I am prepping my solar instal and planning to do a complete roof reseal while I am at it. Anyway, I am changing out the roof vent for the fridge. Strictly speaking, I don't really need much of a roof vent since we have a Danfoss compressor based marine style fridge, but I figure it can't hurt! The new one is metal from PPL and I plan on doing a few mods to it to make it easier to access the top of the fridge for solar wiring etc. The plan is to make the screen easily removable with screws, and to use a tighter mesh since I am not concerned with maximum air flow due to the nature of our fridge. Once I scraped the gunk off of the old one (still the 16 year old original plastic one doing its job, but deteriorating). I was very pleased to note that the plywood of the roof (sub-roof???) visible once the vent was off, is as good as new with no delamination of the fiberglass whatsoever! The plywood is at least ¼", but looks a bit thicker. The fridge vent opening is completely framed out with aluminum tubing. This is laid up fiberglass, not your common SOB Filon covered roof and sidewalls on lesser brands!
Don
Yeah, I'm up there quite often to tilt solar panels, tweak antennas, etc, and it really does feel solid. What will you reseal with? I've used Dicor mostly. Don't know what Xtreme used before they painted the roof end cap seams, but looks like they used some urethane like Dicor around vents.
This 3M product works well.
Amazon.com: 3M Marine 4000 UV Adhesive/Sealant Fast Cure (White, 1/10... (http://amazon.com/3M-Marine-Adhesive-Sealant-Gallon/dp/B000XBDJWC/ref=pd_sim_indust_1?ie=UTF8&refRID=0E0S6EHPV6E60Z7GW3K3)
Not cheap but neither is Dicor.
Roger
Roger, I think he said full roof seal.. hopefully in comes in buckets. Lol
Don from the looks of it the plywood could it be 1/4 or 3/8 marine grade it is denser.. more glue. ^.^d
Okay, some clarification... by full roof seal, I mean seams, new fridge vent, new plumbing vents, resealing the sky light, fantastic fan (actually replacing it with a remote control model ;) ), end caps, ladder mount points, luggage rack removal (needed to gain space for more solar), etc. I hadn't really settled on the sealant for the seams etc. (areas where caulking is appropriate), but reading the 3M chart on the 4000UV, it looks like a good option. I used 3M 5200 extensively on my basement repair (between the ⅛" stainless flat stock and the bottom skin for its adhesive properties, but the 3M 4000UV quick skin time and relatively faster cure, as well as the UV resistance seems to make it ideal for sealing end cap trim, screw heads, etc. For the fridge vent base, I will be using a putty tape similar to what is used on a new water heater install. It remains flexible and gooey forever, and acts as a bedding compound. It is the stuff they sell at CW etc. for vent installs.
As for the seams and end caps, etc., I will have some questions when I get to that part of it. For instance, I assume that nobody removes the end cap trim, cleans off all of the old sealant, and rebels it with new caulking... but, what about removing screws one by one and injecting a bit of sealant into the hole, and reinstalling the screw so that the caulking isn't just covering the screw head. Wouldn't that back for a more secure seal? Thoughts from those who have gone before are welcome! What does Xtreme, MOT, and FOT do when someone presents their coach and says reseal the roof???
Don
When I replaced the fridge vent on my roof I used stainless steel screws and applied clear silicone to the threads. When finished I applied Dicor to the heads of the screws while caulking around the vent. I always use silicone on the threads of any external screws, don't know if it helps but I figure it can do no harm.
Roland
I like Roland use a sealer on threads if I find a screw loose in my 6 month go around coach. I use a Polyurethane though as I do not really like Silicone types.
JohnH
The DW brought home a pack of stainless steel inserts . You put one of these into a stripped screw hole and then screw in your screw. Looked like it was the better answer to using toothpicks.
Slight problem!! I can't find them. Maybe in the coach which is in storage 19 miles away. But, check with your local hardware store. I will check with the superior being in our house and maybe she has some or can call upon that thing I seem to have lost (memory).
The superior being just proved her superiority. I asked and she dug up the pkg.
It is: Woodmate's MR GRIP stripped screw hole repair kit. Works on wood, plastic, and metal, with a moneyback guarantee.
Pack consists of (6) strips--3/4" wide x 2" long and pieces look like the surface on a cheese grater but much smaller "bumps".
I have used Pro Flex brush on sealant for seals, vents, etc on my roof and side windows. It brushes on over the old caulk, remains flexible, and seals well. Easy to use- just a throw away paint brush. Ordered a quart can off Amazon for around $20- still have almost 1/2 left.
I did have a minor leak on my skylight that a couple coats of this sealed and some minor seeping around some seams- all is dry since I did it last February.
I like things simple, easy to use, and that work.
Xtreme says they put silicone on all the removed screws before reinstallation, and I've been doing that too. Silicone would allow subsequent removal if required, but if the screw strips in the hole, might make repair more difficult.
Dave, Just so I am clear... Are you saying that extreme took off the molding when they sealed up top, and then upon reinstallation, they used silicone in the screw holes, or that they removed just the screws and reinstalled them with a dab of silicone as part of the roof sealing protocol, or is it just the screws on all of the misc. stuff that they had to removed to paint the roof?
Thanks, Don
I have been using the 3M 4000 and 4200 sealant/adhesives where I want to maybe get things apart someday. Every hole especially in the roof is usually predrilled. I fill them up with the 3M goo and insert the screw and screw it in. Some comes out and makes a gasket of sorts. I let it set up and then later if I want to cover the screw I add another dab. Rance has been telling me for the last three weeks that you cannot over do sealing up stuff on the roof.
On those big openings like refrigerator vents in the roof or wall, use lots of the 4000 series stuff and put it on with a spatula, just like frosting a cake. Protect any exposed edges of anything especially figerglass or plywood.
Now I want to go up there and do more.
Roger
For what it's worth, Rance told me to seal the roof for preventative maintenance. He said he would use Dicor and probably 2 tubes of it. I did this last week in the Xtreme parking lot, and Rance walked the roof both days and gave me the thumbs up seal of approval. ^.^d
If you already have something off the roof, using a sealant for each screw hole is a great idea, but to back out screws on the roof just to put silicone in them seems like it could do more harm than good.
They didn't take off the molding before prep for the roof painting, but when they removed something before painting that involved taking screws out (e.g. the awnings, mirrors, tail lights, marker lights), they put silicone on the body of the screws before reinstalling. I'm pretty sure they didn't put silicone on any screws that would get painted, since the paint wouldn't stick.
May have used Dicor for that.
When I was in the metalworking machine tool business we used silicone seal to keep screws and bolts from vibrating loose, in addition to sealing the holes. Using silicone instead of Loc-tite enabled us to remove the fastener fairly easily. We did not care to use Loc-tite because Loc-tite has a shelf life and if you used old stuff it didn't hold whereas silicone seal is good if it hasn't hardened.
When I bought our coach I put a nice backup gooping of Loctite Poly seam seal clear all over the penetrations on our roof. It's more or less still clear and very pliable and adhesive. Also hit up all the clearance lights. No leaks.
Everybody has their favorites. I have seen the Sonoborn urethane products retain adhesion, flexibility and new appearance for years in S. TX industrial environments for years so that's what I use. The pour able product (which you may have seen poured into sidewalk expansion joints, grey in color) is SL1, the caulk consistency stuff is NP1. Both products are available in large tube , quart sizes, at trade oriented supply houses. On my list to do is taping a margin around roof trim and using the pour able product to completely cover trim, screws and a margin of the glass. Sealed beyond a shadow of a doubt then. It's self leveling and looks neat when done. Removable with reasonable effort and permanent.
I haven't seen anyone discuss the roof to gutter joint and whether or not any special attention should be noted there. On winnebagos the roof tucks in behind the sidewall via the gutter joint (in the dumb way) so a leak there results in sidewall delamination. I don't think that is how the FT's are built but...
I haven't had a problem with it but the potential is definitely there. The other item is the "gutter" track that runs along the length of the coach a few inches below the top. AC condensate is a constant in the summer and many possible leak points here with the massive number of screws.
Under that trim is the joint between the roof and the side walls, and yes, if water gets in, de lamination can occur. Foretravel used a laminating glue that was not very water resistant, but had great adhesion to the closed cell foam they used. Pay attention to that seam! Any water that comes in through roof leaks ends up collecting and staying at that joint, and that's bad. When you renew that seam, like others, I suggest 3M 4200 or even 3M 5200, since they now have a 5200 release agent if you ever need to remove the 5200 (it's a permanent adhesive / sealant that dynamite won't break). It is used to seal hull to deck seams in yachts and is expected to last 20 years. It is VERY water tight.
I wouldn't use 5200 up there for a couple of reasons. First, it isn't that UV resistant according to what I have read and heard from boat guys. Glue your keel on or other stuff below the water line, sure 5200 is the right stuff. I used quite a bit of 5200 underneath the coach when I did my bulkhead repair. Another reason for not using up top, at least as far as the regular 5200 (not the fast cure), is the 7-14 day cure time. Not sure if the cure would be affect if exposed to rain, or even condensation but it might collect dirt and bugs. I think it would be fine for gluing stuff on and bedding it down, but removal could be a problem.... 4200 might be fine, but 3m's chart doesn't tout it as being UV resistant so laying over a seam or screw heads where it will be exposed might not be optimal. On the other hand, maybe those concerns are more theoretical than practical... Anyway, I bought four cartridges of the 4000 UV today.
Don
Don, did you get them online?
Richard,
I got them at a West Marine right near Alan's place of business in San Diego (Bay Marine Supply (http://baymarinesupply.com/store/)). He let me use his merchant resale number (of course, I still paid sales tax as required for personal use items) to get them at about the same price as Amazon ($13.98 for the white), but without the shipping. Without that discount, they would have been $21.99 plus tax! May be available locally for somewhat less than West Marine, but I was happy to accept the favor from Alan. I was there ordering some other stuff and picking up an FTZ crimper, so it was nice just to go across the street and grab the stuff off of the shelf. I have bought the 3m 5200 at Lowes before, but I don't remember noticing the 4000UV.
Don
I've been getting my 3M 4000 UV from Amazon. Not the cheapest, not the most expensive.
Amazon.com: 3M Marine 4000 UV Adhesive/Sealant Fast Cure (White, 1/10... (http://amazon.com/gp/product/B000XBDJWC/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1)
The 4200 works good if not in in the sun. When I changed clearance light bulbs to LEDs it appeared that FT used 4200 to fill and seal the holes. It is made to be disassembleable. Is that a word?
The 5200 stuff is pretty permanent.
Roger
That's good info. It looks like both a potential problem area if neglected, and due to its out of the way location an area that's easy to overlook. In this case I would go for 5200, for rebedding the joint at least as some joint strength would be a good thing. UV exposure on it is almost negligible. Don't see any 100% way of resealing it without removal, cleanup and screw replacement or total embedment.
A really great place to compare the merits of different sealants and adhesives is Jamestown Distributors. They have great charts, easy to compare info showing strength, removability, UV resistance etc on a wide range of sealants and adhesives. Also available info on the various two part high strength epoxies, isos, caulk tube adhesives. Good prices and fast shipping, no I don't own stock but I do appreciate a full service supply house.
By "renewing the seam", are you suggesting removing the strip, cleaning the surfaces all of residue, reapplying adheive caulk and reinstalling the strip? Some effort will be required and for that level of effort, I would suggest getting a new trim strip with fresh paint on it that hasn't been bent up in the removal process. Make an effort to get caulk in every screw hole in the roof. If you have to put in new holes, pre drill with the correct sized drill, put caulk in the hole (and on the screw) and then assemble. If you are going to do it, make every effort to do it as well as it can be done. It is your coach.
Roger
Roger,
I gather you are referring to Chuck, but I do not plan on removing that trim at present. I have concerns about getting it off intact, and how difficult it would be to clean off the old sealant. That is why I asked earlier what the common practice is in the roof reseal job description, and what is done by the trinity in Nac when asked by the customer to do a roof reseal. If I was close to Nac, I would be tempted to buy enough trim to redo it. I replaced all of the bottom trim on our coach and was happy to pay just over $4 a foot at FOT (IIRC). I think I would have choked on the shipping cost had I not been there :o
Maybe this flat molding is more of a generic commodity, I don't know... But my current plan is to reseal without removing the sidewall to roof or end cap trim. I may elect to remove and replace the screws. I will use the 4000 UV because I am not ruling out replacing it somewhere down the road. If I discover evidence of delaminition somewhere along those joints, then I will have to reevaluate. So far, so good...
Don
That is on my list to do as well. I think I will clean off any excess old material on the upper edge (a small piece of formica scrap works well) and put a bead of 4000UV along that edge and smooth it out to eliminate any place where water can sit. If the screws are not loose I would just put a little 4000UV cap on them. Probably will take half of them before the technique becomes apparent. Waiting for a warm day in the shade do do this. Roger
One thing I do twice annually that yields results is to go up on the roof with a scrub brush and clean it back to white again. Once it is clean, I get on my hands and knees and crawl the roof looking for damage. The scrubbing will not clean the dirt out of cracks or holes as easily and they will show up as black hairlines. Even with the Foretravel armor coat I get cracks translating from the fiberglass below here and there. I have 4 cracks total and now a new tiny hole in the armor coat from a branch falling on us during a storm. FInding these things and patching them before the fiberglass delaminates from the plywood below can save you a ton of grief in the long run. It takes a long time of leaking before the evidence is there, especially with the high grade plywood used so you really have to seek out problems and fix them yourself.
And after studying on it a bit, Chuck doesn't plan on removing it either. You guys have the right idea, just recaulk existing. Will pull screws and dip em in sealant and redrive. Pulling the strip would be a beeg deal.