Front Baffle Seal Thickness w/ Doghouse M20C

[TCUDustoff]

Thread title says it all.  My calipers indicate thicker material than Aircraft Spruce sells and am curious if anybody knows what its supposed to be (3/32 or 1/8).   The Parts Manual I have just calls it a Baffle Seal without any additional details....so helpful!

Also, out of curiosity, has anybody used screw in Baffle Fasteners instead of the battle seal pop rivets that they sell?  Not sure if its worth the extra cost to make future repairs easier or not....

Thanks!

[RLCarter]

@GEE-BEE AEROPRODUCTS has really nice kits, I rolled my own before I knew about the above products. 

[TCUDustoff]

I'm trying to get this done in the next 10 days or so I can attempt to make it to Oshkosh...not sure their lead time...*eek* 

[Guest]

10 hours ago, TCUDustoff said:

Thread title says it all.  My calipers indicate thicker material than Aircraft Spruce sells and am curious if anybody knows what its supposed to be (3/32 or 1/8).   The Parts Manual I have just calls it a Baffle Seal without any additional details....so helpful!

Also, out of curiosity, has anybody used screw in Baffle Fasteners instead of the battle seal pop rivets that they sell?  Not sure if its worth the extra cost to make future repairs easier or not....

Thanks!

I used 1/8” thick fibreglass reinforced silicone 3” wide material riveted to the metal baffle with large area head pop rivets.  With the lower cowl installed and fitted lay the seal on the metal baffle, tucking the front edge into the groove in the cowl.  Mark the back edge of the tape to set the correct amount of overlap on the metal baffle. Remove the cowl, lay the seal on the metal baffle aligning with the marks and rivet in place.  Repeat for the top cowl.

Clarence

[Guest]

I guess I’ll have to surrender my maintenance licence and retire now.

Clarence

[Guest]

The original was a heavy black rubber material 1/8” thick fastened to the metal baffle.  Most of them are hard and brittle after 5 decades of service.

Strangely the OEM supplier is not list as Gee-Bee Aeroproducts.

Clarence

 

[cliffy]

I think we are confusing two different items

Baffle seals for something WITHOUT a dog house and the dog house seal LIP between the cowl and the dog house

I believe the OP is referring to the LIP seal which has to be stiffer than any "regular" baffle seal so as to avoid "blowing out" when airspeed and vibration is applied to the dog house pressure. 

It was original at about 1/8" stiff rubber Most are getting worn out now after half a century. I've seen normal baffle seal material used but it usually blows out of the "catch ring" in the cowl and lots of cooling is lost when this happens

I suspect many of those who have cooling problems with dog houses miss this item when trouble shooting the reason why they have high cylinder head temps. Its hard to see if the lip is placed correctly in the catch ring but it must be done for good dog house sealing. 

 

[Guest]

3 hours ago, cliffy said:

I think we are confusing two different items

Baffle seals for something WITHOUT a dog house and the dog house seal LIP between the cowl and the dog house

I believe the OP is referring to the LIP seal which has to be stiffer than any "regular" baffle seal so as to avoid "blowing out" when airspeed and vibration is applied to the dog house pressure. 

It was original at about 1/8" stiff rubber Most are getting worn out now after half a century. I've seen normal baffle seal material used but it usually blows out of the "catch ring" in the cowl and lots of cooling is lost when this happens

I suspect many of those who have cooling problems with dog houses miss this item when trouble shooting the reason why they have high cylinder head temps. Its hard to see if the lip is placed correctly in the catch ring but it must be done for good dog house sealing. 

 

Great minds think alike, were you “factory trained”?

Clarence

[cliffy]

No just 54 years as an A&P  Just received the FAA C Taylor Award a couple weeks ago

Always wanted to know how things worked or were built. 

[TCUDustoff]

Thanks all.  I think I am going to proceed with the thicker material and the pop rivets.  And to clarify, yes, this is the material between the metal doghouse and the cowling "lip ring."

[A64Pilot]

15 hours ago, cliffy said:

No just 54 years as an A&P  Just received the FAA C Taylor Award a couple weeks ago

Always wanted to know how things worked or were built. 

Congratulations, I’m impressed, really. Many won’t make the required time to be eligible as we started late, I would never make it if Military maintenance time didn’t count.

I think being the kid that always took things apart is pretty normal for mechanics, I think I was three when I found out that the wall outlet wasn’t meant to be disassembled by a screwdriver even though it looked like a screw head, my first trip to the emergency room.

[cctsurf]

2 hours ago, GEE-BEE AEROPRODUCTS said:

There are three baffle seals on the doghouse.

Agreed that there are seals (and I should think about getting a set from you), however, I don't think these are what is being discussed.  As far as I can tell, the original poster was talking about the seal around the front edge of the doghouse, where it meets the cowl.  Part # 11 in the attached image.  It was fairly hard rubber and mine was rotten from its 60 years on the plane.  Non-fiberglass seal doesn't seem to cut it.  As @cliffy said above,

23 hours ago, cliffy said:

I believe the OP is referring to the LIP seal which has to be stiffer than any "regular" baffle seal so as to avoid "blowing out" when airspeed and vibration is applied to the dog house pressure. 

I appreciate your work and assistance for the Mooney Community, @GEE-BEE AEROPRODUCTS.  I highly suggest that we in the Mooneyspace community realize the work that you have done for the community and purchase your products.  At the same time, it can hurt your reputation to get into a argument because there was a misunderstanding of the part in question.

Do you have a solution for that part?  Is there a better solution than 1/8" fiberglass reinforced baffle seal?  Thanks!

[Guest]

13 minutes ago, cctsurf said:

Agreed that there are seals (and I should think about getting a set from you), however, I don't think these are what is being discussed.  As far as I can tell, the original poster was talking about the seal around the front edge of the doghouse, where it meets the cowl.  Part # 11 in the attached image.  It was fairly hard rubber and mine was rotten from its 60 years on the plane.  Non-fiberglass seal doesn't seem to cut it.  As @cliffy said above,

I appreciate your work and assistance for the Mooney Community, @GEE-BEE AEROPRODUCTS.  I highly suggest that we in the Mooneyspace community realize the work that you have done for the community and purchase your products.  At the same time, it can hurt your reputation to get into a argument because there was a misunderstanding of the part in question.

Do you have a solution for that part?  Is there a better solution than 1/8" fiberglass reinforced baffle seal?  Thanks!

Well said!  
 

Clarence

[cliffy]

Nothing disparaging was intended   Only bringing into focus what was mentioned by the OP and NOT shown in the photos. Gee Bee products are top notch and that is not disputable.

Only issue was pictures and verbiage not conducive to clear information on what was being discussed   I had no idea Gee Bee even had the 3 lip seals for the dog house and now that I know   I may very well replace mine at the next annual (10 months). 

[Guest]

3 hours ago, GEE-BEE AEROPRODUCTS said:

I would be happy Clarence to send you a set of silicone seal in .093 and a set of silicone foam also

I also include 1/2 wide x 48 

2024 x .032 metal strips to sandwich the seal

this method of a back up strip only requires a pop rivet every two inches 

I stock

.032

.062

.093

the .032 is used for engine gaskets 

We have every model

Were tso on Franklin Engines

shown are the steel rule dies

we cut two thousand seals per hour

 

My wife already buys some of your products through our MSC.

Clarence

[carusoam]

Typing/writing is such a tough way to get soooo much detail across….

You guys are great!

Best regards,

-a-

[TCUDustoff]

8 hours ago, carusoam said:

Typing/writing is such a tough way to get soooo much detail across….

You guys are great!

Best regards,

-a-

Concur!  I didn't mean to open a can of worms, and it looks like I did   Sometimes with these older airplanes, it's tough to find an answer; unlike a C-172, most mechanics aren't super comfortable or familiar with the peculiarities of our aircraft and I am glad we have this forum to help each other out!

I haven't ordered anything yet and, just to clarify @GEE-BEE AEROPRODUCTS, you can provide both the front-most doghouse lip seal (#11 in the parts manual diagram posted by @cctsurf) as well as upgraded replacements for the felt that seals the starter/generator at the front? I knew you sold kits for the later, more traditional style baffling that seals to the top cowling but didn't realize you did something for our older aircraft. 

Thanks!

[cliffy]

"The future Is fuel cell hydrogen" 

 

YES   Xs 1000%