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PostPosted: Tue Jul 21, 2015 12:42 pm 
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Hi guys, just put my order in for wc782 casting resin, water clear uv clear polyurethane.

I'm going to have a go at recasting this badge and any other badge anyone might need. Will also be posting the process in this thread as a 'how to' for anyone who is interested.

Wc782 is regarded as one of the best water clear casting resins that is also uv stable, so I should get a good long life out of the castings.


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PostPosted: Tue Jul 21, 2015 12:50 pm 
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See if you can make a vacuum chamber to suck any bubbles out of it.

Mick had a go a long time ago and it was too bubbly, he gave the stuff to me to have a go but I never got around to it.... lack of a vacuum chamber stopped me

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PostPosted: Tue Jul 21, 2015 1:59 pm 
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Interested to hear how this goes, have been trying to find a mini k badge!!

Mine is toast :(


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PostPosted: Tue Jul 21, 2015 4:03 pm 
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I cast the mould today. It took a good impression, vacuum chamber is a bit hacked together, works OK until it sucks a seal in.


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PostPosted: Wed Jul 22, 2015 9:58 am 
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I started down this track too, but got no further than preparing the master badge. There are some good online resources about casting tail light lenses that have some useful tips on eliminating bubbles.

Tim

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PostPosted: Wed Jul 22, 2015 1:53 pm 
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When I did mine I used a vac chamber that I set up for my model train casting business. I still found that I got bubbles. I have been told the best way is to use pressure (60psi) in a pressure pot. It also does away with the rise and boiling of the resin when under vacuum.

I just don't have the time at the moment to do any more. Maybe I should if they are wanted so much.

Cheers
Ian


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PostPosted: Wed Jul 22, 2015 7:10 pm 
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I work in the dental tech industry and we always cure in a pressure pot. As per above this raises the boiling point of the monomer to prevent it boiling during curing thus preventing porosity.

A cooking pressure pot can be used for this. We normally submerse the acrylic mould in warm water to aid curing. In our case material is (poly)methylmethacrylate.

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PostPosted: Fri Sep 18, 2015 8:39 pm 
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Hi Guys,

Sorry Iv'e not been updating on this, the rig I was using was turfed (cracked the shits with it leaking, was a pressure pot I was asking to deal with vacuum) So Iv'e built a new one, especially for this resin where I can apply vacuum, pressure and heat (while under pressure) so I can cure this resin optically clear.

Photos attached, the lump at the top is the sprue.

Observations :

This Repro badge for whatever reason is slightly larger that an OEM badge, so it is snug in the surround, however very minimal sanding fixes this (they should be hand polished before fitting at any rate as the silicon is so accurate it picks up the microscopic scratches in the acrylic)

The Urethane is more or less the hardest Urethane available that is UV resistant, that said it is still less hard than the original acrylic. I have to do a small experiment regarding how this badge will fare in the full Australian sun but I am confident it should be fine.

It is more chemically resistant that most Urethanes, which leaves us some options regarding colouring.

Now, I can offer these for sale, but I have no idea what a Repro should be worth, especially considering they're not colored (I am attempting to do this) and there is basically Nil NOS stock of these available, or even ones in decent condition. I can cast your badge (you pay for the silicon around $40) or you could buy a cast from my badge.

I can teach anyone how to make one, but the cost for a single unit just isn't worth the hassle unless, like me, you are into this sort of torture. To make one you need basic tools, some knowledge of resins and moulding, respect for pressure and vacuum and a little electrical know how. The rest is cold hard cash.

Be aware though, I make no claims of longevity, as unlike the originals, this one is brand new.

Image


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PostPosted: Fri Sep 18, 2015 9:40 pm 
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looks fantastic from where I'm sitting!

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PostPosted: Fri Sep 18, 2015 10:00 pm 
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Looks bloody great. The one on my K isn't bad at all though.

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PostPosted: Fri Sep 18, 2015 10:57 pm 
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Do 3d printers use clear plastic or what ever they use

I reckon it would be easier printed on one

I haven't gotten into this type of printing yet only what I've seen on tv shows its still a bit out of my price range to buy one


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PostPosted: Sat Sep 19, 2015 7:21 am 
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Location: san remo nsw
My friend has a 3d printer to do model railway stuff and the clear doesn't come out very clear.
The cast out looks excellent, what paint do you use?


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PostPosted: Sat Sep 19, 2015 9:04 am 
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This is a really good question, I'm not sure what to use as it will need good uv resistance (assuming the urethane is transparent to uv) I have some humbrol model paints but I do not know how these will go.

I may have to look at getting some custom coloured nitrocellulose or 2 pack.


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PostPosted: Sat Sep 19, 2015 9:05 am 
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Location: Under the bonnet son!
That looks fantastic as is! Well done!



No, 3D printing wouldn't be the answer here. As it lays down in layers there will be optical imperfections between each layer which will make it opaque.

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PostPosted: Sat Sep 19, 2015 12:39 pm 
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Must be about time someone done proper mk2 s bonnet badges


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