Universal Cowling

[FS]

Re: Universal Cowling

The challenge is to cleanse the oil from them to make the repairs stick.

How did you overcome that challenge? I had a repair done by an autobody place and it's not quite sticking anymore. Before I try to have it done again I'd like to degrease the thing myself (since it wasn't done properly by the pros).

 

[kgrant]

Re: Universal Cowling

How did you overcome that challenge? I had a repair done by an autobody place and it's not quite sticking anymore. Before I try to have it done again I'd like to degrease the thing myself (since it wasn't done properly by the pros).

I flushed the lower cowling for about two weeks in my hangar. Used Dupont Final Klean 3901s. It's a very strong flash cleaner used in the DuPont Paint process for final prep. (dating myself, Dupont is Axalta now -- we're PPG at work.) It requires very good ventilation. Here's a link. Most auto body supply distributors know it.

I seem to remember starting with my usual cleaner, RAM. Flush Flush Flush. The first week, you'll think it's never going to end. The cowl probably loses a few pounds of oil.
k

 

[Jamesdub]

Re: Universal Cowling

Morning Carl,

First thanks for the 'cordial' and informative response. I was sure you'd blew through my post like a Fla hurricane. I'm impressed!!

I've sat through at least two of your financial model classes and I got it the first time and fully understand the economics involved.

If you are tracking interested parties, I'd be interested in a carbon fiber unit.
Q: Which is considered the stronger of the two materials? Carbon or Glass?
I could really use the weight reduction being I have that metal Hartzell hanging way out on the front . . .

 

[carllee]

Re: Universal Cowling

Morning Carl,

First thanks for the 'cordial' and informative response. I was sure you'd blew through my post like a Fla hurricane. I'm impressed!!

I've sat through at least two of your financial model classes and I got it the first time and fully understand the economics involved.

If you are tracking interested parties, I'd be interested in a carbon fiber unit.
Q: Which is considered the stronger of the two materials? Carbon or Glass?
I could really use the weight reduction being I have that metal Hartzell hanging way out on the front . . .

Once I've finished the work I'm doing on the latching system I'll post the cowling as an "available" part on my website, so you'll be able to inquire about, and I'll be able to track interest in it there.

The carbon is superior in every respect, weight, strength, fire resistance, longevity, rigidity. It is amazing stuff! If you look down the surface of one of the original cowls it is very wavy (sadly this is true of the 114B's as well). This is due to the poor quality of the mold, and from the expansion and contraction of the material. The cowl made from carbon fiber is as smooth as glass, and will remain that way indefinitely.

Fiberglass is what the current cowl is made from and what your current cowl would be repaired with. To really "repair" your current cowl would be no different than making a new one, and as Kelly pointed out probably best done by someone not involved in aviation. You might want to have a discussion with the person that signed off your last annual, and see if they would prefer a part made by a local auto body shop, or a part made from a superior material, that he could inspect, fit and finish. Not sure what his response would be. He might prefer you repair your existing cowl?

I'm happy to work with you. I can have parts made to exactly replicate the existing side scoops, and light nacelle. I just can't afford to make a complete other mold, so these would have to be cut-in after the fact.

 

[N4843W]

Re: Universal Cowling

I should not "jinx" my cowling, but I must be lucky and unusual. My Cowling, 40+ year old, looks great, inside and out. No patches or repairs. Solid. No evidence in log books that it was ever replaced. Seems to defy logic. I think it is just pure dumb luck.

Having said that, I'd be likely to buy yours anyway, Carl! sooner or later ...

 

[Jamesdub]

Re: Universal Cowling

I'm happy to work with you. I can have parts made to exactly replicate the existing side scoops, and light nacelle. I just can't afford to make a complete other mold, so these would have to be cut-in after the fact.

I'm my quest to transform her into a 'B', those are the parts I want to get rid of . . ha ha . .

 

[carllee]

Re: Universal Cowling

I should not "jinx" my cowling, but I must be lucky and unusual. My Cowling, 40+ year old, looks great, inside and out. No patches or repairs. Solid. No evidence in log books that it was ever replaced. Seems to defy logic. I think it is just pure dumb luck.

Having said that, I'd be likely to buy yours anyway, Carl! sooner or later ...

Hi Scott,

If I said the word "all" I shouldn't have because they are not all bad. But, fiberglass work is
complicated, and the results are dependent on so many factors that I believe "all" are suspect. Some of the variables include:

1) Temperature
2) Humidity
3) Product expiration dates
4) Skill level
5) Material quality
6) Cure method
7) Proper mixture of resin and catalyst

I have no doubt that some of the cowls out there were done well, but in general, the 1970's are not known as a very good era for fiberglass products, and, for the most part, the quality of our cowlings reflect that. Also, our cowls are fairly large items - a lot can go wrong when working with such a large part. My fiberglass guy refuses to work on certain days. Even though he is working inside in a controlled environment he won't work on certain days because the potential for the conditions to turn bad is too great.

Because we are faced with so many variables, and unknowns, no amount of repair work on the original cowls can answer all of possible questions.

Again, I'm back to my original intention, like everything else I do, I wanted a new cowl for myself. If anyone else can benefit - Great! Happy to help! I'm not trying to criticize anyone else's airplane, and I'm sure many of the existing cowls out there are just fine, and will last another 40 years.

 

[Pchaser]

Re: Universal Cowling

Carl
Are the carbon fiber cowls hand layer up or vacuum bagged?
How many layers of carbon fiber?
Is it straight carbon fiber or carbon/fiberglass?
Any high density foam or other products used for backer plates or stiffener ribs?
Polyester Or epoxy resin?

 

[carllee]

Re: Universal Cowling

Carl
Are the carbon fiber cowls hand layer up or vacuum bagged?
How many layers of carbon fiber?
Is it straight carbon fiber or carbon/fiberglass?
Any high density foam or other products used for backer plates or stiffener ribs?
Polyester Or epoxy resin?

Hi Fred,

1) Hand Layer
2) 3 overall, 5 around the landing gear nacelle, and cowl flaps, 4 down the center of the top cowl, 5 around the rear of the lower cowl where it attaches to the fuselage, 5 around the flange behind the spinner, 5 on the flanges where the top and bottom cowls meet, 5 on the reinforcement structure attached to the top cowl in front of the firewall + the overall 3 for a total of 8.
3) Carbon Fiber
4) Vinyl Ester

 

[N1049j]

Re: Universal Cowling

I've produced 2 of them already, and are fitting them now I'm not sure if Transport Canada will allow you to produce your own parts though?

Carl I am a US citizen and the plane is based in Taunton Massachusetts where you would ship it.

Chuck

 

[carllee]

Re: Universal Cowling

Carl I am a US citizen and the plane is based in Taunton Massachusetts where you would ship it.

Chuck

Ok, cool

 

[Gonzalo Paez]

Re: Universal Cowling

Great project !! I am in for my 114.


Saludos.

 

[Chip]

Re: Universal Cowling

Wow Carl, this looks amazing. My lower has been patched and modified too many times. I’m ready for a new one.

 

[wilkinsb44]

Re: Universal Cowling

I would definitely be interested. Can you give a wag on price and when they may be available?

 

[carllee]

Here's something to think about as you're hurling yourself through the atmosphere at 150mph. Each of your wing tips is held in place by 17 fasteners, your stinger is held in place by 12 fasteners, but your upper cowling, one of the largest single sections of your air-frame, is held in place by just four .060" +/- .010" latch pins, and 2 two rusty 1/4" dzus fasteners!

 

[Pchaser]

Here's something to think about as you're hurling yourself through the atmosphere at 150mph. Each of your wing tips is held in place by 17 fasteners, your stinger is held in place by 12 fasteners, but your upper cowling, one of the largest single sections of your air-frame, is held in place by just four .060" +/- .010" latch pins, and 2 two rusty 1/4" dzus fasteners!

I smell a unveiling coming!!!!

 

[carllee]

This puts eight AN4 bolts in tension using four quick release levers. Roughly 6 times stronger than the original latching system, but just as easy to release. The latch handle could be engraved with a Commander logo, or used to mount a barrel lock, keyed to match your ignition.

 

[carllee]

I smell a unveiling coming!!!!

Yes, but I have no idea how to make it show up on the "New posts" list. Am I missing something?

 

[gmores]

Yes, but I have no idea how to make it show up on the "New posts" list. Am I missing something?

It was there. Keep in mind that your own post won't show in your own view of New Posts.

 

[rringgold]

Carl, that looks first class!