[C320-list] Sealant/caulking

[Jeffrey Brown]

I'm replacing a few of the stanchions on my boat and wondering what type of sealant or caulking you would recommended. When I pulled out my top hatches several years ago I just used outdoor caulking from Home Depot and don't have any leaks but now that Im not so naive I'm wondering if the high end 3m sealant from west marine is worth it. Hate to buy a huge cartridge for such a small amount that I need.

Jeff Brown
949-350-5123

[Dave Hupe]

Dow 795 is great stuff.  I used it (black) to bed/seal all new stationary salon windows (and eliminated screws that were in my original windows).  A caulk tube is about $15, will last a lot longer after being opened than the 3M stuff, seals great, doesn't set up as rapidly and therefore is easier to work with (although you still need to work quickly), and is available in multiple colors. 
Dave Hupe
1994 Cat 320 (hull #32) 
Holland, MI

[John Meyers]

Butyl tape doesn't harden. Widely used. I got some at Sailrite but you
might find it at RV supply places. This goes into the hole before you
fasten something down. YouTube has some good How To videos.

John Meyers

[Dave Hupe]

I have used butyl tape, Dow 795 and several 3M sealants.......all this summer after having purchased our boat this April.
I rebedded my center cabin Bomar hatch with butyl tape which worked very well.  However, it is hard to make 90 degree or curved corners.  I slightly overlapped the tape where I did the corners.  You need to be careful not to make the overlap areas too thick if you can't tighten hardware down enough to make sure everything seals when compressed. You might also be able to butt the tape tightly at transition points, since it should squeeze together at the butt edges and seal.
I think butyl works good when you are dealing with smaller wood/sheet metal mount hardware that easily penetrates the tape during mounting. However, where you have large bolt type mounting hardware, you can't just lay the tape over the holes and punch the hardware through it.  So, it becomes tough to deal with properly sealing around the hardware.  That is why caulk type sealant may be better in such circumstances. 
I have used 3M products several times and am upset when I use very little and the tube hardens very quickly thereafter. It also dries essentially hard and can dry out over time. The Dow 795 sealant adheres extremely well, stays flexible/rubbery after curing, and has very good elasticity (so it can accommodate future "movement"/flexing without leaking).  The partially used tube can be sealed and it stays good for quite a while.   
Dave Hupe
1994 Cat320 (hull #32)
Holland, MI

[P.F. Ross]

I have used butyl tape to rebed my chaiplates and mast step plate with
great success. Good info from Chris Burti and Warren Updike in Technical
Articles on website. They reference this article which is also very good:

http://www.pbase.com/mainecruising/rebedding_hardware

I tried at least four different kinds of butyl tape and found the kind
offered in the Compass Marine article above ("Bed It" butyl tape) to be the
best by far as far as stretchiness and tackiness goes.

Finally, rebedding stanchions is my next big project as I continue to chase
fresh water leaks on my 23-year-old boat. There already are some good
threads regarding this process but please let us know how your project goes.

Regards,

Frank Ross
Beta Wave #206
Naples, FL

[Genehelfman]

If you can wait 'til October I have mucho butyl tape that I will never use and will be happy to send gratis. Right now I'm in Germany.

Gene helfman

Sent from my iPad

[Chris Burti]

Let me pass on some tips for working with butyl tape.
1. When you need to make a joint, overlap it by the width of the tape. Then
cut across at a 45 degree angle, remove the triangle cutoff on top strip,
lift the top strip and remove the triangle waste on the bottom. This
creates a scarf joint that seals perfectly when the hardware is tightened
down. You can use this technique for square corners as well.

2. If you are having trouble with round corners, cut a three inch section
of tape and roll it in your hands like a noodle. Lay it down around your
curve and roll it flat with the beer bottle you just emptied. Scarf the
joints as above.

3. I have awls in most of my several tool kits made from grinding a long
tapered point on old Phillips screwdrivers where the tips had broken or
worn down. Use one to make your hardware holes.

Fair winds,
Chris Burti
*Commitment,* #867
Farmville, NC

[Warren Updike]

I switched to butyl rubber tape a few years ago after reading advice from Maine Sail blog. Here is the article: https://marinehowto.com/bed-it-tape/ I used these techniques in rebedding chain plates, hatches, and other hardware. The chain plate effort was an experiment and so far it has worked well. There should be a bit on this topic in the Google archives.

Warren and Pattie Updike
1994 C320 "Warr de Mar" #62
Middle River, Chesapeake Bay

[Troy Dunn]

+1 for the Bed It tape from Maine Sail. I used it for bedding in
replacement opening portlights on the cabin top last winter and could not
be happier with the results.

[Ken Geiger]

For Canadians, BED IT is available from Marine Outfitters on line or at their store in Kingston, ON. See at

https://www.marineoutfitters.ca/index.cfm?category=10427%7C11795&product=39379382&code=BIBT&CFID=170004193&CFTOKEN=53732197

Regards

Ken Geiger
Northern Dream #765
On Georgian Bay