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blogfast25
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'Sugru': anyone any experience with this?
https://sugru.com/about
This playdough like, RT air curing material might have some limited applications in home labs.
"Bluetack meets RT cured silicone sealant", something like that...
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j_sum1
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Looks pretty awesome.
I can think of a few things it could be useful for.
Is it actually silicon based or a silicone substitute? I couldn't tell from the website.
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macckone
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From the site, it is some kind of air cured silicone with a filler and color additive.
The exact composition is probably complex.
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aga
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Science fiction become fact, yet again.
"The Mote in God's Eye" by Larry Niven and Jerry Pournelle.
An excellent read.
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hissingnoise
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Deja vu all over again!
http://www.sciencemadness.org/talk/viewthread.php?tid=13257#...
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blogfast25
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Oooopsie.
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Muffn Man
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Oogoo, the DIY Sugru
Check this out:
http://www.instructables.com/id/How-To-Make-Your-Own-Sugru-S...
"Corn starch and clear silicone caulk"
[Edited on 31-5-2016 by Muffn Man]
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blogfast25
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Sugru is likely to use something a bit more sophisticated than corn starch as filler. Precipitated or pyrogenic silica (possibly silane treated)
e.g., both of which are preferred fillers/reinforcing agents for silicone elastomers.
A bit of water getting into your 'Oogoo' and I think you can imagine the result.
Many of these 'instructables' are fairly useless Google fillers, designed to be ad carriers.
[Edited on 1-6-2016 by blogfast25]
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aga
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i bought the multi-coloured 8-pack this morning.
Should arrive well before the universe ends, so what would you like done to it ?
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blogfast25
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Quote: Originally posted by aga | i bought the multi-coloured 8-pack this morning.
Should arrive well before the universe ends, so what would you like done to it ?
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As someone who worked in elastomer R&D for about 10 years, I'd be most interested in post-cured tensile strength and elongation at break but these
are NOT easy to measure accurately at home level.
Also interesting: these same properties after artificial ageing: e.g. after 24 h @ 100 C in air.
Also interesting: tension set. A uniform sample is stretched to 50 % for 24 h. Then the residual deformation is measured, after the tension is
released. It's a rough measure of long term elasticity.
Or liquid absorption: how much does a slab of cured Sugru absorb over a 24 h period of a given liquid? Water, kerosene, xylene are all good fluids to
test the material's resistance to.
Elastomers are interesting materials, both chemically and physically!
[Edited on 31-5-2016 by blogfast25]
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aga
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Would need to get a clue as to the possible extension length before rigging up something that could possibly be anywhere near accurate.
That's 1 knackered.
7 to go and have not even got them yet !
[Edited on 31-5-2016 by aga]
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blogfast25
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Quote: Originally posted by aga | Would need to get a clue as to the possible extension length before rigging up something that could possibly be anywhere near accurate.
That's 1 knackered.
7 to go and they have not even got them yet ! |
ASTM standards prescribe dumbbell specimens for tensile testing:
http://www.ptli.com/testlopedia/subs/Tensile-rubber-sample.a...
You could cut these out from a moulded sheet of Sugru, with a pair of scissors. You could then get a rough idea of E@B by simply stretching the
dumbbell manually until it snaps.
Of course you can use smaller sized dumbbells too.
How much of the stuff have you got?
[Edited on 31-5-2016 by blogfast25]
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aga
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None yet.
I ordered the 8-pack, different colours.
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blogfast25
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I meant: how much are you supposed to receive?
http://www.ptli.com/testlopedia/subs/Tensile-rubber-sample.a...
Wow. £10 for 25 g. Cheap it ain't!
[Edited on 31-5-2016 by blogfast25]
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aga
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i bought from the sugru.com site.
In teensyweensy writing it says 8x 5g packs.
No idea if the entire pack, including packaging weighs 5g or if the product weighs 5g.
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blogfast25
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Quote: Originally posted by aga | i bought from the sugru.com site.
In teensyweensy writing it says 8x 5g packs.
No idea if the entire pack, including packaging weighs 5g or if the product weighs 5g. |
Net weight, no doubt.
Enough for 8 dumbbells!
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battoussai114
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You could play around and figure what filler they're using... I'm pretty sure there are solvents that could take the uncured elastomer away in a
solid-liquid extraction, but I can't name one right now, and once the elastomer is out maybe you could put a sample of what is left in piranha
solution to get rid of any organics and then check if there's some form of silica left.
----Edit----
Seems talc is, at least one, of the fillers: https://sugru.com/pdfs/msds-usa.pdf
[Edited on 1-6-2016 by battoussai114]
Batoussai.
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blogfast25
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Two functional silanes and a polysiloxane as base elastomer: quite sophisticated... Definitely more sophisticated than homemade 'Oogoo'.
Thanks for that!
[Edited on 1-6-2016 by blogfast25]
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Maker
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Quote: Originally posted by blogfast25 | Quote: Originally posted by aga | i bought the multi-coloured 8-pack this morning.
Should arrive well before the universe ends, so what would you like done to it ?
|
As someone who worked in elastomer R&D for about 10 years, I'd be most interested in post-cured tensile strength and elongation at break but these
are NOT easy to measure accurately at home level.
Also interesting: these same properties after artificial ageing: e.g. after 24 h @ 100 C in air.
Also interesting: tension set. A uniform sample is stretched to 50 % for 24 h. Then the residual deformation is measured, after the tension is
released. It's a rough measure of long term elasticity.
Or liquid absorption: how much does a slab of cured Sugru absorb over a 24 h period of a given liquid? Water, kerosene, xylene are all good fluids to
test the material's resistance to.
Elastomers are interesting materials, both chemically and physically!
[Edited on 31-5-2016 by blogfast25] |
From the Formerol website:
Shore A hardness: 70
• Density: 1.3g/cm3
• Tensile strength: 1.89 MPa
• Youngs Modulus: 5.59MPa
• Strain-to-failure: 211%
• DIN Abrasion Resistance: 24% ARI index
• Williams Plasticity: 160mm
• Electrical Resistivity
• Surface 1.40 x 1014 Ohms
• Volume 2.55 x 1014 Ohms
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Muffn Man
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I don't disagree that many Instructables are junk. This one, however, doesn't strike me as being one of them. Also, I was not suggesting that Oogoo
would be technically equal to Sugru. I wanted to present a community of Do-It-Yourselfers and experimenters a VERY cheap and reasonably similar
alternative to Sugru.
If you Google "Oogoo", you will find many pages not affiliated with Instructables where folks have tested the mixture with satisfactory results.
[Edited on 1-6-2016 by Muffn Man]
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blogfast25
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Quote: Originally posted by Maker |
From the Formerol website:
Shore A hardness: 70
• Density: 1.3g/cm3
• Tensile strength: 1.89 MPa
• Youngs Modulus: 5.59MPa
• Strain-to-failure: 211%
• DIN Abrasion Resistance: 24% ARI index
• Williams Plasticity: 160mm
• Electrical Resistivity
• Surface 1.40 x 1014 Ohms
• Volume 2.55 x 1014 Ohms
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What jumps off the page here is the very low value of tensile strength (T.S. = 1.89 MPa). Although silicone elastomers aren't renowned for
high T.S. values, 10 MPa and higher can quite easily be achieved. The E@B of 211 % is correspondingly low too.
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aga
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Behold !
The first mock-up prototype StretchFast25 Stretchy-Snappy-o-Meter.
The bar to the Left will be welded to the substrate, and have a clamp to grab hold of the sample.
The bar in the middle will be welded to a Nut on the thread-screw and also have a clamp to grab the other end of the sample.
This Nut will be part of an anti-backlash arrangement to reduce/eliminate 'throw' when the sample snaps (they should end up pretty much at the right
place after the snap).
That's basically two nuts and a springy thing.
1. The test subject is clamped in.
2. With a mirror behind the plastic ruler (should be Rule, but why argue) we can get some degree of parallax elimination to calibrate zero.
3. Turn the thread-screw little by little whilst wearing an insane and daemoniacal grin, reciting any remembered E.A. Poe, and the subject slowly
stretches.
4. Eventually, he snappeth !
5. Read off the elongation at snap-point.
6. Post results in this thread.
In the photo i just grabbed the closest thing at hand to stand in place of the actual test subject, subergoob or whatever it is.
Other things such as the width of the starting strip and width at certain elongation points can be measured.
Any other suggestions for measurable things ?
[Edited on 1-6-2016 by aga]
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blogfast25
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Quote: Originally posted by aga | Behold !
The first mock-up prototype StretchFast25 Stretchy-Snappy-o-Meter.
The bar to the Left will be welded to the substrate, and have a clamp to grab hold of the sample.
The bar in the middle will be welded to a Nut on the thread-screw and also have a clamp to grab the other end of the sample.
This Nut will be part of an anti-backlash arrangement to reduce/eliminate 'throw' when the sample snaps (they should end up pretty much at the right
place after the snap).
That's basically two nuts and a springy thing.
1. The test subject is clamped in.
2. With a mirror behind the plastic ruler (should be Rule, but why argue) we can get some degree of parallax elimination to calibrate zero.
3. Turn the thread-screw little by little whilst wearing an insane and daemoniacal grin, reciting any remembered E.A. Poe, and the subject slowly
stretches.
4. Eventually, he snappeth !
5. Read off the elongation at snap-point.
6. Post results in this thread.
In the photo i just grabbed the closest thing at hand to stand in place of the actual test subject, subergoob or whatever it is.
Other things such as the width of the starting strip and width at certain elongation points can be measured.
Any other suggestions for measurable things ?
[Edited on 1-6-2016 by aga] |
Nice. Shame it can't actually measure force at breaking point.
Quote: Originally posted by blogfast25 |
Also interesting: these same properties after artificial ageing: e.g. after 24 h @ 100 C in air.
Also interesting: tension set. A uniform sample is stretched to 50 % for 24 h. Then the residual deformation is measured, after the tension is
released. It's a rough measure of long term elasticity.
Or liquid absorption: how much does a slab of cured Sugru absorb over a 24 h period of a given liquid? Water, kerosene, xylene are all good fluids to
test the material's resistance to.
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aga
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Fish-scale at the left, clamped to fixed support, subject clamped to fish-scale part ?
Dunno.
Will await both the subaru and any suggestions.
[Edited on 1-6-2016 by aga]
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blogfast25
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Quote: Originally posted by aga | Fish-scale at the left, clamped to fixed support, subject clamped to fish-scale part ?
Dunno.
Will await both the subaru and any suggestions.
[Edited on 1-6-2016 by aga] |
'On paper' the torque needed to turn 'Twisty bit' (and thus extend the sample) is proportional to the tension (force) in the sample. Unfortunately
poorly defined friction between the nuts and 'Twisty bit' would make that relationship very inaccurate.
[Edited on 1-6-2016 by blogfast25]
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