M20F overhead vent cover replacement

[Vance Harral]

Airplane is a 1976 M20F - one of the late-model Fs that's an "almost J", interior-wise.  An unfortunately-timed bump of turbulence this weekend resulted in one of the partners punching his thumb right through one of the 40-year old, brittle, ABS plastic vent covers.  We're pondering repair options.

Seems like just last week I saw a For Sale post here, where someone was selling four of these things.  Unfortunately I can't find the post now (perhaps it was taken down when a deal was made).  If whoever was selling them still has them, please PM me, as we're freshly in the market.   I'd at least like to know where they came from.  I'm guessing Plane Plastics, though their online catalog doesn't specifically show vent covers.

I refurbished the interior on our airplane about 10 years ago, including repairing some minor cracks in the vent covers.  But it's been so long I can't remember the details of how to get them off for repair or replacement.  My recollection is they only come out after you take down the headliner panels, and that the headliner panels won't come out without first removing all the interior side panels.  I hope my recollection is poor or someone knows a trick to avoid this.  Our last SB208 inspection was pretty recent, so I'd rather not have to pull every dang interior panel if it's not necessary.  I don't even mind the time so much, but every R&R is just another opportunity for cracking.

Tips or advice from anyone who's been through this recently are much appreciated, thanks.

[Yetti]

It's more than the headliner.  You also have to get to the nut on the backside of the knob. Which means pulling down the box that they are mounted to. Which did not look like an easy task. I elected to leave mine unpainted when I painted the plastic.  The thought was to build an in the plane paint tent and do them.  Same for the baggage compartment.

[Vance Harral]

29 minutes ago, Yetti said:

It's more than the headliner.  You also have to get to the nut on the backside of the knob.

Ugh, a neuron just fired.  I remember now, you are correct - there is a nut on the back side.  I was somehow able to get a ratcheting box wrench back there to remove the nut.  Not so bad when the vent is already broken, but more precarious when trying to re-install new/newly-repaired parts.

Thanks for the reminder, despite it being bad news...

[Yetti]

I was considering a properly bent wrench would work.

Edited April 11, 2016 by Yetti

[Marauder]

Since we are talking 75 and 76 Fs, has anyone installed eyeball sockets in place of these?

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[Yetti]

The eyeball vent part would be easy.  Some aluminum, some silicone and some pop rivets.  The trim piece would be the harder part.  Maybe a plastic insert that is painted the same as the plastic double taped to the headliner.

[Marauder]

The eyeball vent part would be easy.  Some aluminum, some silicone and some pop rivets.  The trim piece would be the harder part.  Maybe a plastic insert that is painted the same as the plastic double taped to the headliner.

I know John Breda put an Ovation interior in his plane. Wonder if he did the eyeball and associated trim.

[Brandontwalker]

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[Marauder]

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Alright! Fess up! What did you do? Where did that come from?

[Hector]

Airplane is a 1976 M20F - one of the late-model Fs that's an "almost J", interior-wise.  An unfortunately-timed bump of turbulence this weekend resulted in one of the partners punching his thumb right through one of the 40-year old, brittle, ABS plastic vent covers.  We're pondering repair options.

Seems like just last week I saw a For Sale post here, where someone was selling four of these things.  Unfortunately I can't find the post now (perhaps it was taken down when a deal was made).  If whoever was selling them still has them, please PM me, as we're freshly in the market.   I'd at least like to know where they came from.  I'm guessing Plane Plastics, though their online catalog doesn't specifically show vent covers.

I refurbished the interior on our airplane about 10 years ago, including repairing some minor cracks in the vent covers.  But it's been so long I can't remember the details of how to get them off for repair or replacement.  My recollection is they only come out after you take down the headliner panels, and that the headliner panels won't come out without first removing all the interior side panels.  I hope my recollection is poor or someone knows a trick to avoid this.  Our last SB208 inspection was pretty recent, so I'd rather not have to pull every dang interior panel if it's not necessary.  I don't even mind the time so much, but every R&R is just another opportunity for cracking.

Tips or advice from anyone who's been through this recently are much appreciated, thanks.

Vance, I bought the set of 4 that were on sale here a couple of weeks ago. All four of mine are in very bad shape or I would let you have one. I have yet to replace them. After looking at the task I thought it might be best to tackle it during annual.

[Brandontwalker]

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Alright! Fess up! What did you do? Where did that come from?

Sounds like a loaded questions. Your thoughts first.

[cnoe]

Check out Jetdriven's vent conversion. Sweet!!! May find pics in a search. Out of a Chevy Tahoe if I remember correctly.

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[Vance Harral]

2 minutes ago, Hector said:

Vance, I bought the set of 4 that were on sale here a couple of weeks ago.

Hector, thanks for confirming I wasn't just imagining that for-sale post.  Absolutely no hard feelings about you snapping them up.  Do you recall if the seller got them from Plane Plastics?

[cnoe]

Found the pic I was searching for. Pretty sure these were from a Tahoe.

 

[Brandontwalker]

2 minutes ago, Hector said: Vance, I bought the set of 4 that were on sale here a couple of weeks ago.

Hector, thanks for confirming I wasn't just imagining that for-sale post.  Absolutely no hard feelings about you snapping them up.  Do you recall if the seller got them from Plane Plastics?

I can attest to the fact that plane plastics does not sell the vents.

[Hector]

2 minutes ago, Hector said: Vance, I bought the set of 4 that were on sale here a couple of weeks ago.

Hector, thanks for confirming I wasn't just imagining that for-sale post.  Absolutely no hard feelings about you snapping them up.  Do you recall if the seller got them from Plane Plastics?

I can attest to the fact that plane plastics does not sell the vents.

He did not say and I did not ask. They looked like brand new parts but I don't know for sure.

[Vance Harral]

1 minute ago, bluehighwayflyer said:

They were OEM vents from my personal stash. Practically now made of unobtainium, unfortunately, I believe.

Thanks for the update, Jim, even though it's bad news.  At this point it's almost worth wondering if 3-D printing is the best answer.  The printing part might go pretty smoothly, but I don't know the first thing about how to build a model.  Maybe someone near me has a 3-D scanner that could scan the remaining good ones.

[Yetti]

For recreating the original vents maybe a silicone mold process.  http://www.tapplastics.com/product/mold_making_materials/mold_making_supplies/tap_silicone_rtv_mold_making_system/61

If there was a big enough market, making some molds out of alum would be best.

Hobby king had a 3D printer for $300.

A job and too many other projects helps me know my limitations

[N601RX]

9 hours ago, Vance Harral said:

Thanks for the update, Jim, even though it's bad news.  At this point it's almost worth wondering if 3-D printing is the best answer.  The printing part might go pretty smoothly, but I don't know the first thing about how to build a model.  Maybe someone near me has a 3-D scanner that could scan the remaining good ones.

If someone has enough of an original to go by I can make a 3D model and will make it available to everyone wants it.  I can also print out a prototype and post some pictures.  It may have to have a little more thickness and structure on the back side than the original.

Here is a recently modeled and printed Lycoming valve wobble test fixture.

 

[orionflt]

I like it, 

Brian

[rbridges]

even with mooney up and running, they're not available from the factory?

[jetdriven]

I have 3 good used factory vents like that.   I did make some stuff and put Tahoe vents I which were a nice improvement.  

Them I converted it to the dorsal fin air inlet system which uses wemac overhead vents. 

[carusoam]

Wemac will be able to close better than the nicer looking Tahoe vents...  A winter in the NE consideration...

Best regards,

-a-

[Bob_Belville]

Talk to the parts manager at LASAR. They acquired a lot of used Mooney parts inventory a couple of years ago. FWIW, your covers look just like mine - '66E - so I don't think you'll have to find something from exact make and model. I took everything down and painted it a few years ago. Not a big deal once you figure out how it's assembled.

[M20F-1968]

In answer to you question, the interior of my plane is all Ovation parts, with some cut and paste fiberglass work to make them fit into the F model body length.  You can do anything you want when remodeling with fiberglass.  Pictures are in my gallery.  I am just about to finish all of the interior work and will post some pics. 

If you wanted to replace the old style vents with Wemac vents, you probably should fashion a funnel type arrangement on the back side of the vent to act as a venturi or you may loose a lot of air to the smaller vent size.

John Breda