# butyl tape issue



## peterchech (Sep 2, 2011)

I ordered some butyl tape recently to seal some fittings on my boat. Problem is, it has a an unremovable thin plastic backing on one side. Can I still use this tape?

If I must order a new roll, one without that backing, does anyone have a link where I can get it? (I checked Amazon, but I can't tell if I will just be ordering the same one I ordered last time)


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## PorFin (Sep 10, 2007)

peterchech said:


> I ordered some butyl tape recently to seal some fittings on my boat. Problem is, it has a an unremovable thin plastic backing on one side. Can I still use this tape?
> 
> If I must order a new roll, one without that backing, does anyone have a link where I can get it? (I checked Amazon, but I can't tell if I will just be ordering the same one I ordered last time)


Peter,

You got the wrong stuff, probably the tape used in the construction industry to seal windows into window framing members. This won't work for you.

What you need to get is the stuff sold at RV supply stores, or if you want to order some on line, SN member MaineSail can hook you up with the right product.


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## Maine Sail (Jan 6, 2003)

peterchech said:


> I ordered some butyl tape recently to seal some fittings on my boat. Problem is, it has a an unremovable thin plastic backing on one side. *Can I still use this tape?*
> 
> If I must order a new roll, one without that backing, does anyone have a link where I can get it? (I checked Amazon, but I can't tell if I will just be ordering the same one I ordered last time)


That is very likely not a real "butyl" tape. It sounds like a mastic putty tape... There is a lot of "butyl tapes" out there, sold as "butyl tape", when in-fact it may not even be butyl at all. Much of it is not suitable for bedding deck hardware but you really have no way of knowing what you're getting.

You generally do not want an RV grade tape or a construction grade tape. While some "may work" many of them are nothing more than cheap mastic products loaded with fillers and thickeners and less butyl than you ideally want for longevity. I had one customer send me a roll he bought labeled as "butyl tape" that was WATER SOLUBLE!

Below is a link for a marine formulated product suitable for the marine environment. I formulated it specifically because of issues identical to what you've just experienced..

*Bed-It Tape*

.


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## chuckg5 (Jun 22, 2006)

*buyt tape*

Maine Sail
Hi, ! I'm looking to rebed under the rub rail of the freeboard of our 42' vagabond ketch. this tape looks to thin. the original was black in color and thick. Do you know of a place to purchase this? 
Many thanks
chuck


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## rrh (Jun 4, 2008)

Maine Sail,
I bought some of this tape. It is excellent. A question though, what is the problem with the RV type for marine use?
Thanks
Richard


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## peterchech (Sep 2, 2011)

Thanks for the quick responses, I will def be ordering a few rolls. 

I will be re-bedding the aluminum toe rails, stanchions and chainplates in the spring. The toe rail is prob about 1.5 inches wide. It's a 25' boat. I might as well order enough for that project as well. I notice that the tape is 1/2 inch wide. How many rolls would I need for the toe rail? I'm thinking one 50' roll per rail, is that about right? (two 1/2 inch layers next to one another)


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## rugosa (Aug 30, 2011)

A lot of builders used 1" wide butyl tape on deck joint/toe rails. If you are doubling up on 1/2" to make the inch butt joint it to be 1" rather than leaving a gap - reducing bolt hole leak risk.


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## Maine Sail (Jan 6, 2003)

rrh said:


> Maine Sail,
> I bought some of this tape. It is excellent. A question though, what is the problem with the RV type for marine use?
> Thanks
> Richard


The quality and consistency can be all over the map so it sort of becomes like going to Vegas. Some may be suitable, while others are just pure junk and may not even be "butyl" at all. The range of product I have seen called "butyl tape" is simply stunning. All the way from excellent quality to stuff that literally melts in water...

I guess it would be the same as asking; _"Why can't I just use a polyurethane caulk from Wal*Mart instead of Sikaflex, Boat Life or 3M 4200, its all polyurethane?"_ Not all polyurethane sealants are made the same and not all butyl tapes are made the same.

"Butyl tape" is a very, very broad spectrum generic term like "sailboat".. _"Why can't I race in the America's cup in my Pearson Triton, it's a sailboat?"_ You can't because within the term sailboat there are different types, just as with "butyl tape"..

RV tape is often a gummier, if that is a word, wetter, more solventy, and has more "fillers" in it as opposed to virgin butyl. This can make its ability to stretch, when pressed very thin between a deck and hardware, difficult without a failure. RV tape is generally less dense and less consistent in its extrusion/mix too. This is because it does not have to pass any sort of "industry standard" for quality, consistency, density or other measures.

Much of the tape sold as a butyl tape is not even butyl tape but a "putty tape" and some of it, sold as butyl, may even be water soluble.

While you may get lucky, I have many customers who bough elsewhere first then bought Bed-It Tape and were amazed at the difference.

Here's a few shots of a customers RV tape:

Image courtesy Triton106 
















This is a high filler content tape very typical of RV tape. Instead of stretching it tears and fails..

This is what Bed-It Tape can do...

















And here's a comment about the differences;



Triton106 said:


> I received my order from Maine Sail today for three rolls of Bed-it Tape. I could not wait to see the difference between that and the (brand name removed) butyl tape I ordered from (vendor removed). I cut a 2 inch piece from one of the rolls and stretched it horizontally as far as I could and it clearly is far more stretchy than the (manufacturer removed) tape. I also noticed that the texture of the tape is a lot finer than the other tape.


I am not out to publicly malign other products, just to show there are differences, so have removed the vendor and manufacturer. If you want to try and save money I say go for it, you may get lucky. I like to save where I can too. Bed-It Tape is not the least expensive product you'll find but also not the most but it is a good quality without any guesswork involved.

Hope this helps...


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## 4arch (Jul 7, 2009)

Back before Maine was offering the Bed-it tape, I bought the cheap stuff (which wasn't really any cheaper cost-wise than the Bed-it), not realizing there was any difference. When I started working with the stuff I ordered, I got to thinking all the people talking about how flexible and long lasting butyl tape was must be crazy. Luckily I didn't get that far with my rebedding project and plan to start over again in the spring using better quality products.


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## rrh (Jun 4, 2008)

Maine Sail, 
Again, thanks for the reply and explanation. As I said, I bought a couple of rolls of the Bed-It tape. I am in the process of going through my Watkins 23 for a major overhaul. As I go, every deck fitting is getting this treatment. Glad I found out about it. The differences you noted are consistent with what I saw in the Bed-It and RV tape (I did use the RV stuff on the RV). Now I better see the importance of the difference. Thanks again!


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## mikel1 (Oct 19, 2008)

For all things sailing I believe Maine Sail is the great soothesayer of the east . . .


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## mikel1 (Oct 19, 2008)

OOps soothsayer, no e


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## rbrasi (Mar 21, 2011)

Very timely post, as I have 3 rolls of Bed It en route to me as we speak (type). Sometimes, the only corner you can cut on a project is experience with a variety of products- for this, I leave it to the proven experts to lead me in the right direction. $50 is not a huge sum for piece of mind.


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## dbruce85 (Aug 17, 2007)

A very timley post, I was about to order some butyl tape.
Has anyone ever used any of this, or does it falling into the catagory of too good to be true.
Thanks,
David
Butyl Rubber Sealants and Caulks


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## j34035 (Nov 10, 2006)

I have used a couple of rolls from Mainsail. It is good stuff; better than some other butyl that I have used. 2 rolls go a long way when you are bedding hardware so the dollar impact per project is not all that great. Go for the good stuff.......
DD


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## chuckg5 (Jun 22, 2006)

DeBruce85
Many thanks for the lead on butyl tape. i'm purchasing the 3 rolls of 1 an 1/4"
tape to do under my rub rail.
chuck


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## 4arch (Jul 7, 2009)

rbrasi said:


> $50 is not a huge sum for piece of mind.


For me it's also not a huge sum when I think about how many tubes of caulks and sealants I've wasted over the years when the unused contents of the tube dried out after having only used a small amount. Butyl tape's shelf life is one of its biggest selling points for me as I can tackle one or two deck fittings at a time.


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## BigZ (Jan 3, 2001)

PorFin said:


> Peter,
> 
> You got the wrong stuff, probably the tape used in the construction industry to seal windows into window framing members. This won't work for you.
> 
> What you need to get is the stuff sold at RV supply stores, or if you want to order some on line, SN member MaineSail can hook you up with the right product.


Just to enforce what has been said already, I went to a local RV supplier and picked up some butyl tape off the shelf. When I told the owner what I was doing with it (bedding adjustable tracks) he wouldn't sell it to me. He called his supplier and ordered the right stuff. He happened to be a sailor so he knew the difference. Just got lucky on that one. 
Shop wisely.


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## CarbonSink62 (Sep 29, 2011)

Wow, did I just learn something or what?

MaineSail's 'How To' article was excellent.

Thanks to MaineSail and all posters.

Ken


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## IlsanderGirl (Jun 29, 2017)

I see many places that are listing Butyl tape as used on deck. I was told it would work between the boat and the frame of the portlights. Does anyone know if this is accurate?


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## SHNOOL (Jun 7, 2007)

It will if you have another means to hold the portlight in (screws, etc)... otherwise, you may be better off with Dow 795, as that is what is used by most of the manufacturers these days to bed the portligths from the factory.


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## IlsanderGirl (Jun 29, 2017)

Thanks,
This is so confusing. It seems I get different information every time I talk to someone. I"ve been told "silicon is bad on boats", I've been told, "silicon is fine for glass or plexi to frame, but not for frame to hull". Now you are recommending a silicon product for just that. How do I know who is right? And I thought just doing the work was going to be a challenge. Who knew?


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## Maine Sail (Jan 6, 2003)

IlsanderGirl said:


> Thanks,
> This is so confusing. It seems I get different information every time I talk to someone. I"ve been told "silicon is bad on boats", I've been told, "silicon is fine for glass or plexi to frame, but not for frame to hull". Now you are recommending a silicon product for just that. How do I know who is right? And I thought just doing the work was going to be a challenge. Who knew?


What type of ports are they?

*#1* Bronze, Stainless or Aluminum frame mechanically fastened to boat. 
*#2* Plain clear acrylic or polycarbonate with no frame "_glued to boat_"
*#3* Plastic frame ports such as Beckson, Gray Marine etc.

If they are #1, a product such as Bed-It Tape can be used

If they are #2, Dow 795 or equivalent should be used.

If they are #3, a product like Bed-It could be used but a product like Dow 795 is more optimal. Never use a polysulfide, polyether or polyurethane on Beckson ports due to _compatibility_ issues.


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## IlsanderGirl (Jun 29, 2017)

I believe we are #1, but I will have to verify we are not #3. 
Thanks,


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## SHNOOL (Jun 7, 2007)

As always Maine Sail concise, and spot on... I have used butyl (Bed-It) from you for my last 4 boats... great stuff, kicks butt for sealing all kinds of crazy things (spinlocks, cleats, winches, chainplates, etc).


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## T37Chef (Oct 9, 2006)

I purchased mine through Mainesail and had some RV on hand as well... the difference is apparent. It's my go to for anything bolted though. Good stuff


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## hellosailor (Apr 11, 2006)

IslanderGirl-
Perhaps you dealt with Mark Plastics to obtain replacement OEM portlights for an Islander?
They recommend (or at least used to) plain silicon seal for the bedding to the hull, apparently because it CAN be pulled out as opposed to making a nice permanent seal, which would make replacing the portlights a bit of a bear.
So the instructions you get, may be intended for particular reasons. And sometimes folks don't really know or share all the subtleties of something like that.


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## flyingriki (Sep 27, 2012)

Just ordered the butyl tape and was irritated to see shipping is almost as much as the cost of the product. Don't be surprised....


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## SeaStar58 (Feb 14, 2018)

Yes - Lots of variations of Butyl Tape some Mylar or Aluminum Backed for use on various kinds of roofing and siding projects in place of flashing or seam sealant and a few versions of Unfaced Double Sided for installing/drying in doors, windows, skylights and various fittings. Some such as EternaBond have formulations that can be used under water. I would have both types of wet use tapes on the boat for emergencies in my safety kit next to the StayAfloat. Some is designed for applications where regular maintenance requires easy removal while others are more a permanent adhesive.

Some really cheap look-alike products out there too that are pure garbage and don't hold up in the sun.


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