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Butyl Tape or 3M 4200

Posted: Thu May 30, 2013 10:24 am
by The Dog House
I plan on rebedding my bowrail stanchions this Summer. I'm considering using either Butyl Tape or 3M 4200. Butyl Tape seems easier to use and will provide a good waterproof seal but won't provide much structural integrity. 3M 4200 will provide structural integrity but may be more difficult to get a waterproof seal. Any thoughts on which way I should go?

Re: Butyl Tape or 3M 4200

Posted: Thu May 30, 2013 11:56 am
by todd brinkerhoff
3M 5200

Re: Butyl Tape or 3M 4200

Posted: Thu May 30, 2013 1:01 pm
by lawyerdave71
I vote for Butyl Tape.

I have been using it all over the place on my boat and I love it. Originally, it is what Trojan used.

And it is much cheaper than the 3M stuff and comes in four colors at RV stores - white, grey, black, and brown.

Like I said, I love it - solved all my leak issues.

Re: Butyl Tape or 3M 4200

Posted: Thu May 30, 2013 2:49 pm
by Jerry
Butyl all the way.
Here is a very good write up on the subject.

http://www.sailnet.com/forums/gear-main ... -tape.html

Re: Butyl Tape or 3M 4200

Posted: Thu May 30, 2013 9:03 pm
by prowlersfish
3M 4000 , would be my choice

Re: Butyl Tape or 3M 4200

Posted: Thu May 30, 2013 10:32 pm
by yorklyn
Just did my entire bow rail with butyl. real easy to do and much eaiser to clean up than 4200. I did alot of research and am using butyl on the rail and all the cleats. 3m 4000uv on other misc hardware.

Re: Butyl Tape or 3M 4200

Posted: Fri May 31, 2013 1:42 pm
by The Dog House
prowlersfish wrote:3M 4000 , would be my choice
What advantage does 3M 4000 have over 3M 4200? If I decide to use 4000 or 4200 it would be for their adhesive/bonding properties. Butyl tape would work well for water proofing but I'm afraid my stanchions would still wiggle more than I would like given the height of the bow rail and the age of the screws/deck. What's the adhesive strength of 4000 compared to 4200?

Re: Butyl Tape or 3M 4200

Posted: Sat Jun 01, 2013 3:46 am
by aaronbocknek
my dad used this product for years by pettit ... it's called dolphinite bedding compound. john, my marine mechanic, also swears by it. it's easy to work with and provides a highly waterproof seal.
http://pettitpaint.com/product.asp?id=115

Re: Butyl Tape or 3M 4200

Posted: Sat Jun 01, 2013 10:21 am
by todd brinkerhoff
It would be tough to find stronger than. 5200, especially for a stanchion

Re: Butyl Tape or 3M 4200

Posted: Sat Jun 01, 2013 10:23 am
by todd brinkerhoff
Oh, and 4000 is suppose to be UV resistant, so I use it around my windshields. It sacrifices a little bit of strength to 4200.

Re: Butyl Tape or 3M 4200

Posted: Sat Jun 01, 2013 10:41 am
by Big D
Remember that for a stanchion which is thru-bolted, we are not concerned with how strong the bond is since it only needs to be bedded. The concern is keeping the water out. The fastening strength in this case need only be a product of the bolts, back plate, etc. 5200 is not needed nor should it be a consideration for it's bonding properties in this case. That's what thru-bolting is for. I've used both butyl tape and caulking products and found if done properly, both can be just as effective. I like the tape but let's remember that the longevity of the product and it's ability to keep out water for many years shouldn't be taken for granted. No matter what product you use especially in a cored application, the trick is preventive maintenance; you don't wait for a leak to happen before rebedding and if you use 5200, it won't be as easy. By the time you see a leak below, the core has already been damaged.

Re: Butyl Tape or 3M 4200

Posted: Sat Jun 01, 2013 10:32 pm
by yorklyn
if you have ever had the pleasure of removing a part that was bedded in 5200 you would most likley stay away from it. I dont believe i have a single part on my boat that i would consider "permanant" that would never need to be re-bedded. just because a part is "glued " in place for good does not mean it will remain waterproof. I have had to remove thru-hull fitting that were leaking .since they were bedded with 5200 i had to patch the fiberglass that way damaged during removal. 3m 4000 is not a polyurthane, it is a polyether. Polyurthane (3m 5200 and 4200) are adhesives, 4000 is more of a sealant. I will use 4200 to bed my struts, i used it on my shaft logs and below water thru hulls. I have been using 4000 for the above water line thru hulls . I used butyl on my bow rail , cleats bow lites etc. What i like about the butyl is its ability to remain flexable and seal leaks. My bow rail was origionally bedded with butyl, the only one that leaked was the one below the gas gas fill. butyl will not hold up against gas. i used 4000 on these two instead of butyl. My portholes were bedded with butyl and never leaked. I rebedded them the same way.
if your rails are moving you need to find a way to mechanically secure them, 5200 is not the answer in my opinion.

Re: Butyl Tape or 3M 4200

Posted: Sat Jun 01, 2013 10:42 pm
by The Dog House
My bow rails are screwed into the deck, not through bolted. I would prefer through bolted, but I don't think I can get to the back of the fittings without cutting holes. Given the height of the bow rail I think the screws need a little help holding things together. 5200 is too much since I will need to do this again sometime in the future. I'm currently debating between 4200 and 4000. They are both listed as medium strength adhesives in the 3M brochure. 4000 is uv resistant which is an advantage. It's just a question of how much stronger the 4200 is compared to the 4000. If the difference is small I'll go with the 4000. If the difference is big I'll go with the 4200.

Re: Butyl Tape or 3M 4200

Posted: Sun Jun 02, 2013 7:07 am
by mikeandanne
Having read what you are saying about the screws , maybe you could thru bolt and backplate only the ones that you can access---- then upsize the screws on the others----- that should stiffen things up I would think---- the comments about 5200 are right on ,but it does bond well.---- Mike

Re: Butyl Tape or 3M 4200

Posted: Sun Jun 02, 2013 7:21 am
by Jerry
Lots of good advice here.
I know this has been debated just as much as which prop nut goes on first.... the big one of the little one?....
But, working on boats for as long as i have I do not believe there is any circumstance that could rear its head that I would ever use 5200 anywhere on my boat.