Use of butyl tape to bed hardware to deck

[boeing1]

I fould it works well for me, I countersink the hole for the fastener so the butyl makes a tight seal.

[HappyMdRSailor]

Originally Posted by redhead

Question to all you butyl users.

If I rebed say my stanchions with butyl, and the diesel deck fill is right next to one of the stanchions, (which it is), over the course of my life I am bound to slosh a bit of diesel when filling. I understand that even a slight exposure to petroleum product (even diesel exhaust) will degrade the butyl, thus breaking the seal.

My husband just said "You're going to get howled at".

I said, "So what?"

Any answers?

Distillates do make it soft/dissolve... Honestly I think you're all right.. But if it were me with the same situation, I'd bed the (one) close stanchion with 4200/sika/life etc...

[ohdrinkboy]

I used MaineSail's butyl tape a few years ago for my traveler. Not a drop of leaking water since. I'm a fan.

[jlincoln04078]

A very detailed discussion of bedding with Butyl tape. I've done it and find it far easier and less messy than the other options.
Re-Bedding Deck Hardware With Bed-It Butyl Tape Photo Gallery by Compass Marine How To at pbase.com

[SpiritofGlenans]

Originally Posted by lockie

Butyl can be hard to get to spread thin enough without a fair amount of compressive force, which is why after trying one, I opted for Sika for my windows.

Cheers, Graeme

Butyl putty:
https://www.reddiseals.com/product/h...g-butyl-putty/

[estarzinger]

Originally Posted by HappyMdRSailor

Distillates do make it soft/dissolve... Honestly I think you're all right.. But if it were me with the same situation, I'd bed the (one) close stanchion with 4200/sika/life etc...

I am not going to admit it ever happened to me . . . .but I could imagine a situation where you accidentally overflowed a deck diesel fill and had diesel running down and sitting on the side deck and it took you a bit of time to mop it all up.

[Blue Stocking]

Butyl tape is what holds the glass in place on skyscraper curtain wall systems that do not use pressure plates on the exterior. That ought to tell you something. Try a commercial glass shop for TremCo tape.

[Pegu Club]

There are various butyl tapes out in the market place, used for different applications.
When bedding tasks on a sailboat are to be done use the right butyl, not just any butyl. That would be Mainesail's compass marine butyl, it is the right suff for the job, go on his site and check it out, it's worth your time and energy. Happy sails!

[leftbrainstuff]

Butyl tape is very handy both for bedding, for temp repairs and for fabricating molds.

We use it to bed our prisms. We recently replaced our teak deck with ameriteak. I actually used 4 seals for each prism. Firstly penetrating epoxy for the exposed deck ply. (No deck leaks after 31 years) Then 3M 4000 white to seal the penetration. Then butyl tape where the prism nests in the deck penetration. Then 3M 4000 black to seal the stainless retaining ring flush with the deck.

The butyl allows the glass prism and deck to move relative to each other. This stops the watertight seal failing due to relative movement.

We also use butyl to make epoxy dams. It seals well on uneven surfaces and epoxy doesn't adhere to it.

When we need to reseal our ports, butyl will be part of that solution. Basically anywhere there is relative movement and the need to maintain watertight seal. If you have two machined surfaces then a gasket or gasket compound would be preferred to buttl.

We dont use 5200 anywhere on deck or where seperation may be necessary in the future. Silicone has no place on a boat.

For deck fills and the like we machine a flat face and use buna n gaskets. Butyl will dissolve when exposed to diesel and some hydrocarbons.

Butyl will creep forever. You need the mating surfaces to bottom out otherwise you wont maintain tension on the screws or through bolts. This could lead to relative movement and fretting. Dirt will enter the gaps and wear the butyl away. Butyl also attracts dirt and grit so can look unsightly.


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[ramblinrod]

Originally Posted by scottthardin

My 7.5 year old boat has been sailed a lot and I am now entering a period where numerous leaks are appearing. I had a bit of an urgent situation where I used butyl tape and ss fasteners to bed portlight covers in a way that made sense given that I might change the cover material out in the near future. A friend mentioned that butyl tape could work well for all rebedding issues where fasteners are involved such as stanchions, genoa car tracks, and the ss bases where my shrouds enter the boat and are subsequently attached to chainplate bars.

Have others used butyl tape extensively for above-the-water-line bedding efforts? I always thought marine grade silicon was what one used for such situations but my friend thinks butyl tape will give me longer life and easier serviceability. What do others think?

As is the case with everything, use the correct material for the application.

Silicone Sealant:

Properties: Excellent gasket under compression, very elastic, terrible adhesive, easy to spread, excellent UV resistance, 24 hour cure, faster formulations available, 20 year life expectancy (if bond doesn't fail). Clean-up with vinegar.

Pros: Beads and spreads easily. Skins quickly.

Cons: Poor sealant/material bond.

Unpaintable, wreaks havoc to any surface that will ever need to be painted.

Applications:

Great for mounting Beckson ports and trim rings in fibreglass. (The only sealant that will not void their warranty.)

Glazing acrylic ports in metal frames.

Poor choice for most deck fitting applications. Likely most misapplied product.

Butyl:

Properties:

Excellent gasket, elasticity - excellent elongation / poor spring, poor adhesive, difficult to spread, medium UV resistance, never cures.

Pros: Properties remain consistent for product life.

Cons: Exposed material picks up dirt for life. Can be "worked out" of a joint that has constant movement. Smears onto anything that comes in contact for life.

Not for use where a bond is required to hold parts together.

Applications:

Great for bedding deck fittings that are "firmly" mechanically fastened by other means and don't rely on material for adhesion.

Poor for use in joints that my work, or where objects may come in regular contact with material.

3M 4200 (or 4000 UV):

Properties:

Excellent gasket, good elasticity, good adhesive, good bead and spread, poor UV resistance.

Pros: Much stronger material / adhesive bond than silicone sealant.

Cons: Even 4000 UV will only last a few years in high UV areas before breaking down.

Applications: OK for deck fittings, except for UV issues.

3M 5200:

Properties:

Excellent gasket, excellent elasticity, excellent adhesive, good bead and spread, poor UV resistance.

Pros: Tenacious material / adhesive bond.

Cons: Difficulty breaking bond. Usually requires being cut apart. (Heat makes removal much easier if parts will tolerate.)

Applications: Excellent for hull deck seams and bonding/sealing deck fittings.

Personal Note: 3M 5200 often gets a bad wrap on internet forums for 2 reasons:

Reason 1: It does what it does so well. Some cite difficulty removing components adhered with it. IMHO, it is an excellent deck fitting bedding material for this exact reason, who wants a deck fitting bond to come apart unintentionally?. It has a tenacious bond which is not likely to break (and leak) for the life of the boat. In the "unusual" event that one needs to remove a stanchion base (or similar) just heat it up and push a putty knife under it. Takes 60 seconds.

Reason 2: Many people tighten fasteners excessively, leaving insufficient material thickness in joint.

Instead, fasteners should only be finger tightened until material oozes through join, but leaving at least 1/16" material between parts.

After 5200 cures DO NOT TIGHTEN FASTENERS.

Ramblin Rod
Marine Service Provider
About Sheen Marine

[reed1v]

You raise an excellent point about not torquing down too much on fastenings. folks really should use torque gauges and lock tight paste when tightening nuts on almost anything. You can be too tight as well as too loose. The old method of hand tight than a half turn is a good rule of thumb. We use to slather all bolts with zinc oxide grease to ensure nuts would come off. Now we use lock tight that seems to do as well plus keeps the nuts from loosening. A lot of the younger mechanics no longer use any grease. Not sure that is a good thing.

[mariner36bob]

^RamblinRod's post
should be stickied in category: Constructuon, Maintenance and Refit.

[appick]

As with many here I've used butyl for over 8 years now in rebedding all deck hardware. Originally I used it on my 1961 Columbia 29. When I painted the decks I pulled off all the original wood hatches ect, that had never leaked in 50+ years! Naturally I decided at the time that butyl was probably the best choice to rebed with. I used it and had zero issues with leaks ever since. I even used it for the gasoline fuel fill and had no issues despite the occasional dowsing.

However unlike many here I didn't use Maine sails tape or order it from another website. I ended up giving the stuff down at the hardware store a try it comes in 10oz caulk tubes and I loaded up my caulk gun and away I went. A cloth soaked with some mineral spirits gave me a nice clean edge when wiped up after the fasteners were snugged. The best part about this approach was it was $3.49 a tube and it was white!

Here's a link https://www.menards.com/main/paint/c...36112461400846 to where I got it but it's what was used to seal and caulk flashings around windows in home repair and for glazing windows for over 100 years so it should be availible at most hardware stores. Although it's harder to find as newer caulks and silicone caulks have replaced it even though they don't work as well.

I know Maine sail says not to use this stuff but it worked out great for me was super convenient to use in the caulk gun and the open tube I used has remained usable for over 8 years now. A little goes a long way. The nice part is in the caulk tubes it seems to be thinner and allows you to get just the right amount on what you want to seal instead of having to squeeze a bunch out while tightening it down. Anyways that's my take and experience.

[thinwater]

A "pro" I did not see listed:

Ready to use immediately, no curing time. Often this matters for repairs while cruising, compared to materials like 3M 5300 that take 3-7 days to cure. Easy to keep a little in the tool box.

Yes, It can ooze in some applications. Some it doesn't matter (winch bases are often well hidden by the skirt). I don't understand the common statement that it oozes more in the tropics. It isn't any hotter in the topics than it is in many coastal areas in the summer. 100F is about it anywhere.

Which gets us to the fact that experiences vary because there is no baseline material. I like the spool I have know and hope I don't run out, though I think I remember where I bought it. Like hardware store caulk, there are a few good products, but most is rubbish.

[ramblinrod]

Originally Posted by thinwater

A "pro" I did not see listed:

Ready to use immediately, no curing time. Often this matters for repairs while cruising, compared to materials like 3M 5300 that take 3-7 days to cure. Easy to keep a little in the tool box.

Yes, It can ooze in some applications. Some it doesn't matter (winch bases are often well hidden by the skirt). I don't understand the common statement that it oozes more in the tropics. It isn't any hotter in the topics than it is in many coastal areas in the summer. 100F is about it anywhere.

Which gets us to the fact that experiences vary because there is no baseline material. I like the spool I have know and hope I don't run out, though I think I remember where I bought it. Like hardware store caulk, there are a few good products, but most is rubbish.

Correct, with Butyl there is no cure time.

It never cures.

So one can use the part as normal, as soon as it is applied.

For any bedding compound to work properly, there has to be some thickness to it.

If there is thickness to it, the parts sealed can work the uncured material out, and thin it, to the point it fails.

I carry butyl tape in my service vehicle. I use it to seal keel bolts. This application does not require a bond and is often wet, where others with better adhesive properties, will not bond either. Perfect application for Butyl.

For deck fittings (winches, organizers, clutches, stanchion bases, hull/deck seams) I want the strongest bond (fitting to adhesive and adhesive to fibreglass) I can get. I use 3M 5200 Fast Cure.

For temporary mounting (parts that I may want to take apart soon) that don't require a hard cure, I use Butyl or Mono caulk.

The reason bedding compounds fail are usually:

1. Improper prep. (All)
2. Applied too thin. (All)
3. Environmental breakdown. (Sika Flex, 3M4200, 3M4000 UV)
4. Poor Adhesion (Silicone Sealant)
5. Excessive working (Butyl, Mono)
6. Solvent breakdown (Silicone is least likely to have this).

I have never seen a deck fitting or hull/deck seam applied properly with 3M 5200 fail, EVER (unless the fitting was pulled right out of the deck by excessive load).

On the other hand, I have cursed Butyl when working in olds boats and 35 year old Butyl was smeared all over my coveralls when I got out.

I'm not saying Butyl = Bad, 3M 5200 = Good. I'm saying different materials have different properties and some work better in some applications than others. IMHO, 3M 5200 gets a bad rap, for all the wrong reasons, and Butyl gets over promoted.

Ramblin' Rod
About Sheen Marine