# Butyl Tape = Rope Caulk?



## Tanley (Aug 20, 2009)

Was at the marina and chatted up a guy who was re-bedding his gate stanchion. I asked him where he got the butyl tape and he said he was using rope caulk from Home Depot. The stuff felt tacky, but aren't they two different things? I thought rope caulk hardens over time.

It was a different brand, but basically this stuff

Ace Pliable Rope Caulk (219/ACE)


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## davester (Aug 8, 2007)

I don't think its the same... that looks like the brand moretite (moretight? sp?) which I used in one area (it's working fine so far). I recently picked up some real butyl tape at an rv store and it looks and feels different... the moretite, while pliant and tacky, is almost crumbly by comparison... if you pull it apart, it breaks sooner.

I would guess that moretite, or the stuff pictured, won't harden too fast if at all, since its sold in a cardboard box without any airtight container, but only time will tell. Still, after handling the butyl tape - I think its worth getting the real thing.
Dave


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## US27inKS (Feb 6, 2005)

I believe most rope caulk products are butyl based. The compound is slightly different than butyl tape, but it should work as good. Butyl products range from really gooey to pool liners, so I wouldn't be put off by a slightly different consistency. The purpose of using a butyl product in sealing boat hardware is that it shouldn't harden. I've used rope caulk like this for automotive work for decades. The boxes are never sealed, and I can never remember any rope caulk drying or becoming hard.


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## Maine Sail (Jan 6, 2003)

Rope caulk is NOT butyl tape!!! I would not use it for bedding....


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## primerate84 (Jun 14, 2006)

I agree with Maine, use the butyl tape for re-bedding the stanchions. I used it on my windows and it works great.


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## US27inKS (Feb 6, 2005)

Maine Sail said:


> Rope caulk is NOT butyl tape!!! I would not use it for bedding....


I trust your experience on this. My mistake. Rope caulk sure seems a lot like a butyl product. I know the consistency is a bit different, but you can get butyl rubber pool liners that are nothing like butyl tape.

Any idea what rope caulk is if not butyl??


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## sailingdog (Mar 19, 2006)

I wouldn't use rope caulk. * Get the real stuff, it is only $7 a roll or so... *

I'd point out that there are a lot of butyl rubber based products, and most of them are NOT SUITABLE FOR BEDDING HARDWARE. Just because it has butyl in the name does not indicate that it is a good choice.


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## pdqaltair (Nov 14, 2008)

sailingdog said:


> I wouldn't use rope caulk. * Get the real stuff, it is only $7 a roll or so... *
> 
> I'd point out that there are a lot of butyl rubber based products, and most of them are NOT SUITABLE FOR BEDDING HARDWARE. Just because it has butyl in the name does not indicate that it is a good choice.


... which probablty explains some portion of the occational poor results that are reported.

Sort of like 100% silicone caulk vs. "silicone" latex caulk. Very different.


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## Tanley (Aug 20, 2009)

Back down this weekend and he's re-bedding more stanchions so I ask to watch since I've never seen it done before. Really nice guy, and happy to have some company. Turns out he did these 5 years ago and is starting to get leaks below deck. He used the rope caulk last time around too.

I've never re-bed anything, just have Maine Sails' write up as a reference. But when he pulled off the old stanchion, there was no stretch at all. I didn't touch it, but it looked almost brittle when he pulled the base off. Kind of like the rope caulking I've seen used in home windows after several years - hardens and shrinks a bit with a little cracking. Definitely nothing like what is in Maine Sails' tutorial.

The worse part is that it isn't any cheaper than butyl tape. I can't understand why he wouldn't just use butyl tape?

BTW, he thought they were leaking again because he hadn't counter sunk the holes. Which is a valid point, but after seeing the condition of the rope caulk, I would've thought he'd change the bedding compound.


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## Sabreman (Sep 23, 2006)

I looked at about 10 local hardware & big box stores and couldn't find any real butyl tape. Bought it on eBay. Lots of availability.


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## erps (Aug 2, 2006)

Home Depot sells a brick of butyl type material for under $2. Cut off a piece and roll it out to the desired length.

Gardner Bender 1 Pound, 10Pack Plugs Duct Seal Compound - DS-110 at The Home Depot

Looks like butyl to me.

http://www.pttech.net/products/msdstds/262101.pdf


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## US27inKS (Feb 6, 2005)

3M Strip Calk (brand name not a misspell) is a butyl rubber product. They used to make white and grey, but now I can only find black.

http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UuZjcFSLXTt4xMcNxfXEVuQEcuZgVs6EVs6E666666--


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## Maine Sail (Jan 6, 2003)

Generally real butyl tape is in a roll or in a box divided by a waxy type of paper or a non-stick plastic. 3M makes it in round black which was originally used for automotive windshields. CS Yachts used a gray flat butyl tape that has lasted over 31 years on my boat.

Rope caulk, from the likes of Moretite, Frost King, Ace Hardware and others is 9 times out of 10 a putty not a butyl rubber based product. Putty based tapes can be rolled onto itself and un-rolled without sticking. If you buy something rolled onto itself, and it comes apart and un-rolls it is NOT butyl. Butyl can NEVER be rolled to itself as it just immediately bonds to itself and can not be un-done.

Rope caulks are also quite water soluble and can dry out or worse soften and wash away. Ever see what happens to plumbers putty with the lid off? Rope caulks are not that bad, I suspect they have some petroleum distillates to keep it "wet" longer, but they can become harder over time and water can change the consistency.

There are many types of butyl based rubber but butyl tape is tenaciously sticky and will NEVER dry out or harden and it is impervious to water. It is always sold rolled up between waxy paper.










Oh, and NEVER use black.....


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## sailingdog (Mar 19, 2006)

US27—

The stuff I generally use and recommend is made by Tremco.


LOL... I see MS beat me to it...


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## SeaFever2000 (Sep 10, 2008)

Maine Sail,

Where do you buy the Butyl tape shown in your pic? Thanks!


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## Maine Sail (Jan 6, 2003)

SeaFever2000 said:


> Maine Sail,
> 
> Where do you buy the Butyl tape shown in your pic? Thanks!


I order it from an RV supplier, glass shop or a Tremco distributor. Special ordered it from Portland Glass last time. It is 1/16" thick by 1/2" wide and is TremPro 691. If you call Tremco they can direct you to a local distributor. I buy a case about once every 15 years. Never gos bad so why not. Bought my last case in 1998 and am still using it though down to about three rolls left. A case is usually about 1000 feet..


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## drobarge (Mar 3, 2009)

I'm not going to get into my own resume here but, rope caulk really? Home Depot?.... Really? friggin' big box stores.... They should be called "do it your &^%$*'in self centers" I guess if I was working on a 26X with a 50 horse on the transom I might use it. Sorry I don't mean to put down the fan of rope caulk, but it just conjures up images of the people who walk into our showroom with a big box store junk mail flyer in their hand.

I'm with SD on this one


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## Tanley (Aug 20, 2009)

drobarge said:


> I'm not going to get into my own resume here but, rope caulk really? Home Depot?.... Really? friggin' big box stores.... They should be called "do it your &^%$*'in self centers" I guess if I was working on a 26X with a 50 horse on the transom I might use it. Sorry I don't mean to put down the fan of rope caulk, but it just conjures up images of the people who walk into our showroom with a big box store junk mail flyer in their hand.
> 
> I'm with SD on this one


I'm hoping at this point that everyone's getting the message to NOT use rope caulk. Even though n=1 here, the stuff didn't hold up for 5 seasons on this guys boat. Get the real stuff. Maine Sail's description that rope caulk is like putty is dead on. That's what it looked like when he pulled the stanchion off, dried up putty.


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## erps (Aug 2, 2006)

drobarge said:


> I'm not going to get into my own resume here but, rope caulk really? Home Depot?.... Really? friggin' big box stores.... They should be called "do it your &^%$*'in self centers" I guess if I was working on a 26X with a 50 horse on the transom I might use it. Sorry I don't mean to put down the fan of rope caulk, but it just conjures up images of the people who walk into our showroom with a big box store junk mail flyer in their hand.
> 
> I'm with SD on this one


Ha, ha. You got my number. I buy my heat shrink electrical connectors at Home Depot instead of West Marine, my Dockers pants at Costco instead of the Gap and my tinned electrical wire online instead of from Ancor Marine. It's that kind of thriftiness that allows me to have the boat I have. Hey, but if you want to pay more for the same thing (a brick of butyl used by the HVAC guys instead of a pre-rolled tape of butyl) for 5 to 10 times the price it's you wallet not mine.


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