Defrost and Sealing the seams?

[Pebcak]

Tonight I got a wild hair and about 45 minutes on my hands.  I went out a proceeded to pull my dash apart and find out why my defrost hasn't worked since getting the truck.  Through hours of reading and wisdom from people here, I was sure it was the hinge on the defrost in the dash. And it was.

Luckily I was able to get it all out and looked at by taking out EVERY screw and bolt and the whole thing was so easy to move around to get the vents out with little effort.



No hinge on either picture



Here's a picture of the dash "after" I put the instrument cluster back in, four bolts on the corners and the two screws at the CB speaker mount.  It should stay in place until I get work done.



Below is the duct work out of the dash.  All of them are coming apart at the seams.  It looks like the plastic is melted together a little and then stapled at intervals.  Also, the Defrost vents didn't even look like they were connected to the main vent.  It looked like there was a 1/2" gap between the two.  And idea why?



I'm thinking about sealing all the seams with the one of the following: spray rubber, silicone, furnace tape (aluminium tape) or epoxy.  Or even a combination of them.   What is the opinion of people here of what I can use to get all of this done good enough so I don't have to worry about it again in 5 years?

And last but not least, I had my "Outdoor Helper" with me while working.  At one point he was trying to get INTO the dash as I was working!!  Would be nice if he could hold a screwdriver....  

[PetesPonies]

If the seams will close up, I would put some RTV in there and install some pop rivets to hold everything together better.

[Gary Lewis]

Good job.  

I like the ideal of tape where you can on the joints.  And the pop rivets are a good idea as well.  But I don't know if you can get epoxy to hold to that plastic.

[ctubutis]

I know how you guys feel about sealing the seams, I used to feel & operate in the same fashion.

And then I asked myself - why bother? Sure, it will leak a bit but who cares, it's only air. Spend the time on something else with better return is how I ended up feeling. Staples, rivets, screws, something to help keep the snap-together pieces attached, but sealing up each and every little leak isn't going to make any sort of detectable difference IMO.

As for the gap between the defrost output and the lower assembly, they first used a "gasket" made of sponge-like foam rubber that of course dry-rots and turns to dust. In later years (at least in 90s sedans such as the Taurus SHO) it was made of more substantial material that had an almost tar-like composition (if that makes sense).

[kr98664]

Pebcak wrote

I went out a proceeded to pull my dash apart and find out why my defrost hasn't worked since getting the truck.

The broken hinge is for the panel vent door, only found on factory AC trucks. Details here on how to fabricate a replacement that will outlast you, although for your sanity I'd skip the part explaining how to easily do it without removing the entire plenum:

How to replace the panel vent door hinge


If you'd prefer the stock plastic hinge:


Bronco Graveyard

[Gary Lewis]

I agree with Chris. So, when I said to use tape, I meant on the joints where the foam has gone away. And the pop rivert were to pull parts together that have warped or gapped. Just get it 90% sealed, but not perfect.

[ArdWrknTrk]

West System Gflex epoxy will bond PP and PE plastics together permanently.
Comes in thickened paste and thick syrup forms.
Just follow the prep instructions about sanding the surface clean and oxidizing the bond area with a very quick pass of a propane torch.
Clothespins always worked for me.

You can also use this to bond in the hinge if you like.


Check out their video of cutting a kayak in half with a chainsaw and then the repair.

[ArdWrknTrk]

If I were not going to use foam weatherstrip tape to seal ducts to each other I would use the rubber flashing tape from 3M.

This stuff is meant to seal plastic window and door flanges to Teflon housewrap (Tyvek) and sticks like crazy while allowing quite a bit of stretch.

PM me your address if you have time to finish and I'll send you a few yards of the wider stuff that you can slit in half.
No need to spend $60-100 on a 75' roll for a little job like this.

[Gary Lewis]

I’ve never see that stuff. Cool!

[ArdWrknTrk]

Gary, if you want me to send you some tape lmk.
I think I have 7 & 9" widths, though 5 (in half) might be better for your purposes.

It is very difficult to work with in that if it touches *at all* you are not going to get it off.
And if it touches *itself* fuggetabotit.

[ArdWrknTrk]

Here's a Gflex video




https://m.youtube.com/watch?v=WCS0qrD3MQY

[Gary Lewis]

Jim - I'd love to have some of it as I'd use it on Dad's truck when the time comes.  But, that means there's no hurry as the time isn't coming any time soon.  

[Pebcak]

I'm going to look into this also!  So many choices...  I've got all the duct out and in the house so I can work on them rain or shine right now.

[Pebcak]

I was sitting watching my wife ride her horse and a great idea popped in my head.  I made hinge out of tie wraps!  It's something I had done before when I was in the military and in Iraq and needed to fix a hinge temporarily.  It ended up being a permanent fix though.

Here's the door with the hinge broken.



I drilled four holes on the vent side making sure I didn't hit anything behind or potentially block something with tie wraps inserted.



Next was the four holes on the door and inserting the tie wraps.  I had to make sure that the hole was big enough for the tie wrap to slide through but still snug and the head to stay in place.



Slllloooowwwwllllyyy I tightened all of the tie wraps until the door was even on all sides.



Lastly I ran a couple tests before clipping the ends.  

Here is the video of it all working.

Video

One step closer!!

**Ok, how can I rotate the photos in the post?  They rotated somehow when uploaded.**

[Gary Lewis]

That is ..... innovative.  Interesting.  Novel.  

As for rotating the pics, if you open them in an editing app and then save them it usually fixes them.  You may have to play like you cropped it to be able to save it, but most apps have the smarts to see how the camera was held and fix the pic.

[ArdWrknTrk]

Gary, I found the remnants of a roll of 4" flashing tape.
You could slice this in half and wrap any joint.

It WILL remain sealed!

I probably have your address, but please pm or email, or text it to me again anyhow.
Thanks

[Gary Lewis]

Jim - Email sent. Thanks!

[ArdWrknTrk]

Yeah, what I thought...

I'll try to get it out tomorrow.

This is extremely strechy *and* sticky.
Practice first because it is not forgiving when it makes contact.
 
Easily enough for you to share as well.

[Gary Lewis]

I’ll be happy to share. Thanks!

[Pebcak]

I did rotate it twice and no matter what I rotate it as it still posts the same way.  Weird....

Oh well, everyone can lean their head sideways. *Edit* It did the same thing in the Gallery too. *Edit*