Another butyl putty tape question - refitting windows

[fstarocka]

Hi all - I have a 1974 searay, yesterday my wife and i removed the roof, window frames and windows. Luckily the black rubber still came out in one piece.

The join between the frame and boat were all leaking resulting in drips all over the place (incl cig lighter/charger/me etc) - I was going to silicone the whole lot together with shims and then tighten down later if it started leaking - but have been reading about this butyl stuff all morning.

This article kind of nails it :

Re-Bedding Deck Hardware With Bed-It Tape Photo Gallery by Compass Marine How To at pbase.com

So ive ordered a 30ft light grey roll. Im going to put a thin bead around each join - between the old rubber / glass / rubber and also in the aluminium frame.

Should I use silicone at all - the windows are a VERY tight fit with the original rubber because the windows is a triangle and VERY pointy - by pure origami it was VERY hard to get out.

Also - the whole wrap around frame is bolted down onto f-glass, im also going to counter sink the holes and put a strip of butyl all around - im thinking i might not need silicone at all?

Thoughts?

There is a fair amount of flex in the hull.. and im concerned silicon will shear/tear/split. Or should I "seal" in the butyl with a silicone bead in case it "creeps" in hot weather - were in south california - but mostly use it on the ocean

[Charlie]

Hi The buytl tape you purchased needs to be secured in place as it is not a sealant. I found that secured means that it needs to be bolted. I use Butyl to rebedd anythign on my two boat but had to make holes thru my cabin at the windows and bolt on the wrap around frame. Since yours is already bolted it should be good.

My guess is that the rubber gasket that goes around the window is no longer pliable enough to be water tight. If you can find a means to replace it that could solve your problem. Silicone is not the best choice for port lights. I have used a dow corning product that is used to secure glazing in high rises. Sorry can't remember the number. It may be 795 but I am not sure. One port light that I had gave me grief. I had to rebed it four times. The other three were fine. I finally used the Dow Corning product drilled holes for the frame and used butyl tape and bolts. It has not leaked since and it has been at least five years.

[fstarocka]

Tjanks - yes the frame is bolted to the boat, so thats fine, the windows are quite secure because the rubbers hold them in place -

Maybe a thin layer of clear silicone around the rubbers - it wd be tricky tho, the rubber is still flexible but not much - wd be better to not have salt water collecting inside the frame either.. The rubber does act as a holder for the glass, and pretty well at that. Maybe i can put a strip of the putty inside the rubber and push the glass in, then push the whole lot into another strip of putty inside the frame..

glass
--putty strip
rubber
--putty strip
frame (bolted down)
--putty strip
f-glass

Perhaps a thin bead of silicone with the putty to secure glass to the rubber and rubber to frame - a dual joint kind of thing. can see this getting a tad messy tho - esp when trying to get th e windows in - fyi thay lie VERY flat, not vertical like portholes etc.. front windows are angled about 60 degree and side windows about 80 degrees

[roverhi]

Sillycone belongs in boobs not boats. Hard to clean up, contaminates the area where applied so anything else won't stick, has a bad habit of breaking bond with the material it's against resulting in leaks. Would only use it IF required by certain plastic portlights.

Butyl does not cure into a skin so remains constantly flexible and bonded to whatever it's sealing. Only thing that worked on a poorly fitted large fixed port on my boat. Biggest negative is it continues to ooze out, especially in hot weather, because of its no cure attribute. You may have to go back several times over months and even years to scrape off the butyl that oozes. Not a big thing but a bother if you are a bit anal about appearance.

Dow Corning 795 is a silicone that has very high bonding properties. Supposedly used in building construction to hold windows in place without mechanical clips or frame. Pretty tough stuff so may be an exception to my prohibition against sillycone.

[deblen]

Check the bottom of your aluminum frames for drain holes.
Mine had drain holes that were partially blocked from draining to the outside.
Water would work it's way down by the rubber to glass seal & could not drain to the outside fast enough. This caused a flooding of the bottom alum.groove,which allowed the water to work it's way under the edge of the glass to the inside.
After re-sealing twice,I finally wised up to this situation.
After cleaning & re-working drain holes plus drilling a couple extra drain holes at the lowest points,problem solved.
I used butyl to seat the frames to exterior of house with existing screws.Much nicer to work with than any cartridge bedding compound IMHO.

Cheers/ Len

[fstarocka]

awesome guys thanks for the handy confirmation. This is an old gal and we arent into showroom conditions so no leaks would far outweigh a little bit off the butyl coming out over time. We are constantly tinkering on something here and there.

Ill have a look for those drain holes, i know the side ones have em because they slide both ways but front ones are panels - dont recall seeing drain holes.

Will just have to fiddle with the stuff when it arrives and see how best to get a little bit of silicone in somewhere for light adhesion..

I think alot of the issue with the silicone leaking is the cabin flexing and moving around - they didnt use stainless bolts and so any chance of tightening things down was gone - i have to hand saw each bolt off. With stainless i can at least grease em and snug things up if necessary.

Thanks again all - I hope all turns out, the wife will be VERY happy when the boat stays dry (on the inside!! no more for her)

[jeepbluetj]

Every future owner of your boat will curse you for using silicone. Silicone belongs nowhere on a boat and will generally lead to leaks 'cause it doesn't stick to anything. (Just talking about typical sealants, not adhesives)

Just use the butyl, that's what it's for.

[foufou]

In spite of all the negative comments on silicone I am a big fan. If you use the good stuff mentioned above you will have success. I rebedded all ten of my port lights with no leaks after seven years. All silicone. By masking off adjacent areas the oft mentioned pitfalls of silicone are avoided

Don't believe everything you think

[fstarocka]

Originally Posted by foufou

In spite of all the negative comments on silicone I am a big fan. If you use the good stuff mentioned above you will have success. I rebedded all ten of my port lights with no leaks after seven years. All silicone. By masking off adjacent areas the oft mentioned pitfalls of silicone are avoided

Don't believe everything you think

Hi thanks - what did u use? I read caulking types (less strength) are better as the flex more than the "super strength" silicones..

I recently used a very tough flexible outdoor silicone on the side fittings and even though its only been a few months (incl some VERY rough seas) the stuff is holding up very well, i cant foresee it leaking anytime soon, u cant even pull it apart with your fingers -

Anyway the butyl is arriving - ill see how I can use it the best. I think not being able to hold the cabin roof down tightly led to alot of movement that broke the seal.

Anyway my main attempt will be to get the butyl stuff in

[Suijin]

Marine grade silicone is, in fact, a very suitable sealant for acrylic or polycarbonate glazing because it does not attack the plastic, which polyurethane or polysulfide sealants/adhesives may. Sikaflex 295 is pretty excellent stuff for this task although be sure to check the data sheet for whether it requires using one of their cleaner/primer products.

I helped a friend bed her new glazing on her boat a few years ago with the Dow 795 product. The glazing was held in place by nothing other than the black caulk/adhesive, and the openings were curved and the glazing needed to be curved under slight tension to be positioned in place, and braced until the 795 cured. It was recommended by the supplier who cut the new glazing and while I was dubious about it's ability to hold the glazing in it's curved shape, it worked great once it was cured.

The general rule about silicone products is that their adhesive properties are pretty lousy, comparatively speaking, and they should basically be used as gasket material, much like butyl rubber. That said, 795 seems to have better than average adhesion with respect to silicone.

[Compass790]

We had good results with silicone on windows that are held in with screws or bolts & metal frame. I agree with the posts with problems of adhesion but you make it work like a gasket.Put an even bead bead all around the window & a bit under the bolt or screw heads, install & finger tighten only. Allow silicone to cure & then tighten down. Not sure about your rubber strip secured windows but pretty sure the butyl will weep some in your climate. Maybe ask vehicle windscreen guys what they use?
Keep us posted on how you get on

[KP44]

I use the butyl on land vehicles like travel trailers. I would not dream of using it on my yacht. The marine environment is severe compared to land. A marine adhesive sealant is what a boat needs.

[foufou]

I should have mentioned in earlier comment that I agree that silicone doesn't adhere well to wood. To solve that problem I coat the wood with epoxy. Let ig cure then wash with soap and water. The silicone I used was GE and labeled"extra flexible" or something similar. Bought at Home Depot

Don't believe everything you think

[Boulter]

Hi:

I do everything now with the compass marine butyl.

I did my 6 ports last year. There was water leaking From under the inside aluminium frame of one. I assumed it was a fail. Tightened all the screws again, same leak same rate. Flooded the port with the garden hose yesterday for about 6 hours, no leak. So now my working assumption is that either the handrail or the chainplate is the source of the water and it is travelling down the inside of the headliner where it just happens to emerge at the port.

Love butyl, would not use anything else. I have spent many, many hours clearing away old silicone and don't go near the stuff now.

Boulter

[fstarocka]

lots of mixed replies lol - well butyl arrived today -

fyi yes ill be coating dry dry wood - possibly with f-glass. this thing is 40 yrs old and never been worked on so im pretty sure a good bead of the right silicone will work.. Our side windows in the hull were siliconed in with 5 buck outdoor silicone and they dont leak a drop (yet?) - I made sure the stuff went thru and beaded out a little bit on the inside - let it dry for 2 weeks.

Silicone is a pain to do properly.. the side windows are by far the worst to get out, front ones alot easier - Im thinking since the windows have bolts holding them down well maybe ill use the butyl on the grab rails, they tend to move alot more, ill countersink the holes and put the butyl there..

Will see how the products compare when we get back to the windows

We took her out this week and man its so nice having NOTHING around u on the water, so much better than closed cabin -

but then when the weather gets nasty closed cabin is an obvious bonus - tough call.. im considering making a detachable hard roof system