suggestion.... when applying glass to a mold inside corners or a small female mold, use a small stiff disposable paintbrush and push the cloth into place with the tip -- like stippling paint -- kind of tapping it in. Don't try to brush the resin in like you would paint with it. That will just move the cloth and shred fibers from edges, or pull the cloth from somewhere else and make bubbles and voids. Maybe you already know this, just adding my own experiences here.
I love it when a Plan B comes together!
Steve
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Offline PekkaNF

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Re: Glass fibre mould from the slender plug
« Reply #51 on: July 09, 2018, 11:37:13 AM »
Thnk you,

The gelcoat held ont mould everywhere, but not on the undercuts, where it had wedged. Waxing and separation here was not issue, only on the "decoration" part that had practically undercut, not draft, or what is that taper that enables separation. The wrinkles were real....googling says that often they are product of laying too thin gelcoat...I never seen that problem before and i never had it before, but problems seem to be ofthen (but not always) on the places that had litle gel coat.

I popped open the mold #4, that was made in dark, I literally had to pat down the twill over the gelcoat to see where it was. i tried new to me special foam/fabric I got small sample here. it builds 2 mm on one layer.

This mould is all wrong but for some reason the most important parts seem to be ready for lamination. This plug was way too deep and it has unpractical features, because the whole part was designed to come out at certain "deck height" to fit all parts together. Out of 11 mm of depth only 3-4 mm is used, the yellow wax made it possible to separate mould from plug,

pretty ugly, don't you think

I'll finish moulds and leave them to dry until tomorow. I'll read the messages at night.

What a learing curve.

Thank you,
Pekka

Offline vtsteam

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Re: Glass fibre mould from the slender plug
« Reply #52 on: July 09, 2018, 11:49:17 AM »
Oh, okay, undercuts. That would be a definite problem, and the more you reinforce the mold the worse the problem because you can't stretch it at all to clear the undercuts.

And I take your word for it re, the gel coat being too thin.

Yes, a learning curve for sure! But you seem willing to persevere which is the best way to become expert at anything. I'm sure you will win this battle, Pekka!  :smart:
I love it when a Plan B comes together!
Steve
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Offline PekkaNF

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Re: Glass fibre mould from the slender plug
« Reply #53 on: July 09, 2018, 01:28:19 PM »
Thank you for couragement and advice.

I did sort of postmortem to the worst part (decoration):

1) no matter how much I tried to put gelcoat on top, it flow to bottom...the smallest pits were around half a inch diameter and bottom was filled thick and rim was starved. I have sometimes brushed very thin layer of gelcoat and then mix glass spheres and silica gel to gelcoat and brush that over it. Now I skipped it, thought that those don't have that sharp edge. Big mistake.

2: This was made worse by delaminated fabric, it did not adhere on thight corners. I was thinkking of this and tried to get milled glass fibre to sprinkle there.  Wonder if polyester putty would have worked here?

3: I used half an inch wide strips to laminate it, but it did not work here. I tried to push cloth into corners with stiff brush and even with finger (clove). This might have been last mistake....think that when I pushed one void down, it pulled next out?

i have been waching some videos, but sometimes one hour hands on training with a mentor might be more efficient than 100 hours of videos.

Offline PekkaNF

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Re: Glass fibre mould from the slender plug
« Reply #54 on: July 15, 2018, 08:05:10 AM »
Turned out that that the other make gelcoat had all the problems and another had no problems, even if I pushed it on very thick on thin.

Anyways, most things I tried had a snag here and there. and delayed finsishing it to deadline, but two very late nights saw a lot of progress, last steps really transformed crude parts to fairly convinsing looking parts.

Next time all steps will be done and no very few corners are cut (on drying times etc. basic stuff).

But my dayghter had a sword she is happy


Offline awemawson

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Re: Glass fibre mould from the slender plug
« Reply #55 on: July 15, 2018, 09:12:35 AM »
That should slay a few dragons  :clap:
Andrew Mawson
East Sussex

Offline PekkaNF

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Re: Glass fibre mould from the slender plug
« Reply #56 on: July 15, 2018, 04:42:44 PM »
And it was partly translucent!

That got some attention, some were thinking that it could not be "legal" but when they held it, they concluded that it was pretty light to be dangerous and most just could not get over with the glass fibre part.

It shows some wear, specially gold painted parts, but my daughter thinks that it shows some real character and looks more like weathered.

Most importantly it held 8 hours of constant handling.

Pekka

Offline vtsteam

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Re: Glass fibre mould from the slender plug
« Reply #57 on: July 16, 2018, 07:24:03 AM »
Great job, Pekka ! Looks really fine.  :clap:  :clap:  :clap:

 :mmr:
I love it when a Plan B comes together!
Steve
www.sredmond.com