Leaking Windows

jusw

jusw

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Spent time on Treble C today catching up on some of those jobs I always intend to do but never quite manage.

There was a lot more water in the saloon than normal (it leaks a bit around the windows) so much so that the chartable was wet and the floor of the heads wet through.

On chasing the water path, I'm pretty sure the water is leaking round the main cabin windows.

These seem to be plastic (perspex) windows screwed on top of the GRP cabin. There is an "aluminium trim" painted on around the edge of the glazing.

I think the seal to the mastic or whatever seals the windows is cracked and water has got between and frozen and expanded the gap - certainly most of the screws holding the window in place were a turn or more loose.

The obvious thing to do is to remove the window and re-bed on some sort of mastic - the quick bodge way is to run a bead of bathroom sealant over the offending cracks.

Assuming I do the job properly, what sealant do you guys recommend? - I want it to be easy to use as I don't want sticky finger marks all over the windows when finished!

Any suggestions?


JuSw
 
Sikaflex would be my choice. Expensive, but is both a glue and a sealant. When wet wipes off with white spirit so you should be able to keep your windows clean. It is remarkably tenacious stuff, so have lots of small rags handy which you can use and bin as you use. If you let it dry on your hands it will take over a week to rub off.
 
I began the same job in my boat last weekend. I used Lifecalk sealant (sikaflex equivalent) It is important, I am told that it does not fully cure, but stay flexible so that when the boat tiwsts, as it will, the bond/seal does not break.

My windows had been fitted with silicone and this has done 20 years from new, so not too bad.

I have only done the heads window, the smallest, but am going to tackle the two larger ones this week.

What I did was to mask around the windows before I removed them then after the fitting and the sealant has cured, trim it with a knife and then peel the tape away, all clean and a sharp edge.

Sikaflex have a good site with all the products and applications.
 
"The Right Stuff"

Note that LifeSeal is a correct product for sealing and adhering plexi or polycarbonite ("Lexan") lenses to the cabin side. This product will not attack the plastic.
Note B: Do not screw the new lens down flat such that all the sealant is squeezed out. The thermal expansion rate of the plastic is different than the GRP cabin side.
You need to "float" the lens on a bed of about an eight inch of sealant.

Easiest way I have seen to do this is to place a small O ring at each screw position for final install. This is after the dry fit and all taping off is done inside and out.

Also, after cleaning the cabin side where the lens inside edge will cover it, roughen it with some 80 grit; roughen the bedding side of the lens edge with 80 grit also. You want the two mated surfaces to stay adhered as each expands or contracts from temp. changes.

Next gun on the sealant, place the O rings, and drop the new lens on and start getting the screws in. Press it flat by hand to force out excess sealant, and do not tighten the screws so much that you dimple the plastic.
Messy job.:rolleyes: Messy.

We were instructed by a master boat builder how to do it right in '95. We did all this.
Never a leak to this day... and we live in a rainy climate.

Wear nitrile gloves... and have a plastic-lined pail at hand to hold the masses of paper towels you use when doing the clean up!
:)

We used smoked color Lexan. It came out just beautiful.

Regards,
L
 
If your hatches/ports are GEBO, they have a full complement of original parts to repair/service your boat.

I am very pleased with their service.

If you use a sealant, as mentioned by someone else, use one which does not fully harden.

GL with your repair
 
I've just discovered I need to undertake a similar job. I'm happy with the procedure, but not sure which sealant to use. I have plenty of Sika 291 on hand, but no other (apart from bathroom silicone which I wouldn't consider suitable). I don't really have much experience of the Sika so not sure how flexible it remains once set.

Would Sikaflex 291 be suitable for window bedding, or should I aim to obtain some LifeSeal instead?

Cheers,

Pete
 
Recently done a couple of windows using self adhesive neoprene tape, but you windows obviously have to come out. On a previous boat I used butyl strip which remains flexible (non-setting). With this, though you'll be trimming off the excess for weeks as it gradually squeezes out of the joint. Totally waterproof though. Available from caravan shops. I don't think introducing sealant into a crack will work - can't see you getting all the dirt and moisture out for the sealant to adhere properly. Take 'em out and dry the surfaces with hairdrier/heat gun/acetone
 
Cleaning up.....baby wipes work brilliantly for Sikaflex. I keep asking around but no wiser if it works for all the other stuff; anyone know?
 
Hi there - at last the chance to stop being a lurker and post a solution that has not already been mentioned.

Last year I used Scapa 3507 tape (from here http://hadlo-43547-001.dsvr.co.uk/Pages/seals-bedding.html) to bed new perspex cabin windows. Totally clean job, no mess and totally watertight once the screws are nipped up.

One word of caution - old windows may be brittle - I had hoped to just re-bed two of the smaller windows, but these showed crazing around the screw-holes once the tension was released.
 
Hi there Pygidium.

Thanks for the scapa tape idea - In fact I suddenly remembered today that I have a contact at a company making gaskets!

A quick phone call and they are going to send me some double sided adhesive backed EPDM closed cell foam

Hopefully this will do the trick - I was concerned about using mastic and getting it everywhere - The only problem I forsee is removing the old windows and cleaning them up. Just have to try I suppose.

Many Thanks for all the advice Forum members

JuSw
 
On any parimeter areas that you want clean and clear of whatever product (tube fed) you use, run lengths of paper masking tape down first.

Have a box of tissues ready to just pluck from, to wipe excess off, and as previously mentioned, an open bucket with a plastic liner (old shopping bag).

Most of the frustration from using these products comes from the mess during handling, using rags tends to 're-infect' the area with un-noticed goo.
 
Hunter boats had a nasty habit of glueing the windows in.
As the lexan or whatever got older and the glue cracked our Hunter pilot windows started leaking.
Because they were still stuck in parts it was difficult to wedge open the gap and run a hacksaw or chisel down the gap to clean out the old adhesive some broke when wedged out.
We replaced the windows with a Butyl rubber sealant Farocaulk I think it was called.Stayed rubbery and no leaks now.
 
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