Nicro Solar Vent Installation?

[Therapy]

I am going to mount a couple of Nicro solar vents on the hatches in my new-to-me Gemini.

Instructions say drilling and screwing (3 holes) is optional.

I don't want to drill and screw really, because there is more of a chance of the hatch cracking later and the extra work (plus the special drill bit).

I think 5200 is plenty.

What say you?

[Hud3]

I installed one three years ago, without using screws, and it's stayed put through several offshore passages. No leaks whatsoever. I can't recall if I used 5200 or just marine silicone caulk.

[toewsrus]

Doesn't the 5200 do something to the hatch light?

[Therapy]

Originally Posted by toewsrus

Doesn't the 5200 do something to the hatch light?

Nicro instructions call for polyurethane (5200 is polyurethane) if bedding on hatches without screws.

The hatches are Bomar less than a year old. I guess I should look them up to see what they are made of.

I think this is the hatch(s) I have

http://www.pompanette.com/pompweb.ns...b?OpenDocument

Looks the same to me.

It is acrylic I suppose.

5200 OK??

[Orion Jim]

I just replaced a Nicro solar vent with a brand new Nicro day/night solar vent. The vent was installed on a Bomar hatch and it was fastened with three screws and some type of caulk. The new unit was installed without the screws, as advised in the Nicro instructions. I used standard marine silicone caulk and made sure I filled the three old screw holes which were also covered by the units flange which was caulked liberally. I hope I never have to replace it!

[Therapy]

Not too many replies but so what.

I think I will go with the 5200 and no screws.

Maybe Wednesday morning.

Thanks all.

[Rick]

Acrylic is attacked by polyurethane. Nicro's instructions apply to non-polycarbonate or non-acrylic hatches.

Keep looking for an adhesive that will work. Silicones will ultimately fail without mechanical fastening on acrylic.

[anotherT34C]

Installed one two years ago. No screws, just silicone caulk. No leaks, and it hasn't gone anywhere yet. I'm sure it will someday though. Think I'll just 'glue' it back in when it does.

[GordMay]

A plastic (acrylic/polycarbonate) cutting drill bit has a sharper point (60̊ in lieu of HSS 120̊ bit) and less pitch than a conventional drill.
Slow to medium speeds (slower for thicker sheets) work best when working with acrylics. Keep the sheet cool & lubricated with a cutting fluid (water works). Backup the piece being drilled with plywood or other scrap, to prevent chipping or blowout of the bottom surface. Always start and end the hole at the slowest possible feed rate. Let the bit cool off between holes.
Once you've drilled your hole(s), use a counter sink to relieve the sharp 90̊ corner from both sides of the hole. This is where the possibility of stress cracks will occur, and provides a cavity for a sealant bead.
A hole should not be drilled any closer than 1.5 times the diameter of the hole measured from the centre of the hole to the edge of the acrylic.

[Therapy]

The drill hole is just to get the saw blade into to cut the circle out.

I read 3M 5200 chart yesterday or the day before that had acrylic listed and the strength of the bond. It was not the highest but nothing about not using it on it.

I cannot find it now.

I did find this:
http://multimedia.3m.com/mws/mediawe...Vs6EVs6E666666--

On the products page it shows 5200 OK for plastics.

I found the other:

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

Page two lists acrylic and polycarbonate. Then later is the usual disclaimer........

Applications:
Typical bonding and sealing applications include:
- Fiberglass deck to fiberglass hull
- Wood to fiberglass
- Porthole frames
- Deck fittings
- Moldings
- Trunk joints
- Between struts and planking
- Stern joints and hull planking
Structural bonding and sealing of:
- Wood
- Fiberglass
- Gelcoat
- Primed metal
Sealing of:
- Some plastics (test before assembly)
- Glass

- Metals


CRAPOLA this is complicated!!!!!!!!

[Highlander40]

Silicone has no place on a boat!!!!!

5200 is the right stuff.

[FloridaWriter]

I would use silicone. It will glue the vent down permanently and not damage either the plastic of the vent or the hatch light you are attaching it to. If used correctly silicone will never fail--it is what glues windows to buildings in skyscrapers.

Good luck,

[Therapy]

Originally Posted by FloridaWriter

it is what glues windows to buildings in skyscrapers.

Good luck,

I can't remember but somewhere I read that that stuff that looks like the stuff we can buy in the tubes is not the same at all.

I have also read things from others whom have a much larger knowledge base (THANK YOU CF!!) than I and I stay away from silicone for the most part.

West Marine (I know but I drove all over the place and could not find anything) had a chart from 3M and on that chart there was a line that said Lexan, Plastic and in the column it said "NG" for Not Good. This was, I think, geared toward adhesion mostly...........I think. Note that Lexan and acrylic are not the same thing except that they are both PLASTIC!!! So is the base of the Nicro vent!!!!! What kind is that???? They say use polyurethane. SHEESH!!!

On the same chart was a listing for 3M Fast Cure 4000 UV and it said "Good" or "Very Good" for the Lexan, Plastic line. The tube itself says " on plastics or paints, test for suitability." The tube does not say it is polyurethane like the 5200 tube.

So I guess that is what I am going to be doing. I will be mounting two Nicro Day/Night 4 inchers on two Bomar acrylic (Plastic!!!) hatches as a "test for suitability". So there. I will be able to report back in about a week or a month or a few months or a year or, or, or...............

Since the advent of plastic and the rest of the resultant ROCKET SCIENCE in the world things are just not that simple any more.

I will be leaving early tomorrow to do the job. If anyone KNOWS (read that again please) the 4000 is not good please let me know ASAP.

Thanks again all.

[Highlander40]

Therapy,

Isn't that 3M -4200 fast cure? The rule is- if you ever want to take it apart use 4200. otherwise use 5200 for maximum hold. 5200 is a little stiffer and does not shrink in the cure. Both are similar chemistry.

Generally a fast cure product will not be as strong as the standard cure version. 4200 comes both ways.

Have fun, it's really an easy job. Just check the hatch handle for clearance with the Nicro vent.

Carl

[Therapy]

Originally Posted by Highlander40

Therapy,

Isn't that 3M -4200 fast cure? The rule is- if you ever want to take it apart use 4200. otherwise use 5200 for maximum hold. 5200 is a little stiffer and does not shrink in the cure. Both are similar chemistry.

Generally a fast cure product will not be as strong as the standard cure version. 4200 comes both ways.

Have fun, it's really an easy job. Just check the hatch handle for clearance with the Nicro vent.

Carl

No.
It is Fast Cure 4000 UV

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

Maybe I should use 4200? This is driving me nuts!!


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

Notice the list of plastics/polymers in 4200 is long and 4000 uv is short.

And 5200

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

Now I realise the 400 UV is not the right stuff really. It should be the 4200 or the 5200.

I should have stuck with plan A.


AAYYYIYIYIYIYIYIYIYIYI!!!!!!!!!!!!!!!!!!!!!!