SCRANTON, Pennsylvania USA — Drake Dameräu, known to everyone as Doc, likes to break things. He pulls, twists, bends, snaps, just about anything he can physically do to an item trying to find out at what point it can be destroyed. And, he gets paid to do it, to boot.

Filament wound fiberglass airframe tubing queued up for testing in Doc's lab.

At what point did this tube fail? The answers are on the RocketMaterials.org website.

Dameräu is the Chief Metallurgist and Laboratory Director for General Dynamics at the Scranton Army Ammunition Plant, where they make artillery shells for the U.S. Army, Navy and Air Force. Specializing in failure analysis, Dameräu is also responsible for heat treating processes and all material specifications and testing at the lab.

That's his day job. After hours, you will find Dameräu participating in the hobby of high power rocketry as a member of the Tripoli Rocketry Association and the National Association of Rocketry, where he serves as a L3CC member as well. And his fascination with materials testing has worked its way into his hobby as well.

Back when the UseNET was a usable medium for exchanging messages with like-minded individuals, Dameräu was a regular on the newsgroup rec.models.rockets, or RMR as its users refer to it. Around 2000, Dameräu participated in a discussion there about what glue was appropriate for building hobby rockets. As a result, he ended up creating a website devoted to the analysis of materials used in hobby rocket construction, and that site is known as RocketMaterials.org.

RocketMaterials.org, the High Power Rocketry Strength of Materials website, is a collaborative effort of many contributors combined with Dameräu's earnest devotion to breaking things. Early contributions from Joel Corwith, Nick Stich, Robert DeHate, Bill Kennedy, John Coker, Rick Dickinson, Ken Alger and Jerry Irvine went a long way to creating the wealth of data that the site contains to this day.

"The concept did actually come about by an argument about what glue to use on the RMR forum back in 2000," Dameräu said. "The site was going great until things got hectic at work and at our club."  At the time, Dameräu was working 10 hour days six days a week, as well as served as president of the North Eastern Pennsylvania Rocketry Association (NEPRA), and maintaining the club's website. The end result? Not enough hours in a given day, and as a result, RocketMaterials.org suffered a management slump.

But things change, and the subject at hand is no exception. Dameräu stepped down as NEPRA's president, and the supplier of the expensive testing equipment, the U.S. Army, is finding itself at budgetary odds with Congress. "Since Congress has begun cutting the defense budget, I have more time for testing," Dameräu said.

Yet, Dameräu's strength is in testing things, not updating and maintaining web sites. That's where Darrell Mobley, owner of Rocketry Planet stepped in and offered a win-win solution. Mobley has agreed for his company, uHostMe Internet, to take over the hosting and maintenance of the RocketMaterials.org website, including maintaining the various related domain names, which includes the .com and .net variants.

"Doc's testing is invaluable for hobby rocketry enthusiasts, bringing us important information about the strength of the various materials we use in our rocket construction," Mobley said. "I am glad to assist in keeping that information available to the rocketry community."

The site went live at its new home on New Year's Day, and included a brief freshening of the user interface to eliminate broken links and mismatched image names. Immediate expectations are to publish some new data on Quantum Tube temperature exposure testing, which will provide some insight for individuals who have experienced stuck pistons at colder temperatures, as well as an article on the temperature differentials rockets experience while sitting in the sun on the launch pad. Future plans calls for integration of the data into a content management system to ease site management duties, and would include a discussion forum to allow interaction between site users and testers.

Dameräu is ready to begin a new round of testing, so if you have something you would like put to the test, feel free to submit your request via the online contact form on the website or by emailing This email address is being protected from spam bots, you need Javascript enabled to view it . Vendors particularly are encouraged to submit their products for testing. There is no charge to have your items tested, other than the shipping cost of getting the material to the testing site.

Website: http://www.rocketmaterials.org/

01-03-2008 03:45 AM  #1
jsdemar NAR/TRA L3   Joined: Oct 2006 Posts: 298	Re: Testing of hobby rocketry materials to start up again Quote: Drake Damerau, known to everyone as Doc... Well, there were a couple of exceptions.

01-03-2008 07:21 AM  #2
QuickBurst Certified Level Three TRA   Joined: Aug 2006 Posts: 45	Re: Testing of hobby rocketry materials to start up again Great news. Thank you Darrell and Doc. David Bachelder

01-03-2008 07:47 AM  #3
H_rocket Certified Level Three   Joined: Aug 2006 Posts: 266	Re: Testing of hobby rocketry materials to start up again Now if I can just get Drake to answer an e-mail (I think he is mildly allergic to computers ) I will send him some samples to test.

01-03-2008 08:04 AM  #4
Bexclent Certified Level Two   Joined: Aug 2007 Posts: 70	Re: Testing of hobby rocketry materials to start up again That's awesome guys! Thanks for your dedication to our hobby!

01-03-2008 09:56 AM  #5
R2K Certified Level Three   Joined: Jul 2007 Posts: 115	Re: Testing of hobby rocketry materials to start up again Wow so 3" wound fiberglass tubing can hold up a car...

01-03-2008 12:07 PM  #6
Just Jerry Freeform rockets advocate   Joined: Aug 2006 Posts: 577	Re: Testing of hobby rocketry materials to start up again Actually there is already a vast series of results from testing of traditional HPR materials including regular paper tubes, several styles of phenolic tubes and adhesive bonding methods for all. The shocking thing from the first couple rounds of testing, and that discussion is in the rmr archives, is that good ole paper tubes, yellow aliphatic resin glue, and plywood was shockingly strong and light. http://www.rocketmaterials.../fins/Fin_Cans/index.php Just Jerry

01-03-2008 12:20 PM  #7
ddmobley Administrator   Joined: Jul 2006 Posts: 2170	Re: Testing of hobby rocketry materials to start up again Jerry, thank you for your contributions to the project. You are still the largest contributor to that testing project to date.

01-03-2008 12:20 PM  #8
jsdemar NAR/TRA L3   Joined: Oct 2006 Posts: 298	Re: Testing of hobby rocketry materials to start up again Quote: The shocking thing from the first couple rounds of testing, and that discussion is in the rmr archives, is that good ole paper tubes, yellow aliphatic resin glue, and plywood was shockingly strong and light. http://www.rocketmaterials.../fins/Fin_Cans/index.php The fin can I sent in (thanks to Jerry for the materials) was the strongest with no additional reinforcement. Titebond II, not epoxy. The only stronger fin can was Mark Simpson's which used wood spars in the fillets. For paper-to-paper, it's a myth that epoxy is stronger. -John D.

01-03-2008 01:45 PM  #9
rstaff3 Oddroc-eteer   Joined: Oct 2006 Posts: 142	Re: Testing of hobby rocketry materials to start up again And still there are non-believers...

01-03-2008 05:57 PM  #10
Doc L3CC Member   Joined: Sep 2006 Posts: 72	Re: Testing of hobby rocketry materials to start up again Quote: Now if I can just get Drake to answer an e-mail (I think he is mildly allergic to computers ) I will send him some samples to test. I've never failed to answer an email! At least... That's my story and I'm sticking to it!

01-03-2008 06:36 PM  #11
Steve_Shannon Will fly beer for rockets   Joined: Aug 2006 Posts: 1682	Re: Testing of hobby rocketry materials to start up again Quote: The fin can I sent in (thanks to Jerry for the materials) was the strongest with no additional reinforcement. Titebond II, not epoxy. The only stronger fin can was Mark Simpson's which used wood spars in the fillets. For paper-to-paper, it's a myth that epoxy is stronger. -John D. I'm glad to see this. It makes sense that as long as the adhesive is stronger than the materials being joined other criteria should be used to select the adhesive. I am more comfortable teaching TARC beginners to use Titebond II rather than exposing them to epoxy, but I believe that varied experience with several adhesives and building techniques is valuable, like having more than one tool in the toolbox. Also, this lets me know what to use to build all those USR kits I have...

01-03-2008 11:37 PM  #12
Rocket Flier Certified Level Three   Joined: Dec 2006 Posts: 104	Re: Testing of hobby rocketry materials to start up again Quote: The shocking thing from the first couple rounds of testing, and that discussion is in the rmr archives, is that good ole paper tubes, yellow aliphatic resin glue, and plywood was shockingly strong and light. It would be nice to be able to draw that conclusion. I hope in the future testing can be done to compare woodglue to epoxy rather than comparing individual assembly methods. I wonder if there is a way to mount a portion of bodytube in Doc's device so many samples could be tested to obtain this information. I suspect there is a box of 2x2" plywood squares around here somehere that could be used as sample fins.

01-04-2008 01:08 AM  #13
jsdemar NAR/TRA L3   Joined: Oct 2006 Posts: 298	Re: Testing of hobby rocketry materials to start up again Quote: It would be nice to be able to draw that conclusion. I hope in the future testing can be done to compare woodglue to epoxy rather than comparing individual assembly methods. Look at the fincan test table again. Several pieces were the same materials, donated from the same place (Jerry), and used the same methods. Just the glues was different. One exception is one of the wood glue samples in which wood was added to the fillets. For the one I built, it was just Titebond II fillets with no extra reinforcement. A few years ago, we had 50 student teams build LOC Graduators and LOC IV's all with Titebond II wood glue. No problems at all. -John D.

01-04-2008 03:21 AM  #14
Rocket Flier Certified Level Three   Joined: Dec 2006 Posts: 104	Re: Testing of hobby rocketry materials to start up again Quote: Look at the fincan test table again. Several pieces were the same materials, donated from the same place (Jerry), and used the same methods. Just the glues was different. One exception is one of the wood glue samples in which wood was added to the fillets. For the one I built, it was just Titebond II fillets with no extra reinforcement. I can see nothing that shows all used the same method. These were preslotted tubes or did each have to cut their own slots? Did everyone do any additional sanding on either the fins, or body tubes the same way? Did everyone apply a fillet the same way? Internal/external fillets? How did they form the fillet to ensure it was as uniform as other test samples. What was the temp and humidity at the various locations. The table shows wood filler, foam, and fiberglass was also used. It does not disclose the 'wood glue' or epoxy in most cases and most importantly (for the statement which I quoted "shocking light and strong") does not disclose the weight of each sample before or after assembly. And oddly, the text indicates 6 kits for 3 tests of each kind, but there are more than 6 results in the table. The very first result in the table shows a 'woodglue' failure at 66.185, which is much worse than the epoxy results. That leads to the conclusion that wood glue is worse than epoxy? No, you cannot compare it to the epoxy tests, because you don't know he used the same method of construction as the epoxy guy. Tossing out the 66 because of the 'dark color description' (making the glue suspect), and the extra wood in the fillet, leaves only 1 woodglue test sample. 3 probably wasn't considered statistically significant, but one sure isn't. The only conclusion to be drawn from this data is that a more methodical testing approach is needed (see also John Coker's glue tests). "In God we trust, all others bring data" - Doc.

01-04-2008 06:10 PM  #15
jsdemar NAR/TRA L3   Joined: Oct 2006 Posts: 298	Re: Testing of hobby rocketry materials to start up again Quote: The only conclusion to be drawn from this data is that a more methodical testing approach is needed (see also John Coker's glue tests). Good idea! Build them, take picture of the process, and send them to Doc. Both Mark Simpson and I used Titebond II, which I've found to be the best glue for wood/paper. Elmers is crap. Dark (gorilla?) glue is crap. The "standard method" is to rough sand the surfaces, tack glue the root edges, and apply both external and internal fillets. This is the same method for both types of glue. The pre-slotted "kits" were the same materials, and instruction were given. I don't know if everyone followed them. We were supposed to include comments on any additional steps we did. If the outcome was intended to be a scientific conclusion, the test would be more exact and would have more samples. The goal at the time (MANY years ago) was to have at least something as a comparison. Other than the original 6, a few people submitted additional fincans later on, but it's not clear in the table of results. -John

01-04-2008 06:48 PM  #16
Steve_Shannon Will fly beer for rockets   Joined: Aug 2006 Posts: 1682	Re: Testing of hobby rocketry materials to start up again Although this test is not a perfect comparison of epoxy versus Titebond it does prove that Titebond is suitable for paper/wood construction of high power rockets.

01-04-2008 07:43 PM  #17
Rocket Flier Certified Level Three   Joined: Dec 2006 Posts: 104	Re: Testing of hobby rocketry materials to start up again Quote: Although this test is not a perfect comparison of epoxy versus Titebond it does prove that Titebond is suitable for paper/wood construction of high power rockets. Really? One test sample proves that? I must have missed the data that covers flutter, heat soak and what usually does my rocket fins in, a good thwack from the side.

01-04-2008 08:12 PM  #18
Steve_Shannon Will fly beer for rockets   Joined: Aug 2006 Posts: 1682	Re: Testing of hobby rocketry materials to start up again Quote: Really? One test sample proves that? I must have missed the data that covers flutter, heat soak and what usually does my rocket fins in, a good thwack from the side. Those data did not appear for Titebond. I've never seen that data for epoxy either. Do you have some that you could share? The spec sheet for Titebond shows that after an overnight heat soak of Titebond II at 150°, it has a strength of 1,750 psi. At that bond strength it still causes wood failure (probably paper failure too). At room temperature it is rated at 3,750 psi. The specs say nothing about ability to withstand vibration or impact, but the ability to withstand fin flutter is not really important for most paper and wood rockets. When people start building rockets for that kind of flight they usually switch to stronger base materials anyway which probably will dictate the appropriate adhesive. Of course there will always be exceptions and the person acting as the RSO should want to know what kind of construction was used, especially when checking in a high velocity rocket. I use epoxy for nearly everything, but based on what the limited tests show I would usually allow a person to fly a high power rocket at one of our launches that was constructed with Titebond, especially if that person was John Demar (whom I have never met, but apparently builds a pretty strong fin can using Titebond ).

01-04-2008 08:39 PM  #19
Rocket Flier Certified Level Three   Joined: Dec 2006 Posts: 104	Re: Testing of hobby rocketry materials to start up again Quote: Those data did not appear for Titebond. I've never seen that data for epoxy either. Do you have some that you could share? No, nor am I the one making claims based on one data point. Perhaps a more interesting question is why did the other 2 woodglues fail to perform as well as 3W. Or even why one of the samples submitted by Mark was 1/2 the strength of the other. Quote: I use epoxy for nearly everything, but based on what the limited tests show I would usually allow a person to fly a high power rocket at one of our launches that was constructed with Titebond, especially if that person was John Demar (whom I have never met, but apparently builds a pretty strong fin can using Titebond ). So Jerry having said the same thing for years has no bearing? Hell, I would have built one just because someone said I couldn't. But that's not the point, it's what you claim: "it does prove that Titebond is suitable for paper/wood construction of high power rockets". That data is not there to prove that.

01-04-2008 08:42 PM  #20
Doc L3CC Member   Joined: Sep 2006 Posts: 72	Re: Testing of hobby rocketry materials to start up again There are several things to consider when discussing adhesives. Tensile and shear strength The first one is the strength of the adhesive should be stronger than the substrate. In these tests, we found that both epoxy and wood glue were stronger than the substrate. In these tests, the substrate was cardboard and wood. It can be observed that in most cases the cardboard fails before the adhesive. Impact toughness Another thing to consider is the adhesives’ ductile or brittle nature. An adhesive that has a more ductile fracture mode will absorb a much higher impact than a brittle adhesive. This is needed in rocketry because of the impacts seen in a high thrust to weight motor or a hard landing. Most of the 50/50 ratio epoxy mixtures I have tested have displayed brittle fracture modes of failure. Penetration Another thing to consider is the ability of the adhesive to penetrate into the substrate before it hardens cures or dries. The further the adhesive penetrates into the substrate, the wider the area that the load is distributed. This is one of the reasons that we use fillets. Fillets in welds, structural components or in rocketry, distribute the load over a wider area thereby increasing its strength and fracture toughness. Hot strength All materials become softer when heated. Some materials, like steel don’t become softer until over 1,000°F. Others, like adhesives begin to soften at considerably low temperatures. Heat from motors can heat your adhesive and soften it. The common property with most adhesives is that they become more ductile when heated. Check with the manufacturer for these specifications. My 2¢ Doc “Actual Material Scientist” Damerau

01-04-2008 08:44 PM  #21
Rocket Flier Certified Level Three   Joined: Dec 2006 Posts: 104	Re: Testing of hobby rocketry materials to start up again Quote: Good idea! Build them, take picture of the process, and send them to Doc. There is more than fin can data on Doc's site.

01-04-2008 09:00 PM  #22
Doc L3CC Member   Joined: Sep 2006 Posts: 72	Re: Testing of hobby rocketry materials to start up again Quote: There is more than fin can data on Doc's site. There is more data than you can shake a stick at! I invite everyone to look at all the tests, comment on it, and discuss new or better testing.

01-04-2008 09:26 PM  #23
Rocket Flier Certified Level Three   Joined: Dec 2006 Posts: 104	Re: Testing of hobby rocketry materials to start up again A while back, there was some discussion on the different attachment methods for rail buttons and I was thinking about how to test using sections of bodytubes instead of the whole tubes. The base would be a piece of pipe. A 1/4 (or 1/3) section of bodytube would lay on that, then a 1/2 piece of pipe (cut lengthwise) with a cutout in the middle for the test area would be clamped on top (possibly hose clamp), holding the bodytube in place. You could use the same jig (or is it fixture?) to test surface mounted fins. At the time I wasn't sure it would hold the section well enough to represent a bodytube. The other drawback is it would be tough to come up with a standard fitting pipe, and I'm not sure my rollers can handle thick enough material to make the jig.

01-04-2008 10:59 PM  #24
Steve_Shannon Will fly beer for rockets   Joined: Aug 2006 Posts: 1682	Re: Testing of hobby rocketry materials to start up again Quote: ... Hell, I would have built one just because someone said I couldn't. So is that what this is about? Just because someone said something you must prove them wrong? I have felt that way before also so I understand it. Quote: But that's not the point, it's what you claim: "it does prove that Titebond is suitable for paper/wood construction of high power rockets". That data is not there to prove that. As the old saying goes, you can't argue with success. The fact that John Demar built a fin can with that much strength using Titebond II proves that can be done. It does not prove that it can consistently be done or that anybody could do it. It also does not indicate that Titebond is superior to any other adhesive. It also doesn't mean it is ideal for other high power uses. But, for those high power rockets that would typically be made of wood and paper, the datum (since you correctly observe it is a single point) indicates that a strong fin can was glued up using Titebond II. A strong fin can is the major assembly in a high power rocket and for a single deployment rocket might be the only component that requires glue. As far as strength when heated, and ability to survive fin flutter, no paper/wood rocket that I build is likely to ever be tested in those ways so I am not going to worry about them. I expect others to make those determinations for themselves.

01-04-2008 11:36 PM  #25
Just Jerry Freeform rockets advocate   Joined: Aug 2006 Posts: 577	Re: Testing of hobby rocketry materials to start up again Quote: Really? One test sample proves that? I must have missed the data that covers flutter, heat soak and what usually does my rocket fins in, a good thwack from the side. I have also performed a few field tests The USR Banshee for example uses 0.040" wall tube and 1/8" plywood fins and has been reliably flown using Titebond glue on 320H640 as well as 700J160. This with a wide range of users and construction errors/methods. Just Jerry

01-05-2008 02:57 AM  #26
Rocket Flier Certified Level Three   Joined: Dec 2006 Posts: 104	Re: Testing of hobby rocketry materials to start up again Quote: I have also performed a few field tests The USR Banshee for example uses 0.040" wall tube and 1/8" plywood fins and has been reliably flown using Titebond glue on 320H640 as well as 700J160. This with a wide range of users and construction errors/methods. Just Jerry You might have missed my comment "So Jerry having said the same thing for years has no bearing?"? The September issue of 2004 Wood Magazine included wood glue tests done to some ANSI standard. Their testing used multiple samples, a uniform environment, and applied consistent pressure to the sample. This photo shows how they spread the glue for each sample. rec.woodworking thread. They had rated Elmers ProBond as the top interior and Gorilla Glue the top exterior. I recall the end-grain test line-up differed from the edge grain, but don't know if that was included as part of the final rating. Not all the tests had the wood fiber seperate before the glue joint broke, in (I'm guessing) about 1/2 of the wood glues. Incidentally, the rmr discussion can be found here and discussion of the initial fincan results here.

01-05-2008 10:54 AM  #27
Just Jerry Freeform rockets advocate   Joined: Aug 2006 Posts: 577	Re: Testing of hobby rocketry materials to start up again Thanks for the valuable post Rocket Flier. Nothing beats citations, except new purpose specific data of course. I submitted the (mass quantities of) materials in an effort to DISPROVE my claim that paper and wood construction was superior to the other methods. Oops. For this reason I still strongly endorse LOC kits. Just Jerry

01-06-2008 10:11 AM  #28
Just Jerry Freeform rockets advocate   Joined: Aug 2006 Posts: 577	Re: Testing of hobby rocketry materials to start up again Quote: Incidentally, the rmr discussion can be found here I found a tidbit from 2002 there that I find historically interesting. Quote: It is hard to coperate on this type of test. It is a diversion of company resources so I would stand behind PMLs unwise decision. I am set up to cooperate because I originally set the standards HPR now follows. I have plenty of excess inventory to dispose of because I have been doing it for so long. I appreciate the kind words, and will continue to support the tests fully. But lets not rag on PML or LOC if they are not as fast or full to cooperate. They also have a higher cost basis on parts than I do, due to both purchase quantities and market size. HPR has shrunk some 70% in the past 10 years. My market thank goodness has remained fairly steady. I am not serving the TRA and NAR marketplace simply because they have indicated they do not want me to. If nothing else I do not choose to fight an uphill battle. I will continue to say please, to cooperate, but not beg or force or sue. Jerry -- Jerry Irvine, Box 1242, Claremont, California USA Opinion, the whole thing. \n This email address is being protected from spam bots, you need Javascript enabled to view it > Bring common sense back to rocketry administration. NAR and TRA have not changed their stance but the market drop figure is now approaching 95% from the 1992 peak. Just Jerry

01-06-2008 01:53 PM  #29
ddmobley Administrator   Joined: Jul 2006 Posts: 2170	Re: Testing of hobby rocketry materials to start up again Jerry, I was not around when the testing started. Are you saying that some manufacturers refused to participate in the testing?

01-06-2008 04:04 PM  #30
Chuck_Rudy Banned   Joined: Aug 2007 Posts: 198	Re: Testing of hobby rocketry materials to start up again Bless all you wonderful people out there........I thought this was gonna end up being a dreaded glue thread and I'd return into that slighty lucid, comatose state glue threads seem to force me to venture into. Chuck

01-06-2008 04:39 PM  #31
Just Jerry Freeform rockets advocate   Joined: Aug 2006 Posts: 577	Re: Testing of hobby rocketry materials to start up again Quote: Jerry, I was not around when the testing started. Are you saying that some manufacturers refused to participate in the testing? More like some were "dragooned" by "excited" rmr readers, and they declined. No problem. Users then supplied the small amount of samples of those firms' tubes. Jerry

01-06-2008 10:27 PM  #32
denverdoc Rana sapiens   Joined: Aug 2007 Posts: 1762	Re: Testing of hobby rocketry materials to start up again I believe it was woodworking mag that did a similar test last rear as well--TB II came out on top overall. They compared a number of adhesives including iirc hide glue, Gorilla, epoxy (hardware store variety), a generic alipghatic resin, etc. They also tested iirc a nuber of joint styles. If there is no significant gaps, the aliphatic resins rock. Wood t wood or paper to wood, its the best adhesive, period. If there is a myth it is that it is significantly lighter than epoxy. Not.

01-06-2008 11:56 PM  #33
Rocket Flier Certified Level Three   Joined: Dec 2006 Posts: 104	Re: Testing of hobby rocketry materials to start up again Quote: I believe it was woodworking mag that did a similar test last rear as well--TB II came out on top overall. They compared a number of adhesives including iirc hide glue, Gorilla, epoxy (hardware store variety), a generic alipghatic resin, etc. They also tested iirc a nuber of joint styles. If there is no significant gaps, the aliphatic resins rock. Wood t wood or paper to wood, its the best adhesive, period. If there is a myth it is that it is significantly lighter than epoxy. Not. Fine Woodworking if I'm thinking of the same. It involved more wood joints and so I didn't buy it (not many joint types used in rocketry). Quick search turned up this discussion. Down a little ways dpb posts some followup 'letters to the editor' comments. John McCoy had some points in this thread. I had written the author of the Wood magazine article offering Aeropoxy as well as some others. "No.". Anyway, none of them had tested ply and even if they had, ply is going to depend on which way the 'grain' is because with an odd number of plys one way will have more end grain. Doc doesn't have a windtunnel by any chance?

01-07-2008 05:01 AM  #34
Doc L3CC Member   Joined: Sep 2006 Posts: 72	Re: Testing of hobby rocketry materials to start up again Quote: Doc doesn't have a windtunnel by any chance? No, I wish I did.

01-07-2008 08:31 AM  #35

denverdoc Rana sapiens   Joined: Aug 2007 Posts: 1762

Re: Testing of hobby rocketry materials to start up again Quote: Fine Woodworking if I'm thinking of the same. It involved more wood joints and so I didn't buy it (not many joint types used in rocketry). Quick search turned up this discussion. Down a little ways dpb posts some followup 'letters to the editor' comments. John McCoy had some points in this thread. I had written the author of the Wood magazine article offering Aeropoxy as well as some others. "No.". Anyway, none of them had tested ply and even if they had, ply is going to depend on which way the 'grain' is because with an odd number of plys one way will have more end grain. Doc doesn't have a windtunnel by any chance? Fine Woodworking it was--thanks for the clarification and links. Just goes to show, even when methodical testing is pursued, results vary according to the specifics. Even my interpretation of the results from reading the article while in line at the Orange Demon was a bit different than some of the fellas, but I was reading with rocketry filters in place, by looking at non-oily wood results across the line from sloppy to finely fitting. That said, I personally use both epoxy and yellow glues, in fact 3 or 4 different