Best Fix for a little sealant delamination Front Cap

[NVR2L82AV8]

I was doing a little camper winter pre-inspection this weekend on my AF 990 and noticed a pretty good delamination of sealant right at the EPDM and Fiberglass front cap joint. This pic is looking forward - passenger side. Since this is the first sealant repair I'll be doing whats the best product and procedure? Should I pull up the sealant, clean, and put on new sealant or just clean and apply sealant over and in the gap? Fix thoughts and product recs from experience much appreciated.

[NVR2L82AV8]

Thanks for the great tips....just because I'm ready to get to the repair I've been delayed by rain for the last two days--yep it occasionally rains here. I did do some closer detailed inspection because I was getting a little concerned with some of the diagnosis comments. The thick seal is still firmly attached forward but has come up aft hence the gap you see. I still intend to thoroughly clean, inspect, and reseal then dicor everything. I'm out of town av8n but intend to get after it ASAP. I'll keep you posted once I get into it. Again, thanks for the great tradecraft reccs!!

[dmaxpuller]

WyoTraveler wrote:
You can also use eterna bond tape along with icor self leveling caulk. Really needs attention before damage increases.

Agreed, Eterna Bond alone will do it but I would go chaulking also.

[bobndot]

All good suggestions to seal it up. I think the problem is the construction of the seam.

After taking mine apart with the help of an out of state AF dealer , I saw how the mfg. lapped the roof layers on their units.
The dealer offered a solution to the AF mfg. many times over the years, as he rebuilt the nose caps on a lot of his units. He changed the direction of the layering and sealed the edges of the filon before sealing it up.
After he did that, none came back leaking. As for his method of repair, it all fell on deaf ears as far as AF was concerned.

The downward slope of the AF cab-over roof allows water to gather at that seem when the unit is parked stationary.
Being that this is how most campers spend most of their life (parked) you would think the roof layers (shingles) would be lapped like a roof on your house, to shed water .

AF believes they should lapped in the opposite direction allowing water to shed while your driving in the rain at 60 mph .
Driving in the rain all of the TC's life , it would probably not delaminate . After you seal it you might want to consider moving to a wet climate and drive it 24/7 , they were designed to work that way . 🙂

Once the ends of the filon are penetrated by water its over.
The filon has a cardboard backing in order for it to bend. That cardboard like backing soaks up water like a sponge causing the glue to let go, the filon delaminates from the under structure.

Check your basement and firewall area, that's where some of my rain water settled. Some rolled along the basement frame area , out the back near the dump valves. Water collected at every horizontal area under the kitchen sink, along the outside wall.
****The AF common ground is located between the firewall and the water heater. You can see it in the drivers side corner of the camper if you use a small mirror and flashlight. This rusted and killed all my 12 volt power while on the road.
I connected the generator cable inside my empty generator compartment to restore my common ground to get things working again. It was a temp/perm fix because it worked ,it lasted and saved me from ripping out the water heater to get at that rusted ground.
The rest of the water soaked my mattress completely. I had the pleasure to sell it at a garage sale as a water bed to re-coop some of my lost money.

[billyray50]

I have had great success with Pro flex brushable sealer and eternabond.

[mayo30]

Take the screws out of the strip and edging.Stop when you find ones that aren't rusty or corroded,you have some serious work ahead.

[kerry4951]

One of the first things I did after I bought my AF was run (3) 4" wide Eternabond tape runs along that front roof/cabover seam, overlapping each run.

[trail-explorer]

Post some more pics as the repair progresses.

[Glacier_D]

That metal strip appears to be lifting also. Something wrong there and needs to be addressed immediately. Remove the caulk, clean everything and examine why that strip is lifting up or the roof is flexing down. Most likely some rot in there. Use Sikaflex (follow the directions carefully) it's supposedly better than Dicor. Finish with Eternabond and seal the edges of the Eternabond with sealant.

[WyoTraveler]

You can also use eterna bond tape along with icor self leveling caulk. Really needs attention before damage increases.

[trail-explorer]

ScottG wrote:
I would remove all the loose sealant in that area and uncover the screws in the trim piece that covers the seam. Make sure they are tight and the wood underneath isn't rotten. You need a mechanical junction to keep that point from opening again. You may even want to add another screw of two to keep this area tight. Then reseal with Dicor self leveling caulk.

Ditto.

Dicor self leveling sealant is what's there already.

If nothing more happened than the sealant lifting, then after it's removed, apply more.
I think AF uses butyl rubber putty under the metal strip, which seals up that area should the Dicor separate, but a thorough inspection is a good idea once you get the Dicor sealant removed.

I would remove ALL of the Dicor sealant at the corner, and apply new. Do the same at the other corner

[ScottG]

I would remove all the loose sealant in that area and uncover the screws in the trim piece that covers the seam. Make sure they are tight and the wood underneath isn't rotten. You need a mechanical junction to keep that point from opening again. You may even want to add another screw of two to keep this area tight. Then reseal with Dicor self leveling caulk.