Talk:Pykrete

message: The test ship made in the canadian rockies was just regular ice, not pykrete. —Preceding unsigned comment added by 129.255.141.66 (talk) 21:59, 1 December 2004
Pykrete can be made using any fiberous material. You are not limmeted to sawdust or woodpulp. —Preceding unsigned comment added by 71.240.199.97 (talk) 19:38, 17 April 2005
:If by "any", you mean any non-hydrophobic fiber, then ok. I guess that hydrophobic fibers would, in general, adversely affect most 'strength' properties. (All natural (biological or mineral) fibers, afaik, are hydrophilic.) 98.21.213.85 (talk) 06:10, 9 December 2023 (UTC)
thread_title:  Test ship composition 

message: how long is "quite a while" ?--GregLoutsenko 18:27, 10 Jun 2005 (UTC)
thread_title:  "quite a while" 

message: The article suggests, "You could use it to make cold compresses that mold to your body and last quite a while."  Maybe I'm wrong, but wouldn't the low thermal conductivity of pykrete (i.e. why it melts so slowly) prevent the "cold compress" from doing its intended job?  To be effective, a cold compress should be thermally conductive, draw heat from your body, and melt itself rather efficiently, shouldn't it? --Ds13 July 3, 2005 05:03 (UTC)
:Actually, no. If you wanted a compress to absorb as much heat as possible as quickly as possible, you would apply ice directly to your skin. That would be uncomfortable, of course, so people insulate the ice (making it melt more slowly) with a thick cloth. What you want is for the compress to absorb some heat for a long time, which Pykrete might do just fine in a thinner cloth. --Tysto 07:19, 11 November 2005 (UTC)
thread_title:  Cold compress of pykrete 

message: I was curious about this sentence in the article:
:Of course ice always slowly deforms under pressure anyway, and this isn't really affected by the presence of the pulp.
Does this mean under pressure, such as when a bullet slams into it, ice is not readily pushed out of the way of the bullet, like say flesh might be? If so, is the presence of the wood pulp just to keep the ice from shattering, such as rebar in concrete, instead of the wood actually adding bullet-stopping capability on its own? --Fxer 09:36, 25 December 2005 (UTC)
replies: text: The presence of the wood pulp has two effects. 1) It slows down melting 2) it stops propagation of cracks and thus drastically improves the toughness of Pykrete over that of pure ice. The deformation statement refers to the behaviour of ice when subjected to prolonged, steady pressure. It has no relevance when discussing the impact of a bullet. -- Derek Ross | Talk 16:16, 11 March 2006 (UTC)
thread_title:  Durability of ice 

message: Moved from a bad edit to the main article:
FWIW: This reference documents some of the "citation wanted" tags in the pykrete article.
I don't seem to have the book any more, but this is how it appears in the British Library site:
LAMPE, David. Pyke, the Unknown Genius. [With plates, including portraits.] 1959 010601.a.14.
Hope that helps someone! Sorry, I don't know offhand how to edit this to taste. Possibly someone at your end can use the information at leisure.
Cheers,
Jon
--Ry Jones 18:29, 6 October 2007 (UTC)
thread_title:  Bad edit 

message: The article says that the sawdust raises the melting point but not by how much.
Does anyone know what the melting point of Pykrete is?
: I doubt that adding sawdust changes the melting point.  The sawdust acts as an insulator, which slows the rate of melting.
:: Mixtures always have higher melting points than the pure solvent.  I know pykrete isn't technically a solution but this still applies.  —Preceding unsigned comment added by 141.219.76.65 (talk) 01:32, 19 November 2008 (UTC)
replies: text:  Actually, lower: Freezing point depression --Jaded-view (talk) 04:56, 19 May 2009 (UTC)
replies: text:  Sounds like we should scatter newspapers on the glaciers.  Solves the retreat of glaciers *and* the financial problems that newspaper companies are having! Mcswell (talk) 19:01, 14 August 2009 (UTC)
thread_title:  Melting Point 

message: This cleanup just wiped out two of the four pictures. Does anybody know where they came from to re-list them as fair use? I'm linking to the diff so we won't forget the descriptions. — RevRagnarok Talk Contrib 12:31, 1 May 2007 (UTC)
thread_title:  Missing images 

message: Since sawdust is lighter than water it would float on the water prior to freezing - hence the pykerete would have to actually be a block of ice with a layer of sawdust frozen on one side of it, right?
:Apparently not. Saturated wood is barely lighter than water, so keeping it mixed may not be that hard.  ·:· Will Beback  ·:· 23:55, 29 December 2007 (UTC)
replies: text: I would think that once waterlogged the mixture would be agitated in some way until a slush consistancy kept the fibers in place.  —Preceding unsigned comment added by 24.235.213.213 (talk) 23:09, 31 October 2009 (UTC)
thread_title:  A mixture of sawdust and ice... 

message: The article stated: "Pykrete has a crush resistance of greater than 21 megapascals (3,000 psi) so a 25 mm (1 in) column could support the weight of a typical car." - This sentence made no sense. If the 25mm/1 inch dimension referred to the cross section, as one can infer that it did, then the units should have been square mm or inches. However, the sentence was still misleading because it assumed some unspecified short column length without stating so. As the column gets longer, at some point the increasing slenderness ratio (Kl/r) would dictate a buckling failure long before the crush resistance could be reached.Rodney420 (talk) 19:33, 19 May 2008 (UTC)
thread_title: Durability

message: hi there, there is no factual baisis for the nyp prior claim  —Preceding unsigned comment added by 77.44.114.50 (talk) 13:31, 8 January 2009 (UTC)
replies: text: Well, let's see...  Does the attribution by the major researcher (Perutz -- see the refs in the article) count as 'factual'...? Pete G. (talk) 01:33, 27 January 2009 (UTC)
thread_title:  no factual evidence of new york poly  

message: I think a section with the latest Mythbusters experiment using Pykrete to build a boat would be a good addition to the page.
Sailingsumo (talk) 01:37, 17 April 2009 (UTC)
replies: text: After watching that episode, I think the pictured block in the article is an incorrect mixture. It's described as "50% water, 50% wood pulp by volume", whereas on Mythbusters they use 14% wood pulp, 86% water by weight. It looked significantly different and (based on the picture) held up better against having a bullet fired at it. Basically, I think the picture is probably inaccurate, and most likely disqualified as original research. 71.42.29.11 (talk) 07:16, 21 April 2009 (UTC)
replies: text:  According to Max Perutz, who did the  original research on it, anywhere between 7 and 14% is suitable, so the Mythbusters would (as usual) be right.  I don't think a 50% ratio would be anywhere close to optimal. Pete G. (talk) 02:11, 23 April 2009 (UTC)
thread_title:  Mythbusters 

message: The contents of the section critical of the mythbusters' conclusions sounds reasonable to me, in general.  But unless it can be given good sourcing to who, external to Wikipedia, has made the criticism, it really looks to me as if it is the section's author who is making this criticism.  And this would then most definitely be Original Research, and thus be improper to have here on the page. - TexasAndroid (talk) 22:16, 6 May 2009 (UTC)
thread_title:  Mythbusters criticism and original research 

message: I just edited the article to change the link to ".45 caliber" in the Mythbusters section. The old link went to the article for .45 ACP, which is a handgun round. I did a little digging with the show paused, and the rifle they used is a lever-action Winchester Model 1866 chambered for the .45-70 cartridge. The narrator on the show describes the bullet as a ".45 caliber slug," and a lever-action rifle chambered in .45 ACP would be very unlikely. —Preceding unsigned comment added by 72.48.48.242 (talk) 02:16, 16 May 2009 (UTC)
thread_title:  .45 caliber link 

message: I was looking at the comparison of ice and Pykrete and was surprised to see that Pykrete is heaver than ice. The question arises; how did it get heaver when sawdust replaced 14 % of the water?
Looking further I came up with a cubic meter of water weighing 1000Kg, A cubic meter of ice at 919Kg (chart in article says 910) and cubic meter of Pykrete at 980Kg. It left me wondering how adding sawdust to ice could result in an increase in density. Maybe this number is wrong or maybe the sawdust caused the water to expand less as it crystallized?
My understanding from the article was that the ratio of water to sawdust was measured by weight. I'm just trying to figure out how you replace water with an equal weight of sawdust and come out heaver.Corumplex (talk) 23:45, 25 December 2021 (UTC)
thread_title:  Please Explain Weight