Baffling

[markejackson02]

Have a new engine in a 1977 J model.  New baffling.  Have had high oil temps and was trying to get the baffling folded properly to make sure the airflow is good.  Sunday, I removed the cowling top to fold the baffling over.  The baffling tends to curl backwards so just dropping the cowling on means it's all messed up.  An hour later, using dowling rods and much colorful language, I finally got all the baffling folded properly with the cowling closed.

 

There's got to be a better way.  Anyone have any tried and true methods for doing this?

 

Thanks

 

Mark Jackson

N201TK M20J KAXH

[N201MKTurbo]

Do you have your corners fastened together? Where is it folding the wrong way?

[Cruiser]

large cable ties work great. Cut the head off and tuck the strap between the flexible baffle material and the metal with the pointed end sticking up above the baffle. When you lower the cowl it will fold the cable tie strap into the engine compartment forcing the baffle to fold the same way. It also adds resistance between the rivets and helps keep the baffle material from folding back because of air pressure when in flight. After a while, the baffle will take a set and the cable ties will no longer be needed.

 

Of course, if your baffles are worn this will not solve that problem.

[markejackson02]

Do you have your corners.... They are not. I thought about riveting the corners so they were folded inwards. Sent from my iPhone using Tapatalk

[kortopates]

These are what you need to tie the corners together: http://www.aircraftspruce.com/catalog/appages/bafflefastener.php?clickkey=3900 ;rather than rivets. Install them between the corners to create the bend in the correct position. Since the fastener will likely rub against the cowling, install the smooth flat side out towards the cowling.

[orionflt]

When I am installing new baffle material I will take high temp RTV and a spring clamp, I will put some of the RTV on the corners and position them to the proper shape, then i clamp them until the RTV drys. No rivets, screws or anything else to rub against and wear the cowling.

[bumper]

These are what you need to tie the corners together: http://www.aircraftspruce.com/catalog/appages/bafflefastener.php?clickkey=3900 ;rather than rivets. Install them between the corners to create the bend in the correct position. Since the fastener will likely rub against the cowling, install the smooth flat side out towards the cowling.

Less expensive, search <aluminum chicago screws> on Amazon etc. 3/16 is probably about right. You'll get 100 for not much more than the cost of 12 if they have anything to do with aviation. They should also be available at your local stationary store, as they are used for loose leaf binding etc.

 

bumper

[N201MKTurbo]

I just use a countersunk screw and a dimpled washer on the cowl side and a flat washer and nut on the engine side. It lays flat against the baffle seal and does not wear the cowl.

 

You might want to do a trial fit with an alligator clip or a paper clamp to get the correct amount of overlap.

[kortopates]

When I am installing new baffle material I will take high temp RTV and a spring clamp, I will put some of the RTV on the corners and position them to the proper shape, then i clamp them until the RTV drys. No rivets, screws or anything else to rub against and wear the cowling.

Great tip!

I try to put the fastener low enough on the material to avoid it from touching the cowl but sometimes there is no avoiding it. Will have to try this.

Sent from my iPhone using Tapatalk

[markejackson02]

The first flight with the baffling fixed resulted on temps that didn't get much above 50% of the green.

Going to visit the PMA dept at Lowes to get the correct screws.

Sent from my iPhone using Tapatalk

[KSMooniac]

Out of curiosity, where did you get the new baffling, and how much did it cost?  (You can PM if you don't want to post it publically)

 

I'm just about done cleaning and painting my baffling and it sure has taken a lot of time.

[markejackson02]

It came with the overhauled engine.  They r&r a lot of the sheet metal around the engine as well.

[markejackson02]

I ended up getting "Binding Post Screws" aka Chicago Screws.  Folded over the baffling and inserted the screws, which I topped with RTV sealant to prevent chaffing on the cowling.

 

 

[Guest]

Mark,

Nice clean engine installation!

Clarence

[bumper]

After applying a dollop of silicone caulk, you can smooth and blend it with your finger so it looks mo' better - - but first get your finger good and wet (spit works, haven't tried water). The silicone won't stick to your wet finger. Lick - repeat. :c)

 

bumper

[Hank]

After applying a dollop of silicone caulk, you can smooth and blend it with your finger so it looks mo' better - - but first get your finger good and wet (spit works, haven't tried water). The silicone won't stick to your wet finger. Lick - repeat. :c)

 

bumper

 

Spit works excellent for smoothing silicone; water only makes your finger wet, but won't prevent the silicone from sticking to it. I ran out of spit once and used a cup of water with bad results, so I drank it to create more spit.

[carusoam]

I've seen professional clean room installers using cases of silicone.

Their special spit was a mixture of water and liquid soap. Kept things from sticking to the fingers...

Not sure if it would off gas during the use of the clean room afterwords...

Best regards,

-a-

[jetdriven]

 

Have a new engine in a 1977 J model.  New baffling.  Have had high oil temps and was trying to get the baffling folded properly to make sure the airflow is good.  Sunday, I removed the cowling top to fold the baffling over.  The baffling tends to curl backwards so just dropping the cowling on means it's all messed up.  An hour later, using dowling rods and much colorful language, I finally got all the baffling folded properly with the cowling closed.

 

There's got to be a better way.  Anyone have any tried and true methods for doing this?

 

Thanks

 

Mark Jackson

N201TK M20J KAXH

 

 

That gap at the rear baffle to the top cowl is kinda large, ours kept blowing backwards, then we riveted a couple 2" wide by 3" long plates of 2024-T3 .032 amuminum on the inside of baffle seal material itself to stiffen it up. It hasnt blown backwards since.

[N601RX]

Liquid dish washing soap works well for smoothing PRC down. I assume it would work well with silicon also.

[Marauder]

Speaking of silicone. Other than scraping it off, is there anything that will remove it?

[carusoam]

I only remember putting it on by the case load...

A few panels were removed and replaced but the physical scraping stays in my memory...

Steady hand and a sharp knife.

Best regards,

-a-

[jetdriven]

Polygone will remove prc and silicone. You can get it from spruce