On Apr 26, 2018, at 2:33 AM, James Alton lokiyawl2@... [amelyachtowners] <amelyachtowners@...> wrote:

Ryan,

   Well I have used mineral spirits/paint thinner (for oil based paints,  not urethanes)  on Acrylics for 40 years on countless boats without any obvious negative effects but that is the only testing that I have done.  I always tape to keep the worst of the caulking off.  Scrap the bulk of the material off with something soft like the soft plastic spreaders used for applying bondo and then finish cleaning with rags and the paint thinner.  Also, if you only clean up a small area at a time, your caulking will be easier to remove.  Once you disturb the bead and spread it out thin, it cures much more quickly.

   Bill R. is definitely right that if you use a lower strength silicone that the future removal will be much easier.  My reasons for using the 3145 is because the caulking can last the life of the new plexiglass without leakage and I would rather fight with the removal aspect at the end than to deal with leaks and having to redo the caulking.  There seems to always be a piper to pay!  (grin)  The 3145 btw  is also non corrosive so the stainless screws fair a bit better than if you use the more common silicones with the acetic acid in them.  I think that there are other non corrosive silicones with a lower strength than the 3145 out there but don’t know of any that are clear or white off hand.  Perhaps others can help. 

Best of luck with your project.

James

SV Sueño

Maramu #220 

  

On Apr 25, 2018, at 6:07 PM, Bill Rouse brouse@... [amelyachtowners] <amelyachtowners@...> wrote:

Silicone RTV. If you get any squeezed out when screwing down, cut it with a razor and peel it off. Let the screws do the securing and the RTV, the sealing. The next owner will be thankful.

Best,

CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Amel School www.amelschool.com
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970

On Wed, Apr 25, 2018, 19:47 Ryan Meador ryan.d.meador@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Pat and Ian, that might be a workable idea, but it would be a lot of work.  Getting the masking tape right to paint the edges (to cover the sealant) was a huge job, and this would be the same again.

James, both of your ideas seem like much less work.  I had not considered using longer screws.  That still leaves the problem of getting the butyl tape into position, and it's very frustrating to cut... so I think perhaps I'll go the silicone route.  I also was not aware silicone could be easily wiped off acrylic.  I thought I would have to use a solvent (like acetone) which would attack it.  I'm surprised mineral spirits is safe; I usually consider that harsher than acetone.

Does anyone have a recommendation for a silicone?

Thanks,

Ryan

SM 233 Iteration

Boston, MA, USA

On Wed, Apr 25, 2018 at 1:06 PM, James Alton lokiyawl2@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Ryan,

   If you want to use the butyl tape, just get some longer screws, pins or even some drill bits that fit the holes in your window panels.  Next locate a few corner holes in your frame.  Insert two long screws pins or whatever you are using into the matching holes in your new plexiglass and hold the new panel an inch or two above your window frame.  You can now work the long screws or pins into the holes you exposed in the frame and at that point lower the plexiglass into perfect position on the first try.  From that point just install several of your permanent screws and remove the temporary long locating screws or pins.  If you still have concerns, do a dry run without the butyl.  You will need some extra hands.  And no worries cleaning most silicones off of acrylic.  You can pretty much remove it with a clean rag.  Mineral spirits or paint thinner is safe for the acrylic if needed.  Don't use anything harsh like acetone.  I will let someone else recommend the sealant.  I will be using the Dow Corning 3145 Gray on mine.  

Best,

James

SV Sueno

Maramu #220

On Apr 25, 2018 11:08 AM, "Ryan Meador ryan.d.meador@... [amelyachtowners]" <amelyachtowners@...> wrote:

 

Hi all,

I'm replacing my dodger windows. I've had the acrylic fabricated, I've painted the edges, I've filled and drilled the screw holes.... The only thing I'm missing is the sealant.

I had intended to use butyl tape, but the stuff I got is way too stickly to work with. It's almost impossible to cut, and even if I got it in place, I'd be unable to fine tune the window position before screwing.

I think the original sealant was a type of silicone. Does anyone know what it was and how it was applied? I'm scared it will squish out onto the window and I won't be able to get it off the acrylic.

Thanks,

Ryan

SM 233 Iteration

Boston, MA, USA