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Old Dec 09, 2012, 11:27 PM
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Thanks Brian! Its only taken about 23 years and who knows how many kits/arfs to get to this point and learn all these little nifty tricks like the control arm jig.

Thomas
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Old Dec 10, 2012, 08:49 PM
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First parts out of the mold:




While they look good, the layup schedule needs a bit of refinement.

Canopy frame:
Over-all I am happy with the frame. It is a bit more flexible than I want and its pretty thin. I can fix both by a 2nd layer of carbon cloth and a 3rd of fiberglass, but at the expense of more weight.. If the canopy is made functional/removable a G-10 frame will enhance the strength of it immensely! Soo... I'll actually do a combination of things. Once, i'll reduce the amount of carbon I used by putting overlapping "strips" where just the frame is, so I eliminate much of the waste where the carbon will be removed due to the clear canopy. This overlapping of fabrics will add some thickness in the corners and more strength where it is needed, and either a Glass/balsa laminate or G-10 frame will be made up (probably glass and balsa.. again to save weight).

Main Gear Doors:
The upper-strut doors are perfect. roughly 1/8" thick and plenty strong! The wheel door covers are not though. Once i started doing the layup on the main doors I realized I should of done the foam or balsa sandwhich on them as well. the doors are stiff currently (due to the CF) but have no strength what so ever.. So since the doors are ready for a secondary bonding (due to the peel-ply), I'll cut the strut doors loose, trim the wheel door covers to shape and then PVA the gear door mold and place the door covers back into the mold while the PVA is wet. As the wet pva dries, it will effectively attach the door parts back to the mold. Then i'll go ahead and laminate the foam door material. This should strengthen the doors plenty, as long as I can heat up the foam to get it to conform to the curve of the door edges.
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Old Dec 11, 2012, 10:39 PM
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Alrighty.. the wife let me out in the shop a bit this evening, so I got some work done, which will be the last till saturday (at the earliest) as I have an annual flight review next week at work and our flight check pilots are becoming a real PITA in how they want things done...

Anyways,
First up was making up the resin trap for the resin infusion process. Its just some 2" schedule 40 PVC pipe with a cap on each end. One cap has a brass MIP to barb fitting on it for the vacuum pump/reservoir to hookup to, and another brass fitting about 6-9" below that for the vacuum tube INside the vacuum bag to hook up to. About $40 in parts, compared to $340 for a commercially available one.



Got a few picture of the vacuum form plug:




Then I did the entire mold sealing and mold release process. I'm not using the conventional Wax and PVA method, that involves allot of "elbow grease". This method, is what they call a "semi-permanent". Essentially, you clean wash all the old wax and PVA off the mold surface. Then use a specialized mold cleaner to clean all the last bit of previous mold release agent off. Then there is a specialized mold sealer that you put 3 coats on. Essentially, you wipe it on, let it sit till it starts to evaporate, then wipe it back off. Wait 15 minutes between coats, and then 20 minutes after the final coat. After the 20 minute wait from the final coat, you repeat the same process for the Mold release agent. Do that three times, and then wait 10-15 minutes after the last coat. It took about 3 hours in total to clean, seal and release application. The plus side to this system, is once you do this, you only have to re-apply the mold release after every Couple of parts (some people can get a dozen parts out of a mold between applications!). But since the stuff is fairly cheap ($30/pint!) and it only takes about 10 minutes to do all of the horten molds, i'll reapply after every part.. to put it into perspective, I maybe used 3 or 4oz out of the pint can to do 3 coats of release on all of the molds!
Once all the release was applied, the mold flanges were taped off:



Then with the flanges taped off, I sprayed the primer in the molds.. YES! We will have primed in the mold parts! I Really don't understand why EVERYONE doesn't do this. It only adds an extra hour or two of labor and about $40 in materials but makes the parts coming out of the mold much nicer IMO!

Top:


Bottom:



Depending on how much study time i get for my flight review, I hope we will be able to get out to the shop on saturday and lay in all the cloth in the molds. I also need to do a test layup as well sometime between now and then to test the layup schedule to ensure it will be strong enough.
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Old Dec 11, 2012, 10:45 PM
JOHN 3:16
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Depending on how much study time i get for my flight review
What/for whom do you fly for a living?
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Old Dec 11, 2012, 10:49 PM
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What/for whom do you fly for a living?
King Air 90's
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Old Dec 12, 2012, 03:48 AM
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looking very nice Invert! That crows weave of yours should be handy for some of those complex curves.

Regarding that wax method, is it freecoat? I'm always looking for a superior method!
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Old Dec 12, 2012, 06:09 AM
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looking very nice Invert! That crows weave of yours should be handy for some of those complex curves.

Regarding that wax method, is it freecoat? I'm always looking for a superior method!
Yup, sure is. Its the first time i have uses it, so i hope it turns out good. It is definitely alot better than waxing and buffing! I was dreading that part of the F14 build.
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Old Dec 12, 2012, 03:17 PM
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Hey invert, what's the brand on that mold release you are using?

Can't wait to see the pulled parts.

Dennis
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Old Dec 12, 2012, 04:01 PM
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Hey invert, what's the brand on that mold release you are using?

Can't wait to see the pulled parts.

Dennis
Frekote
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Old Dec 13, 2012, 10:18 AM
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We did a test layup schedule last night. i'll be pulling it off the board here soon to test its strength. hopefully it works out well and we can start making parts this weekend
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Old Dec 13, 2012, 04:09 PM
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Guess what this means!:




If you havent figured it out, it means the test layup piece i did last night came out fantastic! Strength is great, weight is a little higher than i would like, but for the first one i can deal with that, as its easier to fix that than it be to light.

So the above picture is showing the first layer of glass going into place in the mold. Still have allot to do in order to infuse them this weekend.
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Old Dec 13, 2012, 04:55 PM
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Did you come up with an idea of how to pad the sharp corners? Or did the glass lay down nicely?
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Old Dec 13, 2012, 04:58 PM
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Did you come up with an idea of how to pad the sharp corners? Or did the glass lay down nicely?
The glass layed in nicely, but i also cut the rib sandwhich material to force the glass in to corner.
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Old Dec 13, 2012, 11:17 PM
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The ribs are going in before infusion? I'm now officially lost...
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Old Dec 14, 2012, 06:02 AM
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The ribs are going in before infusion? I'm now officially lost...
The foam tip ribs are a composite sandwhich material that will be infused during the process
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