Replacing windows

[eastcoastbernie]

I have earmarked this coming weekend and the weekend after to remove my existing windows and replace with new ones. The plan is to replace them this coming weekend, send 'em off to the window-making people to use them as a pattern for the new ones, then fit the new ones the following weekend.

If anyone has any hints and tips for getting the old ones out and fitting the new ones, I would be most grateful.

They are simple, frameless windows. They appear to be held on with fittings that go right the way through from outside to inside, with a layer of sikaflex or something round the outside edge.

 

[30boat]

If they are plain perspex,and it appears they are,you have to take into account thermal expansion wich is something perspex does a lot.The screw holes should be oversize to acomodate movement.Never countersink them .As the perspexs expands in the heat the compression loads generated by the screw heads are large enough to crack it.So use screws with heads that sit flat on the surface.I always apply a bed of sealant and allow it to cure for an hour or so.Then right before fitting the perspex I lay another thin coat on the already cured sealant .Remember to fill the oversized screwholes with goo and tighten lightly.The next day you can do the final tightening but don't overdo it.You now have what is essentially a gasket.The window can later be further tightened if it starts to leak.
There are several sealants you can use.UV proof Sikaflex (can't remember the name ) is very good .I had very good results with good quality silicone.It doesn't stick too strongly(good for later removal and cleaning) it's elastic so moves with the window and is inexpensive.

 

[BobnLesley]

'Never countersink them .As the perspexs expands in the heat the compression loads generated by the screw heads are large enough to crack it'

which explains to this moron why three successive motorbike fairing screens have done exactly that.

 

[Adamastor]

Why not use a credit card? "Hello, is this Acme Window Refurb, Inc.? Can you fix my Luxury-Yacht windows? I'll pay handsomely!"
Else if the glass is stuck in into a mastic bed (Stika-flex), use a piano-wire or trace-wire (single strand fishing-wire) to saw it out. Over here, we use evil SS wire for fish-traces when shark or 'cuda fishing, for example. It's single-strand the size of 40lb monofilament, and hard as hell.
You put a bend about 1/2" from the end and literally poke the end thru the bedding-compound. The bend steers the wire round the corners. Then you use it like a wire-saw and saw the mastic thru. Hope this helps!

 

[VicS]

[ QUOTE ]
fittings that go right the way through from outside to inside

[/ QUOTE ] "Interscrews" if they just have a slotted screw type head inside and out.

The snag with those is that they always AFAIK come countersunk! However they consist of a screw and a tubular nut. The screws could be replaced with pan headed screws. and fitted from the outside ... perhaps. The countersunk ones are fine for fitting framed windows.

They are usually M5 but Westerly used a smaller one(M3.5), that is difficult to get, at one time

www.projectplastics.co.uk in Colchester is my suggestion for a supplier in your area if one needed. They can preshape them to fit curved cabin sides if necessary.

 

[jerryat]

I wouldn't use Sikaflex or any other mastic. Get some of the purpose made window/hatch bedding adhesive closed-cell foam tape from your nearest friendly chandler instead. Check the total length you need for each window because it comes in 3 metre lengths and you may need to buy an extra roll or two. You only really want the one joint (where the single length of tape meets) at the bottom of the window. It'll work round quite tight corners too! It's very cheap but very effective.

Remove the backing tape and stick it to the window edge leaving a little bit projecting. Hold window in place, push small electrical size screwdriver through each hole, followed by the bolt, and tighten up.

The foam crushes to almost nothing and is totally watertight. When you're happy, just run a Stanley knife round the window edge and remove the strip. That's it - no mess - inside or out! /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

 

[holly1]

If you use the foam tape you see it through the perspex it looks rubbish

 

[LittleSister]

I haven't done so yet, but others on the forum have recommended using Scapa 3507 tape to bed windows instead of Sikaflex or similar (I have some on order). Said to avoid mess of mastic and be easier to remove window later.

It is obtainable from various outlets, but check out Hadlow Marine Services - they have good web-site and can supply by the metre or in 10m rolls.

They also have on their web-site various very good information sheets available to download about removing/fitting/repairing various types of boat windows.

 

[VicS]

I don't know about the tape verses sealant argument but if you use Sikaflex use the one for plastic windows Sikaflex 295 UV It does not contain solvents that might damage the plastic and it is UV resistant.

 

[30boat]

I've seen windows where the tape had squeezed out but maybe it was of the wrong type.In order to hide the tape from sight a black strip can be painted around the perimeter of the window with spray paint.Automotive paint sticks very well to perspex even without sanding and providing the masking is done well it looks good.Jeanneau and Beneteau do it only with aluminium paint.I should be done on the outside face.

 

[jerryat]

[ QUOTE ]
If you use the foam tape you see it through the perspex it looks rubbish

[/ QUOTE ]

Sorry, that just should not occur if done properly!

All you do is stick to the adhesive side of the tape to the coachroof instead of the other way round. When the window bolts are tightened, it forms a perfect black/dark grey band round the window. I know this works 'cos I've done on at least three boats!!

It looks a hell of a lot better than mastic, that's certain!!!

 

[maxi77]

[ QUOTE ]
If you use the foam tape you see it through the perspex it looks rubbish

[/ QUOTE ]

But waterproof if properly done, what do you want, good looks or no leaks, I know where my vote is.

 

[Sixpence]

Hi Bernie, busy doing the same thing myself at the moment so until I'm done I can't say how good the seal is going to be, but if you contact Oundle marina, they sell a sort of thin plasticine type stuff on a roll (pay per metre) and so far it seems to work just fine, just don't tighten the screws too much. Trim off any excess inside and out and the final look is good.
As for removing the windows, don't forget a hammer and punch to (gently) force the screws through the windows and hull. Don't hit too hard or you could end up with bits of perspex instead of a whole template.
Looking forward to seeing the new look Beyond Reason, though they looked fine to me.