Leopard (2012+)

[Limpet]

Are all the saloon windows polymer on the 2012+ Leopards?
Plexi has 10x the thermal expansion as compared to glass and is purported to be the reason why the windows leak, as it breaks the seal over time.

[LauraMarie Cat]

So, what is the solution? Glass has 1/15th strength of Acrylic. Fully tempered glass is 5x stronger, so 1/5th the strength of Acrylic. More importantly glass fails ugly and dangerously, leaving the inside of the boat totally exposed. A hard tap on tempered glass and it explodes into small bits.

Polycarbonate (Lexan) is very strong, but does it have a lot less expansion to avoid the seal failure issue?

[Limpet]

I would imagine the solution would be a more flexible bonding solution. One with more thickness and flex, yet very good adhesion.

[LauraMarie Cat]

Limpet,
Since you seem very interested in the issue of failing Leopard windows (seals and cracking), I suggest you check out the substantial Groups IO threads for Leopard Catamaran owners that delve deeply into this topic.
https://groups.io/g/Leopardcatamaranowners

[capn_billl]

Every Leopard I've seen, including mine has at least one cracked window. very annoying.

[LauraMarie Cat]

capn billl,

Wow, I didn't know it was that bad with failing acrylic! I wonder if the cracking issue is the same for other brands of catamarans with large saloon windows? This discussion might be worth taking to a broader forum to include all large catamarans with big windows.

The combination of the brittleness of acrylic, the very large thermal expansion rate of acrylic and the huge windows used in a Cat with the twisting action between the two hulls may all be combining to simply be an unresolvable issue. This is more reason to consider changing away from acrylic to glass or polycarbonate.

Polycarbonate is extremely strong, but also very vulnerable to both UV and scratching, so if anyone goes that direction, be certain the polycarbonate has both sides covered with a UV / scratch resistant film. The upside is that polycarbonate is so strong, it can be thinner.

Glass must be laminated and possibly tempered as well and fairly thick to have adequate strength, but still there is the potential risk for breakage. Laminated safety glass is the way to go, because its much stronger than a monolithic panel and it will stay together when broken, but glass is heavy. Two 1/4" laminated panels are slightly more than twice as heavy as 1/2" thick acrylic. Do not use the standard PVB interlayer for lamination, because it is vulnerable to delamination in wet environments. Use EVA at a minimum, but by far the best is an SGP interlayer (ionoplast) to make SentryGlas.

All window choices have tradeoffs in cost / performance / weight / scratch & UV resistance. Choose wisely and also choose your sealants wisely.