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Topic: Eternabond under A/C (Read 234 times) previous topic - next topic
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Eternabond under A/C
Completing the Eternabond project that I take in small bites this day and that.

I can see the sealant under the A/C and it doesn't look too good. No leaks yet but.......

How the heck can I get that sealed? Is that something that requires a shop? Only taken Ruby to a repair service three times in 13 years; two issues with the generator and one with the fridge. From there some general engine work from the Ford dealer and everything else me. I find it painful to think about others fondling my Ruby!! 😁

Appreciate opinions.

Thanks, Dave
Ruby, the red 2004 26' RK hauling Dave and Kristine hither and yon
Re: Eternabond under A/C
Reply #1 –
Normal RV's don't have sealant under the rooftop A/C unit.  The seal is made with a gasket.  There are 4 bolts that you can reach from inside the coach that compress the gasket.  The gasket will compress over time and eventually need to be replaced. 

Lazy Daze isn't a normal RV manufacturer, so I think they also use polyurethane sealant to glue the bottom of the gasket to the roof.

A common mistake some people make is to squirt sealant around the base of the rooftop A/C.  This seals the condensate drain holes, leaving that water with no good place to go. 

Long story short - seal the A/C with a gasket and don't add any sealant.  A leaking gasket needs to be compressed or replaced.   

Rich
'03 MB in NC

2003 MB
Re: Eternabond under A/C
Reply #2 –
Quote from: rich  - 
A common mistake some people make is to squirt sealant around the base of the rooftop A/C.  This seals the condensate drain holes, leaving that water with no good place to go. 
Long story short - seal the A/C with a gasket and don't add any sealant.  A leaking gasket needs to be compressed or replaced.   

On the LD's that I have checked, the A/C'S gasket is glued to the roof.
As Rich suggested, snug up the A/C's hold down bolts and leave it alone unless there is a leak.
The hold down bolts are located behind the interior trim piece. The cover is held down by 4-6 small screws, usually hidden under the air filters.
If there is a leak, you will know it, the A/C is at the lowest spot on the roof. It's the first place I look for leaks, when it is raining.

A leak, coming out of the A/C's interior cover, can be caused several things, besides a bad gasket.
Plugged condensation drains are a common cause, so check them before replacing the gasket, if a leak occurs.
If a roof leaks in an area near the rooftop A/C, it can travel on top of the interior's ceiling paneling and drain into the interior around the A/C's cover.
The hole can be several feet away and still drain from the A/C.

The A/C's roof cover should be removed periodically to clean the debris build up, inside the cover, that can clog the evaporator's fin and condenser drains.
It is also a good time to clean around the perimeter of the A/C, which has limited access when the cover is in place.

I have also found tiny leaks in the roof's aluminum skin, cause by small rocks getting trapped under an antenna or possibly stepped on, poking a very small, hard to find hole. Once found, a 2"X 2" piece of Eternabond tape makes a permanent patch.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Eternabond under A/C
Reply #3 –
Thanks fellas, awesome info as always. No leaks yet (knock wood) but doing fall maintenance on the rig so timely advice.

Funny thing about a fall maintenace To-Do list is as you check off items from the list new items magically appear. Why, two more popped on there as I lay in bed last night thinking about the ol' girl!!! 😆
Ruby, the red 2004 26' RK hauling Dave and Kristine hither and yon
Re: Eternabond under A/C
Reply #4 –
"Funny thing about a fall maintenance To-Do list is as you check off items from the list new items magically appear."
---
My 'seasonal' maintenance task list goes without a break from January through December.  ;) 
2003 TK has a new home
Re: Eternabond under A/C
Reply #5 –
"My 'seasonal' maintenance task list goes without a break from January through December.  ;)"

This schedule ensures that my ambition, other demands, and mindset all align so my best work results. 
Paul
'92 Mid Bath
Re: Eternabond under A/C
Reply #6 –
Epilogue: gasket is pliable and looks in great shape. It's a pretty easy observation that probably needs to be added to my annual tasks list.
Ruby, the red 2004 26' RK hauling Dave and Kristine hither and yon