Adhesive for attaching Filon to roof

[76Scoutman]

Howdy all. I have been working over the past few months on repairing my pop up truck camper after the roof had an RUD (Rapid Unscheduled Dissassembly). I've been reading up on all my options for getting the roof back on and have located a place in town that stocks Filon which will save me on $1-200 worth of shipping costs. The question that's making me cross-eyed at the moment is what adhesive to use to glue the stuff down with.

My TC is made with wooden ribs, lauan ceiling, and Styrofoam insulation that is skinned with Filon. Actually the original roof was probably closer to flex roof which is just a textured version of Filon. Either way it's a continuous sheet of FRP (fiberglass reinforced plastic). The front edge is curved down so the Filon has to conform to that contour. The side walls of the roof section are a laminated Filon/Plywood/etc that are attached to the wooden roof ribs.

Adhesion surface would be approx 95% Styrofoam and 5% wood

Other roofing options such as Rubber/EPDM, PVC, and TPO roofs have been eliminated due to the fact that they all need to be stuck down to a sheet of lauan or similar hard sheet roof which I'm not adding. Aluminum has been eliminated also so those options aren't even on my table.


Adhesives----
-I see some say contact cement which to me is a general term. Lowes has DAP Contact Adhesive but reading the fine print says not to use it with Styrofoam. The RV dealer I'm getting the Filon through said they use contact adhesive but I haven't asked what type yet.

-Some say Stabond E-183 which is actually the recommended glue for Filon but I'm not sure if it will eat the foam that it will be glued to. At $174 for the gallon + $30 hazmat fee + shipping costs via special carrier--- this is not a gamble I want to take. I believe it is applied with a spray gun and is extremely flammable.

-I just stumbled on a Titebond product that I can get on Home Depot's site. It's http://www.homedepot.com/p/Titebond-3-5-gal-Greenchoice-Advanced-Polymer-Adhesive-4319/203506897#.Uk...Titebond Advanced Polymer Panel Adhesive. I just spoke with their tech support and it sounds like it would work pretty well. It costs more than the Filon I'll be getting but if it works then it'll be worth it. It trowels onto the Filon and is moisture activated so it sounds much easier to work with.

Anyway, I'm looking for some experience from the RV forum on the best product to use. I'll see if I can get some picts posted soon and this will give me a place to add anything else I may find....

[76Scoutman]

So I just ordered a 3.5 gallon container of Titebond Advanced Polymer Adhesive from HomeDepot online.

http://www.homedepot.com/p/Titebond-3-5-gal-Greenchoice-Advanced-Polymer-Adhesive-4319/203506897#.Ul...


~$135, shipped
-no hazmat or special shipping to deal with
-no special application tools other than a trowel
-it works on non-porous and porous substrates
-adheres to just about everything including Styrofoam
-easy to clean up
-mold/mildew resistant
-moisture cures
-exterior and interior uses

So far this was my best option. I know there are many other alternatives and some of those are approved for use on Filon but most of those I felt were not right for me and my application.

[RVUSA]

polyester resin used for fiberglassing will melt styrofoam. Anything epoxy based will adhere well.

So if you use luan on top of the foam, whats going on the luan? Rubber?

what I would do is head to home depot and grab a qt of the floor adhesive. Test it on some styrofoam and if it doesnt melt it, I would go get a gallon of it and trowel the adhesive on just as a floor job and then screw the luan to the frame. You really want the structual integrity of the whole roof to keep it from all falling apart in transit.

[76Scoutman]

Yea, I have NO desire to lay fiberglass by hand. Been there, done that, don't wanna do it again.

I'll do some more looking into the silkaflex stuff. I still wonder on these 'caulk' type tubes... do I just buy a bunch of them and squeeze them out and spread with a trowel or what? Is it intended to be used on the ribs or for everything? I would have thought I would be looking for a pour-able product that I can spread with a brush or roller. The threads I found were using it on the ribs only.

I still haven't ruled out the Titebond product. I was reading a thread here on RV.net the other night and saw someone else using it too.

So my latest is that I went and visited another local RV shop. They have the Filon for $8.50 per linear foot off of an 8' wide roll. The stuff is flexible enough to easily do the front bend radius that I have. The last question is adhesive.

I talked to one of the head tech guys there and we talked about some other alternatives. One of the other approaches would be going with a 1/8" luan glued to the ribs and foam, screwed to the ribs with countersunk screws, and then a pvc or epdm roof applied on top of that. The 1/8" luan which I (didn't know it came that thin) is one of the parts I'm still nervous about. Cost wise, this approach would be more because I would have the cost of the first glue, filon, pvc glue, and pvc material which all add up to way more than my original plan.

[Bumpyroad]

gatorcq wrote:
This is what is used by RV

sikaflex 252

And yes it is used on Filon to foam

I see that is a polyurethane adhesive so evidently any of them should work. 3M 5200 is the same.
bumpy

[gatorcq]

This is what is used by RV

sikaflex 252

And yes it is used on Filon to foam

[Bumpyroad]

JoeH wrote:
I'd consider going to a marine supply house and getting fiberglass and resin to redo the roof.
The proper resin will not effect the foam.. many hi tech boats are build with a foam core covered with glass

if you are talking about laying fiberglass cloth down over the foam/wood ribs I guarantee it will end up looking like a sloppy, bumpy mess.
putting down a layer of plywood and glassing that in would be slightly better in appearance.
bumpy

[JoeH]

I'd consider going to a marine supply house and getting fiberglass and resin to redo the roof.
The proper resin will not effect the foam.. many hi tech boats are build with a foam core covered with glass

[76Scoutman]

Have I mentioned I hate Butyl tape?

[76Scoutman]

From what I've read I need to find a water based or other similar type based adhesive. The solvent based ones are the ones that seem to melt the foam.

The old material was glued down very well. I was able to peel it off but it took some work to do pulling on large pieces and working with a putty knife.

All of my curves are in the same plane, no compound curves to deal with.

Here's before shot and an after shot of how the front repair turned out. Before the front was a laminated ply/osb 'wood' with white sheet aluminum on the inside and outside, I imagine just like the rear picture below...




The repair was using PVC board with many cuts to make it fit in all the right places...



And then screwed in place. I took a sander to the edge to make it match the contour of the side panels.



Here's a shot of the rear when I took it apart. You can see where it was glued to the roof and the rear most rib but not to the curved down portion. The flex roof was tucked into the rear trim and mostly held in place by trim screws from the drip chanel and rear clearance lights. This is one of the things that let it curve over the rear nicely.



Here you can see the air gap behind the rear curve down.

[SteveAE]

When I built my small camper/large canopy, I glued the filon to a luan roof deck that covered the foam insulation with Weldwood contact cement from Home Depot. That was in 2006 and there is one or two bubbles up there now where the glue has failed....I suspect due to heat (heat softens contact cement).

I have found it very difficult to glue to open cell foams because the glue dissolves the foam. The one exception has been a black closed cell foam that I used to use for whitewater canoe outfitting. I have successfully glued this foam with (Weldwood) contact cement many times. The joints are solid to the point where the foam fails before the joints do. It takes two coats on the foam though because the first coat soaks in somewhat. That foam is very expensive though.

However you do manage to bond your filon down, be careful of compound bends when you lay it out. I really struggled with the bend over the front cap when transitioning from the slightly arched roof. I wound up just putting a seam at that transition, but perhaps someone else has a better suggestion.

I hope this has helped some.
Steve

[Chris_Bryant]

I'm not at all sure that Filon is meant to be bonded directly to foam- all of the application notes I have seen say it need to be bonded to luan- especially for roof applications.

[76Scoutman]

So digging through one of my RV parts catalogs that I got from one of the RV dealers here I found a product that's made by Composet Products LLC. It's a kit to repair delamination. Just another option I need to look into. Seems like most of the better options are in the ~$150 range. Ouch.

http://www.delamrepair.com/composet_4_002.htmhttp://www.delamrepair.com/composet_4_002.htm

[76Scoutman]

Ok, lets try this again.

This is where I stand right now with the extra vent hole and additional roof supports in place. I'm still cleaning Butyl tape off of everything and will be headed to the RV place to get the Filon tomorrow. If I can get adhesive locally, I may be able to begin putting the roof back on this weekend. That may be wishful thinking...

[76Scoutman]

I'll do some more looking into that. Thanks for the link mapguy.

I spoke with one of the local RV places here and they use a product from Benders that is a spray adhesive #631. It comes in spray cans so it's easy to apply. Turns out they have a slew of other products too. I called them yesterday afternoon but they had closed up shop for the day.

http://www.bendersweb.com/chemicals.htm#ADHESIVES