Battle of the Epoxies: A Road to BALLS Experiment

[JimJarvis50]

No, ideally from the inside. I think that makes a little more sense to me.

Also Jim, on a more personal note I have not yet had time to go to the post office. I should be able to tomorrow.

Now I'm going to have to go back and figure out the cool tool he used to do that.

Just count to 10 backwards and let em have it.

Jim

 

[A5tr0 An0n]

Just count to 10 backwards and let em have it.

I hope that is directed towards the USPS.

Now I'm going to have to go back and figure out the cool tool he used to do that.

Jim

I will save you the trouble. IMO it is a brilliant invention.

 

[Aksrockets]

...0.125" G10 fin with 5 layers of carbon and 2 layers of t2t would....

When have you mentioned those 5 layers in the past? My apologies for misreading your build schedule if you have, but I read your entire L3 thread and this thread with no mention of 5 additional layers. Definitely a step in the right direction but I'm still curious as to why you won't use a CF core. If you are interested in a material with vibration dampening qualities, why not use Kevlar instead?

Pegasus III IMO failed (initially at least) from delamination and it was a mongoose, which means it was not stable for that kind of flight to begin with.

I agree with you that delamination was a huge part of it (probably the main cause) and though it makes since that stability would play a part in it, It doesnt look like any instabilty caused shreds I've seen.

...Also unless he had custom fins (I do not think he did), then they were not .25" thick. I think you might be confusing the 1/4" bevel on the fins with the thickness but I could be wrong on...

I'm fairly certain that the fins are .25in. A .25in bevel is too small for fins thick enough to be on a 98MD.

Do you mean Cotronics 4461? Thats their low viscosity high temp epoxy

Yes, thats what I meant. Sorry, I mistyped.

Explain.

Alex

 

[CarVac]

I agree with you that delamination was a huge part of it (probably the main cause) and though it makes since that stability would play a part in it, It doesnt look like any instabilty caused shreds I've seen.

The Mongoose shred looked almost exactly like the Project60k shred; a slight (1 degree ish) nudge, followed by an abrupt 90 degree turn with some tumbling afterwards. Project60k's failure was almost certainly caused by a fin falling off first..

 

[A5tr0 An0n]

When have you mentioned those 5 layers in the past? My apologies for misreading your build schedule if you have, but I read your entire L3 thread and this thread with no mention of 5 additional layers. Definitely a step in the right direction but I'm still curious as to why you won't use a CF core. If you are interested in a material with vibration dampening qualities, why not use Kevlar instead?

It was mentioned in item # 7 in the list on the first page of the L3 thread. "The basic thought on the fins are that they will be as small as reasonable stability allows to reduce the aerodynamic loads they will experience. They will be ~3mm thick of G10 FG plate that is layered with 3k aerospace grade CF and also capable of 600F."
It does not specify the amount of layers but does mention I will be doing it. I have thought about it, but have started focusing on this thread before progressing further.

I agree with you that delamination was a huge part of it (probably the main cause) and though it makes since that stability would play a part in it, It doesnt look like any instabilty caused shreds I've seen.

It might not look like it, but that does not mean it is not it. At those velocities the forces acting on the fins once unstable would be more than they could bare. This would be due to a angle of incidence from the ~90 degree alpha (or close to it). So it could have failed so rapidly that it looked different than normal. Whether delamination played a role or not, I do not know. Nonetheless I do not think a 0.25" thick CF fin + 4 layers adding ~0.336" of thickness to the fins would flutter under normal flight conditions.
*This thickness is assuming that each layer is ~0.042" thick.

I'm fairly certain that the fins are .25in. A .25in bevel is too small for fins thick enough to be on a 98MD.

That is the stock dimensions of the Mongoose 98mm kit. The reason I know this is I looked into using one originally about a year or so ago. I found the mongoose to be unstable, like many other rockets and weak in many areas. IMO 0.25" fins are thicker than needed. However that has been the tradiontal method of most amateur builders, "build it tough, tough, with a little bit of tougher on the side."

Part of what intrigues me so much about a flight profile is to see what is really "bare necessities," in the sense of survival. Instead of being on the far left or far right I am trying to build a vehicle in the center to start this determination. Honestly I wanted to be a little closer to the left but have been persuaded other wise.

Do you mean Cotronics 4461? Thats their low viscosity high temp epoxy

Look into the 4460 it has a service temp of 600F with slightly better properties (if I remember correctly). I have used both, the big difference between them is that the 4460 has a mandatory cure of 250F for 4hrs. For optimum properties, I believe the post cure is 450F.

*Cotronics definition of "optimum properties," is the 600F rating. Without the post cure it is not capable of a service temperature of 600F, even with its 250F cure. That tends to be a repeating thing for Cotronics, i.e. 4525, 4461, & 4460.

 

[CarVac]

Part of what intrigues me so much about a flight profile is to see what is really "bare necessities," in the sense of survival. Instead of being on the far left or far right I am trying to build a vehicle in the center to start this determination. Honestly I wanted to be a little closer to the left but have been persuaded other wise.

I want to say, with as little boasting as possible, that I already know that less is more in terms of what is required for survival. If you can make your fins smaller, then the forces will be lower. If you have no airframe, then you won't have an airframe failure. An 8-pound rocket can be made to physically survive an N5800 flight; now it just needs to be tuned to remain stable at Mach 4.2.

That said, you don't need to be pushing the bare minimum to have easily the most epic L3 certification flight ever, and I'm sure you don't really want to straight-up copy what's been done before.

 

[A5tr0 An0n]

I want to say, with as little boasting as possible, that I already know that less is more in terms of what is required for survival. If you can make your fins smaller, then the forces will be lower. If you have no airframe, then you won't have an airframe failure. An 8-pound rocket can be made to physically survive an N5800 flight; now it just needs to be tuned to remain stable at Mach 4.2.

That said, you don't need to be pushing the bare minimum to have easily the most epic L3 certification flight ever, and I'm sure you don't really want to straight-up copy what's been done before.

Honestly Carlo, I am already on the ditching the "airframe," train. After this flight I am moving on to that, if everything goes as plan (usually doesn't). I liked the name you and Chris gave to your rocket, btw. I like names like that. I couldn't agree with you more. That is why I decided on the brackets and etc… to not go the bare minimum. :/

 

[A5tr0 An0n]

Just a quick update. I am hoping to have the first "batch," of samples done by the end of this week or early next week. This testing will find which surface preparation is ideal (at least in this regard). I will have four different uniform samples that will test 4 different surface preparation methods. Pictures are of course to come… as well as data.

Also a bit of change is that I have gotten the help of someone working for an epoxy manufacture and they are going to use their testing machinery to analyze my samples… so I will be sending some of the samples off to the lab!

Cheers
Mat

 

[jolevich]

If memory serves me right, Rocketpoxy G5000 has a Tg of 150F and a TS of 7500psi. So for that reason I opted out of it, I think it is more similar to ES6209. I am not sure how hot the fillet will get but 150F has me on edge. There will be a mixture of heating from the aerodynamics, motor casing, and sitting on the desert floor, so I would like to accommodate that. ES6265 has a Tg of 350F and a TS 8000psi-10000psi(?).

I wish you would get your facts accurate before you publish them here on the forum, it really does everyone a disservice and will eventually make this forum a place where manufacturers will not want to deal with it and the “crazy chatter” will water this down for everyone to use as a serious place to get good accurate information. To set the record straight Rocketpoxy G5000 has a Tg of over 176F (was tested by several independent labs) I do not know where you got the 150F you obviously did not get that from the manufacturer or any published data sheet so did you just make this number up out of thin air? Also regarding Aeropoxy ES6265 ( which I am not saying anything negative about it as it is a decent high strength structural epoxy) but it has a Tg of 192F this is straight from the manufacturer which if you had bothered to check with them you would have known this as they are very upfront about this and you would know it is not the 350F you are publishing here on the forum as “truth”. Also the tensile strength of Rocketpoxy is 7,600 psi and the TS of ES6265 is 6,500 psi which is right off the Aeropoxy data sheet on their website and again you would have known this if you had done some quick checking on the data sheets and that it is not the 10,000 psi you claim ( and published ) the ES6265 has. Rocketpoxy would be more similar to ES6265 then ES6209, except the ES6265 would be much more brittle. Yes one of the major trade offs of a higher temp epoxy is that they generally become more brittle. We feel that Rocketpoxy G5000 is the perfect tradeoffs of high strength, not brittle, and a decent temperature rating that is good for about 98% of all high powered flights. I’ll give you a quick test you can do put about ¼ - 3/8 inch layer of epoxy into a plastic cup and let it harden, then whack all your samples with a hammer, you will notice quickly which epoxy did not shatter like glass ( hint the RP G5000 will not shatter) You can have a very high temp epoxy but if it is very brittle this may cause failure well before any temperature comes into play, I’m saying just think about it there are many dimensions to all of this and it is hard to take this serious if you were not willing to do the most basic work to get the specifications correct that you are publishing here as “knowledge”. Sorry if I came across a little harsh but really I get of tired of trying to defend against these types of unfair postings with bad and non factual information that can cause harm to a good product. If you searched out Mach madness here on the forum you will know that Rocketpoxy G5000 was used to construct basically G10 and carbon fiber fins epoxied to a very hot aluminum metal motor tube going close to Mach 3 with absolutely no structural loss from either heat or stress , the Rocketpoxy G5000 constructed rockets won this two years in a row now. Also we have two of the largest rocket distributors Apogee rockets and Wildman rocketry carrying Rocketpoxy G5000 and believe me these distributors only carry product they know are very beneficial to their customer base and have been tested extensively, and Rocketpoxy has become very popular among many of the high powered fiberglass and carbon fiber rocket builders so I’m not sure why you wouldn’t want to include RPG5000 into the tests.
Some Quick facts ES6209 is basically an unfilled standard epoxy I am not knocking it but just want you to get the facts straight since you are publishing them here for many to read ( that ES6209 is not at all similar to Rocketpoxy G5000) that’s why ES6209 has a viscosity of 50,000 centipoise you would need to add lots of fillers and thickening agents to make it anything even close to Rocketpoxy G5000 or a product like the ES6265 which is why Rocketpoxy and ES6265 has a viscosity of 350,000+ centipoise (basically a paste). If you love to formulate epoxies and have the time and knowledge to add and mix the correct amounts and types of fillers needed to make a superior high strength epoxy then the ES6209 is for you, if you want a high strength epoxy to use right out of the jar where an expert chemist with lots of test data has already done all the hard work for you then use something like the Rocketpoxy G5000 or ES6265. That is why filled epoxies do have better physical properties than unfilled epoxies and most that wish to use an epoxy ready to build with will prefer them, also that is why filled epoxies may cost a little more than an unfilled epoxy. Hope this cleared up a few facts regarding what was said about the Rocketpoxy G5000 and what is the real data.

 

[CarVac]

I wish you would get your facts accurate before you publish them here on the forum, it really does everyone a disservice and will eventually make this forum a place where manufacturers will not want to deal with it and the “crazy chatter” will water this down for everyone to use as a serious place to get good accurate information. To set the record straight Rocketpoxy G5000 has a Tg of over 176F (was tested by several independent labs) I do not know where you got the 150F you obviously did not get that from the manufacturer or any published data sheet so did you just make this number up out of thin air? Also regarding Aeropoxy ES6265 ( which I am not saying anything negative about it as it is a decent high strength structural epoxy) but it has a Tg of 192F this is straight from the manufacturer which if you had bothered to check with them you would have known this as they are very upfront about this and you would know it is not the 350F you are publishing here on the forum as “truth”. Also the tensile strength of Rocketpoxy is 7,600 psi and the TS of ES6265 is 6,500 psi which is right off the Aeropoxy data sheet on their website and again you would have known this if you had done some quick checking on the data sheets and that it is not the 10,000 psi you claim ( and published ) the ES6265 has. Rocketpoxy would be more similar to ES6265 then ES6209, except the ES6265 would be much more brittle. Yes one of the major trade offs of a higher temp epoxy is that they generally become more brittle. We feel that Rocketpoxy G5000 is the perfect tradeoffs of high strength, not brittle, and a decent temperature rating that is good for about 98% of all high powered flights. I’ll give you a quick test you can do put about ¼ - 3/8 inch layer of epoxy into a plastic cup and let it harden, then whack all your samples with a hammer, you will notice quickly which epoxy did not shatter like glass ( hint the RP G5000 will not shatter) You can have a very high temp epoxy but if it is very brittle this may cause failure well before any temperature comes into play, I’m saying just think about it there are many dimensions to all of this and it is hard to take this serious if you were not willing to do the most basic work to get the specifications correct that your are publishing here as “knowledge”. Sorry if I came across a little harsh but really I get of tired of trying to defend against these types of unfair postings with bad and non factual information that can cause harm to a good product. If you searched out Mach madness here on the forum you will know that Rocketpoxy G5000 was used to construct basically G10 and carbon fiber fins epoxied to a very hot aluminum metal motor tube going close to Mach 3 with absolutely no structural loss from either heat or stress , the Rocketpoxy G5000 constructed rockets won this two years in a row now. Also we have two of the largest rocket distributors Apogee rockets and Wildman rocketry carrying Rocketpoxy G5000 and believe me these distributors only carry product they know are very beneficial to their customer base and have been tested extensively, and Rocketpoxy has become very popular among many of the high powered fiberglass and carbon fiber rocket builders so I’m not sure why you wouldn’t want to include RPG5000 into the tests.
Some Quick facts ES6209 is basically an unfilled standard epoxy I am not knocking it but just want you to get the facts straight since you are publishing them here for many to read ( that ES6209 is not at all similar to Rocketpoxy G5000) that’s why ES6209 has a viscosity of 50,000 centipoise you would need to add lots of fillers and thickening agents to make it anything even close to Rocketpoxy G5000 or a product like the ES6265 which is why Rocketpoxy and ES6265 has a viscosity of 350,000+ centipoise (basically a paste). If you love to formulate epoxies and have the time and knowledge to add and mix the correct amounts and types of fillers needed to make a superior high strength epoxy then the ES6209 is for you, if you want a high strength epoxy to use right out of the jar where an expert chemist with lots of test data has already done all the hard work for you then use something like the Rocketpoxy G5000 or ES6265. That is why filled epoxies do have better physical properties than unfilled epoxies and most that wish to use an epoxy ready to build with will prefer them, also that is why filled epoxies may cost a little more than an unfilled epoxy. Hope this cleared up a few facts regarding what was said about the Rocketpoxy G5000 and what is the real data.

In what measure is 6265 more brittle? It has 8% elongation at break while G5000 has 6.3%.

 

[jolevich]

Elongation is not the only measurement of brittleness, go do the hammer whacking cup test that I mentioned above and then you will understand grasshopper. Again I’m not knocking the ES6265 for some applications it is a good product but it is more brittle than RPG5000 on tests that we have done, I know that you are the poster boy for Aeropoxy and probably use this for your builds so I won’t even try to battle you on this, but be honest have you even ever used Rocketpoxy to construct and launch a rocket? Probably not so it’s hard to take this seriously that you know much real "air time" data about RP. I do not have time to educate everyone here about epoxy chemistry and will not be trying to do this, plus you college students have way too much time to constantly be on the forum here and I really do not have time to go back and forth here, just wanted to defend a good product against unfactual blather here on the forum in case others come across this. I just didn’t think it fair to have incorrect specifications on a good product listed here without some rebuttal.

 

[MarkH]

Anecdotally speaking, the Cotronics 4461 is more brittle than Aeropoxy PR2032. I usually leave my excess epoxy harden in a cup, so I can poke at it and gauge the cure progress of the layup. After curing, the 4461 shatters pretty easily when squeezing the bottom of the cup or picking at it with a nail, whereas the Aeropoxy PR2032 has some toughness and doesn't shatter.

Having said that, I'm not sure it matters when using an apparently more brittle high temp epoxy in a layup, since the CF or FG is providing the strength, and the epoxy is embedded in the layup. The first time I used the 4461, vacuum bagging uni CF layers to a fin can, I ended up with some wrinkles in the layup and decided to remove the layup. Pulling the uni CF off by grabbing the exposed fibers at the end was nearly impossible, as they would break - the adhesion would not let the fibers go. ... I ended up sanding off the uni CF, and doing it again. Luckily I only had done one of 3 sides.

 

[CarVac]

Elongation is not the only measurement of brittleness, go do the hammer whacking cup test that I mentioned above and then you will understand grasshopper. Again I’m not knocking the ES6265 for some applications it is a good product but it is more brittle than RPG5000 on tests that we have done, I know that you are the poster boy for Aeropoxy so I won’t even try to battle you on this, but be honest have you even ever used Rocketpoxy to construct and launch a rocket? Probably not so it’s hard to take this seriously. I do not have time to educate everyone here about epoxy chemistry and will not be trying to do this, plus you college students have way too much time to constantly be on the forum here and I really do not have time to go back and forth here, just wanted to defend a good product against unfactual blather here on the forum in case others come across this. I just didn’t think it fair to have incorrect specifications on a good product listed here without some rebuttal.

I am not a poster boy for Aeropoxy. I am just curious. I like 6209 for its handling properties, but when I need real strength I do want to know what is the best option. You don't need to educate me on the chemistry, but I have seen no conclusive evidence of your claims yet. Can you say that your Mach Madness rockets would have failed with 6265 fillets?

What about the Izod impact test? Would G5000 outperform es6265 on that?

BTW: I have not yet worked with Rocketpoxy nor ES6265 yet. As much as I want to compare them myself, I haven't because I don't actually build rockets often enough to warrant purchasing three similar-purposed structural epoxies.

I do agree that incorrectly listed specifications by the OP are a real problem though, and he needs to get his facts straight in his posts or else we cannot be assured of his tests' rigor.

 

[A5tr0 An0n]

I wish you would get your facts accurate before you publish them here on the forum, it really does everyone a disservice and will eventually make this forum a place where manufacturers will not want to deal with it and the “crazy chatter” will water this down for everyone to use as a serious place to get good accurate information. To set the record straight Rocketpoxy G5000 has a Tg of over 176F (was tested by several independent labs) I do not know where you got the 150F you obviously did not get that from the manufacturer or any published data sheet so did you just make this number up out of thin air? Also regarding Aeropoxy ES6265 ( which I am not saying anything negative about it as it is a decent high strength structural epoxy) but it has a Tg of 192F this is straight from the manufacturer which if you had bothered to check with them you would have known this as they are very upfront about this and you would know it is not the 350F you are publishing here on the forum as “truth”. Also the tensile strength of Rocketpoxy is 7,600 psi and the TS of ES6265 is 6,500 psi which is right off the Aeropoxy data sheet on their website and again you would have known this if you had done some quick checking on the data sheets and that it is not the 10,000 psi you claim ( and published ) the ES6265 has. Rocketpoxy would be more similar to ES6265 then ES6209, except the ES6265 would be much more brittle. Yes one of the major trade offs of a higher temp epoxy is that they generally become more brittle. We feel that Rocketpoxy G5000 is the perfect tradeoffs of high strength, not brittle, and a decent temperature rating that is good for about 98% of all high powered flights. I’ll give you a quick test you can do put about ¼ - 3/8 inch layer of epoxy into a plastic cup and let it harden, then whack all your samples with a hammer, you will notice quickly which epoxy did not shatter like glass ( hint the RP G5000 will not shatter) You can have a very high temp epoxy but if it is very brittle this may cause failure well before any temperature comes into play, I’m saying just think about it there are many dimensions to all of this and it is hard to take this serious if you were not willing to do the most basic work to get the specifications correct that you are publishing here as “knowledge”. Sorry if I came across a little harsh but really I get of tired of trying to defend against these types of unfair postings with bad and non factual information that can cause harm to a good product. If you searched out Mach madness here on the forum you will know that Rocketpoxy G5000 was used to construct basically G10 and carbon fiber fins epoxied to a very hot aluminum metal motor tube going close to Mach 3 with absolutely no structural loss from either heat or stress , the Rocketpoxy G5000 constructed rockets won this two years in a row now. Also we have two of the largest rocket distributors Apogee rockets and Wildman rocketry carrying Rocketpoxy G5000 and believe me these distributors only carry product they know are very beneficial to their customer base and have been tested extensively, and Rocketpoxy has become very popular among many of the high powered fiberglass and carbon fiber rocket builders so I’m not sure why you wouldn’t want to include RPG5000 into the tests.
Some Quick facts ES6209 is basically an unfilled standard epoxy I am not knocking it but just want you to get the facts straight since you are publishing them here for many to read ( that ES6209 is not at all similar to Rocketpoxy G5000) that’s why ES6209 has a viscosity of 50,000 centipoise you would need to add lots of fillers and thickening agents to make it anything even close to Rocketpoxy G5000 or a product like the ES6265 which is why Rocketpoxy and ES6265 has a viscosity of 350,000+ centipoise (basically a paste). If you love to formulate epoxies and have the time and knowledge to add and mix the correct amounts and types of fillers needed to make a superior high strength epoxy then the ES6209 is for you, if you want a high strength epoxy to use right out of the jar where an expert chemist with lots of test data has already done all the hard work for you then use something like the Rocketpoxy G5000 or ES6265. That is why filled epoxies do have better physical properties than unfilled epoxies and most that wish to use an epoxy ready to build with will prefer them, also that is why filled epoxies may cost a little more than an unfilled epoxy. Hope this cleared up a few facts regarding what was said about the Rocketpoxy G5000 and what is the real data.

Oh yay, I have made another friend. I could care less about how you feel and that you are tired, it is no excuse to be a d**k. You are so emotional about Rocketpoxy G5000, I take it you work at Glenmarc Industries. Great business philosophy, "attack everyone who says something incorrectly," brilliant.

EDIT: Oh how interesting… you own the company eh? Seeing as Glenmarc Industries domain is registered under your name and you are listed as the president, that explains why you are so sensitive. You need to relax… it is a more professional appearance.

I wish you would get your facts accurate before you publish them here on the forum, it really does everyone a disservice and will eventually make this forum a place where manufacturers will not want to deal with it and the “crazy chatter” will water this down for everyone to use as a serious place to get good accurate information.

"If memory serves me right" <-- This clearly indicates that I am not reading this from any data sheets but rather pulling it out of my memory bank and is not meant as "fact," and "knowledge," as you mentioned. I am sorry that you can not understand that. In case you still do not understand, that was not meant as a "fact." Sorry if I came off a little harsh, but I am tired of you keyboard warriors picking and choosing what you attack (sarcasm).

Forums are defined as "a place, meeting, or medium where ideas and views on a particular issue can be exchanged." Note the term views and not facts. I do agree with you in some regards but do not think one should come to a forum for serious data, especially when manufactures have data sheets for those purposes (as you mentioned). Since we should only post facts and not thoughts (even when they are clearly describe as recollection), maybe we should start telling others what temperatures and materials were used during the testing? On that note, do you happen to have any documents that you could share from the several independent labs on Rocketepoxy G500? For example shear, peel, etc results? Especially how different strength properties degrade at certain temperatures? That would be helpful to reconsider Rocketpoxy G5000 for other than initial testing. I am aware some manufactures do and do not test various things due to what they think is standard and not. Just curious. Oh and BTW I do own some Rocketpoxy G5000 and have used it.

You are right, I did use Tg incorrectly when talking about ES6265 & Rocketpoxy G5000. I was meaning it has a max service temp. of 300F and 175F (at the time I thought 150F). I was responding quickly and without much thought. The conversation in which I responded, did not require more than that and that is my opinion. In the relation I made to Rocketpoxy G5000 and ES6209 that was in regards to them both (being neat epoxy resins) having close tensile strengths and operating temps. Now on the GlenMarc Industries G5000 data sheet there is no mention of its Tg but only mention of its typical service and maximum operating temperatures. I was meaning its operating temperature,so my bad, but no worries. For Rocketypoxy G5000's data sheet it does not mention the definition of typical operating temperature; what is that definition? To clarify as the temperature increases certain strength properties typically decrease and there is a certain point which it is rated to. This is dependent on (I assume), the manufacture but could be the testing standardization I suppose. For a further example Henkel has the following definition for service temperature, "Service temperature is defined as that temperature at which this adhesive still retains 1000 psi/6.9 MPa) using
test method ASTM D1002 and is 350°F/177°C." Answers to those questions would be great, seeing as I am curious of it.

 

[beezwax]

Wow....if you ever get summoned to court, don't try and represent yourself. Hire a good lawyer and let them do the talking

 

[dixontj93060]

Oh yay, I have made another friend. I could care less about how you feel and that you are tired, it is no excuse to be a d**k. You are so emotional about Rocketpoxy G5000, I take it you work at Glenmarc Industries. Great business philosophy, "attack everyone who says something incorrectly," brilliant.

EDIT: Oh how interesting… you own the company eh? Seeing as Glenmarc Industries domain is registered under your name and you are listed as the president, that explains why you are so sensitive. You need to relax… it is a more professional appearance.



"If memory serves me right" <-- This clearly indicates that I am not reading this from any data sheets but rather pulling it out of my memory bank and is not meant as "fact," and "knowledge," as you mentioned. I am sorry that you can not understand that. In case you still do not understand, that was not meant as a "fact." Sorry if I came off a little harsh, but I am tired of you keyboard warriors picking and choosing what you attack (sarcasm).

John did not attack you, he corrected you. Across multiple threads on multiple topics you have been corrected and you immediately take it as an attack; it isn't, it is a correction and you should take it to heart--John knows more about epoxy in his little finger than you will likely garner in the next decade. So it is simple. If you don't want to be corrected do your homework and don't make incorrect statements.

 

[flynfrog]

John do you have the elevated temp lap shear data for G5000?



Ps. I feel its pretty bad form not to post a disclaimer you work/own the company if you are posting about its products. I used to detail cars and the forum got overran with paid shills pushing products. Not saying this is what you are doing but it would help clear up any confusion.

 

[A5tr0 An0n]

John did not attack you, he corrected you. Across multiple threads on multiple topics you have been corrected and you immediately take it as an attack; it isn't, it is a correction and you should take it to heart--John knows more about epoxy in his little finger than you will likely garner in the next decade. So it is simple. If you don't want to be corrected do your homework and don't make incorrect statements.

I really thought Purdue would of taught you how to thoroughly read. That was a blatantly offensive (synonym for attack) post. That is simple.

Now someone told me that you were a very nice guy so I forgot about it, but seeing as you want to talk again, then answer my unanswered questions from the other thread. Who has coached me? Where have I been corrected multiple times across multiple threads? Where have I been all over the place with my opinions (not sure how that is a bad thing though)? I could careless about corrections, but to correct someone in the manner you and your "buddy," do, that is distasteful. The only "attacks," have come from John Olevich and yourself (Tim Dixon). See below.

Actually, I didn't repeat what you said, I clarified your wish-washiness. You've been all over the place with your opinions on this thread. One of your last statements is quoted above which is dead wrong. And you only got that close after much coaching from others. Inaccuracies needed to be negated/clarified for others reading this thread.

Now let me give you an example of a well worded and non offensive correction.

Tim, regarding the dead wrong statement:

Actually, I didn't repeat what you said, I clarified your wish-washiness. You've been all over the place with your opinions on this thread. One of your last statements is quoted above which is dead wrong. And you only got that close after much coaching from others. Inaccuracies needed to be negated/clarified for others reading this thread.

I'm not so sure I would agree. I use a 3-inch-long brass tube for my BP containment. I use about 1.5 grams of BP, which means that the bottom one-third of the tube is filled with BP. This tube can remain unsealed (such that you can look down the tube and see the powder), and then placed in a nearly complete vacuum, and I assure you that 100% of the BP will burn. The trick is that the extra length of tubing causes some backpressure to build, which makes the BP burn faster, and this progresses to the point where the BP burns very quickly. So, maybe the statement in question should be that you don't initially need pressure (because you don't, if your method allows pressure to build) and the charge indeed does not need to be sealed.

In spite of the fact that this happened every time I've tried it, I still take Bob's advice to seal the charge. I do this because while I know the BP will burn under with the physical configuration I use, I'm much less sure about how an ematch will perform. I put a thin (1/32"?) layer of epoxy over the end of the tube just to seal in the air so that the ematch can fire at atmospheric pressure. Once the ematch fires, the deal is done. The picture shows the sealed tubes as I have used them in my high altitude flights.

You make erroneous statements and have no idea who you are even making them towards; you should really work on the practice what you preach thing.

Now I am willing to let "differences" go and shake hands, because I can honestly careless about a feud with you. There are more important things to do. Your call.

 

[A5tr0 An0n]

I have done the 2nd selection cut of the epoxies I might use. I am now getting ready to go on to the 3rd and final selection. I have only decided on 2 so far. Here is a chart that I put together that I have been using to help me decide. I would love to hear any opinions you guys might have in the selection process.

If any corrections need to be made to the chart then please notify me and I will update it.

Sources:
https://bayfiles.net/file/1f9N4/RAuwBJ/PoxyZip.zip

Cheers
Mat

 

[dixontj93060]

I really thought Purdue would of taught you how to thoroughly read. That was a blatantly offensive (synonym for attack) post. That is simple.

Now someone told me that you were a very nice guy so I forgot about it, but seeing as you want to talk again, then answer my unanswered questions from the other thread. Who has coached me? Where have I been corrected multiple times across multiple threads? Where have I been all over the place with my opinions (not sure how that is a bad thing though)? I could careless about corrections, but to correct someone in the manner you and your "buddy," do, that is distasteful. The only "attacks," have come from John Olevich and yourself (Tim Dixon). See below.



Now let me give you an example of a well worded and non offensive correction.



You make erroneous statements and have no idea who you are even making them towards; you should really work on the practice what you preach thing.

Now I am willing to let "differences" go and shake hands, because I can honestly careless about a feud with you. There are more important things to do. Your call.

Erroneous statements, no, not generally. If it is important, I will try to itemize this for you across all the threads including the coaching from TRF members that commented on your postings where you changed position/direction because of it. These are just areas where I would expect a person getting ready for a L3 as challenging as you have outlined would have "down pat." Saying that, if Jim Jarvis is your TAP, you are in good hands and will likely do great!

BTW, on the last portion that you cut/pasted from Jim Jarvis, you conveniently took that comment out of context from a series of 3 or 4 posts where the discussion concluded that because of the specific physical structure of Jim's charges (metal, long/narrow tubes) that he was actually achieving containment ("sealing") not through a physical barrier but through back pressure as the charge wave attempted to exit the structure.

But I will try to cover the above with everything else later. Normally this week might be good given I'm off work, but I'm doing fin analysis for a couple other big projects (for other rocketeers) which tend to be a bit time consuming.

 

[astrojase]

op:

 

[bobkrech]

Gentlemen

A technical discussion is fine. Insults are not.

Get back on point or this thread is going to disappear.

And will not come back.

Bob

 

[A5tr0 An0n]

op:

Anyways for anyone watching I do have some samples at the lab that I am awaiting to hear the results back from. When I hear I will update this thread with all the details.


Bob,

Thank you and I agree that we should all leave our apex attitudes out of this forum. I will keep my post clean and ignore the others.


Cheers.

 

[A5tr0 An0n]

For anyone wondering the list has been further reduced and is now a matter of which ones I can buy most readily and for under $3k lol (some places have minimums).

 

[ksaves2]

For anyone wondering the list has been further reduced and is now a matter of which ones I can buy most readily and for under $3k lol (some places have minimums).

Screen Shot 2014-07-05 at 11.56.07 AM by AstroAnon, on Flickr

Duralco 4225IP is $100.00 for a pint now: https://www.cotronics.com/catalog/05 4525 4525IP.pdf

I used to get it from an outfit called SIS but that was when it was $70.00

I'd like to see what some of the suppliers are going to charge for the other adhesives on your list. Some of them look promising too. But again, the problem is being
able to get them in the amounts that you need. Kurt

 

[flynfrog]

you can get small quainites of most of those from

https://www.rshughes.com/

 

[A5tr0 An0n]

Duralco 4225IP is $100.00 for a pint now: https://www.cotronics.com/catalog/05 4525 4525IP.pdf

I used to get it from an outfit called SIS but that was when it was $70.00

I'd like to see what some of the suppliers are going to charge for the other adhesives on your list. Some of them look promising too. But again, the problem is being
able to get them in the amounts that you need. Kurt

Cotronics is pretty easy and inexpensive from my experience. The others are not that bad also, it is just the minimum orders that get you. See below.

The 9394 is ~$104/pint with no minimum order.
The 9394 C-2 Aero I have requested a price for the quart size; they sell the 6oz for ~$58 with a minimum order of 50, so that comes out to ~$2900.
The 9392 is ~$284/qt. with no minimum order.
The 9360 is ~$27/50ml OR ~$68/200ml with a minimum order of 50 so ~$3,400. (The 50ml has no minimum order.)
The Epibond 100 I have also requested a quote for.

Please note that some of these numbers are rounded up and that all of them come from one distributor.


Cheers,
Mat

 

[A5tr0 An0n]

you can get small quainites of most of those from

https://www.rshughes.com/

I ran searches for all the Loctite/Henkel and Araldite Epibond that I have listed on my chart and came up with no results.

 

[bobkrech]

There are 10's of thousands of epoxy systems. There a less than a dozen manufactures of the chemicals used to formulate them.

https://www.momentive.com/ is one of the big boys. Check out their product page.

https://www.momentive.com/EpoxyPhenolicComposites/ is apparently their new epoxy web page. https://www.hexion.com was another but it now takes you back to the parent company as does https://www.resins.com

These guys are where the big boys by their resins and linkers. https://www.momentive.com/ProductFamily/epoxy_intermediates.aspx?id=225 is the webpage for their resins and curatives.

Typical resins and curing agent data sheets are here. https://www.momentive.com/Products/TechnicalDataSheets.aspx?id=27567 These are the components that are blended into the epoxy systems you can buy from retail and wholesale supply houses. If you are serious about epoxies spend several hours reading these datasheet to see the differences.

They will only sell to corporations, not individuals, so don't waste you time trying to buy anything from them unless you can set up a corporate account, and they have a minimum order of several hundred dollars, but the normal quantities sold are in drums and tank cars.

Bob

 

[astrojase]

I tried the link to the source files you mentioned above but it didn't work, would you mind updating it?

Where you say 'more information on that other forum', what are you talking about?

Sorry, but I am having trouble trying to work out how credible your seemingly authoritative results are - probably just me though.