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Old Jul 30, 2005, 12:20 PM
Tearing the Skies a new one...
Sensiblenick's Avatar
Sweden: Ystad
Joined Oct 2004
4,013 Posts
Lost Foam Moulding Question: urgent answers and mindless chatter needed...

So.. i find myself at work at 7pm on a saturday night, So bored that I could quite easily imagine myself doing increadably silly things to amuse myself.
While I sketch out profiles and flagrantly abuse the company photocopier, I'm gonna be furiously updating this thread in a hope to get answers...

I have just realised that there's lots of Polystyrene foam laying ...... the REALLY soft white granular foam around...

QUESTION.


Is this suitable for lost foam moulding??? I mean.. Despite making moulds and playing with carbon fiber, I appear to have been running far before I learnt the basics behind crawling.

I'd imagine that so long as Detail isn't the highest priority, I'm safe... right? And it'll be easier to cut out later??.. yeah??

C'mon... I'd even accept advice from DevilsCries at this point... LOL.


LET THE MINDLESS BANTER BEGIN!!!
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Last edited by Sensiblenick; Jul 30, 2005 at 12:43 PM. Reason: Polysteyrene... the REALLY soft white granular foam
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Old Jul 30, 2005, 12:54 PM
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seaotter's Avatar
Colorado, United States
Joined Nov 2002
253 Posts
Poly Styrene? wasn't she the singer for x-ray specs?

in my very limited experience, the white popcorn foam isn't your best bet for lost foam. the higher density foams sand it round a whole lot better.

but if you're just bored and screwing around, go for it.
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Old Jul 30, 2005, 01:02 PM
Tearing the Skies a new one...
Sensiblenick's Avatar
Sweden: Ystad
Joined Oct 2004
4,013 Posts
woohooo!!! an answer!!

I have spent many years sanding it round and wise in the art I am. The force of Bring is with me.... and besides... I'll be taping it up before I cover it in carbon.... Should work... right?

8pm and still at work. This SUCKS!!!

Poly.... mmmmmmm
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Old Jul 30, 2005, 01:28 PM
Tearing the Skies a new one...
Sensiblenick's Avatar
Sweden: Ystad
Joined Oct 2004
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hmm... Thanks Otter... I'll give it a go
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Old Jul 30, 2005, 02:02 PM
built flown + crashed it
Pewsey, Great Britain (UK)
Joined Oct 2004
408 Posts
i have messed about with that stuff before "discovering" blue foam. It works great, only observation i have is to always sand in one direction, have a go you will soon see what i mean.
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Old Jul 30, 2005, 02:08 PM
Tearing the Skies a new one...
Sensiblenick's Avatar
Sweden: Ystad
Joined Oct 2004
4,013 Posts
Blue Foam = In shops
Time = 21:00hrs
Shops = Closed
White foam = Here
Here = At Work
White Foam At Work = SCRAP.

Hmm.. Algebra's easy.

I've been working on this formula.... whaddya recon?

Slinky + escalator = Endless Fun
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Old Jul 30, 2005, 02:09 PM
Tearing the Skies a new one...
Sensiblenick's Avatar
Sweden: Ystad
Joined Oct 2004
4,013 Posts
Oh...and I'll only stroke it in one Direction Target... thanks for the Advice!!
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Old Jul 30, 2005, 02:17 PM
Plane 0 Gravity 1
ryk_d2003's Avatar
Bangor,Northern Ireland
Joined Sep 2003
330 Posts
As long as u sand slowly white foam is OK.
Shape a fuse cover it in packing tape.
Wax it as we all know u can!
Glass it.
Set it.
And melt out foam with whatever highly volitile liquid u can find
and I'm sure u have some good ones lying around in work. Bit like my dad used to bring home in big glass jars when he worked in R&D for Shorts
Then pull out whats left of the tape.
Tada a Fuse.
But on a side note with all that lovely stuff lying around and access to milling machines what about THIS
for a bit of fun

Eryk
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Old Jul 30, 2005, 02:18 PM
built flown + crashed it
Pewsey, Great Britain (UK)
Joined Oct 2004
408 Posts
what you gonna make?baby jart, really big jart. Here is an idea, attatch 2 bits together with..... something... uh bits of wire, contact spray ..whatever is lying around, sand to shape using join line as reference, split into 2 halves, lay on flat plastic like surface and make a dam round it... maybe more foam, pour plaster over both halves, leave for a few days, paint some epoxy on the surface and you have got a new retox mold. Uh you got any plaster there?
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Old Jul 30, 2005, 03:52 PM
Tearing the Skies a new one...
Sensiblenick's Avatar
Sweden: Ystad
Joined Oct 2004
4,013 Posts
holy cow Thermalled.. you sound like a guy who's trying to give directions to work a VCR while changing a nappy on a baby and drinking a cup of coffee!!!

(nappy=dung-hamper for babies or grandparents)

I'm not saying what I'm up to. Nothing will be posted until I've got the JART-V ready to fly....

Suffice to say this... it's quater to 11, I'm dog tired, and laminating 20mm Polystyrene foam with 3M spray adhesive is like trying to juggle tennis balls while wearing Velcro Gloves.

And once you've managed, Shoving it through a Band saw is FUTILE¨... However, I do have something to take home.....

Tomorrow I are laminating Pink foam with Epoxy... That'll learn it!!
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Old Jul 30, 2005, 04:58 PM
Tearing the Skies a new one...
Sensiblenick's Avatar
Sweden: Ystad
Joined Oct 2004
4,013 Posts
The reason I was at work was because of a Möhippa or Hen night, (Bachelorette thingy for you US peeps)

I've just got home to .... well, I was expecting carnage... but it seems ok... and so does the AWESOME trifle and punch. I HIT GOLD!!!

I think Anna must have dropped 2 ltrs of vodka into this thing, and it KICKS!! lalalala
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Old Jul 30, 2005, 06:51 PM
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gorgeflyer's Avatar
The Gorge
Joined Mar 2002
794 Posts
White foam is great stuff for lost foam method. Used to make indestuctable fusalges for Ninjas in the early 90's using eps for the foam. I had rolls of braided fiberglass (think chinese handcuffs) that was left over from making windsurfing masts. Great for fuses, crap for masts unless you like to swim towing a board and a ripped sail. Anyway, we would shape and glass the fuse and then pour acetone down the end and the foam would disolve in no time flat. Don't smoke while doing this.
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Old Jul 30, 2005, 09:14 PM
It's not a Toomah.
cwayland's Avatar
Orange County California
Joined Apr 2005
388 Posts
I am also making a lost foam fuse for the first time. Is there any way to keep polystryrene from turning into masses of little white pebbles that fly all over the place? Can you wet sand it?

Clint
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Old Jul 30, 2005, 11:10 PM
Registered User
Australia, NSW, Hornsby
Joined Jul 2005
772 Posts
The best stuff I've found is the foam they use to make surfboards.
It's stiff & sands easily & is Polyester resin safe (much cheaper here than Epoxy resin).
The only hitch is you can't melt it with Acetone, you've got to dig it all out manualy.
There is probably something that would melt this stuff but I haven't found it yet.
On that point, anyone know what to use to melt surfboard blank foam ?

If you want to use white PS foam, Make a keel from Balsa in the shape you want the Fuse, put a sheet of foam either side & glue it together.
That'll give you a more rigid plug, roughly sand it to shape & then cover it with tape.
Glass it up, melt the foam out & then crush up the balsa to remove it.
Too easy.

Al
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Old Jul 30, 2005, 11:24 PM
Something MUST FLY!
IMoonBark's Avatar
OC, there is no "The OC"
Joined Jun 2004
1,070 Posts
I have no experience with lost foam, but I have enormous quantities of useless chatter so I can share some of that.

I will be using lost foam method on my SSDC FFish... blue foam will be the base material unless you can convince me that the EPS a la Devilscries is worthy of the effort. I have a ton of that but I don't want to waste my glass and epoxy on a poor substitute.

Any thoughts?

Told ya I got worthless chatter! HA!
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