Vent install Question

[PKFK]

Hi folks -

Looking for experience and advice.

I currently have this:

http://www.beckson.com/vent2.html

And want to replace it with this:
http://www.marinco.com/product/4-daynight-2000-stainless-steel-solar-vent

**But in the 3 inch model **

The problem I have is that the new vent (3") requires a 3-3/4 " hole.
The "old" vent had a 4" hole thru the deck.

Can I install the *new* vent (whick only needs a 3-3/4" hole in the old vent's spot (which has the 4" hole) ???

Anyone tried this??? And will it work ??

Any advise is appreciated.

Thanks !

 

[sailingdog]

Unfortunately, since you're going with a smaller vent, you'll have to fill the hole and then redrill, if you want to do the installation properly.

 

[seadaddler]

Did You

Have you tried the replacement vent in place of the old vent to check for actual fit,1/4 '' doesn't sound all that much.
If you can get the new screw holes to screw into solid material and than fill the space with silicon it would be good to go.
As long as the mounting holes have plenty of meat to hold onto to me would be fine and just make sure you seal it with silicon to make it water tight.
Nick

 

[Prime Time]

another option

Another option would be to mount a thin piece of plywood (say 1/4 inch) over the old hole and mount the new vent thru the plywood. I like plywood since it is stronger than an equivalent thickness of other woods. I would seal it with epoxy and probably make moldings for the edges for appearances.

 

[Ron20324]

That's only another 1/8 gap all around. I don't know how big of an "O" ring (or vacuum cleaner belt?) you can get to go around the vent and against the thin thickness of the deck, then caulk as normal on-deck. Is it an option to cut the old thru-deck "tube" of the old vent and slide it over the new one?

 

[PKFK]

Good Ideas !!

Thanks for the suiggestions folks - I figured if I asked about that on thiis forum I would get some helpful ideas.

I will be back to the boat in a couple days to have another look - the 1/8 inch gap may not be that big a deal - as long as I epoxy-seal the core and caulk carefully. I think that re-using the old "thru-deck-tube" is worth looking at as well.

I will post back once I settle on the approach.....additional suggestions are most welcome in the meantime.

 

[Chris Burti]

For a fast, cheap and good looking repair, try the following.

Just buy a $4 white HDPE plastic cutting board at T.J. Max. Cut out a 6" circle and then cut your 3-3/4" hole. Round over the upper outside edge with a rasp, mount the circle over the old hole with sealant and secure with 5 or 6 #10 countersunk, oval head s.s screws. Then mount the vent in the 'adapter', you may need to use nuts and bolts instad of screws. If the hull core is exposed in the old hole seal it properly first with epoxy.

Note, since the boards are made of high density polyethylene, typical adhesives won't stick, so don't aggravate yourself later by using 5200 on the project.

 

[sand sailor]

you may want to think about gluing

not screwing the new one in place just a thought

 

[PKFK]

Completed the install.

In the end, it was easier than I thought (first time ever that happened on a boat project).

The old hole size was so close that it didn't matter - the flanges on the new unit were large enough that there was no problem in getting material for the mounting screws to bite into.

After I removed the old vent, I filled all the old screw holes with epoxy, and also epoxy-sealed the deck core (was not done by factory - but deck was dry as a chip - phew).

When I installed the new unit, I filled the very small gap between the interior trim ring and the deck hole with butyl tape, and then installed the new outer piece of the vent as per instructions, using generous amounts of silicone caulk.

Did the job on the weekend, and checked the boat yesterday after some very heavy rains, and all was fine.

Thanks again for the suggested workarounds, but I was glad that they were not needed in the end !

 

[Chris Burti]

We especially thank you for the follow-up, this information will be invaluable the next time the question comes up!