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  #331  
Old 12-02-2015, 03:43 PM
crabandy crabandy is offline
 
Join Date: Jan 2010
Location: Ottawa, Ks
Posts: 2,309
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The plenum I received from BillL fit my standard Van's baffling like a glove once I removed my black baffle material.





Unfortunately there seems to be some difference in the vertical position of the front of the plenum. My baffling for the Van's cowling is trimmed to a tight 1/2 inch all the way around, that leaves about 3/4 inch of metal baffling above the front corner of the #1 cylinder. Seems the Sam James cowling must have more vertical clearance in the area, Bill was nice enough to send me a template of his front baffle for the #1 cylinder which is approximately 3/4 inch taller than mine. In order to keep 1/2 inch clearance from the top cowling I had to lower the front of the plenum.



The piece of paper shows the bottom of the top cowling with a 1/2 inch clearance line, the plenum is well below that.



I was hoping to possibly trim the outboard front corners slightly, but I think there is just too much variation in the shapes between the Van's and Sam James cowling.





Although this doesn't look like it's going to work for my installation, I think BillL's Plenum is a great product for anyone installing a Sam Jame's cowling. His product, price and service was unbeatable.
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  #332  
Old 12-02-2015, 04:33 PM
crabandy crabandy is offline
 
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More destruction, man I was so proud of those ramps. I used foam/glass to continue the spinner curve of the cowling onto inlet ramps so the black baffle material had a nice smooth transition to push against. I didn't have the heart to throw them away...



The top cowling is cleaned up and block sanded, I never smoothed the surface originally and just roughed it up and covered it with epoxy. I'm thinking of using the top cowling as a mold for making a plenum but it's going to take some work first. I would rather build the plenum over the existing baffling, but I can work with the top cowling at home in a semi-heated garage (and in the house next to the woodstove when the wife is at work!). Here's a pic before the first thin coat of filler/micro.

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  #333  
Old 12-02-2015, 08:40 PM
Reflex Reflex is offline
 
Join Date: Jan 2015
Location: Kansas
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Andy,

You're welcome to borrow a little room from me. I normally keep the shop around 60 degrees. I'm guessing I'm 20 - 25 minutes north of you.

I'm just starting on a 14. Could use a bit of advice, tutelage, and would share a cup of coffee.



Send me a PM if you're interested.

Fred
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  #334  
Old 12-14-2015, 10:58 AM
crabandy crabandy is offline
 
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Location: Ottawa, Ks
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I figured the inside of the cowling would be a good test bed for trying drywall mud as a pinhole filler, I figure the extra heat should help expose anything and if it does the areas will be under the cowling. The inside of the cowling was coated with raw epoxy but never properly block sanded, I added a thin coat of filler and sanded smooth. I then spread drywall mud on with a rubber scraper, I added a second coat later just smooshing it around the surface with my hands. As expected it sanded of very easily, it seemed to fill the little scratches, small and large pinholes well.






I carefully cleaned it up and squeegeed on a coat of epoxy primer. I wet/block sanded this and then sprayed a coat of epoxy primer that I also wet sanded.



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  #335  
Old 12-14-2015, 11:09 AM
crabandy crabandy is offline
 
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I buffed on a layer of wax, and a couple coats of PVA. This was my first time using PVA and I sprayed my first coat on too heavy, I had some runs and drops on the vertical surfaces. I used AEROPOXY and laid up 4 layers of 9oz glass, so far this is one of my better fiberglass pieces. I covered the layup in peel ply and topped it off with scrap glass to soak up any extra resin,l. I tried really hard to squeeze out all the extra epoxy and air bubbles while it was between sheets of plastic before I applied the epoxy infused glass to the cowling.


It half cured in the garage at 65-70 last night .I'm trying for a 110* cure with my wood stove and instant read thermometer.

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  #336  
Old 12-14-2015, 05:32 PM
Aero_Octaveus Aero_Octaveus is offline
 
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Location: Edmonton, AB
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Quote:
Originally Posted by Reflex View Post
Andy,

You're welcome to borrow a little room from me. I normally keep the shop around 60 degrees. I'm guessing I'm 20 - 25 minutes north of you.

I'm just starting on a 14. Could use a bit of advice, tutelage, and would share a cup of coffee.



Send me a PM if you're interested.

Fred
Fred... Does that extend to Canadians? I'll come use your shop!!!
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  #337  
Old 12-17-2015, 06:00 PM
crabandy crabandy is offline
 
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Location: Ottawa, Ks
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Another RV guy swapped me BillL's plenum for an RVBit's plenum, it fit the Van's cowling slightly better but still too flat on the outboard edges to suit me.





I wish I could fit this on the airplane, but this lets me work from home so to speak. I roughly trimmed the plenum to the metal baffling, now to try to make some flanges. The aft baffle sits at an angle, I marked/sanded this angle on some foam and glued it with micro in place on the cowl to hold the correct shape. I also formed additional foam blocks for the forward flanges. This stiffened my floppy plenum up considerably, it may still require additional strength.



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  #338  
Old 12-17-2015, 06:13 PM
crabandy crabandy is offline
 
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I'm playing around with making my own round inlets for the front of the cowl. Time to fire up my Wife's router for the first time, It was her not so popular Christmas present several years ago.......go ahead and laugh I really should've known better....
I ordered a circle jig and several router bits, the first cut was on the circle jig itself to make room for a 7/8 core box bit.



I also ordered a chunk of HDPE plastic to route shapes into, fairly cheap and nothing is supposed to stick to it. I cut my first groove, Man this thing makes a mess!



I filled the grove with a wet mixture of West Systems and Flox topped with a single ply of 8.9 oz scraps, I set a cheap plastic cutting board on top weighted down to try and flatten things out. It worked pretty well, nice flat surface and just a little bit of prying popped it right out.





My original impression is that the ring is too large for my cowling, 6 inch inner diameter is just shy of 8 inch outer diameter. I want to play with making a smaller radius on the inside of the ring and maybe a 5 1/2 or 5 3/4 diameter opening.
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Last edited by crabandy : 12-17-2015 at 06:16 PM.
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  #339  
Old 12-17-2015, 10:12 PM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
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Andy,

I tried to make flanges like you have and it did not work well - the cause was the engine twist. The engine is twisted to the right side, although the crank flange is in the center.

The baffle width is 31.5" wide and parallel. The sides are perpendicular to the back baffle too. But the engine is twisted.

If your current path does not flow well, You might consider taking the insulation and fastening it to the baffles, then placing the cover over the top, when it fits in place, you can check the clearance to the cowl, then glue to the insulation.

If your path works, then. . . . (like Roseanne Rosanna-danna ) never mind.
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  #340  
Old 12-17-2015, 11:37 PM
crabandy crabandy is offline
 
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Location: Ottawa, Ks
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BillL, in my best New York accent.....
"What are ya tryin' to do, make me sick?!

I believe you are right in fastening the foam to the baffles and then gluing the plenum top to the foam, I wish I would have thought of that first. As it is I'm hoping to see how it fits or doesn't fit tomorrow. Oh well it's only fiberglass, I can always grind it off make a mess and do it all over again.
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