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Topic: Roof repair related questions . . . (Read 2873 times) previous topic - next topic
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Roof repair related questions . . .
So we just completed the Eternabond job on the roof of our "new"-er to us, 2006 Mid-Bath (The Bantha). 

1.  The original owners had taken good care of the rig, but we just discovered quite a few hairline cracks above the cab and around the faux windows.  Attaching pics.  What is the best way to repair/waterproof these?

2.  Can/should we use eternabond around vents.  We started to but then started wondering whether or not that was unwise, in case we ever need to replace a vent/fan cover.  Has anyone successfully cut into Eternabond tape to make a repair?  Last 2 pics attached for reference.

Thank you in advance for your replies!
Leilani
2004 23.5' Twin/King (Baby Beluga sold)
2006 26.5’ Mid Bath (Bantha current)
Re: Roof repair related questions . . .
Reply #1 –
That's a lot of gell-coat spider cracking, probably the result of uneven expansion on hot, sunny days between the white and black surfaces. Do these types of cracks leak, I'm not sure but they are not uncommon.
In boat repair, gell-coat cracking is usually repaired by grinding the crack out with a Dremmel tool or die grinder and then filled with a two-park gell-coat epoxy. This would be a huge project with your LD.
You might consider a less intensive method where the cracks are cleaned and then packed with gell-coat epoxy. epoxy can be tinted or left white and painted after curing.
https://www.youtube.com/watch?v=mLaqbcnBf7I

The vent sealant worries more than the spider cracking. The Factory sealant has failed and there are visible rusted screws. I would remove as much of the original sealant as possible, clean, replace the rusted screws with stainless steel screws and then recoat with a polyurethane sealant. I would assume all the vents are in similar condition. A vibratory tool with a sharp chisel blade works great for removing old sealant.
Eternabond does not permanently bond to common sealants, the only benefit of covering the sealant is to reduce future UV damage.

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: Roof repair related questions . . .
Reply #2 –
One note about Eternabond - it does not adhere well to the top of itself when overlapping, due to organic contamination probably during application. Best to clean the top surface area of the previous strip of the stuff where you intend to overlap. Acetone then isopropyl alcohol.

Steve
2004 FL
2013 Honda Fit
Re: Roof repair related questions . . .
Reply #3 –
Thank you, Larry & Steve, for your input. 

We have a couple questions regarding the repair of the rusted screws on vents, etc.:
     What brand polyurethane sealant would you recommend? 
     Is it necessary to try & remove ALL the old sealant or just enough around the screws to replace them, and then reseal (after cleaning) over everything?
Leilani
2004 23.5' Twin/King (Baby Beluga sold)
2006 26.5’ Mid Bath (Bantha current)
Re: Roof repair related questions . . .
Reply #4 –
At a recent LD caravan meeting I asked the tech talk person about using eternabond around removable items such as vents.
E.G. if you ever needed to remove the vent is it easy to cut through the eternabond to remove the vent (and reseal after putting in a new vent).
The answer was an adamant yes.
If you want to contact him I can reach out to him for an ok to pass along contact info (or give you more examples) - many LD caravan ers are not on this forum.

I found Eternabond tech support very easy to reach and answered all kinds of questions (about how to prep surfaces to get good adherence).  I suggest reaching out to them about your situation.

I have read various answers on this forum about prep (take old sealant down to metal then eternabond, ok to clean off them put eternabond over the sealant even kfntart sealant is not perfect, don’t  remove old sealant but apply more where needed than eternabond on top, etc.).

Likely there are different answers because when I talked to eternabond they recommend one way but as I asked questions they said other ways will also work fine.
Big issue is making sure the eternabond will adhere well.
One adamant answer from them was using their additional liquid product if the temperature was too cold.

I suggest check with eternabond tech support for your situation, asking lots of questions and see what you feel comfortable doing.

Screws:  There is a difference between the sealant shrinking/pulling away from the screw vs the screw “popping up” where it is working it’s way out (lots of movement on RVs.  If you can’t clearly see the difference, I would suggest replacing all screws that worked their way out of the sealant (not difficult or expensive).  Make sure you put some appropriate sealant in the screw hole before putting the new one in (and the screw is rated for outdoor weather).
Jane & Scott
Currently have a 1989 TK  LD we did a lot of upgrades on.
Bigfoot 25RQ Twin on order with early summer 2024 ETA

Our smartphone autocorrects into very poor English.
 We disclaim the illusion of ignorance this creates as we have enough ignorance we rightly claim.
Re: Roof repair related questions . . .
Reply #5 –
One last note:  There is no way to just look at sealant and know 100% of it is preventing all moisture from penetrating.

We recently were in an area with a very different rain pattern (length of rain, heaviness of rain, how long a little bit sits on the roof, etc.).

We got a small leak (a drop every minute or two).  We could use our FLIR thermo camera to see where the water was pooling in the roof.  Nothing was exactly at that pooling place (water travels) but we redid a couple places that looks likely based on location.  That didn’t fix it. 
Then then we  redid a small spot that looked Very robust but that the only other spot within 3’.  While the existing sealant looked very good, we found a screw that had not been set into sealant.  Redoing that spot fixed the leak.

We also found places that looked sketchy before we worked on them but as we removed sealant (we took the choice to go to bare metal), the sealant was actually in very good condition.

Just giving examples that just looking from outside can’t give you definitive answers.
Jane & Scott
Currently have a 1989 TK  LD we did a lot of upgrades on.
Bigfoot 25RQ Twin on order with early summer 2024 ETA

Our smartphone autocorrects into very poor English.
 We disclaim the illusion of ignorance this creates as we have enough ignorance we rightly claim.
Re: Roof repair related questions . . .
Reply #6 –
Thank you so much for the additional information.  This is all very helpful!!
Quote from: Jane and Scott  - 
One last note:  There is no way to just look at sealant and know 100% of it is preventing all moisture from penetrating.

We recently were in an area with a very different rain pattern (length of rain, heaviness of rain, how long a little bit sits on the roof, etc.).

We got a small leak (a drop every minute or two).  We could use our FLIR thermo camera to see where the water was pooling in the roof.  Nothing was exactly at that pooling place (water travels) but we redid a couple places that looks likely based on location.  That didn’t fix it. 
Then then we  redid a small spot that looked Very robust but that the only other spot within 3’.  While the existing sealant looked very good, we found a screw that had not been set into sealant.  Redoing that spot fixed the leak.

We also found places that looked sketchy before we worked on them but as we removed sealant (we took the choice to go to bare metal), the sealant was actually in very good condition.

Just giving examples that just looking from outside can’t give you definitive answers.
Leilani
2004 23.5' Twin/King (Baby Beluga sold)
2006 26.5’ Mid Bath (Bantha current)
Re: Roof repair related questions . . .
Reply #7 –
Quote from: Jane and Scott  - 
At a recent LD caravan meeting, I asked the tech talk person about using Eternabond around removable items such as vents.
E.G. if you ever needed to remove the vent is it easy to cut through the Eternabond to remove the vent (and reseal after putting in a new vent). The answer was an adamant yes.

I have read various answers on this forum about prep (take old sealant down to metal then Eternabond, ok to clean up old sealant and apply more where needed than Eternabond on top, works fine when the old sealant is not perfect, etc.).
Big issue is making sure the Eternabond will adhere well.

With the aluminum roof cleaned down to clean, shinney metal, Eternabond would be a great way of sealing a vent to the roof.
When wanting to use Eternabond over a vent previously sealed with polyurethane, removing the old sealant is going to be difficult to completely remove without damaging the plastic vent roof flange.
If Eternabond is to be used as the primary seal remember that it doesn't stick well to old sealant.  For this reason, I suggest resealing with polyurethane sealant.

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: Roof repair related questions . . .
Reply #9 –
pic
Linda B
Green 2021 RB
2022 Ford Maverick toad
Re: Roof repair related questions . . .
Reply #10 –
If you can legally buy it in your state, 3M 5200 Fast Cure is my choice after 30 years of trying the available polyurethane sealants it’s not cheap but it’s the best, IMO

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: Roof repair related questions . . .
Reply #11 –
Quote from: Larry W  - 
If you can legally buy it in your state, 3M 5200 Fast Cure is my choice after 30 years of trying the available polyurethane sealants it’s not cheap but it’s the best, IMO

Larry

Larry,

Do you put the 3M 5200 on top of the screw heads for as well? Do you use lap sealant at all?
1999 MB, 7.3L PowerStroke