DIY high temperature composite pulse jets

Moderator: Mike Everman

Jutte
Posts: 332
Joined: Wed Aug 22, 2007 11:01 am
Antipspambot question: 0
Location: NZ

DIY high temperature composite pulse jets

Post by Jutte » Fri Sep 09, 2011 7:02 am

Hi everyone - interested to get your comments on the YouTube video
entitled...
"DIY high temperature composite pulse jets ".
The engines look to be a Thermojet,Chinese and a mini sort of M40ish looking engine.
The thermojet shows a pretty interesting thrust to weight ratio - see the vid and you will
see what I mean.
The later engines are shown briefly in running segments. I don't know if this was just a time thing or the bigger engines
exhibiting thermal heat stresses and therefore cracking over longer running periods.
The guy "Amazing DIYprojects" (or something to that effect) is selling plans for these composite jets.
An interesting development for sure - does anyone know what material he is using?
Anyway AmazingDIYproject guy - if your reading this -
well done Dude!

Mark
Posts: 10754
Joined: Sat Oct 11, 2003 10:14 pm

Re: DIY high temperature composite pulse jets

Post by Mark » Fri Sep 09, 2011 8:02 am

Here's a couple posts/ideas from the metiz youtube topic a few days ago. I noticed "Adding comments has been disabled for this video." But here's mine.
viewtopic.php?f=10&t=4208&p=74266#p74194
http://www.uksealants.co.uk/product.asp?idproduct=91

And some other kind with the same "fire rating of 120 minutes (test report 7830)."
Test Results – Test Report 7830:
Wall Thickness Width of Joint Depth of Joint Application Fire Rating
200mm 10mm 45mm Unexposed side of the wall
120 min. TI
120 min. FR
Rating: EI 120
TI = Thermal Insulation; the time during which the temperature on the unexposed side of the wall does not rise by more
than 180°C
FR = Flame Resistance; the time during which the joints stops flames from penetrating the wall
Fire Rating: Draft European Commission Decision RG N170 REV.1
http://www.soudal.com/soudalweb/product ... 02&ID=2533
http://www.soudal.com/soudalweb/images/ ... t%20HT.pdf
Presentation is Everything

ace_fedde
Posts: 421
Joined: Mon Feb 16, 2009 9:26 pm
Antipspambot question: 0
Location: The Netherlands

Re: DIY high temperature composite pulse jets

Post by ace_fedde » Fri Sep 09, 2011 9:42 am

in another forum Mark wrote: "Water glass is a useful binder of solids, such as vermiculite and perlite. When blended with the aforementioned lightweight aggregates, water glass can be used to make hard, high-temperature insulation boards used for refractories, passive fire protection and high temperature insulations, such as moulded pipe insulation applications. When mixed with finely divided mineral powders, such as vermiculite dust (which is common scrap from the exfoliation process), one can produce high temperature adhesives. The intumescence disappears in the presence of finely divided mineral dust, whereby the waterglass becomes a mere matrix. Waterglass is inexpensive and abundantly available, which makes its use popular in many refractory applications."
http://en.wikipedia.org/wiki/Sodium_silicate
Hi all,
Welcome into my kitchen, actually into my oven :lol:
The brick that you see is made over a year ago from perlite and water glass, but just recently i decided to test it at 250 celcius in my oven. It survived.
The foam that you see started with a film of water glass onto a sheet of stainless that, I thought, had hardened during a couple of days. But probably there was still enough cristal water in the hardened film of water glass so it formed the foam when treated in the oven.
Looks like if you want to make something heat (250 C = heat??) resistant with water glass it has to dry/harden for a very long period.

Fedde
Attachments
P1050631.JPG
Your scepticism is fuel for my brain.

ace_fedde
Posts: 421
Joined: Mon Feb 16, 2009 9:26 pm
Antipspambot question: 0
Location: The Netherlands

Re: DIY high temperature composite pulse jets

Post by ace_fedde » Fri Sep 09, 2011 9:44 am

:lol: :lol: :lol:
Attachments
P1050632.JPG
Your scepticism is fuel for my brain.

Mark
Posts: 10754
Joined: Sat Oct 11, 2003 10:14 pm

Re: DIY high temperature composite pulse jets

Post by Mark » Fri Sep 09, 2011 10:22 am

Thermosteel is a mixture of sodium silicate and steel fines. I think you're suppose to gradually/gently heat it to drive off the water. I bought some once but didn't use it for over a year and it just turned into a hard rock in the original container unopened. I also have a quart of sodium silicate that is very old and in the bottom quarter of the plastic bottle you can see it has turned into a solid substance with the thick liquid silicate above it.
http://bluemagicusa.com/bm_files/msds/T ... 20MSDS.pdf

Curing
"Air dry at room temerature for 3 to 4 hours, then gradually heat repair for 10-15 minutes to fully cure. If bubbling accurs, Thermosteel was cured too rapidly or the surface was not adequately cleaned and dried. Allow the surface to cool, scrape off the blistered material, reapply product to the area that bubbled."
Sometimes you see instructions to heat thermal adhesives or cements, to set it or drive off the water or fluid portion, so that bonding can occur.
Last edited by Mark on Fri Sep 09, 2011 3:38 pm, edited 1 time in total.
Presentation is Everything

ace_fedde
Posts: 421
Joined: Mon Feb 16, 2009 9:26 pm
Antipspambot question: 0
Location: The Netherlands

Re: DIY high temperature composite pulse jets

Post by ace_fedde » Fri Sep 09, 2011 11:53 am

Unfortunatly water glass, that is so easy to use, melts already at 1088 C. Not really usable for PJ construction.
I would like to experiment with charcoal as construction material. It has a melting temperature of above 3000 C.

I have a pottery oven that easely reaches the temperatures needed for carbonisation.
Just make your PJ parts out of wood and turn them into charcoal, glue them together with caramel and again it goes for carbonisation.
But...
Have to find some very heat resistent coating against oxidation, carbondioxide doesn't work that well as construction material :lol:

I'm thinking the proces that is used to spray or damp metals on surfaces and use chrome. The chrome might come close to it's melting temperature due to the isolation qualities of charcoal, but no mechanical strenght is required of the chrome coating. Somebody has the tools to do it for me? :lol:

Fedde
Your scepticism is fuel for my brain.

Mark
Posts: 10754
Joined: Sat Oct 11, 2003 10:14 pm

Re: DIY high temperature composite pulse jets

Post by Mark » Fri Sep 09, 2011 2:43 pm

Thermosteel is rated at 2400 F or 1316 C. But it isn't very strong. Something such as a high temperature glass/quartz fiber matrix would help to give it something to hold onto. It may be that sodium silicate breaks down or reacts with hardening agents to form some other crosslinked compounds.
http://epoxyputty.com/thermosteel.htm

Here's some other stuff, note the physical properties.
http://www.cotronics.com/vo/cotr/pdf/907gf.pdf

Again here is the stuff in the pulsejet video which used some sort of fiber cloth or muffler wrap probably and Calofer adhesive good for 1500C.
"It does not contain asbestos or other harmful components, very hard setting, does not crumble or crack after cure, fire rating of 120 minutes (test report 7830)."
http://www.uksealants.co.uk/product.asp?idproduct=91
Presentation is Everything

ace_fedde
Posts: 421
Joined: Mon Feb 16, 2009 9:26 pm
Antipspambot question: 0
Location: The Netherlands

Re: DIY high temperature composite pulse jets

Post by ace_fedde » Fri Sep 09, 2011 4:58 pm

ace_fedde wrote:Have to find some very heat resistent coating against oxidation, carbondioxide doesn't work that well as construction material :lol:
Fedde
Took one fiber out of a sheet of carbon fiber and tried to light it. It didn't burn, melt or oxidize! :shock:

Fedde
Your scepticism is fuel for my brain.

Mark
Posts: 10754
Joined: Sat Oct 11, 2003 10:14 pm

Re: DIY high temperature composite pulse jets

Post by Mark » Fri Sep 09, 2011 5:09 pm

Carbon dioxide activation.
"Mix a fine grained sand (try about a 100 mesh to begin with) with 3% to 4% by weight of the sodium silicate. Mixing can be accomplished in a small container by hand for small jobs. Larger batches can be mixed in a muller. Pack the treated sand into a core box that forms the desired shape. Insert any wires, rods or other support items as required. To solidify the core, apply CO2 gas from a low pressure source such as a beverage gas cylinder. The gas can be applied using a hose and any convenient nozzle. The nozzle could be just the end of the tube, or a diffuser such as a standard kitchen funnel. The object is to push the gas thru the core from one end to the other, and activate the sodium silicate to bind the sand. It's also practical place the core mold in a plastic bag and flood it with CO2 to kick off the core inside."
http://www.budgetcastingsupply.com/Sodium_Silicate.php

"Though sodium silicate bonded sand will eventually harden with exposure to air (the water component in the binder evaporates setting the sand), waiting for this reaction to complete in ambient conditions would be quite unsatisfactory. To contract moulding times, a CATALYIST is added into the sand which both accelerates and controls the hardening process. The catalyst for sodium silicate sands can be in the form of an added ESTER or powder (FERROSILICON), which is injected into the sand during milling. The addition of the ester creates a thermo-reactive SELF SETTING moulding sand with a relatively short hardening time [ref]. However, by far the most popular catalyst for the hardening of sodium silicate bonded sand is pressurised CARBON DIOXIDE gas or CO2."
http://www.artenero.com.au/9_sandcasting/sodsil_11.html
Presentation is Everything

Mark
Posts: 10754
Joined: Sat Oct 11, 2003 10:14 pm

Re: DIY high temperature composite pulse jets

Post by Mark » Fri Sep 09, 2011 6:13 pm

From the comments section.
Na2SiO3 + CO2 --> Na2CO3 + SiO2 + ∆T
Sodium silicate reacts with carbon dioxide to form sodium carbonate, silicon dioxide (quartz) and heat.
http://www.youtube.com/watch?v=UPQmgeTFHEc
Presentation is Everything

ace_fedde
Posts: 421
Joined: Mon Feb 16, 2009 9:26 pm
Antipspambot question: 0
Location: The Netherlands

Re: DIY high temperature composite pulse jets

Post by ace_fedde » Fri Sep 09, 2011 7:09 pm

Hmm, would the object stay intact if one washes out the Na2CO3 with water? Leaving a quartz spunchy structure?
Very heat resistant!!
Your scepticism is fuel for my brain.

ace_fedde
Posts: 421
Joined: Mon Feb 16, 2009 9:26 pm
Antipspambot question: 0
Location: The Netherlands

Re: DIY high temperature composite pulse jets

Post by ace_fedde » Fri Sep 09, 2011 7:35 pm

ace_fedde wrote:I'm thinking the proces that is used to spray or damp metals on surfaces and use chrome. The chrome might come close to it's melting temperature due to the isolation qualities of charcoal, but no mechanical strenght is required of the chrome coating.
Or just a galvanic process? After all carbon is a (semi) conductor.
Your scepticism is fuel for my brain.

metiz
Posts: 1522
Joined: Fri Apr 21, 2006 6:34 pm
Antipspambot question: 125
Location: Netherlands

Re: DIY high temperature composite pulse jets

Post by metiz » Fri Sep 09, 2011 7:38 pm

ace_fedde wrote:
ace_fedde wrote:Have to find some very heat resistent coating against oxidation, carbondioxide doesn't work that well as construction material :lol:
Fedde
Took one fiber out of a sheet of carbon fiber and tried to light it. It didn't burn, melt or oxidize! :shock:

Fedde
carbon fibre should work for heat resistance and strength (obviously) but how are you going to bond it? the resin will melt and burn. I guess you could use some of the addiatives mentioned in this thread as a bonding agent...
Quantify the world.

ace_fedde
Posts: 421
Joined: Mon Feb 16, 2009 9:26 pm
Antipspambot question: 0
Location: The Netherlands

Re: DIY high temperature composite pulse jets

Post by ace_fedde » Fri Sep 09, 2011 8:18 pm

I don't (yet) intend to use carbonfiber for construction, I just took a single fiber because I wanted to test carbon's resistance against oxidation at high temperatures. A thin fiber is a perfect test object for that.
However I could use carbonfiber and use caramel as a bonder (and carbonize it by heat after applying).

Also I found foldable carbon sheet for sale in China, pretty expensive though...
Your scepticism is fuel for my brain.

Mark
Posts: 10754
Joined: Sat Oct 11, 2003 10:14 pm

Re: DIY high temperature composite pulse jets

Post by Mark » Fri Sep 09, 2011 8:32 pm

Some curious formulations with waterglass and good general information/food for thought/materials science stuff.
http://ferrocement.net/ferro/files/waterglass.pdf
Presentation is Everything

Post Reply