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Scale 25% Krier Kraft build, a tribute to grampa.

Discussion in 'Giant / Scale Scratch and Kit Build Threads' started by Bipeguy03, Jun 13, 2016.

   
  1. Previously on CSI: SMURF, the grizzly smurf massacre found in the work shop continues to grow, and Smurfette has been missing for 5 days. Warning, some may find the following images disturbing; Parental discretion is advised.

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    I guess what I mean is, I put the first layer of primer on the cowling plug this afternoon!

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  2. Jetpainter

    Jetpainter 640cc Uber Pimp

    Now you get to chase down pinholes! :)

    A good tip for that, if your interested, is before you sand your primer take a strong flashlight and shine it across the surface at a shallow angle. Even small pinholes look like giant craters when you do that. I then used Dolphin Glaze, a polyester filler to fill them.
     
  3. Yer getting there, keep at it,
    Doc
     
  4. Yay composite work!! Lol So the last few days I've been slinging some resin at some cloth. Finished the cowl plug and also laid up a wheel pant.

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    Used grampa's molds to lay up a mate for the wheel pant that was already in the mold, definitely using the pant he made I think it will be cool to have a part of grampa flying on my airplane. Grampa's 35 year old molds still make good parts! ;)

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    Finally have 2 wheel pants! I used 2 layers of 4oz unidirectional cloth at 30*, a small reinforcement piece of 4oz bidirectional cloth around the mount area, and lastly a layer of 6oz bidirectional cloth.

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    Working on making the parting line box for the cowl. And finally seeing the airplane with 2 wheel pants :D

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    After 7 coats of mirror glaze wax and 3 coats of free coat mold release, I filled in all the gaps around the parting line with modeling clay and set about laying up the first half of the mold.

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    I mixed up some thixotropic silica (also known as thilly silly lol) to make a gel coat to build up in the tight corners of the parting line and around the draft of the front of the cowl. I then laid the mold up using a first layer of 3oz bidirectional then followed it with 3 layer of 8oz bidirectional

    I need to get some more 8oz cloth for the other side, but tomorrow hopefully it all comes out good and I can get to making the other side of the mold.
     
    Snoopy1, HRRC Flyer, Doc and 6 others like this.
  5. stangflyer

    stangflyer I like 'em "BIG"!

    Huh!!! I am now officially impressed...."AGAIN". Nicely done....nicely done indeed. Really looking forward to seeing this complete.
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    Bipeguy03, Doc and pawnshopmike like this.
  6. BalsaDust

    BalsaDust Moderator

    Badass.
     
    Bipeguy03 and pawnshopmike like this.
  7. Nice work! You'll have a cowl in no time now. What are you going to use to "key" the mold halves?
    Doc
     
    Bipeguy03 likes this.
  8. HRRC Flyer

    HRRC Flyer GSN Sponsor Tier 1

    Now that Gentlemen is only one of the MANY reasons this build is so AWESOME. . . . . . . . .:yesss:. Hey @Bipeguy03 , I know you have to be on cloud 9 knowing that part of your grandpa's handy work will soon take to the skies again. Personally, I wouldn't be able to hold back my emotions, but I'm an old softie anyway. . . . . :laughing:.

    Let the building continue.
     
  9. Thanks all, I really do appreciate all the kind words!

    So bad news is, for the first time ever FreeKote mold release has let me down. The plug stuck in the mold in a spot around the front ring. #@%^!%@$$#^!!!!!!

    Good news, the plug only got screwed up on the side where it stuck, the other side just has a couple of dents. The mold itself is just fine. After getting the plug out a couple of minutes of scraping with a credit card blank and doing some wet sanding it will be just fine. Had to patch a couple of air bubble spots but it will get the job done.

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    Where the plug stuck, all of the other marks and dents and dings are from screwdrivers, paint sticks, putty knives ect trying to get the mold off. Luckily we got it done with only 2 dents to the plug on the other side of the part line, so I should be able to get the mold finished.

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    After a little bit of scrubbing the mold looks fine. A few air bubble pockets need to be patched but nothing drastic. It should make a good part.

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    I cut up some scrap luan I had to add a stiffener to the outside of the mold, I bonded it to the mold with resin and thixotropic silica after tacking it in place with CA. This made a rather flimsy mold rock solid and should help keep it from warping due to the shrinkage of the poly-ester resin.

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    After I patched the air bubble pockets with some resin and thixotropic silica.

    For anyone that is curious, thixotropic silica is a resin thickening agent that helps make a strong and hard gel. It's really good for building up tight corners were cloth won't lay and making a brush able gel coat. Most important thing about mixing thixo into resin is to use enough. when you first mix in some of the powder it will look clumpy in the resin, you need to keep adding thixo until the silica particles are close enough together to tear at each other, spreading out the resin over the silica. You will know that has happened when the mixture looks like a peanut butter type consistency without any lumps of little white balls of silica.
     
    Alky6, Doc, pawnshopmike and 2 others like this.
  10. stangflyer

    stangflyer I like 'em "BIG"!

    I sure am glad you explained all this. But it is still Greek to me. I don't think I could ever entertain such a project. I have zero patients and want results...."NOW". LOL.... I am really looking forward to seeing your final cowl results.
     
    pawnshopmike likes this.

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