Dicor curing question / vent cap replacement

Jay_and_Kat

Sometime next month, we need to replace our sewer vent cap.  The old one got torn off at some point when we last put the camper into winter storage, so as a short term fix we rednecked a cap over the opening and then put a camper cover over that.

So looking on Dicors' site for the lap sealant, they state it skins over in 5 mins and is waterproof in 4 hours (presuming the temp is between 50 and 70F.)  My concern is, we're in Michigan.  We might start the project with sunny skies and warm, but before the end of the day, we might be staring at rain.  So for those who've used Dicor before, the question we have is, once we've got it on and it's at least past the skinned over stage, if the weather is threatening to turn to rain, could we throw our camper cover over the camper and let it sit overnight, or should we plan to change our plan to work on the camper waiting for a clear weekend?

bergger

I've never used lap sealant but have used many other types of caulk to seal things such as roof vents and stove pipes on our house.  Ideally I think doing it on a perfectly clear day is best, but that's if you can afford to wait.  If not I think if you have enough time to let it skin over, then protect it you should be fine.  I would tent it with a durable plastic tarp or trash bag and maybe tape down the plastic to prevent water intrusion.  Your camper cover will not keep out all the water if it rains.  

SLJ

I've used Dicor lap sealant for several years. Self leveling for the roof and non-leveling for the sides. I don't think weather would have any affect on it after an hour and a cover shouldn't be a problem although I don't think to would be necessary.  What I don't do and I think is more important is move it for 24 hours so there's no chance of stressing it while it cures. Just make sure the surfaces are both completely clean before it's applied. The stuff is really easy to use.

Jay_and_Kat

Currently our plan is to bring the camper home one Friday next month (when it's hopefully warmed up and there's no rain in the forecast,) for "maintenance and cleaning" before our first trip of the season.

So replacing the vent for the sewer, re-lubing the bearings, taking all the gear stored in the camper out, cleaning up the interior, probably flushing the water lines (but not sanitizing, yet,) that sort of thing.

Jay_and_Kat

I think I should've listened to @SLJ about not moving the camper for a day after putting the Dicor down...

We did our vent cap replacement today, and once it had skinned over took it back to our storage lot.  Well, looks like that might've made a small "ridge" of dicor.  Hopefully it'll re-level itself out, although can I add an extra bead to the front edge if needed, without peeling up the dicor I just put down?

This video: How To: Replace an RV Plumbing Vent is what I followed.  A couple minor (god I hope minor) items though, that I ran into:

• It looks like nuCamp might use both dicor and a caulk to seal up the vent / vent cap.  There was a translucent material between the cap and roof and around the vent pipe itself (around the vent pipe I left alone, on the roof I removed as much as possible)
• Standard vent caps might be a BIT taller than what nuCamp uses, the stock vent has the pipe poking through the opening in the center a smidge, the vent I got from GeneralRV is the right diameter, but the vent pipe didn't reach the opening.  So there's a bit of a gap there (it's under the cap on the vent, so it should be OK.)

Overall I'd put this as a 4 out of 10 on the difficulty scale, and probably it'll get lower as I have to do it again.
Next on the maintenance hit parade, greasing the axle bearings!

NHTabfan

I had to replace our whole vent and cap on our 2021 400. I ordered my vent cap from NuCamp. The shipping is expensive, but I looked for the matching cap other places & not only could I not find a black vent cap, the prices were far higher than NuCamp was charging ($2.29). I knew what NuCamp was selling would match perfectly. So I ordered directly from NuCamp. Since I was already paying for shipping, I also purchased a half dozen of the screen/shade clips.

Anyway, I used this video from YouTube. https://youtu.be/Tr79TZAfi3k?si=Q4XVdHJ_Yw5ev5Fs (if link isn't live, cut & paste into your browser).

The video is concise, and it talks about the butyl tape that is used in addition to the Dicor Lap Sealant. I struggled to get the butyl tape off, but between rubbing alcohol and mineral spirits, I got it completely clean. I'm not going to lie, it took me probably over an hour to get all the goo off without damaging the roof. I used a plastic paint scraper and my hands. 

I'll attach a series of pictures so you can see the process.  I ended up using a highlighter to mark where the screws go so when I put the vent back on. You can barely see the green lines extending from the screw holes in the pic where the vent is clean. Top left is what was waiting for me on top of the camper. Top right was the ugly part of removing all of the old lap sealant, butyl tape, and fixture. Bottom left: sparkly clean. Bottom right: finished job.

I didn't touch the sealant around the pipe itself as it was in good condition. 

Horigan

Nice!  A heat gun really helps with butyl tape removal in the future.