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making own carbon fiber sheets?

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rocketsonly

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Is there any specific methods for making carbon fiber sheets from CF cloth?

I was thinking along the lines of having a release agent on a flat surface, and some cloth over it, then wetting it, then another layer of a release agent, then a hard board, then some weights?
(wow, that was a huge run on sentence, hopefully my English teacher doesn't browse through TRF)

Any ideas? comments?
 

11bravo

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I was thinking of two slabs of aluminum or steel, say 1/2 inch thick and maybe 12x24 inches. Could be larger if needed. Round the edges of one side of each off with a torch.
Advantage: Steel- MUCH cheaper.
Advantage: Aluminum- MUCH lighter.
Believe it or not, you could get the steel for not all that much, prices vary so I cannot say how much for sure. You may however need a buddy or two to make your sheets.
The process I envision is release agent on the insides of the panels and the cloth/epoxy combo with as many layers as you want in between.
Put the whole thing in a plastic bag and apply a vacuum to squish it flat.
Vacuum bagging will almost assure that the plates stay parallel resulting in uniform sheets whereas with weights you may have one side a little heavier resulting in uneven sheets.

Greg
 

rocketsonly

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Originally posted by 11Bravo
I was thinking of two slabs of aluminum or steel, say 1/2 inch thick and maybe 12x24 inches. Could be larger if needed. Round the edges of one side of each off with a torch.
Advantage: Steel- MUCH cheaper.
Advantage: Aluminum- MUCH lighter.
Believe it or not, you could get the steel for not all that much, prices vary so I cannot say how much for sure. You may however need a buddy or two to make your sheets.
The process I envision is release agent on the insides of the panels and the cloth/epoxy combo with as many layers as you want in between.
Put the whole thing in a plastic bag and apply a vacuum to squish it flat.
Vacuum bagging will almost assure that the plates stay parallel resulting in uniform sheets whereas with weights you may have one side a little heavier resulting in uneven sheets.

Greg
Or something along the lines of that. Get the two slabs and drill holes in each corner (threaded or not). Put some sort of release on each side and 'wet' out the cloth. Then screw both slabs together. You could screw it pretty tightly.

And if needed, you could vacuum bag the whole thing.
 

DynaSoar

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Originally posted by rocketsonly
Or something along the lines of that. Get the two slabs and drill holes in each corner (threaded or not). Put some sort of release on each side and 'wet' out the cloth. Then screw both slabs together. You could screw it pretty tightly.

And if needed, you could vacuum bag the whole thing.
Looks like we may find out pretty quick. I just got the OK to buy th12" prepreg tape on ROL. An old oven and a couple plates of steel, and it's in business.
 

shockwaveriderz

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folks I did this back in the 80's with prepreg cf cloth....it would arrive in dry ice styrofoam containers....it was a complete total waste of my time and energy .......now if i need any stiff cf sheeting I just buy it from ACP or CST.......
 

rocketsonly

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Originally posted by shockwaveriderz
folks I did this back in the 80's with prepreg cf cloth....it would arrive in dry ice styrofoam containers....it was a complete total waste of my time and energy .......now if i need any stiff cf sheeting I just buy it from ACP or CST.......
Why so? It seems pretty simple.
 

Rubr_Duky

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I've made my own CF sheets, and even CF & Basswood laminant for fin cores & bulkheads.

Using 2 pieces oa Aluminum, roughly 6" x 12" (small I know, but it's scalable) and about 1/2" thick. Make sure you clean up the alimunim reall good, otherwise you'll get a poor texture. I got a nearly mirror finish on some of mine. Take a paper towel & some mineral spirits, or paint thinner, and rub until your arm falls off, and then with acetone, do it three more times. a real light coat of spray release, and rub that in lightly. If you want to do this more than once, a trick my Dad taught me was to heat cycle the aluminum with the mold release on it... stick it in the oven (if it's small enough) at about 375° for about an hour, and then let it cool. give another light coat before you lay it up.

I just used C clamps to hold the two pieces together, but you want to be careful about warping the two sides, you'll get a different thickness in the middle.

Oven cure if you wish, or if it will fit, and to break it apart, just use a slotted screwdriver, and pry it apart. It'll go *snap* and then you can get the sheet out. trim the edges, and you've got your sheet. You could also use spacers under the clamps to keep a consistent thickness. I also did it using peel-ply called bleederlease from Airtech (search google) and got a nice texture on both sides. don't need to be so generous with the spray release that way. the texture is good if you're going to bod anything to it, otherwise just hit it with some sandpaper before you do.

:D
RD
 

GL-P

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I've made foamboard fins by taking a peice of foam board, fibrelgassing the topside, turining it over and fibreglassing the bottom. I then slide it in between two pieces of waxpaper. I then put MDF on the top and bottom. It works pretty well. The fins did slightly warp eventually though.
 

edwardw

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Geoff Elder has some good tutorials on layup of composites. I'm sure Google can help you

Edward
 

Ryan S.

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I had done it with FG.

just lay the cloth and a peice of glass (or release covered flat surface) and add more glass always twisting at a 45 degree angle untill you have enough, then put more release and lots of heavy stuff, works great
 

AlexM

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I was thinking, if you had some honeycomb material, it makes a really light and strong fin if you do it right.
 

DynaSoar

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Originally posted by shockwaveriderz
folks I did this back in the 80's with prepreg cf cloth....it would arrive in dry ice styrofoam containers....it was a complete total waste of my time and energy .......now if i need any stiff cf sheeting I just buy it from ACP or CST.......
Don't leave me hanging shockie, DETAILS. I plan on starting manufacturing in a month or so.
 

11bravo

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The problem I see with the holes and bolts idea is warping of the "slabs"; yeah they will warp a bit, small but it will be there.
The vacuum technique uses atmospheric pressure to apply the "weight" so it is uniform across the whole area.
Vacuum pumps are actually easy to come by, every refrigerator has one on the back side.
Go to an appliance store and see if they have one or more; they'll probably have a barrel full of them and in my experience will give them away.
Only catch is finding one that works, it'll need to have come off of a frige that was just replaced instead of one that died.
For instructions on how to build a system for vacuum bagging, see-

http://www.berkut13.com/sucker.htm

Actually, the more that I think about it, you could use rather thin material for the "slabs" exactly because the vacuum results in equal pressure all over.
 

shockwaveriderz

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Dynasoar; Well I had the bright idea to sell unidirectional prepreg sheets .. I used heavy metal plates with bolt holes around the peripheral edges to apply constant and continius pressure ...At first I just waxed the metal plates......then I went to using oversize mylar sheet .014".... I did not have the ability to oven cure as the pros would do...so I air cured......it works but......


If I was to do it all over again, I would create a small vacuum heat press sorta like the pros do it so I could cure under uniform heat and pressure.....

Dyna: theres no doubt you can do it and probably well, but why reinvent the wheel? There are several companies that can provide you with various CF materials in various thicknesses using actual hitech production equipment ....


I just decided that I did not really want to produce cf materials and perhaps get an epoxy sensitivity or get cancer from inhaling all this stuff......


Take alook at all the CF products avilable from these 2 vendors......

http://www.acp-composites.com/

http://www.cstsales.com/

heres plans for a vacuum press....just place it inside a "hot box" oven and cure under heat and pressure..

http://www.joewoodworker.com/veneering/pumpsys-construction.htm
 

DynaSoar

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Originally posted by shockwaveriderz
Dynasoar; Well I had the bright idea to sell unidirectional prepreg sheets .. I used heavy metal plates with bolt holes around the peripheral edges to apply constant and continius pressure ...At first I just waxed the metal plates......then I went to using oversize mylar sheet .014".... I did not have the ability to oven cure as the pros would do...so I air cured......it works but......

If I was to do it all over again, I would create a small vacuum heat press sorta like the pros do it so I could cure under uniform heat and pressure.....

Dyna: theres no doubt you can do it and probably well, but why reinvent the wheel? There are several companies that can provide you with various CF materials in various thicknesses using actual hitech production equipment ....

I just decided that I did not really want to produce cf materials and perhaps get an epoxy sensitivity or get cancer from inhaling all this stuff......

Take alook at all the CF products avilable from these 2 vendors......
Why re-invent the wheel? Because someone took the wheel, turned it on its side, made the spokes flat and angled them, and invented the turbine blade.

I know there's places I can buy it from. I think I can make it cheaper and sell it for less. I can also make it custom cut, and since I know rocketry, know what it is people are asking for when they order it. I think I can improve the manufacturing process by making it simpler and cheaper, something I have *lot* of experience doing with lots of other hitech stuff. Frinstances: solar curing oven. Thermal box, glass lid, vent fan on a thermocouple. For break away, I've got a couple different mixtures in mind that are dirt cheap; some of the stuff I could have for the hauling away from an oil refinery. Those hi tech production places have to pay for their fancy equipment. I tend to approach equipment like Mother Earth News approaches stuff, hacked out of raw timber if possible. The results don't understand fancy. I just have a knack for pulling one technology into another in ways that weren't thought of before.

As for the hazmat angle, I had all the pertinent training the Air Force had to offer on the subject, from diesel fuel through RFNA. Some days I went to work in a space suit and climbed into JP4 tanks, and some days worked around B-52s loaded with a gigaton of live evil. I know my substances, hazards and precautions.

The vacuum system is already paid for and scheduled for shipping. And, I've already had an inquiry from a retailer. I've scoped out the probable competition in the niche I'm picking and know my benefit over them.

Worst that can happen is I don't make back my thousand dollars, which I wouldn't have put in if I couldn't deal with that, and I'll be giving away sheets of CF at all the launches in Texas. And I go back to brain science to get my pizza money. I'm sure I can waste a fair amount learning how, sell the good stuff for cheaper than others and still at least break even.

At the very least the guys from Rocketguts and I are going to learn how, and make some money for their TARC team, and learn some more stuff, and have some fun, and have some of the coolest rockets on the planet or off. After that it's gravy.
 
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