What material used in my hatches?

[Dean Abramson]

On our 1984 CD31, we have two Bomar hatches. What material is the "clear" part? (In the case of ours, not very clear at all anymore. I suspect they came new as tinted, but ours are now also yellowed, scratched, abraded.)

Is that Lexan?

I think silicone gets along well with Lexan, and we want to seal to some tiny cracks in the seals around the hatches. In case my hand is not steady (a good bet), I want something that will not harm the Lexan (or whatever it is) if it gets on there.

Thanks.

[mathiasben]

I replaced the forward hatch on my CD27 last year and used G.E. Ultraglaze sealant to bed the replacement lexan into the frame.

[Dean Abramson]

Thanks, Mathias. I appreciate it.

[Frenchy]

The material is Polycarbonate (Lexan). If you decide to replace, a newer scratch-resistant and costlier iteration is
available. - Jean

[S/V Ethan Grey]

The material is Polycarbonate (Lexan). If you decide to replace, a newer scratch-resistant and costlier iteration is
available. - Jean

Hi Jean,
What material and where would I find it? My front hatch is cracked.
Thanks,
David

[Paul D.]

If you are in a metro area, You should be able to get the same thickness acrylic or lexan sheet of plastic at an industrial plastics shop. You may have more options with acrylic. The shop may possibly cut, shape and drill it to your measurements or if you can give them the old lens too. Otherwise it is not too hard to DIY but I would watch a few you tube videos for cutting and drilling acrylic as there are a few tricks to it, taping the edges and using lubricant when drilling etc.

While I have not yet replaced my hatch lens' yet, I have made a few acrylic replacement parts and found it not too difficult.

Good luck!

[hilbert]

Cast acrylic is worth considering when replacing the original polycarbonate lens, see the following links for an explanation:

https://hatchmasters.com/acrylic-vs-polycarbonate/

https://www.sailnet.com/forums/783864-post9.html

Last year, I replaced 1/4" polycarbonate with 3/8" cast acrylic (57% Transparent Light Smoke) from Tap Plastics.
They cut the piece, rounded the corners and rounded the top edges to my specifications for just under $75, before shipping.

For the most part, I followed Maine Sail's above recommendations for the install.
However for the sealant, I used BoatLife's Black Life Seal, which is a combination of silicone & polyurethane (not to be confused with BoatLife's Life-Calk, which is plysulfide).

Before:


New lens with gap for sealant:


After:

[S/V Ethan Grey]

hilbert how do you like the thickness & transparency? Would you go thicker/thinner? Would you go dark smoke 36 or keep what you ordered? I'm looking at doing the same thing and would greatly appreciate the information that you sent to Tap Plastics. I'm assuming the CD28 & CD30 hatches are the same, but they may not be. Also, did you get routed edges? My front hatch plexiglass is completely broken, so I need to replace it soon. Thanks! -david

[hilbert]

David, here is a screen shot from the invoice. The prices were from a year ago:



Transparency is a mater of taste. You can always add a shade on the interior, but you can't increase transmitted light. The light smoke 57% takes the edge off sunlight and provides privacy from the exterior.

I think that increasing the thickness from 1/4" to 3/8" adds robustness. With rounded edges, the extra 1/8" looks very natural,



The frame was not perfectly square. One of the dimensions was an 1/8" longer. I measured length and width and then subtracted a 1/4" from each to leave 1/8" gap for sealant all around.
I verified the 1" corner radius by printing out a circle with a 2" diameter,



I did not select the option for routed edges.

[S/V Ethan Grey]

Hilbert, thank you for the really helpful information!

[S/V Ethan Grey]

Well, it only took me a year from order to actual replacement, but it is finally done. It wasn't too difficult and the results are fantastic, if I do say so myself. In hindsight, I should have removed the old paint off of the frame, but I was more concerned with replacing the acrylic. I think I'll try polishing the aluminum frame like I did my motorcycle frame back in the day.