[DesertXL]

The hole is on the bottom. Should I use fiberglass resin for the hole repair?
Should I drill the rivets out of the pressboard and remove it? The plastic is in good shape so I will clear coat it. Any suggestions on which type of clear coat? Brush or spray?
As Always Thank you!

Howdy Michael Rosepal,

On the hole, and yuppers I wasn't orientating it properly in mind and thought it was atop, I would use fiberglass resin and cloth since the hole is a decent size hole and the cloth will keep it from cracking. As for drilling out the rivets, it's a crap-shoot because you have the propensity to do more damage that way, especially if they are those rosette style rivets. I haven't paid much attention to a heater only 3rd gen full size Ford because our chosen cars are factory HVAC ones and the heater only parts car systems were just pitched. I am currently working on the interior side HVAC plenum and I had to drill out countless rosette style rivets and even being careful it's easy to cause more damage. You'll have to make the decision based on your confidence.

For the clear coat, you can use a rattle can variety for convenience as your sealing it and not building up a thick layer.

I forgot to answer your question on the blower, I apologize it was very late/early morning when I read through it and my brain was shutting down. I would bead / coal slag / sand blast that blower wheel then spray paint it. If your coats are reasonably even it will be in balance. Also I would strongly encourage you to go through the motor and if anything grease/oil the bushings as they are going to be very dry by now. This also gives you a chance to check the brushes and commutator as well as dress it off. This is important because the blower is buried under the wing and you do not want to have to service that again, at least in your lifetime

To Actions point about a drain hole, even though yours in heater only. I did notice on the factory HVAC versions of your car the heater core plenum has a small drain hole in it. I would assume this is for two reasons; first being since it's right in the fresh air inlet from the cowl any water splash that makes it through the inlet hole and through the heater core needs to drain out the engine bay side so it doesn't end up in the interior cabin. Secondly in case the heater core develops a reasonable small leak it can also drain out the engine bay side rather than the cabin. It's about 3/16" hole. If yours doesn't have one it may be a good idea to add one in the low point.

Just thoughts.

Cheers

 

[Action]

If the circled hole is not intentional, yes close the hole.
And as DesertXL pointed out, the material used to create the plenum is very old at this point. A coating would be a prudent thing to do.

If it were me, I would want a stock look. So, I might be inclined to coat the interior with something black. The exterior I would want some low gloss clear coating.

Action

 

[Michael Rosepal]

Action and DesertXL thank you for the help. I appreciate both of you!

 

[DesertXL]

Action and DesertXL thank you for the help. I appreciate both of you!

You're most welcome. Anytime.

Cheers

 

[Michael Rosepal]

I am going out to get a fiberglass repair kit. I do have JB weld putty and epoxy for plas from another repair. Would that work on the repair or will it not bond as well?

 

[DesertXL]

I am going out to get a fiberglass repair kit. I do have JB weld putty and epoxy for plas from another repair. Would that work on the repair or will it not bond as well?

Hello,

If you have those handy, they will probably work just fine as the hole isn't too big. Using a cloth mesh would help strengthen whatever resin you use.

Cheers

 

[Michael Rosepal]

Hello,

If you have those handy, they will probably work just fine as the hole isn't too big. Using a cloth mesh would help strengthen whatever resin you use.

Cheers

thank you

 

[Michael Rosepal]

Do I need to put the tape back on the blower motor? If so what type of tape?

 

[DesertXL]

Do I need to put the tape back on the blower motor? If so what type of tape?

Hello,

Might you have some pictures of the blower motor? The reason I ask is the heater only blower motor is different than the factory HVAC one and I've never dealt with a heater only motor. In order to answer your question technically I would need to see if the tape is keeping moisture out from a realistic opening or series of openings say from a chamfered field laminated frame.

Cheers

 

[Michael Rosepal]

The tape went over the seam and the width of the tape covered the 2 lines.

 

[Action]

Hmmmm I have never seen tape in that location.
However I have not had that many full sized Fords from that era

I would guess the tape is to keep moisture out of that joint. And at this point it may not make much difference.
Unless your ride will be a daily driver, the most amount of water it will ever encounter is a car washing.

With that said the humidity in your area is far higher than Phoenix or ABQ.

Action

 

[Michael Rosepal]

Not sure what covered this opening, can’t find any plugs this size. Any suggestions?

 

[DesertXL]

View attachment 51142


The tape went over the seam and the width of the tape covered the 2 lines.

Hello,

The seam looks pretty well sealed on its own, but I would probably use a couple rounds of 2" wide PVC tape or even something like Gorilla tape. The blower motor on heater only 3rd gens were under the wing and above the apron so getting water in/on it was a long shot. But doesn't hurt to cover that base since it's out of the car. The factory HVAC blowers have forced air cooling through them, so any water vapour inside the motor didn't last long. The heater only motors are such low torque/power motors forced air cooling wasn't needed.

Cheers

 

[DesertXL]

View attachment 51143
Not sure what covered this opening, can’t find any plugs this size. Any suggestions?

That's the opening for access to the convertible body mount. The non convertibles have two such openings, no plug(s) go here as this is a brace to the exterior of the floor pan.

Cheers

 

[Michael Rosepal]

That's the opening for access to the convertible body mount. The non convertibles have two such openings, no plug(s) go here as this is a brace to the exterior of the floor pan.

Cheers

Thanks

 

[Michael Rosepal]

DesertXL against your advice I took the heater box apart. Went very slow and was able to not damage the holes or parts. The inside was very dirty and did not want to upset the pressboard with to much water. The pressboard has a little damage from age, should I repair it or just let it be? Sending another picture of the damage.

 

[Michael Rosepal]

 

[Michael Rosepal]

Also will aluminum pop rivets work okay to reattach? I also noticed there was some sort of form a gasket on there to seal it. So I’ll also be applying that to it.

 

[DesertXL]

View attachment 51160
DesertXL against your advice I took the heater box apart. Went very slow and was able to not damage the holes or parts. The inside was very dirty and did not want to upset the pressboard with to much water. The pressboard has a little damage from age, should I repair it or just let it be? Sending another picture of the damage.

Hello Michael Rosepal,

Hymmm, that's a good question on repairing the pressboard. I would try, even though I have not had to deal with that material before. I guess JB Weld would be good a good first choice.

Cheers

 

[DesertXL]

Also will aluminum pop rivets work okay to reattach? I also noticed there was some sort of form a gasket on there to seal it. So I’ll also be applying that to it.

Hello again,

Aluminum pop rivets would work, but you'll need to use washers to spread the load on both ends of the rivet and you'll have to be careful on how much crimping force because you can still split the plastic or the pressboard. That's why Ford used those rossett rivets, it not only spread the load out but also doesn't crush as tight. I use 10-32 stainless button head bolts with acorn nuts when putting things like this back together. I use a flat washer and a lock washer under the acorn nut.

I am not sure what Ford used on the heater only plenums, but for the sealant on the factory HVAC plenums they used Automotive Bedding Compound. That is the automotive equivalent to Plumbers Putty, if you ever installed a drain in a sink before. It's the same consistency and behavior just rated for much higher temperatures and a little more chemical resistant.

Cheers