How to Have Sexy Windows !?

[Northeaster]

It has been a couple of years since I did mine, but I think I found the recommended primer paint for the 3M VHB tape on the 3M website.

[Northeaster]

copy and paste didn't work so well so here is the link. Suggests 3M primer 94 for glass / plastics:

http://multimedia.3m.com/mws/mediawe...Vs6EVs6E666666--

Surface Concern Suggested Primer Alternatives

Steel or Aluminum Surface must be clean None suggested Abrasion may clean surface, 3M™ Adhesion
Promoter 111 for increased adhesion.
Copper, Brass, Bronze Oxidation after bonding Lacquer or varnish

(b) Architectural grade coatings
Concrete, Brick Non-unified or rough surface, 3M™ Rubber and Vinyl Spray 80 Concrete sealer, paint
moisture
Glass, Stone, Ceramic Tile High humidity, moisture 3M™ Silane Glass Treatment AP 115 or 3M™ Primer 94
similar silane coupling agent in IPA/water
mixture(b)

Wood (soft, hard Weak fiber layer on surface 3M™ Rubber and Vinyl Spray 80, Urethane paint, varnish
particle board, etc.) (e.g., low surface strength) 3M™ Fastbond™ 30 Contact Adhesive
Plastics: Polyolefin Low adhesion 3M™ Primer 94 (additional surface Flame treatment, Corona treatment
preparation may be required)
Non-olefin Additives, low adhesion 3M™ Primer 94, 3M™ Scotch-Grip™ Abrade or

Plastic Adhesive 2262(a) 3M™ VHB™ Tapes 4932/4952/5925/5952/5962

[elhix]

Originally Posted by mikereed100

Use Sikaflex 209 primer. It should be next to the 295UV at the chandlery.

This might be the stuff as it's black whereas the VHB primer is yellow.

Thing is I'm not specifically after a primer as the VHB tape - according to 3M - doesn't need one on polycarbonate, they just suggest lightly abrading the surface. I'm more interested in a paint that will cover the area of lexan that is stuck to the boat and therefore cover the VHB and Sikaflex - the messy bits - to tidy things up and block UV.

I've ordered some of the Sika 209...

[Christian Van H]

Originally Posted by elhix

I've ordered some of the Sika 209...

Be VERY careful with this stuff. It has the consistency of water, and stains all it comes in contact with instantly. It etches the plastic, and dries almost too quickly. When masking, remember that it's like water, and think about what would happen if you painted water on... it trickles and can ruin an EXPENSIVE piece of Lexan right quick. Be forewarned...

[Sunspot Baby]

The 209 primer can be cleaned off with alcohol if done soon after drip or run and the alcohol is easy on the lexan.

George

[rtbates]

The sexiest PORT by a huge margin is made of bronze and glass and it OPENS and it doesn't leak a drop after 26 years of service and the glass is as clear as the day it was installed....

Bronze and Stainless Marine Hardware, Seacocks, Portholes, Thru Hulls - Spartan Marine Hardware and Accessories

Houses have windows boats SHOULD have ports..

[elhix]

Originally Posted by rtbates

The sexiest PORT by a huge margin is made of bronze and glass and it OPENS and it doesn't leak a drop after 26 years of service and the glass is as clear as the day it was installed....

Houses have windows boats SHOULD have ports..

I've got ports AND windows...is that bad? Is my boat a house??

[Northeaster]

elhix - I thiink that many people have primed the new polycarbonate or acrylic not just to get a better grip, from the sealant or VHB tape, but also to hide the uneven tape look, as seen from outside (depending on your level of tint).
Even though my acrylic seems darl, you would definitely have been able to see the mess of tape - space - squished dow 795 sealant from the outside, if I had not have primed the edge of the acrylic with the black 3M primer 94 (or equivalent). As my new windows had about 2" of overlap on all sides, I primed this overlap area, and none of the tape or squished, uneven sealant can be seen, when looking at them from outside (on the deck).
You may want to mock aup a crap piece of lexan, and tape / seal it to something, to see if the mess is visible, before you proceed with all of them.

[elhix]

Originally Posted by Northeaster

elhix - I thiink that many people have primed the new polycarbonate or acrylic not just to get a better grip, from the sealant or VHB tape, but also to hide the uneven tape look, as seen from outside (depending on your level of tint).

Thanks Northeaster,

Yes that's exactly what I was after - the hiding effect - as they say VHB sticks well enough to polycarb without a primer. The sikaflex primer arrived today, it's black so I'll use that.

[mikereed100]

elhix,

I used VHB tape with Dow 795 to fill in on my windows without any paint or primer and nothing shows through, but my windows are glass with a darker tint than most acrylic or polycarbonate. I second Northeaster's suggestion to try a bit without primer first and see how it looks.

Best of luck,
Mike

[elhix]

'Sexy' windows achieved today! Not too difficult really. Two things helped: the window surrounding area is black - like the sika - and the lexan came with a helpfull protective film that was invaluable as a mask.

VHB 4991 - sticks instantly, no second chances but is pretty conformable and unlike the guy in the article I was able to go all the way round the window in one shot.

sikaflex primer - as mentioned elsewhere is very watery stuff and hard to apply with a brush (goes tacky instantly), I found a wad of fleecy material from an old jumper brilliant for applying it with no drips or problems.

[GordMay]

C&C (Flush Frameless) Portlight Replacement
➥ Portlight Replacement

[Triton318]

Does anyone know the thermal expansion for tempered glass? Is it closer to fiberglass (i.e. cabin side) than acrylic or polycarbonate? And is there a sealant/adhesive that would make a strong bond between glass and gelcoat?

[GordMay]

I don’t think that tempering changes the thermal coefficient of expansion of the basic float glass plate:

See ➥ Glass Types

And ➥ Coefficients of Linear Expansion

[mikereed100]

Originally Posted by Triton318

Does anyone know the thermal expansion for tempered glass? Is it closer to fiberglass (i.e. cabin side) than acrylic or polycarbonate? And is there a sealant/adhesive that would make a strong bond between glass and gelcoat?

In addition to the VHB tape and Sikaflex that Ehilix used Butyl rubber tape and Dow 795 are both suitable and easy to work with.

Mike