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[Amel Yacht Owners] Super Maramu Dodger window replacement


Bill & Judy Rouse <yahoogroups@...>
 

Graham,

Good question. I do not know the answer because the Plexiglass supplier I used to cut the pieces chose the paint. He did an exact job predrilling all of the holes which matched up exactly.

I can see a few tiny places where he used too much sealant to secure the foam gasket for the port side opening windshield. Take care with the use of sealant on the gasket. Possibly if you can use your router to cut a slightly smaller slot for the gasket, you will not need to use sealant. My guess is this is how Amel did it. Try with some scraps of plexiglass before you decide.

I believe that the paint us an important part of making this look good. I used gray tinted plexiglass. Through the plexiglass the white paint he used looks gray. Probably should have used black paint, but white looks OK. 

Bill Rouse
BeBe Amel 53 #387
Sent from my tablet
+1832-380-4970 USA Voice Mail

On May 12, 2016 9:38 AM, "crwggb@... [amelyachtowners]" <amelyachtowners@...> wrote:
 

I am replacing the perspex windows on my fixed wind screen. On removal of the old ones it was observed that the edges of the windows were painted to hide the sealant when in position. Can any one tell me what sort of paint was used for this job and how the perspex was treated prior to painting to allow maximum adhesion.


I believe there has been a thread on this subject before but for the life of me I cant find it, perhaps someone has the message number?


Graham Boyd

SM140 Sula

Hong Kong


amelliahona <no_reply@...>
 

Hi Bill and all: 

I am preparing to replace my dodger windows due to crazing.  I measured the existing plexiglass (aka acrylic, perspex) and it is 10 mm thick (equivalent to 0.3937 inches thick.  The closest available here on the western side of the Atlantic is 3/8 ths inch thick = 0.375 inches thick.  Difference of almost 19 thousandths of an inch.  I don't have much choice but it worries me a bit that structurally it isn't as strong as the original.  Any thoughts?

Bill, as you used something other than clear plexiglass did you find that detrimental to visibility at night?  I have seen a few boats with the smoked plexiglass and they do look cool and I suspect are less susceptible to crazing.  What are folks thoughts on that?

What sealant have folks used?  I am seeing the Dow Corning 795 is recommended by many.  Thoughts on this?

Thanks for the thoughts on using gel coat to mask the edges of the plexiglass where sealant  interfaces.

Thanks in advance for sharing your experiences. 

Gary S. Silver    Amel Super Maramu 2000   Hull # 335  - Currently Puerto Del Rey Puerto Rico


Bill & Judy Rouse <yahoogroups@...>
 

Gary,

We used 10mm Plexiglass brand because it supposedly scratches less. We picked a gray tint. We tried to pick a tint darkness about the same as a 54 or 55. Yes, visibility is slightly changed, but it was not an issue for us and far outweighs the advantages in full sun...And you can always open the helm side. We also had sunbrella sunscreens made for the front, that allows opening the port side. We also cut new lock-downs for the port side. With the groove for the D gasket, the notching, and beveling required for the port side, you may want to consider a pro. Our total installed costs for 4 pieces plus the latches was about 900 euro, however I was told the guy increased the price about 200 the next time. 

I am not sure which sealant was used. When you remove the sides and the starboard front, you will see that about 1" is painted. This is important to get the right look. 


CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Galveston Island
Sent using Google Fi
+1(832) 380-4970

   


On Mar 28, 2017 00:10, "amelliahona" <no_reply@...> wrote:
 

Hi Bill and all: 


I am preparing to replace my dodger windows due to crazing.  I measured the existing plexiglass (aka acrylic, perspex) and it is 10 mm thick (equivalent to 0.3937 inches thick.  The closest available here on the western side of the Atlantic is 3/8 ths inch thick = 0.375 inches thick.  Difference of almost 19 thousandths of an inch.  I don't have much choice but it worries me a bit that structurally it isn't as strong as the original.  Any thoughts?

Bill, as you used something other than clear plexiglass did you find that detrimental to visibility at night?  I have seen a few boats with the smoked plexiglass and they do look cool and I suspect are less susceptible to crazing.  What are folks thoughts on that?

What sealant have folks used?  I am seeing the Dow Corning 795 is recommended by many.  Thoughts on this?

Thanks for the thoughts on using gel coat to mask the edges of the plexiglass where sealant  interfaces.

Thanks in advance for sharing your experiences. 

Gary S. Silver    Amel Super Maramu 2000   Hull # 335  - Currently Puerto Del Rey Puerto Rico



Ben and Gayle Super Maramu #347
 

Hi Gary,
I replaced my windows in St Martin last year with a tinted acrylic and they are much better than clear on a sunny day and nite time vision is not an issue.  However, after requesting 10mm they instead installed 9mm (.354) and it is too thin. It decreases the weight of the panes causing an open port windshield too flutter in a strong wind.  I would recommend staying closer to 10mm.  I will replace my windshield again in Martinique this summer with 10mm.
Ben

Ben and Gayle 
La Bella Vita
SM #347
6S


On Mar 28, 2017, at 6:40 AM, 'Bill & Judy Rouse' yahoogroups@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Gary,

We used 10mm Plexiglass brand because it supposedly scratches less. We picked a gray tint. We tried to pick a tint darkness about the same as a 54 or 55. Yes, visibility is slightly changed, but it was not an issue for us and far outweighs the advantages in full sun...And you can always open the helm side. We also had sunbrella sunscreens made for the front, that allows opening the port side. We also cut new lock-downs for the port side. With the groove for the D gasket, the notching, and beveling required for the port side, you may want to consider a pro. Our total installed costs for 4 pieces plus the latches was about 900 euro, however I was told the guy increased the price about 200 the next time. 

I am not sure which sealant was used. When you remove the sides and the starboard front, you will see that about 1" is painted. This is important to get the right look. 


CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Galveston Island
Sent using Google Fi
+1(832) 380-4970

   


On Mar 28, 2017 00:10, "amelliahona" <no_reply@...> wrote:
 

Hi Bill and all: 


I am preparing to replace my dodger windows due to crazing.  I measured the existing plexiglass (aka acrylic, perspex) and it is 10 mm thick (equivalent to 0.3937 inches thick.  The closest available here on the western side of the Atlantic is 3/8 ths inch thick = 0.375 inches thick.  Difference of almost 19 thousandths of an inch.  I don't have much choice but it worries me a bit that structurally it isn't as strong as the original.  Any thoughts?

Bill, as you used something other than clear plexiglass did you find that detrimental to visibility at night?  I have seen a few boats with the smoked plexiglass and they do look cool and I suspect are less susceptible to crazing.  What are folks thoughts on that?

What sealant have folks used?  I am seeing the Dow Corning 795 is recommended by many.  Thoughts on this?

Thanks for the thoughts on using gel coat to mask the edges of the plexiglass where sealant  interfaces.

Thanks in advance for sharing your experiences. 

Gary S. Silver    Amel Super Maramu 2000   Hull # 335  - Currently Puerto Del Rey Puerto Rico



greatketch@...
 

Gary,

My engineering opinion is that going with the 3/8 thickness will be just fine.  It's 96% of the thickness of the original, and it is not like 3/8" material was available in France and rejected because it was too weak...

It is unlikely that the darker color will significantly affect the crazing that occurs with long term UV exposure, since that is predominantly a surface effect.  I am not a fan of the tinted windows, but that is really just my own esthetic, not an engineering judgement.

Choice of material for this application is always a trade-off.  Lexan (and similar brands) are stronger to impast failure, but shorter lived in UV exposure without custom coating. Here is a good summary:

I am not sure what the original material was on the windscreen. The panels on my boat were replaced with 3/8" clear plexiglass by the previous owner.

Bill Kinney
SM#160 Harmonie
Ponce, PR