Butyl tape for sealing windows - good idea?

[belfert]

I have a water leak and I think it is coming from around my Peninsula/Motion window.  Per Craig Shepard's suggestion, I did not use the foam sealing tape Peninsula/Motion supplied and used butyl caulk instead.  (Craig said the foam just leaked on his windows.)

The butyl caulk was a huge mess to apply and does not seal all that well.  I've had to pull and reinstall several windows already.  Would the butyl tape they use on RVs work for thses windows?

[gumpy]

I used the butyl tape on one or two of my windows. It was much easier to use, and seemed to work just as well as the caulk.

The secret on using the caulk is to make sure you get two good thick beads all the way around. Let it squeeze out when you install the window, then take a putty knife and a plastic bag. Clean the excess caulk off with the knife, and use the plastic bag on the other hand as a glove to clean off the knife. You can then just invert the bag into the garbage can. Use mineral spirits and plenty of paper rags (rags-in-a-box) to clean off the residue around the window.

[Dallas]

I've used both the Butyl caulk and the tape. Both work well, but can be messy.

Another good choice I've found and have been using lately is PL Brand Polyurethane Roof and Flashing Sealant

http://www.stickwithpl.com/Products.aspx?ID=Polyurethane-Roof-Flashing-Sealant

It's available at Home Depot, Menards, Bennet Lumber, Park Supply, Justus Lumber, Hiawatha Lumber, Scherer Bros. and Ace Hardware, just to name a few.

Cost is around $5.00/tube

I even fixed all the leaks in my old windshield rubber with it and you can barely tell it's there. It doesn't shrink like a lot of caulks, it will stick to itself unlike Silicone, and it doesn't get hard and crumbly.

IHTH,

Dallas

[belfert]

I used Polyurethane caulk to seal the roof and to seal the aluminum to cover the old windows, but Craig said not to use it for the windows. 

The window would be almost impossible to remove if necessary if poly caulk was used.

[belfert]

One other thing:  Will the butyl tape dry out and crack with time?

I seem to recall this being an issue with windows on travel trailers.  This may be more of an issue on an aluminum sided travel trailer because the sides are not at all flat.  I've heard recommendations to pull and reseal travel trailer windows every three to four years.

[Dallas]

Polyurethane caulk IS hard to remove. Newell coaches use it on their windows and seals and if you have to remove one for a repair, it can be a real bugger.
However, how often are you going to be taking the windows out and replacing them? I personally don't want to do it more than once on any of them.
To remove a window that's had polyurethane sealant used on it, I get one of those 99¢ throwaway utility knives that will extend out 4 or 5" and slide it up under the sealing surface, cutting the sealant. To replace the window, you don't need to clean all of the old sealant off, just the major lumps and bumps. Applying new sealant over the old works because the new sealant will bond to the old sealant, unlike silicone which won't bond to itself once one part is dry.
Wet sealant will clean up with mineral spirits so you don't have any left over nasty stuff. It's also paintable and accepts stains.

I've had a number of problems with butyl tape on roof vents. It seems that when it gets some age on it, it quits sticking to one side or the other. I still have about half a case of it, but it's getting some age on it so I think I'll just toss it in the dumpster.

Just my way of doing things. Other people have other ways.

Dallas

[DavidInWilmNC]

I've used both butyl caulk and the PL sealer Dallas mentions.  I really like that black polyurethane sealer (the PL).  Like he said, it's nearly impossible to separate two surfaces sealed with it.  I used it around my windshield (no more leaks!) and where window gaskets have dried, shrunk, and don't quite meet and leaked.  It's about the messiest stuff in a tube I've ever used, but it sure sticks and seals well.  It kinda smells like dark chocolate when it cures, which is an added plus!    Make sure and wear 'disposable' clothes and gloves when you use it. 

I've used butyl tape on my bus, camper, and a friends' RV.  It seemed to work pretty well.  I think it doesn't do as well if it's exposed to air and sunlight.  That is, the things that completely covered it and had a very small gap were stuck / sealed very well.  The edges where exposed to sun and air were dried and not too sticky.  There's also a sealer tape that's sold in an RV store locally that looks like butyl, but it's not.  Do not confuse the two.  The other tape does not hold up well.  As messy as butyl tape can be when it's warm, I can't imagine using it in caulk form.  It is much easier to work with when it's a bit cool. 

David

[brojcol]

I too used the poly sealant on my windows.  What I like about it is that I used the black and it really gave a professional looking finish when I took my time with it.   

It worked so well, I used it to seal an old air conditioner in a room in my house.

Oh yeah, I had another leak around one of my moon windows and discovered it while it was raining.  I didn't want to use the poly when it was wet, but though, 'what the heck'.  It worked like a charm.

[gumpy]

I used the polyurethane on a couple of my windows when I first installed them. It did work great, until I had to remove one of them because of a leak in the construction of the window. It was nearly impossible to get it out without doing damage.

If you're sure your windows will never need to be removed again, it's good stuff. If you think you might want to remove them for maintenance, or possibly when you paint the bus, then use butyl, either tape or caulk.

[H3Jim]

or use the rubber sealant (Dichor) used to seal RV rubber roofs.  Very durable, very sticky, about the same price as the PPL.  I've used it to seal all my roof holes.  Sticks to anything and very messy to work with if you get any on anything else other than what you are trying to seal.  But it won't leak again.

[JackConrad]

Butyl rubber tape is all I use to install RV type windows.  When I first started installing my windows, a friend that runs an RV service facilty siad he used to use putty tape and had several "comebacks". After changing to butyl rubber tape, he had no "comebacks". So far, I have never had a leak and have been able to remove a window without damage.  Jack

[belfert]

How would I know that what the RV dealer sold me this morning was really butyl rubber tape and not some other type of sealing tape?

They had five different types of rolls of sealing tape all labeled as butyl rubber, but they didn't look all the same.