Butyl Tape

[Doug J]

I just read a compelling article "Re-Bedding Deck Hardware", as posted on Compass Marine. http://www.pbase.com/mainecruising/rebedding_hardware
Now I feel like I need to re-bed all my deck hardware. After reading the article I think I will always use Butyl Tape from now on, and will bevel all holes.
Maybe someone here knows the name of the writer, I couldn't seem to find it. I find it interesting he is strongly apposed to Don Casey's method of "tighten twice", the practice of not tightening all the way, letting the sealant setup, then tighten again. I can honestly say this never seemed right to me, it seems that by using this method the seal will be broken by disturing the hardware. This article explains whats wrong with that method very well, makes real good sense to me!
Compass Marine offers what is referred to as marine grade butyl tape. I have some butyl tape left over from when I had my motorhome. It's suggested there's a difference between RV and marine grade butyl tape. Does anyone know about this? Are there different types of butyl tape?

 

[Stu Jackson]

Doug,

Maine Sail is one of the "Featured Contributors" on this 'board, under the Forums tab at the top of the page.

You'll usually see his material right here.

His butyl tape article is right there.

http://forums.catalina.sailboatowners.com/forumdisplay.php?f=135

 

[Maine Sail]

I have some butyl tape left over from when I had my motorhome. It's suggested there's a difference between RV and marine grade butyl tape. Does anyone know about this? Are there different types of butyl tape?

Doug,

You can try what you have, and should, because you already have it, but there are differences between the architectural grade and RV grade butyl tapes.

There is no such thing as a "marine grade butyl" only butyl that is better suited to hold up in the marine environment and butyl that is less so.

I spent many months trying to find just the right mix of density, flexibility and a product that was not to solvent rich. The RV butyl tapes have a higher solvent content, tend to be messier and have a low durometer rating. They are meant to simply "gum" between two pieces of sheet metal roofing. For bedding hardware you ideally want a butyl that is not to hard and not too soft either.. Many of the architectural grade tapes are to hard and many of the roofing or RV tapes are too soft. The product I have is manufactured in smaller quantities because the durometer ratings for glass work have increased over the years and some of it is just to dense to ooze out the way you need it to..

I did this research and sourced the product so folks could get the best results from that article. I once thought butyl was butyl until I ordered some RV stuff that was really a very poor product. Then I tried another roll from a different supplier and again was underwhelmed so I began comparing them multiple manufacturers and grades until I found a good one..

Don't get me wrong I like and highly respect Don Casey but the bent nail trick and the tighten twice methods sometimes make me think he wrote those articles while at Woodstock...

 

[Steve Dion]

One of the boats in our marina had new ports installed a few years ago. They were instructed to use butyl to bed them. The boat was in Mexico and there was no butyl to be found, so the owner used caulking. Well a few years later every one of the ports were leaking.

We ordered 4 rolls of butyl from MaineSail and the ports are now being rebedded (probably for the last time).

 

[Merlin Clark]

I did all of my hardware and trim with butyl this last winter and could not beleive how good this stuff (Compass Marines butyl tape) was to work with.
I had just painted and made all new trim and was really dreading using a caulk type bedding to install everything. I don't know about anyone else, but I can't seem to get near a tube of marine caulk without it getting everywhere and my "helper"s time was limited and not having to (warm body inside and warm body on deck) tighten twice was a huge bonus.

 

[Steve Dion]

Just as a side note about "cheap" RV butyl. One of our fellow sailors used some butyl that came from a friends auto shop. After a couple of hears the stuff was still oozing out.

We purchased the product from MaineSail and have not had this issue at all.

 

[ehh]

I ordered a couple of rolls of butyl tape. Our new boat has had a problem with leaking through the deck/hull joint that nothing fixed. We cleaned and caulked the whole joint. Time will tell, but I'd be real surprised if it ever leaked again.

 

[LuzSD]

Please excuse this question if it is blatantly ignorant, I have not read everything about Butyl tape but understand it is great for bedding hardware to deck. Is it also something we can use to seal our Lexan hatch in the V berth to the aluminum frame? We tried to reseal with something black and gooey and ended up with a very wet V berth after a huge rain. Thanks for advise, be kind if I am way off base.

 

[Steve Dion]

Luz:

This product is not appropriate for that purpose. If you are using mechanical fasterners and want to prevent water intrusion butyl is normally a good solution.

If you are trying to keep acrylic in place you should be looking at something like DOW795 or one of the Sika products. You need to be aware of using some of the caulking products may weaken acrylic, so be careful.

 

[Merlin Clark]

Please excuse this question if it is blatantly ignorant, I have not read everything about Butyl tape but understand it is great for bedding hardware to deck. Is it also something we can use to seal our Lexan hatch in the V berth to the aluminum frame? We tried to reseal with something black and gooey and ended up with a very wet V berth after a huge rain. Thanks for advise, be kind if I am way off base.

I haven't rebedded windows but Don's post here was very interesting and made an impression: http://forums.sbo.sailboatowners.com/showpost.php?p=814816&postcount=4

 

[woodster]

Please excuse this question if it is blatantly ignorant, I have not read everything about Butyl tape but understand it is great for bedding hardware to deck. Is it also something we can use to seal our Lexan hatch in the V berth to the aluminum frame? We tried to reseal with something black and gooey and ended up with a very wet V berth after a huge rain. Thanks for advise, be kind if I am way off base.

you may want to look into Sikaflex 295 uv ...i have been studying this subject a lot of late and i keep coming back to this product..i have even called some of the plexie mfgs and it seems to be the best for your purpose....i did rebed a hatch on my buddys boat last year and it has been in the water all of this year with some auto glass bedding sealent and its still holding so far (X fingers lol) but after researching i have found this sika product better suited for this....obtw SBO has it in there sore at a good price about $4 dollars cheaper than the competor price...when you use it make sure you sand the contact surfaces on both the plexie and the hatch to insure a good bond...and it will not hurt to mask every thing off that you dont want it to get on in regards to the hatch and plexie..it is urithane based and has a 500% elasticity when cured along with the fact that it is saltwater friendly as well......it works on plexie glass along with polycarbonet as well...

hope this helps

regards

woody

 

[LuzSD]

Thank you all for such good advise, I will print it all and take it to the boat this weekend. I really appreciate your help, it is one of those jobs that takes time and preparation and it would be great to pick the right materials and do the job right.

Have a great weekend sailing everyone.