Removing vent boxes

[dcobbett]

I'd like to remove the vent boxes behind the grills on both sides of the hull so I can use the space for bilge pump discharge fittings and add pull up cleats in the rails above the grills.
[image][/image]


Does anyone know if the boxes are part of the inner liner piece, or are they only attached to the hull piece. I've searched old projects/photo's, etc. and could not find a clear example of that area.

[Capt Chuck]

dcobbett

Those vent boxes should be plastic. You can remove them without issues. You then will have clear access for bolting your flush mount cleats and installation of bilge discharge thru hulls.

BTW: I know many disagree but DO NOT fill in the vent holes. You need that ventilation under the decks

[Lenny]

Glad you mentioned this DC I have filled the exisitng vent holes that were on the top ove the I/O doghouse and want to cut these in the sides what are the dimensions and does anyone know where I can buy them??

[bigeasy1]

I'm in the process of restoring a 74 Tsunami,and just removed the vent boxes you asked about.
They are plastic,and are bedded directly to the hull,not the liner.Mine were attached to the hull with big sloppy globs of what looked like some putty made with some thickend resin.
They didn't come off easily,i had to use the Roto-zip,and a chisel to get the globs of gook off,so i could remove the boxes.Also keep in mind,that i had the rear cap,and inner stern liner removed.I don't know how you'd be able to easily remove them without doing this.
Maybe the following photos will be of some help to you.



ready to be removed,you can see where i had to crack the thickened resin.



starting to remove the box



box now removed from hull






Showing liner cut and starboard side.

Good luck with your project.

[dcobbett]

John123,

Great pictures. Thanks. Just what I needed to see.

want2fish,

There is a 1/2"+/_ wide steel flange on the back side of the steel vent grates that were on my hull. The flange measures 3-1/2" x 11-7/8"-. I've seen them for sale in various catalogs and retail @ BoatUS.

[Finster]

I think they used several methods. On my '78 they were simply molded black plastic boxes, rivited in place. I yanked'em.

[bigeasy1]

I think you're right that they used several methods.My boxes in the pictures were also plastic,but they glassed completely over them.
I think that in the early seventies,a lot depended on who was doing the layup that particular day.I hate to say it,but the glass work in this boat,was very sloppy in the unseen areas like the bilge etc.
Several areas of way too much resin(puddles),and others of resin starved glass.I know it's not pleasant work,and they didn't have the working conditions of today.God only knows what these guys earned to do this dirty work. It's probably why there seems to be a big difference between some boats of the same year and models.

[mbo_1971]

is it me or is that vent on backwards?

[dcobbett]

mbo_1971,

The boat belonged to the Michigan DNR and that's how it was set up when I got it. The port and starboard boxes are ducted differently and the one on the port side was rigged with an exhaust blower. Intake and exhaust concept. Seemed to work; bilge was dry as a bone when I got the boat, but there were a lot of dead lady bugs laying around.