help sealing windows..

[TactilePaul]

So.., windows are going back in v soon, (rain friday!!), but as posted a few days ago - I have different curves along sealing faces..

One thing we all learned from that thread, there are many, many ways and opinions,!
I would love the Abromast or tape methods to work, and I would pursue them, BUT, when faces meet in the middle there is a few mm gap at the edges, the window is too straight, boat is more curved,
What about expansion, should I be trying to hold that back with the screws?, or is this a force I can't fight?.. what about trying to force the window into shape of hull by screwing ends very tight I dont think I would be able to bend it!, or want to!!????
I think my current plan is to set a small bead of sikaflex along the middle 1/3 top and bottom and let that go off, this will prevent the middle section squeezing too much out when i tighten, then do the whole window with sikaflex or similar, the more flexible the better I feel?? I'd prefer tape, but this would require differing thickness, and Abromast has failed me twice, the main problem with sealant removing it, i don't see this as insurmountable, we have easy access to get a saw blade all around and cut out in future..?
any thoughts / advice hugely appreciated. I have repaired the area below and have drilled and plugged the holes with resin filler.. I think the problem is all in that corner.
Thanks.

 

[Deleted member 36384]

Read the data on this page and do the correct thing. I think your idea of mixing sealants and allowing some to set is not a good idea. It's all been done before: -

http://hadlowmarine.com/Pages/Downloads.html

Repair all the holes by filling with GRP and redialling as appropriate.

 

[Boathook]

Just make sure that the repaired corner is flat. You could also put a screw in there as well if the frame looks like it is trying to bend out.
I bedded my window frames down on arbomast br butyl sealant. Used too much (as usual) and took some cleaning, even after removing masking tape but no leaks from that area after years.

 

[Mait]

That's a nice link, thanks! I've got the same job to do...

...
http://hadlowmarine.com/Pages/Downloads.html
...

 

[TactilePaul]

Read the data on this page and do the correct thing. I think your idea of mixing sealants and allowing some to set is not a good idea. It's all been done before: -

http://hadlowmarine.com/Pages/Downloads.html

Repair all the holes by filling with GRP and redialling as appropriate.

if you read post properly you'd know that I need to bend my windows in order for a uniform thickness tape soloution to work, and also that I have filled the holes with GRP allready.. I think when you say 'not a good idea' and 'do the right thing' , your just patronisingly sending me back to the text book answer anyone can google, this forum is for help with tricky jobs that can't be done easily.. and 'redialling' ?? not an enginering term I am familiar with sorry..

 

[Stemar]

I had a similar problem on Jissel. After several tries with neoprene tape to seal the frames, and all sortds of goop and rubber seals to seal the perspex in the frames, I got oversized perspex, shaped to the outside of the frames, cut the frames to leave just the outside part as a trim and through-bolted the whole lot using a nice marine ply trim and domed nuts on the inside. The result was a dry boat for the first time in years.

 

[rotrax]

Butyl tape - can be bought up to 5mm thick and in a few colours. I was given some in a cream colour that almost - but not quite - matches our Island Packet.

Once windows are fitted it can be easily - and cleanly - trimmed with a craft knife.

Fitted four large - 600mm X 250mm - and eight round 250 mm ports to our steel Hartley a few years ago, not one leak. It had several issues regarding curves/shape to overcome. The windows were fixed internally, leaving a step which rusted. Now fitted like Stemar's externally.

Butyl tape was rolled into 2mm threads and wound around the screws and under the washers too. Little mess, almost like working with blutack.

Well pleased.

 

[Tintin]

if you read post properly you'd know that I need to bend my windows in order for a uniform thickness tape soloution to work, and also that I have filled the holes with GRP allready.. I think when you say 'not a good idea' and 'do the right thing' , your just patronisingly sending me back to the text book answer anyone can google, this forum is for help with tricky jobs that can't be done easily.. and 'redialling' ?? not an enginering term I am familiar with sorry..

It was the best advice. Anything else will be a right PITA and you'll be re-doing it regularly.

Been there, done that, got the T-shirt.

Of course it wasn't what you wanted to read, but shooting the messenger a) isn't particularly nice and b) makes people think twice about offering their advice from years of experience.