bedding seal for simple screw on frameless acrylic windows

[Dellquay13]

I'm looking for a simple tape type seal for my new windows. I don't want to gun some gunk in, and I don't want anything as damaging to remove as sikaflex adhesive.
I used a grey butyl type tape on a roll called gebo(?) in the past and it never stopped oozing out, so I'd rather not go that route again.
Has anyone tried the single adhesive sided uPVC tape (25mm x 3mm) on frameless perspex windows?
TIA,
Chris

 

[PetiteFleur]

I've used Butyl tape but you must fit a stainless washer on each screw position, between hull and window to prevent it all squeezing out.

 

[VicS]

Eagle Boat Windows suggest a tape called SCAPA but they don't supply it. They also suggest the use ofvspacing washers when windows are fixed to a curved surface
Fitting a frameless window with fasteners

Also take a look at this page of Hadlow Marine's website
http://hadlowmarine.com/Pages/seals-bedding.html

 

[michael_w]

Follow the instructions in the Sikaflex marine manual or do the same job several times.

 

[Stemar]

I'd use butyl tape, with PetiteFleur's washers.

I tried neoprene tape. Is that what you mean? uPVC is what they use to make double glazing frames. I don't know if that was what leaked, or if it was the seals between Perspex and frame, but butyl was what finally kept the rain out for me.

 

[rotrax]

Fitted ten acrillic frameless windows four years ago to our steel Hartley 32 in Wellington, NZ. Six round ports, four oblong windows.

Used black butyl tape and washers. I did not tighten fully for two weeks, then tightened to what my 'feel' told me was about right and then trimmed the squeezed out tape.

I have trimmed a few bits here and there, but nothing significant. I have no leaks from these windows and unlike Sika, should they need to be removed it will be easy.

 

[Rappey]

Pvc foam tape all the way. I use the double sided. It's worked for double glazed units for at least 30 years.
I use the 10mm wide as 25mm might be trouble to bend around corners. Can always run two 10mm strips side by side.
Mast base, windows, hatches, stanchion bases, swan neck . Brilliant stuff with a superb neat finish.
Buy it from a double glazing supplier so you know you get the correct tape as similar tapes can slide out.
Stick it to one side then cover it with soapy water so you can slide/align it before it sticks. The sticky part is to hold tape in place.
Have used lots of butyl and pvc tape. Pvc is far neater and quicker and never had a leak.

 

[Dellquay13]

Eagle Boat Windows suggest a tape called SCAPA but they don't supply it. They also suggest the use ofvspacing washers when windows are fixed to a curved surface
Fitting a frameless window with fasteners

Also take a look at this page of Hadlow Marine's website
http://hadlowmarine.com/Pages/seals-bedding.html

It was reading the Hadlow page that made me ask about the upvc tape. I've seen a few sites selling scapa 3507 tape, so I was looking for anyone's experience of it or other brands.

 

[Dellquay13]

Pvc foam tape all the way. I use the double sided. It's worked for double glazed units for at least 30 years.
I use the 10mm wide as 25mm might be trouble to bend around corners. Can always run two 10mm strips side by side.
Mast base, windows, hatches, stanchion bases, swan neck . Brilliant stuff with a superb neat finish.
Buy it from a double glazing supplier so you know you get the correct tape as similar tapes can slide out.
Stick it to one side then cover it with soapy water so you can slide/align it before it sticks. The sticky part is to hold tape in place.
Have used lots of butyl and pvc tape. Pvc is far neater and quicker and never had a leak.

Do you have to bend the tape round corners? Can you cut it neatly and butt joint it without leaks? Did you screw down through the tape?
Thanks,
Chris

 

[geem]

We have tried butyl tape but in the Tropics the heat makes it flow out. A real mess to clean up. For our frameless windows that bolt through, we use Geocel Works. It not a sticky or as difficult to remove as Sikaflex but it seals really well. It comes in different colours. We bed all our deck fittings with it as well. Been using it for 10 years and very happy with it

 

[Sailing steve]

I've just put new frameless acrylic windows in my boat. and sealed them with Scapa tape.

P

It was reading the Hadlow page that made me ask about the upvc tape. I've seen a few sites selling scapa 3507 tape, so I was looking for anyone's experience of it or other brands.

I've just made and fitted new frameless acrylic windows on my boat too and used Scapa tape supplied by Hadlow marine. I used a combination of 50mm wide tape and 240mm wide sheet.

Pressure washed it yesterday in preparation for launch and not a single leak anywhere. Well pleased with that.

 

[rotrax]

We have tried butyl tape but in the Tropics the heat makes it flow out. A real mess to clean up. For our frameless windows that bolt through, we use Geocel Works. It not a sticky or as difficult to remove as Sikaflex but it seals really well. It comes in different colours. We bed all our deck fittings with it as well. Been using it for 10 years and very happy with it

Really?

It is not very sticky in my direct experience and if trimmed close to the window edge with a craft knife just peels off. Any minor residue wipes away with white spirit.

It can get pretty hot in Wellington and I have no issue with my black butyl glazing tape. The trick is, I believe, to 'nip' it down and leave it for a bit, then re-tighten after a couple of weeks and trim off.

It works for me, no leaks, no significant leakage once it has had its second tighten.

 

[Neeves]

Eagle Boat Windows suggest a tape called SCAPA but they don't supply it. They also suggest the use ofvspacing washers when windows are fixed to a curved surface
Fitting a frameless window with fasteners

Also take a look at this page of Hadlow Marine's website
http://hadlowmarine.com/Pages/seals-bedding.html

Scapa are a UK company and make all the tapes you know of and many you don't. Ring them up and speak to their technical department. We use their amalgamating tape - its as good as any.

Jonathan

 

[Neeves]

Use a scrap piece of acrylic - and make your self an acrylic chisel or scraper. Bevel the working edge to 45 degrees, sharpen it as you would a chisel - it will remove Sika and other mastics without damaging the gel coat, because the gel coat is harder than the acrylic. You do need to keep the working edge sharp - so unless you have an on site sharpener make 2 or 6 scrapers.

Jonathan

 

[geem]

Really?

It is not very sticky in my direct experience and if trimmed close to the window edge with a craft knife just peels off. Any minor residue wipes away with white spirit.

It can get pretty hot in Wellington and I have no issue with my black butyl glazing tape. The trick is, I believe, to 'nip' it down and leave it for a bit, then re-tighten after a couple of weeks and trim off.

It works for me, no leaks, no significant leakage once it has had its second tighten.

We had it on windows, behind instruments in the cockpit and under our steering pedestal. It squeezed out of all of them over time. If you happened to touch it, the sticky mess ruined clothes. I see no advantage over a bedding compound that isn't prone to heat damage. There may be better products than the one we used but either way, Geocel Works does what we need to do leak free and no sticky mess?

 

[rotrax]

No sticky mess with the black glazing butyl I purchased from a 'TradeMe' supplier in Wellington.

It was mildly sticky when removed from the backing papers but this soon hardened after being squeezed out of the joints until it was like plasticine.

As I said, after squeezing out after its second tighten, running a craft knife around allowed it to be easily peeled away, with fingers, no gloves needed.

In fact, the removed butyl was rolled into a ball and re-used for other jobs.

I am not sure what you used, but my direct experience with black butyl glazing tape in NZ and off white Butyl glazing tape here in the UK, neither act as you have found.

Two years ago I bedded in a second bow roller and this year the Hoyt boom base and a new winch using butyl tape. What squeezed out was quickly and easily peeled away, just like plasticine.

 

[geem]

No sticky mess with the black glazing butyl I purchased from a 'TradeMe' supplier in Wellington.

It was mildly sticky when removed from the backing papers but this soon hardened after being squeezed out of the joints until it was like plasticine.

As I said, after squeezing out after its second tighten, running a craft knife around allowed it to be easily peeled away, with fingers, no gloves needed.

In fact, the removed butyl was rolled into a ball and re-used for other jobs.

I am not sure what you used, but my direct experience with black butyl glazing tape in NZ and off white Butyl glazing tape here in the UK, neither act as you have found.

Two years ago I bedded in a second bow roller and this year the Hoyt boom base and a new winch using butyl tape. What squeezed out was quickly and easily peeled away, just like plasticine.

Just looking at the climate in Wellington. It's like the UK. The temperatures here in the Caribbean are dramatically different. It rarely drops below 21degC at night. The daily temperatures are 27-29degC and it's currently winter. It's a lot hotter in the summer. When we leave our boat for the summer in Curacao, the cabin temperature reaches over 45degC regularly. So yes, I am sure butyl is a good solution in a temperate climate but it's not in a Tropical climate.
Every type of mastic, Sikaflex etc is tested to its limits in this climate. Our friends 10 year old Jen 45 pilothouse has had all the pilothouse windows fail. The windows are simply dropping out.

 

[Dellquay13]

Just fitted my new windows with scapa 3507 uPVC tape, and it was a doddle... ????

 

[aidancoughlan]

I used MarineSeal 033 in 2007 on all my windows, and the windows never leaked between then and when I sold the boat over 10 years later.
Buy Marineseal 033 Online - Premium Sealants & Primers by Marine Mastics

It is a soft, two-part non-adhesive , non-setting putty, and didn't squeeze out over time like Butyl tape does. I seem to recall it being white when I used it, but it seems like it's only available in black now.
It was easy enough to use, and I remember being happy with it at the time , apart from it's subsequent performance doing well.

Soft and non-adhesive like Butyl, but not as "oozy" over time.