BA Baracus Build Thread

Come on Chris you mush have unwrapped this baby by now, you can't leave us hanging op:

mpitfield said:

Come on Chris you mush have unwrapped this baby by now, you can't leave us hanging op:

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Actually, I need to keep you hanging - it hasn't fully hardened. The shop is actually a shed in his back yard, and with the snow it didn't stay above the 77F needed for the initial cure. To quote my buddy, 'it's slow. Not short bus slow, just cold slow'. Pics tomorrow.

Barkley said:

Actually, I need to keep you hanging - it hasn't fully hardened. The shop is actually a shed in his back yard, and with the snow it didn't stay above the 77F needed for the initial cure. To quote my buddy, 'it's slow. Not short bus slow, just cold slow'. Pics tomorrow.

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That is the number one reason I built the oven. It really annoyed the hell out of me that it still was not hardened during the cold.

Now all it takes is just one hour .


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Can't wait to see it. I made an oven for curing paint last year and LOVE it! I made a 2x2x6 foot box out of blue foam, used a heating element, fan, and $10 temp controller from ebay. doesn't look like much but it cures paint nicely at 140 F.

Your killing us man, how did it turn out?


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Sorry, for the radio silence, there is a trifecta of distance, illness and Christmas that prevents me from getting back to the shop. Short answer is it didn't turn out the way I wanted it to, and I'm trying to figure out exactly why. The bad news is that I think there's just enough wrong with it that I'll need to make another tube for this project. The good news is that I'll have 7 feet of 3" tube made from a high temp epoxy. When I get the next one the way I want it I'll post cure both at the same time.

Barkley said:

Sorry, for the radio silence, there is a trifecta of distance, illness and Christmas that prevents me from getting back to the shop. Short answer is it didn't turn out the way I wanted it to, and I'm trying to figure out exactly why. The bad news is that I think there's just enough wrong with it that I'll need to make another tube for this project. The good news is that I'll have 7 feet of 3" tube made from a high temp epoxy. When I get the next one the way I want it I'll post cure both at the same time.

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Post pics still lol


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I'm not sure if it was the culprit or not, but I've never had good results vacuum bagging a tube. I tried very hard to make it work, but I always ended up with a long wrinkle where the two sides of the bag meet along the tube. Plus a wavy, wrinkly surface from the breather. Your pic of the tube in the bag gave me flashbacks.

Heat shrink tube or spiral heat shrink tape have worked great for me.

watheyak said:

I'm not sure if it was the culprit or not, but I've never had good results vacuum bagging a tube. I tried very hard to make it work, but I always ended up with a long wrinkle where the two sides of the bag meet along the tube. Plus a wavy, wrinkly surface from the breather. Your pic of the tube in the bag gave me flashbacks.

Heat shrink tube or spiral heat shrink tape have worked great for me.

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Ouch, well at least I know what I can expect to see soon. My former high school teacher wanted me to try to vacumn bag a tube instead of shrink tape in order to avoid building a curing oven. Lets just say his students are not as dedicated to this to take time to do this after school hours.

Never the less I always prefer shrink tape.

Please post pics, maybe we can help.

Thanks


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My buddy with build skills was on the build team for this:



He's forgotten more about carbon layups than I'll ever know, so I'm grateful that he thinks this is a cool project.

Barkley said:

My buddy with build skills was on the build team for this:

View attachment 307678

He's forgotten more about carbon layups than I'll ever know, so I'm grateful that he thinks this is a cool project.

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I think I saw a youtube video on those. Cant remember the name of the video, but it was awesome.

My respects to your buddy. By the way how did you like carbon over fiberglass?


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OK, so update time. I have a case of a stuck tube - it released, but got about 9 inches down the mandrel and wouldn't budge. My buddy took an 8:1 kevlar mainsheet, wrapped it around a tree, and ... it snapped while he pulled. So, now I've put it into the blast freezer at work. That'll shrink the alloy mandrel down as small as it'll go - if it's just stuck, that should free it. If the mandrel has uneven thickness or a case of the banana, then I may have to cut it off and reboot. Should know in 24 hours - fingers crossed.

2nd attempt. After 24 hours it still isn't hard enough. Pics when I can. I've never used an epoxy with a 3+ hour pot life before, and I can see why it needs post cure.

Barkley said:

2nd attempt. After 24 hours it still isn't hard enough. Pics when I can. I've never used an epoxy with a 3+ hour pot life before, and I can see why it needs post cure.

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You need to roast that sucker man . Did this one turn out without wrinkles though?


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SinfulDarkLord said:

You need to roast that sucker man . Did this one turn out without wrinkles though?


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Wrinkle free. The last one had both wrinkles and the vacuum pulled epoxy past the Mylar film somehow. Anyway, calling a Mulligan on the last one and hopefully getting this one right.

Barkley said:

Wrinkle free. The last one had both wrinkles and the vacuum pulled epoxy past the Mylar film somehow. Anyway, calling a Mulligan on the last one and hopefully getting this one right.

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Sweet, what was the approach this time that resulted in wrinkle free? I always like to know what works and what doesnt.


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No vac bag this time, and trying something new. 3 wraps, then adding 3 more (bagged). The heat gun discoloured the epoxy with the last tube, so just used a hair dryer down the mandrel this time. 7 feet of cloth weighing 400 grams, overall weight 700 grams, so a good ratio, so I'll check the hoop strength after and see if one more wrap is necessary. The second set of wraps are on now and this epoxy has a 2 day cure at Canadian-outdoor-partially-heated workshop room temp, so I'm hoping to have a finished tube on Sunday. Yes, the post cure will be important.

Going to make my NC the right way this time, turning a wooden blank on a lathe, making the molds, then doing the layup. I figure this won't be my only 3 inch rocket, so why not invest the time. I'm also debating whether to make one glass and one kevlar - I was convinced full carbon wasn't the way to go as it would have required a phased array which would have been too big a jump for my current skill set. I'd like to get this one back.

A close up of the finished tube. Still needs to be prettied up a bit, but good hoop strength that will only get better when it hits the oven.



So, I'm hoping to make fin plate on Saturday. When I was talking with my buddy about the fins he decided to let me have a bit of this stuff:



This stuff is beautiful. Also, you'll notice the strands on the 45. 10 layers of alternating normal twill and this 45/135 should make things good and stiff, and yes I'm using the same high temp epoxy.

You're killing me with how sexy this stuff is....

Thats one fine carbon tube. Good work Barkley, keep up the good work. That 45/-45 is beautiful.


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Picked up some of this today.



The milled carbon should make solid fillets, but I need to work while it's wet because it's hell to sand. Given that this epoxy sets up in days not hours, there's all kinds of time for the work to sag, so hopefully just a little bit of cabosil should keep the work from sagging. I'll do a little test while I'm laying up the fin plate.

LOL!!

Plate. Soon there will be fins.

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Barkley said:

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Picture appears broken to me.


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SinfulDarkLord said:

Picture appears broken to me.


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Appears fine to me.

blackbrandt said:

Appears fine to me.

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Must be the app then


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The picture in 54 appears broken to me also. 53 is fine.

It's a 2 inch thick by 8 inch by 3 foot section of mahogany. To be ripped, laminated, then turned on a lathe for the positive nose cone blank - the moment I have time without it being too late in the evening. Running a saw after hours... you can't really do it in a condo.

Aha! I knew that was too big for finstock! I can't wait to see this cone.